uster countum 3

USTER® QUANTUM 3 Application Handbook

Yarn clearing on winding machines

Textile Technology / V1.0 / April 2011 / 316 050-10020

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USTER® QUANTUM 3

Table of contents Status Foreword 04.2011

1 Introduction 04.2011 2 Basics of yarn measurement and yarn clearing 04.2011 3 Disturbing thick- and thin places 04.2011 4 Count variations 04.2011 5 Splice clearing 04.2011 6 Periodic yarn faults 04.2011 7 Quality parameters of a yarn 04.2011 8 Foreign fibers 04.2011 9 Vegetable Matter Clearing 04.2011 10 Detection of polypropylene fibers with USTER® QUANTUM 3 04.2011 11 Various settings and applications of USTER® QUANTUM 3 04.2011 12 Clearing of special yarns 04.2011 13 The first hour at the new clearer system 04.2011 14 Frequently asked questions 04.2011 15 Technical specifications 04.2011 16 Appendix 04.2011

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Editorial team:

Dr. Serap Dönmez Kretzschmar Ulf Schneider Richard Furter Peter Schmid © Copyright 2010 by Uster Technologies AG. All rights reserved. All and any information contained in this document is non-binding. The supplier reserves the right to modify the products at any time. Any liability of the supplier for damages resulting from possible discrepancies between this document and the characteristics of the products is explicitly excluded. April 2011 veronesi\TT\Schulung Dokumente\On-Line\Garnreiniger\UQ3\ApplicationHandbook_UsterQuantum3

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Table of contents

1 Introduction ............................................................................................................................ 1.1

1.1 Purpose of the application handbook ....................................................................................... 1.1

1.2 Yarn faults and yarn clearer ....................................................................................................... 1.1

1.3 Short history of the USTER® yarn clearers ............................................................................... 1.3

1.4 Origin of seldom-occurring yarn faults ..................................................................................... 1.5 1.4.1 Separation of frequent and seldom-occurring yarn faults .............................................................. 1.5 1.4.2 Distinction between frequent and seldom-occurring yarn faults .................................................... 1.6

1.5 Classification of seldom-occurring thick and thin places ....................................................... 1.7

1.6 Allocation of seldom-occurring yarn faults to the Classimat matrix ...................................... 1.8

1.7 Structure of the USTER® QUANTUM 3..................................................................................... 1.11 1.7.1 Features of USTER® QUANTUM 3 and options .......................................................................... 1.12 1.7.2 Features versus measuring head types ...................................................................................... 1.13

2 Basics of yarn measurement and yarn clearing .................................................................. 2.1

2.1 Purpose of this chapter .............................................................................................................. 2.1

2.2 Monitoring of thick places .......................................................................................................... 2.1 2.2.1 The capacitive measuring principle ............................................................................................... 2.2 2.2.2 The optical measuring principle ..................................................................................................... 2.2 2.2.3 Yarn signal definitions .................................................................................................................... 2.3 2.2.4 Characteristics of the two measuring principles ............................................................................ 2.5 2.2.5 Environmental influences on yarn measurement and yarn clearing .............................................. 2.6 2.2.6 Selection of the suitable measuring principle ................................................................................ 2.7

2.3 Monitoring of foreign fibers in the yarn .................................................................................... 2.7 2.3.1 Characteristics of the sensor for foreign fibers .............................................................................. 2.8

2.4 Communication of the yarn clearer with the winding machine .............................................. 2.9 2.4.1 Zero point adjustment .................................................................................................................... 2.9 2.4.2 Calibration process on a running yarn ........................................................................................... 2.9 2.4.3 Yarn detector ............................................................................................................................... 2.11 2.4.4 Winding speed ............................................................................................................................. 2.13

3 Disturbing thick and thin places........................................................................................... 3.1

3.1 Introduction .................................................................................................................................. 3.1

3.2 Definition of the yarn body ......................................................................................................... 3.1

3.3 Interpretation of the yarn body .................................................................................................. 3.5

3.4 Disturbing thick places ............................................................................................................... 3.5 3.4.1 Classification matrix ....................................................................................................................... 3.5 3.4.2 Thick and thin places ..................................................................................................................... 3.7

3.5 Clearing limits for thick places .................................................................................................. 3.9 3.5.1 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 3.10 3.5.2 Setting a smart clearing limit for disturbing thick places (NSL) ................................................... 3.11

3.6 Disturbing thin places ............................................................................................................... 3.14 3.6.1 Classification matrix ..................................................................................................................... 3.14

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3.7 Clearing limits for thin places .................................................................................................. 3.14 3.7.1 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 3.15 3.7.2 Setting a smart clearing limit for disturbing thin places (T) .......................................................... 3.17

3.8 The effect of thick and thin places on the fabric appearance ............................................... 3.19 3.8.1 Thick places ................................................................................................................................. 3.19 3.8.2 Reasons and measures to minimize seldom-occurring thick places ........................................... 3.24 3.8.3 Thin places .................................................................................................................................. 3.25 3.8.4 Reasons and measures to minimize seldom-occurring thin places ............................................ 3.27

4 Count variations .................................................................................................................... 4.1

4.1 Introduction .................................................................................................................................. 4.1

4.2 Definition of the yarn body for long-term variations (C and CC faults) ................................. 4.1

4.3 Count deviations .......................................................................................................................... 4.3 4.3.1 Determination of the mean value of a yarn .................................................................................... 4.3 4.3.2 Purpose of yarn count deviation monitoring................................................................................... 4.3 4.3.3 Monitoring of yarn count deviations during start-up in the C – channel ......................................... 4.4 4.3.4 Monitoring of the yarn count while winding with the CC-channel ................................................... 4.5

4.4 C and CC settings ........................................................................................................................ 4.6 4.4.1 Yarn count deviations at start up (C) settings ................................................................................ 4.6 4.4.2 Setting a smart clearing limit for yarn count monitoring (CC) ........................................................ 4.8

4.5 Calculation of yarn count deviations ....................................................................................... 4.12 4.5.1 Determination of count deviations with the clearer installation .................................................... 4.12 4.5.2 Calculation of the count deviations of wrong bobbins (capacitive measurement) ....................... 4.13 4.5.3 Calculation of count variations of wrong bobbins – optical measurement ................................... 4.15 4.5.4 Calculation of count variation of wrong bobbins with a diagram .................................................. 4.16 4.5.5 Relationship between the mass and diameter deviation with the USTER® Calculator ................ 4.17

4.6 Example for the setting of the C-channel ................................................................................ 4.18

4.7 The effect of count deviations on the fabric appearance ...................................................... 4.19 4.7.1 Mixing two different yarn counts .................................................................................................. 4.19 4.7.2 Reasons and measures to minimize count variations ................................................................. 4.23

5. Splice Clearing ...................................................................................................................... 5.1

5.1 Introduction .................................................................................................................................. 5.1

5.2 Scatter plot of splices ................................................................................................................. 5.1

5.3 Splices .......................................................................................................................................... 5.3 5.3.1 Visual appearance ......................................................................................................................... 5.3 5.3.2 Practical example .......................................................................................................................... 5.4 5.3.3 Basic principles of splicing ............................................................................................................. 5.6 5.3.4 Wet Splicing ................................................................................................................................... 5.7

5.4 Splice classification of the USTER® QUANTUM 3 .................................................................... 5.8

5.5 Clearing limits for splice clearing (Jp and Jm) ......................................................................... 5.9 5.5.1 Standard way of optimizing clearing limits: Manual clearing limits entry ....................................... 5.9 5.5.2 Setting a smart clearing limit for splices (Jp/Jm) ......................................................................... 5.10

5.6 Upper yarn detection (U) ........................................................................................................... 5.13

5.7 Minimizing the number of splices ............................................................................................ 5.14

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5.7.1 Critical items which affect the number of splices ......................................................................... 5.14 5.7.2 Mean time between two splices ................................................................................................... 5.15 5.7.3 Field test ...................................................................................................................................... 5.16 5.7.4 Relationship between the productivity on winding machines and splices .................................... 5.17

6 Periodic yarn faults ............................................................................................................... 6.1

6.2 Influence of the yarn speed on the winding machine .............................................................. 6.2

6.3 Further reasons for periodic defects ......................................................................................... 6.2

6.4 Periodic fault registration with the PF ....................................................................................... 6.3 6.4.1 Setting for Periodic Faults (PF / Optional Q Data) ......................................................................... 6.3

6.5 The effect of periodic faults on the fabric appearance ............................................................ 6.6 6.5.1 Reasons and measures to minimize periodic mass variations ...................................................... 6.8

7. Quality parameters of a yarn................................................................................................. 7.1

7.1 Introduction .................................................................................................................................. 7.1

7.2 Yarn evenness ............................................................................................................................. 7.3 7.2.1 Definition of the coefficient of variation CV .................................................................................... 7.4 7.2.2 Reasons and effects of the yarn irregularity .................................................................................. 7.4 7.2.3 Deviation of the CV mean value of a group of clearers (CV–MV) ................................................. 7.5 7.2.4 Deviation of the CV of a single winding position (CV-SP) ............................................................. 7.6 7.2.5 Settings .......................................................................................................................................... 7.7 7.2.6 Display of the CV values ................................................................................................................ 7.9

7.3 Imperfections ............................................................................................................................. 7.10 7.3.1 Definition of imperfections ........................................................................................................... 7.11 7.3.2 Settings ........................................................................................................................................ 7.13 7.3.3 Display of the imperfection results ............................................................................................... 7.15

7.4 Class-Alarm ................................................................................................................................ 7.15 7.4.1 Definition of the classes ............................................................................................................... 7.16 7.4.2 Reasons and effects of the faults ................................................................................................ 7.17 7.4.3 Settings ........................................................................................................................................ 7.17 7.4.4 Display of the class alarms .......................................................................................................... 7.18

7.5 Tailored classes (Option Advanced Classes) ......................................................................... 7.19 7.5.1 Settings ........................................................................................................................................ 7.20 7.5.2 Display of the tailored classes ..................................................................................................... 7.21

7.6 Adjustment of the individual alarm possibilities .................................................................... 7.22

7.7 Hairiness ..................................................................................................................................... 7.22 7.7.1 Principles of operation of the hairiness measuring systems........................................................ 7.22 7.7.2 Settings ........................................................................................................................................ 7.25 7.7.3 Display of the hairiness values .................................................................................................... 7.27 7.7.4 How do hairiness variations affect woven and knitted fabrics? ................................................... 7.28 7.7.5 Hairiness monitoring on the machine .......................................................................................... 7.28 7.7.6 On-line tests versus off-line tests ................................................................................................ 7.29 7.7.7 Basic hairiness differences between the different spinning methods .......................................... 7.30 7.7.8 Practical examples ...................................................................................................................... 7.31

7.8 Indication of ejected bobbins ................................................................................................... 7.33

7.9 Criteria to select the limits for quality characteristics ........................................................... 7.33

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7.9.1 Installation of a quality management system to eliminate outliers ............................................... 7.34 7.9.2 Tracing back outlier bobbins to the source .................................................................................. 7.36 7.9.3 Examples from the industry ......................................................................................................... 7.38 7.9.4 Recommendations for a sampling plan ....................................................................................... 7.39 7.9.5 Conclusion ................................................................................................................................... 7.41

7.10 Yarn evenness (CV), hairiness and imperfections and their effect on the fabric appearance ................................................................................................................................ 7.41

7.10.1 Reasons and measures to minimize random mass variations .................................................... 7.41 7.10.2 Reasons and measures to minimize imperfections ..................................................................... 7.43 7.10.3 Reasons and measures to minimize excessive hairiness and hairiness variations .................... 7.46

8 Foreign fibers ........................................................................................................................ 8.1

8.1 Introduction .................................................................................................................................. 8.1

8.2 Dense Area ................................................................................................................................... 8.3

8.3 Foreign fibers ............................................................................................................................... 8.5 8.3.1 Types of foreign material in cotton ................................................................................................. 8.5 8.3.2 Degree of contamination of bales .................................................................................................. 8.8 8.3.3 Size and appearance of foreign matter in spinning mills ............................................................. 8.10 8.3.4 Frequency of foreign fibers in spinning mills ................................................................................ 8.11 8.3.5 Foreign fiber risk calculated for a spinning mill ............................................................................ 8.12

8.4 Classification matrix of foreign fibers with the USTER® QUANTUM 3 ................................. 8.12

8.5 Clearing limits ............................................................................................................................ 8.13 8.5.1 General references for foreign fiber clearing ............................................................................... 8.14 8.5.2 Clearing limits for dark foreign fibers in light yarn ........................................................................ 8.14 8.5.3 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 8.15 8.5.4 Setting a smart clearing limit for dark foreign matter (FD) ........................................................... 8.17

8.6 Foreign fibers and their effect on the various production processes ................................. 8.19 8.6.1 Methods to eliminate foreign material and frequency of foreign material .................................... 8.21 8.6.2 Effect of large foreign particles on the spinning process ............................................................. 8.24 8.6.3 Alarm options for frequent foreign fibers in yarns with clearers ................................................... 8.24 8.6.4 Limits of foreign fiber elimination ................................................................................................. 8.25 8.6.5 Process disturbances while beaming, weaving and knitting caused by foreign matter ............... 8.25 8.6.6 Recommended approach to eliminate foreign fibers ................................................................... 8.25 8.6.7 Field tests in China ...................................................................................................................... 8.26

8.7 Foreign fibers and their effect on the fabric appearance ...................................................... 8.30 8.7.1 Reasons and measures to minimize foreign fibers in yarns ........................................................ 8.33

9 Vegetable Matter Clearing .................................................................................................... 9.1

9.1 Introduction .................................................................................................................................. 9.1 9.1.1 Vegetable matter ........................................................................................................................... 9.2 9.1.2 Distribution of vegetables and foreign fibers .................................................................................. 9.3

9.2 Dense area for vegetable matter (VEG) ..................................................................................... 9.3

9.3 Classification matrix of vegetable matters with the USTER® QUANTUM 3 ........................... 9.6

9.4 Clearing limits .............................................................................................................................. 9.6 9.4.1 Setting a clearing limit for vegetable matter (VEG) ........................................................................ 9.7

9.5 Vegetable matters and their effect on the fabric appearance ................................................. 9.9

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9.5.1 Field test ........................................................................................................................................ 9.9 9.5.2 Reasons and measures to minimize vegetable matter in yarns .................................................. 9.11

10 Detection of polypropylene fibers with USTER® QUANTUM 3 ......................................... 10.1

10.1 Introduction ................................................................................................................................ 10.1 10.1.1 Configuration of a PP-clearer ...................................................................................................... 10.3 10.1.2 Frequency of PP fibers ................................................................................................................ 10.4 10.1.3 Application range of PP-clearing, ring-spun yarn ........................................................................ 10.6

10.2 Scatter plot ................................................................................................................................. 10.7

10.3 Clearing limits for polypropylene fibers .................................................................................. 10.9 10.3.1 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 10.9 10.3.2 Setting a smart clearing limit for polypropylene fibers ............................................................... 10.10

10.4 Polypropylene fibers and their effect on the fabric appearance ......................................... 10.12 10.4.1 Reasons and measures to minimize foreign fibers in yarns ...................................................... 10.13

11 Various settings and applications of USTER®QUANTUM 3 .............................................. 11.1

11.1 Comparison of different clearing limits and article settings ................................................. 11.1 11.1.1 Comparison of various clearing limits .......................................................................................... 11.1 11.1.2 Recreate or recall of the factory settings of the default articles ................................................... 11.3

11.2 Display of Data and Alarms ...................................................................................................... 11.3 11.2.1 Display of Data and Alarms with the help of bar graphs .............................................................. 11.3 11.2.2 Display of Data and Alarms with the help of exception reports ................................................... 11.5 11.2.3 Display of yarn faults with the help of textile alarms .................................................................... 11.6

11.3 Collecting defects ........................................................................................................................ 11.8 11.3.1 Introduction .................................................................................................................................. 11.8 11.3.2 Event display by the red light at the sensor (iMH-LED) ............................................................... 11.8 11.3.3 Yarn fault cards ............................................................................................................................ 11.9

11.4 Monitoring of winding functions ............................................................................................ 11.11 11.4.1 Monitoring of the yarn joint process with the USTER® QUANTUM 3 ........................................ 11.14 11.4.2 Monitoring of the settings ........................................................................................................... 11.14 11.4.3 Splice classification .................................................................................................................... 11.14 11.4.4 Yarn jump monitoring (JPM, JPA) ............................................................................................. 11.15 11.4.5 Drum signal monitoring (DSM) .................................................................................................. 11.16 11.4.6 Drum wrap monitoring (DWM, DWA) ........................................................................................ 11.16 11.4.7 Cut monitoring CTM .................................................................................................................. 11.17 11.4.8 Zero point monitoring ZPM ........................................................................................................ 11.17

12. Clearing of special yarns .................................................................................................... 12.1

12.1 Introduction to fancy yarns ...................................................................................................... 12.1

12.2 Clearing of fancy yarns ............................................................................................................. 12.1

12.3 Clearing of slub yarns ............................................................................................................... 12.3

12.4 Clearing of yarns with nep or loop effects .............................................................................. 12.5

12.5 Melange yarns ............................................................................................................................ 12.6

12.6 Core yarn .................................................................................................................................... 12.7

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13 The first hour at the new clearer system ........................................................................... 13.1

13.1 Introduction ................................................................................................................................ 13.1

13.2 Short description of the settings ............................................................................................. 13.1

14 Frequently asked questions ............................................................................................... 14.1

14.1 Product related questions ........................................................................................................ 14.1 14.1.1 What type of sensing principles does USTER® QUANTUM 3 offer? ........................................... 14.1 14.1.2 How does the USTER® QUANTUM 3 differ from competing products? ...................................... 14.1 14.1.3 What are the main new functions of the USTER® QUANTUM 3? ............................................... 14.2 14.1.4 What are the new quality parameters measured by the USTER® QUANTUM 3? ....................... 14.3 14.1.5 What is the yarn count range of USTER® QUANTUM 3 and which sensing method will

fulfill the quality requirement? ...................................................................................................... 14.4 14.1.6 What is new with the USTER® QUANTUM 3 optical basic clearer? ............................................ 14.4 14.1.7 What is the difference to UQC2 Vegetable Filter? ....................................................................... 14.4 14.1.8 What is the advantage of the USTER® QUANTUM 3 for core yarns? ......................................... 14.4 14.1.9 What is the benefit of slub yarn setting in USTER® QUANTUM 3? ............................................. 14.5 14.1.10 How is the PP performance of the new clearer? ......................................................................... 14.5 14.1.11 How are the repair costs of USTER® QUANTUM 3? ................................................................... 14.5 14.1.12 What are the advantages from a maintenance point of view?..................................................... 14.5 14.1.13 Can the USTER® QUANTUM 3 is installed be winders of previous generations? ...................... 14.5 14.1.14 Why does the USTER® QUANTUM 3 have a bigger housing? ................................................... 14.6 14.1.15 What is the purpose of the arrow LEDs on the measuring head? ............................................... 14.6

14.2 Application related questions .................................................................................................. 14.6 14.2.1 What kind of yarn clearer do I need for my application? ............................................................. 14.6 14.2.2 How is it possible to simplify the definition of clearing limits? ...................................................... 14.6 14.2.3 How can one find the optimal setting for basic clearing? Is it the same as before? .................... 14.7 14.2.4 What is the best basic setting for my yarn? ................................................................................. 14.7 14.2.5 How can one find the optimum setting for good fabric appearance and for optimum

productivity? ................................................................................................................................. 14.7 14.2.6 Which setting shall I use to make sure that no Classimat objectionable faults will remain? ....... 14.7 14.2.7 What is the USTER® QUANTUM 3 advantage with respect to compact yarns? ......................... 14.8 14.2.8 When should I use the vegetable clearing? ................................................................................. 14.8 14.2.9 Why cannot all vegetables pass using Vegetable Matter Clearing when they are not

disturbing? ................................................................................................................................... 14.8 14.2.10 We have an USTER® QUANTUM clearer or other clearer generations - can we copy

the setting because it was acceptable until now? ........................................................................ 14.9 14.2.11 What is different with the continuous count channel? Is the settings process easier? ................ 14.9 14.2.12 How can one set up the splice clearing curve? ........................................................................... 14.9 14.2.13 How can one find/identify rogue splicers? ................................................................................. 14.10 14.2.14 What FD setting should I keep for a cotton yarn? (In case of no specific requirement from the

buyer) ......................................................................................................................................... 14.10 14.2.15 USTER® QUANTUM 3 has more than 40 classes, but in USTER® QUANTUM 2, we

only have 23 classes- What is the purpose of these additional classifications in USTER® QUANTUM 3? ............................................................................................................................ 14.10

14.2.16 USTER® QUANTUM 3 has new sensor technology in basic and FM clearing – are the results comparable to the old classification? ............................................................................. 14.11

14.2.17 Can I use the QUANTUM 3 for wet splicer applications? .......................................................... 14.11 14.2.18 Is it possible to classify foreign fibers? ...................................................................................... 14.12 14.2.19 What are the experience values for cuts in ring spinning mills with foreign fiber clearers? ..... 14.12

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14.2.20 Can we compare the classification of C15 on C20 in USTER® QUANTUM 3 ........................... 14.13 14.2.21 Is the USTER® QUANTUM 3 classification comparable to the USTER® STATISTICS? ........... 14.13

15 Technical specifications ..................................................................................................... 15.1

15.1 Basics of USTER® QUANTUM 3 ............................................................................................... 15.1 15.1.1 Architecture .................................................................................................................................. 15.1 15.1.2 Scope of application .................................................................................................................... 15.1 15.1.3 Scope of supply ........................................................................................................................... 15.1 15.1.4 Miscellaneous .............................................................................................................................. 15.2

15.2 Structure of the USTER® QUANTUM 3..................................................................................... 15.2 15.2.1 Features of USTER® QUANTUM 3 and options .......................................................................... 15.2 15.2.2 Features versus measuring head types ...................................................................................... 15.3

15.3 Comparison, capacitive versus optical measuring principle for basic clearing ................. 15.4

15.4 Winding machines ..................................................................................................................... 15.5

15.5 Count range of the USTER® QUANTUM 3 ............................................................................... 15.5

15.6 Architecture, sensor principles and configuration ................................................................ 15.6

15.7 Elimination of disturbing yarn faults ....................................................................................... 15.7

15.8 Supervision of the machine operations .................................................................................. 15.8

15.9 Determination of quality characteristics ................................................................................. 15.9

15.10 Cut alarms, Quality alarms, Special Counters and Logbook .............................................. 15.11

15.11 Reports ..................................................................................................................................... 15.13

15.12 Clearing of various yarn types ............................................................................................... 15.15

15.13 Recommendations how to use clearers ................................................................................ 15.16 15.13.1 Sensor systems versus end use of yarn .................................................................................... 15.16 15.13.2 Poor environmental conditions .................................................................................................. 15.18

16 Appendix .............................................................................................................................. 16.1

16.1 Standard settings ...................................................................................................................... 16.1 16.1.1 Standard settings for the capacitive clearer – Capacitive Default ............................................... 16.1 16.1.2 Standard settings for the optical clearer – Optical Default .......................................................... 16.2

16.2 Abbreviations ............................................................................................................................. 16.3

16.3 Explanation of terms ................................................................................................................. 16.7

16.4 International Systems of units ............................................................................................... 16.11 16.4.1 International system ................................................................................................................... 16.11 16.4.2 'SI' system .................................................................................................................................. 16.11 16.4.3 Conversion table for yarn count systems ................................................................................... 16.13 16.4.4 Conversion of English units into metric units ............................................................................. 16.14

16.5 Bibliography ............................................................................................................................. 16.15

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Foreword It is still not possible to produce a fault-free yarn in a spinning mill for various reasons. The drawing process is not a perfect process and can produce imperfections. Another source for ir-regularities in ring spinning is the availability of fiber flies in the air which are frequently spun into the yarn as well as accumulations of fiber fragments and dust at yarn guiding elements. In ring-spinning, all fiber and yarn guiding elements, ring travelers, pressure rollers, belts and spin-dles can contribute to yarn faults, particularly in case of defects. In OE-rotor spinning, the opening rollers and dirty rotor grooves are sources of yarn faults. In air-jet spinning the formation of faults depends on the quality of the raw material and the mainte-nance of the spinning devices. Natural fibers contain foreign matter which mostly cannot be eliminated completely and stickiness of cotton can contribute to the formation of thick and thin places. Therefore, one important rule of modern quality management cannot be implemented completely: “Preventive actions have to be taken rather than corrections afterwards!” As a result, an electronic monitoring system is required to eliminate disturbing faults in the yarn. In ring spinning the monitoring system is located on the winding machine. This system does not only eliminate disturbing faults in yarns, but also separates bobbins with high unevenness, high imperfections, high hairiness, etc. For all known spinning methods of today it is necessary to have a yarn monitoring system in the last production process of the spinning mill, which stops the production position if disturbing faults occur. The machine must automatically remove the faults and replace it by a splice or by a piecer. The first electronic yarn clearers were already installed on winders in 1960. At that time thick places could be removed only. In the last five decades, the electronic yarn clearer experienced an enormous development. In the meantime a monitoring system has been developed which cannot only remove faults but is also in a position to provide information on quality characteristics of the yarn. In the last years, new quality characteristics were added such as the hairiness of yarns and the quality of splic-es. As physical principle for electronic yarn clearing the capacitive and the optical principle have been established. Both principles have their strengths in specific applications. The experts of Uster Tech-nologies will help the spinning mills to find the best solution. With the introduction of the electronic laboratory and on-line systems the yarn quality has improved steadily. Therefore, faults which were not removed ten years ago are found disturbing today. An ex-ample for this is the compact yarn. As a result, the requirements for yarn clearing are also increasing permanently. With the higher capability of the electronic yarn clearer, there is a need for more information to make best use of these systems. We hope that our customers can fully benefit from their investment into the USTER® QUANTUM 3 with this detailed knowhow. R. Furter April 2011

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Introduction 1

USTER® QUANTUM 3 1.1

1 Introduction 1.1 Purpose of the application handbook In order to be able to use the USTER® QUANTUM 3 with all its possibilities to its optimum, it is neces-sary to have a comprehensive knowledge about the clearer. It contains the experience we gained over the years and should fulfill the following purposes:

• Introduction to yarn clearing for beginners and students

• Instructions for optimum use for the quality management of a spinning mill

• Basis for the application training for the instructor In order to understand the explanations in this application handbook, it is advantageous, if:

• you have some knowledge about the textile production process, particularly the winding process

• you are in a position to operate a winding machine with the USTER® QUANTUM 3 installed when going through the Application Handbook

Validity of this Application Handbook

The explanations in this Application Handbook refer to the functions of the USTER® QUANTUM 3. They are subject to change without notice. Abbreviations and explanation of terms

In the appendix of this book (section 16.2 and 16.3) a list of all the abbreviations and explanations of terms is given. 1.2 Yarn faults and yarn clearer The principles of the spinning process for short- and long-staple yarns remained the same for many decades. Changes took place especially in the field of automation and production quantity per produc-tion hour in order to reach the highest production of yarn and with a good quality at the least expens-es for personnel, capital and energy. For this, a significant technological progress in each process stage was essential. Despite this progress and many years of experience in spinning technology, it is still not possible to produce a fault-free yarn. Depending on the raw material and condition of the machinery, there are about 20 to 100 events over a length of 100 km yarn, which do not correspond to the desired appear-ance of yarns in fabrics. This means, that the yarn exhibits a disturbing yarn fault every 1 to 5 km. These kinds of yarn faults are places, which are too thick or too thin. Foreign fibers or contaminated fibers in the yarn are also counted as disturbing yarn faults. Fig. 1-1 shows the most important yarn fault categories which have to be eliminated on the winding machine in most of the cases.

1 Introduction

1.2 USTER® QUANTUM 3

Fig. 1-1 1st row: Disturbing thick places / 2nd row: Vegetables / 3rd row: Disturbing colored inorganic fibers /

4th row: Disturbing white inorganic fibers (polypropylene) Yarn faults cause disruptions in the subsequent process stages, which affect production and quality. Yarn faults, which are already processed into woven or knitted fabric, can only be removed at very high costs or not at all. Therefore, the yarn processing industry demands a fault-free yarn from the yarn producer. The spinner has to fulfill these demands; otherwise he cannot sell the yarn at reason-able prices. The spinner can fulfill these demands by a combination of two measures: 1. Prevent the origin of yarn faults by adequate measures. 2. Remove yarn faults by the aid of yarn clearers.

Introduction 1


The measures to avoid the origin of yarn faults are numerous and start with the choice of the raw ma-terial, the maintenance of the machines up to the cleanliness in the spinning mill. Well educated, mo-tivated personnel and an efficient quality management play also an important role. Yarn faults, which are still produced despite all measures, are removed according to the following principle:

Fig. 1-2 Principle of yarn clearing on the winding machine 1. During the winding process from bobbin to cone, the yarn is permanently monitored for yarn faults

with an electronic device, the yarn clearer. 2. As soon as the yarn clearer detects a yarn fault, the yarn will be cut by the cutter if the fault ex-

ceeds the limits. For this purpose the winding process is interrupted. 3. The yarn fault is removed by the suction device of the winding machine. 4. Both ends, the upper yarn from the cone as well as the lower yarn from the bobbin, have to be

joined again. The yarn joint is done by splicing with a splicing device or knotting with a knotting device. The latter is only used very rarely for special yarns. A good splice should not be recog-nized by the human eye. Up to date yarn clearers also monitor the quality of the yarn joint.

5. The winding process continues until the next fault occurs or the end of the bobbin is reached. 1.3 Short history of the USTER® yarn clearers In 1960 Uster Technologies launched the first electronic yarn clearer, the USTER® SPECTOMATIC. With one single, central setting the threshold at which the cutter should be activated could be deter-mined. Once on the market, the demands for the yarn clearer rose steadily. Since then, Uster Tech-nologies could always fulfill the demands of the customers to their full satisfaction with innovative clearer models.

1 Introduction


Fig. 1-3 shows the improvements and features since 1960 up to the eighth generation of the USTER® QUANTUM 3 of today for winding machines.

Fig. 1-3 Uster clearer generations and their additional functions for winding machines The numerous functions of the USTER® QUANTUM 3 for a comprehensive yarn control can be summed up as follows:

• Monitoring and elimination of disturbing yarn faults

• Monitoring and controlling of machine functions

• Determination of quality parameters of the yarn

• Triggering of alarms if outlier bobbins occur

• Visualization of data on the display, for reports, information systems and for the subsequent pro-cess stages

Introduction 1


In order to define and control all these functions, various settings to fulfill all the requirements in the textile industry can be carried out at the USTER® QUANTUM 3. This stands in contrast to one single setting of the first clearer generation. 1.4 Origin of seldom-occurring yarn faults 1.4.1 Separation of frequent and seldom-occurring yarn faults During the spinning process, a card sliver with about 20'000 to 40'000 fibers in the cross-section is drawn to a yarn with about 40 to 1000 fibers in the cross-section. During the spinning process it is not possible to keep the number of fibers in the cross-section constant at every moment. This leads to random variations of the mass. Only spinning mills with a permanent improvement pro-cess are able to keep these random variations within close limits. These variations are measured by the evenness tester in the laboratory. They are a measure for the unevenness of the yarn and are called imperfections. They occur so frequently that they are not elimi-nated from the yarn (Fig. 1-4). Their number of imperfections is generally given per 1000 m of yarn. In contrast to the frequent yarn faults, there are also the seldom-occurring yarn faults. The difference between the frequent yarn faults and the seldom-occurring yarn faults is mainly given by the larger mass or diameter deviation. As these faults occur only seldom, their number is expressed per 100'000 m. These faults are monitored and classified by the USTER® CLASSIMAT or by the clearer installa-tion on the machine.

Fig. 1-4 Frequent yarn faults and seldom-occurring yarn faults. The deviations in percent are either mass or diameter related, depending on the type of sensor.

1 Introduction


The average mass increase for thick places has to exceed +75% for faults below 2 cm, 45% for faults below 4 cm length and +30% for faults longer than 4 cm to be counted by the classifying system of the USTER® QUANTUM CLEARER. In the area of thin places the average mass of a fault has to drop at least 20% to be counted.

Fig. 1-5 Classification matrix for disturbing thick and thin places 1.4.2 Distinction between frequent and seldom-occurring yarn faults Fig. 1-6 shows the position of the frequent yarn faults (imperfections, green area in Fig. 1-6) in com-parison to the position of the seldom-occurring yarn faults in the classification matrix. It is obvious, that both types of yarn faults differ from each other clearly by their. In addition, the areas of the clearer settings N, S, L, T, CCp and CCm are indicated. This shows where the settings are effective. N = neps, S = short thick places, L = long thick places, T = thin plac-es, CCp = count deviations in positive direction, CCm = count deviation in minus direction.

Fig. 1-6 Positions of the frequent versus the seldom-occurring yarn faults

Introduction 1


1.5 Classification of seldom-occurring thick and thin places Classifications are used in spinning mills either as on-line monitoring system as a feature of the clear-ing system on automatic winding machines or as an analyzing instrument on manual winding ma-chines in textile laboratories, and they play a very important role to analyze seldom-occurring yarn faults. Fig. 1-7 shows the classification matrix of this analyzing system with a few examples of seldom-occurring yarn faults for the thick place classes A1 to D4 which are assigned by the system to the respective classes.

Fig. 1-7 Classes of the USTER® CLASSIMAT QUANTUM system. The new classes are not shown in this figure

It is obvious that the appearance of seldom-occurring faults in a fabric depends on various items:

• The cross-section of the fault compared to the mean value

• The length of the fault

• The count of the yarn

• The yarn density in the fabric

• The type of fabric (weaving or knitting)

1 Introduction


1.6 Allocation of seldom-occurring yarn faults to the Classimat matrix A basic rule in quality management is a preventive maintenance rather than corrections afterwards. Unfortunately, this is not yet possible with the technology of today. Textile specialists in spinning mills who have to conquer disturbing yarn faults have to find the origin of such yarn faults. Table 1 shows a selection of sources which produce seldom-occurring faults in the respective catego-ries. It is a collection of reasons over many years why such events happened. The classes A0 to I2 correspond to the matrix, Fig. 1-5.

Classes Possible reason of faults Comments A (Thick place) A0 Extended class, mainly used for ply yarn and compact yarn

A1 Bad condition of carding, blow room, trash in yarn (Short thick places)

A2 Bad condition of carding, blow room, trash in yarn

A3 Neps, fluff, foreign matters, dirty drafting zone

A4 Ring front zone dirty, fly in trumpet (Unacceptable faults)

B (Thick place) B0 Extended class, mainly used for ply yarn and compact yarn

B1 Fibers damage in process, spindle without aprons (Short thick places)

B2 Fibers damage in process, spindle without aprons

B3 Fluff in travelers, unsuitable travelers, bad piecing

B4 Slub from ring spinning department (Unacceptable faults)

C (Thick place) C0 Extended class, mainly used for ply yarn and compact yarn

C1 Bad piecing in cans, sliver entanglements (Short thick places)

C2 Bad piecing in cans, sliver entanglements

C3 Piecing, ring spinning (Unacceptable faults)

C4 Floating fibers, fly, slub (Unacceptable faults)

D (Thick place) D0 Extended class, mainly used for ply yarn and compact yarn

D1 Floating fibers

D2 Gauge problem of roving frame, spacer problem (Unacceptable faults)

D3 Fluff in ring spinning or roving (Unacceptable faults)

D4 Fluff in ring spinning or roving (Unacceptable faults)

E (Thick place) E Double yarn, count variation (Spinners double)

F (Thick place) F Bad piecing in ring yarns, roving & back process (Long thick places)

G (Thick place) G Bad piecing in ring, roving & back process etc. (Long thick places)

H (Thin place) H1 Mostly eccentric bobbins on roving & ring frames, eccentric spindles, drawing problems

(Thin places)

H2 Poor handling of material during processes (Thin places)

I (Thin place) I1 This type of faults is mostly produced by separation of parts of sliver or roving prior to spinning

(Long thin places)

I2 This type of faults is mostly produced by separation of parts of sliver or roving prior to spinning

(Long thin places)

Table 1 Classimat defects / Classification and sources of origin. New classes are not mentioned in Table 1.

Introduction 1


Disturbing yarn faults caused by raw material and card

These faults depend on the quality of the raw material. For natural fibers, they depend mainly on the physical properties such as fiber fineness, length and short fiber content. For synthetic fibers, the faults depend mainly on the disentanglement of single fibers. Insufficient disentanglement can lead to felted single fibers, which might be caused by softeners, oil additives, lubricants or climatic conditions. Disturbing yarn faults caused by processes prior to spinning

These faults are characterized by extreme diameter variations or poor friction of the fibers. Often, it is a matter of fiber packages, which are not caught in the draw-box of prior processes and were not drawn apart. Therefore, they show a big increase of the mass or diameter in the yarn. Disturbing yarn faults caused in spinning

Most disturbing yarn faults are caused by spun-in fly in the area of the ring spinning machine and by fiber residues, which cling to the draw-box or other parts of the spinning machine and which are swept away from time to time and are spun into the yarn. Furthermore, it is possible that different setting possibilities of the ring spinning machine, as e.g. draft or distance settings of the draw-box, have an influence on the number of seldom-occurring yarn faults. Thick places in a woven fabric are shown in Fig. 1-8 to Fig. 1-9. Here we can see a spun-in fly failure. This refers to free fibers which fall into the drafting elements or onto the roving which is being fed into the drawing unit of the ring spinning machine and are then twisted into the yarn along their entire length.

Fig. 1-8 Flying fibers which fall onto the roving or

into the drafting elements and are then twisted into the yarn

Fig. 1-9 Thick place in woven fabric as a result of a spun-in fly

1 Introduction


As most of these yarn faults can lead to problems in the subsequent processes or are disturbing in the end product, they must be removed from the yarn and replaced by a splice. The art of yarn clear-ing consists of cutting out the most disturbing faults without influencing the efficiency of the machine too much. Therefore, yarn clearing is always a compromise. Foreign fibers

Foreign fibers in the yarn belong also to the group of seldom-occurring yarn faults. The cause for for-eign fibers are contaminations, which get crushed in the spinning process, especially by the card, and are noticed as foreign fibers in the yarn at the end of the spinning process. Further explanations con-cerning this subject can be found in chapter 8, "Foreign fibers", of this Application Handbook.

Fig. 1-10 Classification matrix for foreign fibers and vegetables

Fig. 1-11 Foreign fiber in a yarn Fig. 1-12 Vegetable in a yarn

Introduction 1


1.7 Structure of the USTER® QUANTUM 3 The USTER® QUANTUM 3 is the successor of the USTER® QUANTUM 2. This new clearer genera-tion is focused on simplifying the complexities of yarn clearing and thereby enable the user to easily and fully exploit all clearer capabilities and to optimize production costs every day. The USTER® QUANTUM 3 interprets and displays the yarn characteristics within minutes and proposes a starting point for clearing limits with a cut forecast by pressing a single button. One of the key highlights is the integration of the well-known USTER® knowhow in the system on the winder. Another exciting new innovation is a completely new foreign fiber clearing technology with vegetable clearing which is able to detect all colors and separates foreign matter into two separate pools: foreign fibers and vegetables. This separation improves the foreign fiber clearing efficiency significantly by reducing cuts for the same quality or gets a better quality for the same cuts.

Fig. 1-13 New features of USTER® QUANTUM 3

1 Introduction


1.7.1 Features of USTER® QUANTUM 3 and options Table 1-2 shows the individual features of the options.

OPTIONS FEATURES COMMENTS

Basic clear-ing

Yarn Body (N, S, L, T, CC) Visualization of the yarn characteristics Smart limits (N, S, L, T, CC) A proposed starting point for clearing limits

Scatter plot (N, S, L, T, C, CC, J) Visualization of the thick and thin places, count deviations and splices.

N, S, L, T Elimination of the disturbing thick and thin places C, CC Count deviation clearing and monitoring Jp, Jm Splice Clearing Cut forecast A forecast of cut numbers per 100 km Technical alarms Alert for technical problems Textile alarms Alert for textile problems

Foreign matter

Vegetable Clearing

(Option)

Dense Area (FD, VEG) Identification of range where foreign fibers are located

Smart limit (FD) A proposed starting point for foreign fiber clearing limits

Scatter plot (FD) Visualization of dark foreign fibers

Dark foreign matter (FD) Elimination of dark foreign fibers

On-line foreign matter classification Classification of foreign fibers

Identification of vegetables Separation of vegetable matter

On-line vegetable classification Classification of vegetable matter

Polypropyl-ene fibers (Option)

Smart limit (PP) A proposed starting point for polypropylene clearing limit

Scatter plot (PP) Visualization of polypropylene fibers

Q-Data (Op-tion)

Evenness (CV) Determination of the yarn evenness

Imperfections Determination of the frequent thick places, thin places and neps

Basic on-line classification (NSLT, FD, J and VEG)

Classification of disturbing thick and thin places, foreign fibers, splices and vegetables

Class alarms Triggering of alarm if the number of disturbing faults has exceed the selected number of faults

Periodic Faults (PF) Detection of periodic faults

Hairiness (Option)

Absolute hairiness measurement Determination of the hairiness value

Exception spindle detection Recognition of spindles with excessive hairiness

Expert (Op-tion) Expert

Access to the data output for Expert System and central-ized data collection and reporting

Advanced Classifica-tion (Op-tion)

Extended Classes Classification of additional classes in NSLT, F, VEG

Tailored classes Classes can be selected by customers

Lab On-line (Option) Software pack

Software pack consists of Hairiness, Advanced Classifica-tion and Expert

Table 1-2 Features of Basic Clearing and options

Introduction 1


1.7.2 Features versus measuring head types Table 1-3 below describes what type of USTER® QUANTUM 3 sensor for each measuring head is appropriate for which kind of application.

USTER® QUANTUM 3 SENSORS

MEASURING HEAD TYPES Capacitive C15

Capacitive C20

Capacitive C15 F30

Capacitive C20 F30

Optical O30

Optical O30 F30

FEA

TUR

ES

BASIC X X X X X X

FOREIGN MATTER (Option) --- --- X X --- X

VEGETABLE (Option) --- --- X X --- ---

POLYPROPYLENE (Option) --- --- O* O* --- ---

Q-DATA (Option) O O X X O X

HAIRINESS (Option) --- --- O O --- O

USTER® QUANTUM EXPERT 3 O O O O O O

ADVANCED CLASSI-FICATION (Option) O O O O O O

LAB ONLINE (Option) --- --- O O --- O

Table 1-3 The USTER® QUANTUM 3 sensors and options Key:

X This feature is included in this version of the sensor

O Product Option Key (POK) is needed to have access to the feature mentioned in the header of this col-umn

O* Hardware upgrade required in the Central Clearing Unit 6 (CCU6) to have access to the feature

--- Not available with this iMH type

1 Introduction


Basics of yarn measurements and yarn clearing 2


2 Basics of yarn measurement and yarn clearing 2.1 Purpose of this chapter This chapter explains the sensor technology and its characteristics, which is used in the USTER® QUANTUM 3. The basics of the yarn signal analysis and the yarn clearing are illustrated in the follow-ing figures and should support the understanding of the additional chapters of this application hand-book. 2.2 Monitoring of thick places In order to be able to monitor and to evaluate thick and thin places as well as deviations from the nominal yarn count, the thickness of the yarn must be converted into a proportional electrical voltage. The course of the voltage is called yarn signal.

Yarn piece with thick place

Electrical yarn signal

0

+ V

- V

Fig. 2-1 Yarn signal, result of a thick place In the USTER® QUANTUM 3, the conversion is carried out either with the sensor of the capacitive measuring principle or with the sensor of the optical measuring principle. The sensor is part of the intelligent measuring head iMH which also consists of the electronic system to convert mass or diam-eter variations into a proportional electric signal. There are very high demands for both measuring principles regarding the resolution and precision of the results. The sensor must be able to monitor a yarn which runs with up to 120 km/h through the sensor and to detect even very short faults. In order to achieve this, the yarn signal is determined eve-ry 2 mm.

2 Basics of yarn measurements and yarn clearing


2.2.1 The capacitive measuring principle

2

1

3

4

5

Fig. 2-2 Capacitive sensor The electrical measuring condenser (1) forms the sensor for the capacitive monitoring of the yarn mass. This is done by two parallel metal plates, the electrodes. In the space in between (2), the two electrodes build an electrical field when putting on an electrical alternating voltage (3). If a yarn (4) is brought into this field, the capacitance of the measuring condenser changes. From this change, an electrical signal, the yarn signal (5), is derived. The change of the capacitance depends, besides of the mass of the yarn and of the dielectric constant of the fiber material used and the moisture content of the yarn. With the capacitive measuring principle, the yarn signal corresponds to the yarn mass, which is locat-ed in the measuring field. Changes of the yarn mass cause a proportional change of the yarn signal. 2.2.2 The optical measuring principle

12

4

5

3

Fig. 2-3 Optical sensor The infrared light source (1) and the photocell (3) represent the sensor for the optical monitoring of the yarn thickness. The infrared light is scattered by a diffusor (2) in the measuring zone and reaches the photocell (3). The photocell generates an electric signal, which is proportional to the light intensity. If a yarn (4) is brought into the measuring zone, parts of the light will be absorbed by the yarn. The amount of light, which hits the photocell, is smaller. From this change, an electrical signal, the yarn signal (5), is derived.



With the optical measuring principle the yarn signal corresponds to the diameter of the usually circular shape of the yarn, which is located inside the measuring field. Changes of the yarn diameter cause a proportional change of the yarn signal. 2.2.3 Yarn signal definitions Independent of the used measuring principle, the evaluation is carried out on the basis of the relative yarn signal change in contrast to the base value. The base value corresponds to the count of the wound yarn.

1 2 3 4 5

- 100%- 50%

0%+ 50%

+ 100%+ 150%+ 200%

Fig. 2-4 Definition of the yarn signal 1. No yarn in the measuring field: in this state, the yarn signal is defined as –100%. 2. A yarn of a certain count is inserted into the measuring field. The yarn signal changes from –100%

to 0%. The change of 100% corresponds to the yarn count. 3. The yarn is moved in the measuring field. The yarn signal corresponds to the yarn evenness. The

mean value of the evenness variation is defined as 0%. 0% is the base value for the deviations of a positive thick place and a negative thin place.

4. Thick place in the measuring field: the deviation is measured in % to the base value. In the exam-

ple (Fig. 2-4), the deviation is +130%. If the signal exceeds the clearing limit set, the fault will be cut.

5. As soon as the yarn leaves the measuring field, the yarn signal drops to –100%. The definitions are valid for both measuring principles. The change in percent refers to the cross-section in case of the capacitive measuring principle and the diameter in the case of the optical measuring principle. This means that an increase or decrease of the yarn mass produces different deviations (%) of the yarn signal depending on the physical principle of the sensor. Table 2-1 shows the relationship be-tween the cross-section and the diameter changes.



Yarn Yarn signal (capacitive) Yarn signal (optical)

Regular yarn 0% base value 0% base value

Thick places with double cross-section

Increase of cross-section: +100% Increase of diameter: +41%

Thin place with half of the cross-section

Decrease of cross-section: -50% Decrease of diameter: -29%

Table 2-1 Relationship between the cross-section and diameter The higher resolution of the capacitive sensor is particularly helpful in areas where already small de-viations from the nominal value can be disturbing for the human eye (e.g. in compact spinning as a result of the missing hairiness). This table indicates that the used measuring principle must always be known. Otherwise, it can lead to misinterpretation. Fig. 2-5 shows the relationship between the cross-section and the diameter changes.

Fig. 2-5 Optical and capacitive measuring systems



Example: The mass of a thick place in the measuring zone increases by +300% compared to the mean of the yarn. How much is the rise of the signal of the optical system? According to Fig. 2-5 the optical signal (proportional to the diameter) increases by +100%. Remarks: This is valid for yarn faults with equal density of the fibers esp. long, well twisted yarn

faults. For short and fluffy yarn faults the diameter deviations is more or less the same as the mass deviation.

2.2.4 Characteristics of the two measuring principles Why are there two different measuring principles for yarn clearing? The requirements in the textile industry depend on the textile fibers and the end-use. The experts of Uster Technologies can support the users to select the best clearer. The following Table 2-2 shows the most important differences of their properties. Characteristics capacitive principle optical principle Proportionality Corresponds to the mass/cross-

section of the yarn or the number of fibers in the measuring field

Corresponds to the diameter of the yarn

Measuring field length The yarn signal is the mean value of the piece of yarn which is located in the measuring field. Length: 4 mm

The yarn signal is the mean val-ue of the piece of yarn which is located in the measuring field. Length: 3 mm

Evaluation of the yarn fault

Normal yarn fault

The fault is evaluated with the full increase of the cross-section in per-cent.

The fault is evaluated with the full increase of the diameter in per-cent.

Voluminous, visually large appearing yarn fault

As the number of additional fibers is not extremely high, this yarn fault is recognized as relatively insignificant.

The very voluminous yarn fault absorbs a lot of additional light. Therefore, the fault is considered as significant.

Short yarn faults, length: 3 mm

The fault is evaluated with the full increase of mass.

The fault is evaluated with the full increase of the diameter.

Very compact yarn fault

The distance between two white lines is 1 cm.

The fault is evaluated with the full increase of the cross-section. Due to the higher number of fibers in the cross-section, the thick place can absorb more dye stuff and appears darker in the end product.

This compact yarn fault absorbs only a small amount of light. The increase of the diameter is con-sidered as too insignificant in comparison to the cross-section.

Table 2-2 Properties of the measuring principles



2.2.5 Environmental influences on yarn measurement and yarn clearing Environmental influences and material characteristics have different effects on both measuring princi-ples. Therefore, for certain applications one measuring principle may be more appropriate than the other one. Table 2-3 shows the most important influences on the yarn measurement and the yarn clearing with both measuring principles, respectively.

Influence Capacitive measuring principle Optical measuring principle

Fiber material Most fiber materials can be measured with both measuring principles.

Yarns, which contain electrically conductive fibers or are treated with electrically conduc-tive spinning additives, cannot be measured.

Can be measured without limitations.

Colored yarns No or only little influence Color differences within the bobbins can lead to different sensitivities (see 2.4.2, Calibration process on a running yarn), but can also serve for the monitoring of color differences.

Dark yarns require in most cases other settings than light yarns.

Fiber blends No or only little influence

Wrong fiber blends can be monitored within certain fiber differences with the C- and CC-channel (see chapter "Count variations").

Wax If the wax device is located below the yarn clearer, there is the tendency of a dirty meas-uring field. The selection of a suitable wax can keep the contamination within acceptable limits. The capacitive measuring field is less affected by wax.

Contamination Usually, the measuring field is cleaned to a great extent by the yarn hairiness. The change of the yarn signal caused by the contamination is compensated within certain limits. If the contamination gets too high, a technical alarm is triggered.

Atmospheric humidity

Normal variations in the humidity have no influence.

Yarn moisture Normal variations have no influence as long as the yarn structure doesn’t change.

Non-homogenous yarn humidity can lead to unjustified cuts.

Very dry yarns exhibit a higher hairiness. This suggests a larger diameter and can lead to unjustified cuts.

If wet splicing is used, Uster Technologies must be consulted.

Table 2-3 Environmental influences and their effects



Moisture of the yarn / Capacitive measuring system One characteristic of textile material is the ability to absorb moisture. The moisture that can be ab-sorbed depends on the relative humidity of the environment. Cotton contains about:

• 6,6 percent by weight of moisture at a relative humidity of 50%

• 8,2 percent by weight of moisture at a relative humidity of 65%

• 10,2 percent by weight of moisture at a relative humidity of 80% Besides the yarn, the capacitive measuring principle measures also the moisture of the yarn. There-fore, and as the deviations of the yarn fault are always referred the mean value of the yarn signal, a homogenous distribution of the humidity along the yarn should be striven for. Large variations in the distribution of the moisture can lead to unjustified cuts. In order to reach a high and constant production and quality, a stable climate and the avoidance of fast changing variations of the relative humidity, respectively, are needed. Blended yarns made out of various colored fibers (melange) / Optical measuring system In a blend of various colored fibers with high light reflection differences (e.g. black/white), disturb-ances in the blend can lead to clearer cuts. This characteristics, however, can be used with the inten-tion to control the fiber blend in such yarns. 2.2.6 Selection of the suitable measuring principle Yarn clearing is the final control in a spinning mill. In order to produce the best possible yarn quality, all capabilities of a yarn clearer system should to be used. This also includes the selection of the most suitable measuring principle. The previous explanations and the chapter "Technical Specifications", Chapter 15 should help to make the best choice. If you are not completely sure, please do not hesi-tate to contact a representative of Uster Technologies, who will be glad to assist you. 2.3 Monitoring of foreign fibers in the yarn The demands of the world market on the yarn quality have risen steadily over the last couple of years, also in regard of foreign fiber faults. Today, it is expected from a yarn clearer that it detects a single colored fiber in the yarn.



2.3.1 Characteristics of the sensor for foreign fibers Intensity In contrast to the human eye, the foreign fiber sensor measures the contrast between the yarn itself and the foreign fiber. The intensity of the contrast does not only depend on the color of the foreign fiber, but also on its surface structure. The wavelength of the light sources which are used in the sen-sor also plays an important role. The signal which is generated by the foreign fiber sensor is defined as the intensity of the foreign fiber. The intensity of the foreign fiber – or, to be more precise, the change of the light reflection – is given in % foreign fiber signal. For dark foreign fibers in a white yarn: 0% = Reflection of the yarn without foreign fiber 100% = Reflection of a completely black foreign fiber The following Table 2-4 shows some foreign fiber faults as seen by the human eye and by the sensor:

Human eye Reflection sensor Intensity

16%

16%

9%

32%

7%

Table 2-4 Evaluation of foreign fibers Length The duration of the signal corresponds to the foreign fiber length. The length is given in mm. Detailed explanations for the monitoring of foreign fibers can be found in chapter 8 "Foreign fibers". With the multicolor light source of the USTER® QUANTUM 3 it is possible to detect foreign fibers of all colors.



2.4 Communication of the yarn clearer with the winding machine In order to recognize the status of the winding machine, an exchange of information is needed be-tween the clearer and the winder. 2.4.1 Zero point adjustment If there is no yarn in the measuring field, the yarn signal must show –100%. Dirt and changes inside the measuring field can cause that the yarn signal is not –100% when yarn is removed from the measuring field. With the zero point adjustment, these deviations are compensated and the yarn sig-nal is set on –100% again. The zero point adjustment is carried out before the splicing process, i.e. when the measuring field is empty. If the control range is not sufficient for the zero point adjustment to set the yarn signal to -100% (measuring field too dirty or blocked with fly), a technical alarm for the respective sensor is triggered. 2.4.2 Calibration process on a running yarn As already explained, thick and thin places in a yarn are registered as deviation from the nominal yarn value in percent. Foreign fibers are registered as changes of the light reflection in percent. In order to make this possible, the sensor has to collect know-how on the yarn first, i.e. the sensor needs a start-up process on the running yarn. The determination of the nominal yarn count, in the following called the calibration value, is carried out automatically during the start-up of a new article and is adjusted continuously at every start of a wind-ing position. The ADMV-value * regulates the amplification of the yarn signal, so that the nominal yarn count represents 0%. There are separate ADMV-values for the thick and thin place detection as well as for the foreign fiber detection.

Fig. 2-6 Calibration process. Course of the calibration process for thick and thin place clearing.

* ADMV = Analog Digital Mean Value, represents the yarn mean value



This yarn mean value is the mean value of all clearers of a group. With this value it is possible to cal-culate percentage deviations between two or several yarns. The ADMV value consists not only of the yarn count, but also of yarn properties such as fiber type, moisture, color, etc. The number of the start-ups per group and winding position during production changes (red rectangle) until it reaches the value of 200, and because the calculated mean value is statistically stable, after 200 the count will not change anymore.

Fig. 2-7 Deviations to the nominal value Storing of the calibration values for the optical sensor When processing colored yarns with the optical sensor, color sensitivity differences between the sen-sors can lead to start-up problems and to changes in the clearing sensitivity. In order to avoid this problem, it can be switched to "O-Single Adj" by means of the article. This has the effect that the calibration value is calculated for each sensor individually and not per group. Calibration procedure for foreign fiber clearing Each sensor calculates its own individual foreign fiber calibration. The fine adjustment of the calibra-tion value is also carried out for each single sensor. The principle procedure is the same as for thick places.



2.4.3 Yarn detector The yarn detector monitors the status of the yarn in the measuring field: yarn not available, yarn not moving, yarn moving. The yarn detector controls some functions of the machine. Static yarn detector SYD The static yarn detector detects, if there is yarn in the measuring field or not:

No yarn in the measuring field SYD = turned off

Yarn in the measuring field SYD = turned on

If the SYD is turned off, the DYD cannot be turned on.

-100%

0%

No yarn

Yarn mean value

threshold

on

offSYDStatic yarn detector

Fig. 2-8 Status of the static yarn detector SYD The SYD is switched on as soon as the threshold is reached. Dynamic yarn detector DYD The dynamic yarn detector DYD determines if the yarn in the measuring field is running or not. Yarn in the measuring field is stopped DYD = off Yarn in the measuring field runs DYD = on

• If the DYD is turned off, the clearing channels are blocked.

• If the DYD is turned off, the winding position will not / is stopped. The DYD is turned on by the yarn signal change, which is caused by the unevenness of the running yarn. The sensitivity and the timing for turning on and off are set. For exceptional cases (processing of special yarns) a manual adjustment of the yarn detector settings according to the sensor type as well as to the winding machine type is available.



Yarn detector test function The status of the static and dynamic yarn detector can be displayed at the iMH-LED (iMH = intelligent measuring head / LED = light emitting diode), Fig. 2-9: service / special functions / iMH LED display. SYD/DYD, press OK. No yarn: off SYD: DYD:

Fig. 2-9 Setting of the iMH-LED display function

Fig. 2-10 Display of the status of the yarn detector at the iMH-LED Use this test mode, if there are any problems with the yarn detector, i.e. if there are any winding posi-tions which do not run or do not stop when the yarn breaks.



2.4.4 Winding speed Fault length Besides the mass or diameter variation, the fault length is also decisive for the evaluation of a yarn fault. The fault length is determined by the time, during which the fault runs through the measuring field. Again, this time depends on the yarn speed and the winding speed, respectively. Wound length The clearer also determines the length of the wound yarn. The wound length is calculated from the winding speed and the time during which the dynamic yarn detector is turned on. Winding speed In order to calculate the fault length and the wound yarn length correctly, the clearer needs the information about the winding speed.

1

2

3

Fig. 2-11 Winding machine / Drum drive with drum impulse sensor The winding speed and the yarn speed, respectively, are defined by the friction drive between the guide drum (1) and the cross-wound cone (2). The sensor (3) delivers a certain number of drum impulses per rotation of the guide drum. These impulses are evaluated by the yarn clearer to measure the winding speed. Older or more simple winding machines do not have a drum sensor. For clearer installations on such machines, the winding speed must be set at the control unit.



The winding speed which is given by the drum impulse or the setting at the control unit does not al-ways correspond to the effective yarn speed. The yarn speed is additionally influenced by the follow-ing parameters: • Yarn displacement

Depending on the subsequent processes of the yarn, cones with various conical shapes are used. With a cone of e.g. 9°15", the speed variation can be significant.

• Slippage

If the guide drum turns faster than the cone, slippage occurs. Thus, the yarn runs at lower speed through the measuring field. A yarn fault appears longer than it is in reality. Incorrect cuts during start-up or during winding and incorrectly inspected yarn joints (splices/knots) can be the conse-quences in the extreme case. Slippage occurs at a fast start-up of the guide drum or when the processed material exhibits a low static friction. In order to avoid slippage it is necessary to set the start-up curve so that the cross-wound cone starts synchronously with the guide drum. This is of special importance for the pro-duction of cross-wound cones with a large diameter.

• Ribbon winding

If the diameter of the cross-wound cone stands in a even number ratio to the diameter of the guide drum, ribbon winding can occur. The anti-patterning device, which is generated by the varia-tion of the drum speed, avoids this. Variations of the winding speed are the result. These varia-tions are registered on winding machines with the drum impulse sensor and thus taken into ac-count by the yarn clearer. The desired slight slippage is not taken into account.

Disturbing thick and thin places 3


3 Disturbing thick and thin places 3.1 Introduction This chapter will explain the classification and monitoring of disturbing thick and thin places. Staple fiber yarns always have a specific unevenness. The reasons for their origin are diverse. At a certain size (mass or diameter and length) this unevenness will be disturbing in the yarn. Electronic yarn clearing is a process in which disturbing yarn faults are detected and eliminated. In ring spinning, yarn clearing is carried out on winding machines with a winding speed of up to 2500 m/min. Yarn monitoring and yarn clearing is based on the mean value of the yarn. This yarn value is deter-mined by the measuring head itself. This is valid for the capacitive as well as for the optical measuring head. During the spinning process, it is not possible to keep the number of fibers in the cross-section con-stant at every moment. This leads to random variations of the mass or the diameter. Only those spin-ning mills with a permanent improvement process are able to keep these random variations within close limits. 3.2 Definition of the yarn body The USTER® QUANTUM 3 interprets and displays the yarn characteristics with the help of the yarn body. The powerful capacitive and optical sensors of the USTER® QUANTUM 3 can determine the full yarn body including very short and fine defects. The clearer analyzes the yarn fault distribution and displays the yarn profile, which is called “yarn body”, in a few seconds or minutes. The yarn body is simply the normal yarn with its set of expected natural variations and represents the nominal yarn with its tolerable, frequent yarn faults. Yarn body is a new yarn characteristic, and we know from the expe-rience so far that the yarn body changes according to the raw material and the spinning process. By analyzing the shape of the yarn bodies out of different raw material varieties and process changes, we can discover patterns and build up references. Based on the references, the operator can identify changes. The yarn body becomes always wider in the direction of the short yarn variations, e.g. short faults occur more frequently. On the contrary, the yarn body becomes smaller in the direction of the long yarn variations. The yarn body is a significant tool to help finding the optimum clearing limits, not only for thick places (NSL) and thin places (T), but also yarn count deviations (later called C and CC faults). The yarn body is composed of two parts:

• Dark green area representing the real yarn body.

• Light green area representing yarn body variations.

3 Disturbing thick and thin places


In Fig. 3-1, the dark green area represents the yarn body and the light green area the yarn body varia-tions, and this figure shows that the yarn body becomes wider in the direction of the short yarn faults. The short yarn faults with a significant mass or diameter deviation from the mean value (zero line) are considered less disturbing by the human eye compared with long yarn faults with little deviation. Short faults also occur more often. The number of clearer cuts increases considerably if the clearing limit is set in the green area. The vertical scale represents the yarn mass or diameter increase and decrease, and the horizontal axis represents the faults length in cm. In Fig. 3-1, besides two green areas, there are also green dots which represent remaining events in the yarn and red dots which represent cut yarn faults (disturbing events). The number of expected fault cuts per 100 km together with setting limits are shown with red color (in Fig. 3-1, top right corner, 311,6 km of yarn was wound and the expected fault cuts for thick places calculated per 100 km is 96,0 cuts). The cut ratio will be statistically representative after running 100 km of yarn. At a winding speed of 1500 m/min and 60 winding positions per machine, it lasts approximately 1 minute.

Fig. 3-1 Frequent and seldom-occurring yarn faults. Measured yarn length: 311,6 km. The expected fault cuts for thin places calculated per 100 km is 4,5 (bottom, right corner). The total for thick and thin places is 100,5 per 100 km, which is too high as a cut rate. Therefore, the clearing curve has to be moved away from the yarn body. Since both dark and light green areas together constitute the yarn body, it is recommended that the clearer should not cut into the yarn body. If the clearing limit is laid within these green areas, the cuts will increase significantly and the productivity will be lower.

Area of the yarn body

Area of the disturbing faults

Area of the disturbing faults



Development of the yarn body / Example of Ne 30/1, 100% cotton yarn The clearing system calculates the yarn body already after a few seconds. The yarn body will be more accurate after some additional kilometers.

Fig. 3-2 Yarn body after 4,6 km Fig. 3-3 Yarn body after 49,2 km Fig. 3-4 Yarn body after 72,6 km At the beginning the variation shown as the light green area is not yet stable due to the statistical cal-culations. But already after 30 km of running yarn the variation has stabilized and the optimization process for the clearing limits can start. There is practically no difference anymore between Fig. 3-3 and Fig. 3-4. If we calculate the duration of the above mentioned start-up for a link system with 23 winding posi-tions and a stand-alone winding machine with 60 winding position, it results in the following time spans: Yarn length Winder speed Winding positions Duration Winding positions Duration

4,6 km 1400 m/min 23 0,14 min 60 0,05 min

49,2 km 1400 m/min 23 1,53 min 60 0,59 min

72,6 km 1400 m/min 23 2,25 min 60 0,86 min Examples of various yarn bodies

Fig. 3-5 Yarn body, cotton 100%, combed, knitting, 276 km (left), 238 km (right), count Nec 40, clearer C20,

yarn with 39,4 cuts / 100 km on the left, yarn with 81,8 cuts / 100 km on the right.



Fig. 3-6 Yarn body, polyester 100%, Nec 40, 523 km, knitting, (left), 382 km weaving, (right), clearer C15

Fig. 3-7 Yarn body, cotton 100%, carded, knitting, 413 km (left), 553 km (right), count Nec 40, clearer C15

Fig. 3-8 Yarn body, Nec 40, 35% cotton/65% viscose, weaving, 353 km (left), Nec 40, 55% cotton / 45% pol-

yester, weaving, 361 km (right), clearer C15



3.3 Interpretation of the yarn body The Fig. 3-5 to Fig. 3-8 demonstrate that the shape of the yarn body strongly depends on the quality and the raw material of the yarn. For reasons of a better comparison the eight yarns are all of the same count. A comparison of yarn bodies of various counts and raw material has unveiled the follow-ing:

• Due to the higher irregularity the yarn body of carded yarns is wider than those of combed yarns

• Since fine count yarns have a higher irregularity than coarse count yarns, the yarn body of fine yarns is wider than those of coarse yarns

• The man-made polyester cut staple fibers have a significant effect on the light green area from 0,1 to 4 cm

• The highest deviation of the yarn body from the zero line in the thin place area can be recognized at the mean length of the fibers, i.e. at about 2 cm, in blended yarns at about 3 cm.

• The seldom-occurring faults (red dots) have a different but characteristic distribution. Therefore, an automatic determination of the clearing curve can minimize the number of cuts.

The yarn body, therefore, is a significant support tool to only cut really disturbing faults and to opti-mize the number of cuts. The yarn body is affected by the yarn unevenness, by the number and type of thin places, thick places and neps, by the characteristics of the raw material and by the spinning process. 3.4 Disturbing thick places 3.4.1 Classification matrix As already described in the introduction of this application handbook, seldom-occurring yarn faults are classified in the classification matrix of the USTER® CLASSIMAT. Besides the classification matrix, the cut thick places are divided in three groups (Fig. 3-9):

• N – faults: thick places from 0,2 cm to < 1 cm → very short thick places (S fault)

• S – faults: thick places from 1 cm to < 8 cm → short thick places (L fault)

• L – faults: thick places as of 8 cm → long thick places



Fig. 3-9 Classification system for the settings N, S and L Fig. 3-9 shows a setting example of the clearing curve when pressing the key NSLT. Fig. 3-10 shows the classification matrix of thick and thin places. With the help of new extended clas-ses, the user can monitor and control critical (e.g. short and fine) defects which often determine the fabric appearance.

Fig. 3-10 Classification matrix for NSL For a broad understanding of the faults, it is recommended to base the assessment for the setting of the yarn clearer mainly on the evaluation of the yarn body and the scatter plot and less on the counts of the classification.

N S L



3.4.2 Thick and thin places Thick and thin places are evaluated by their visual impression, if they are disturbing or not-disturbing. The conversion into the "language" of the clearer, i.e. the fixing of the clearing limits, must be possible on the basis of the visual evaluation. Therefore, each modern yarn clearer must fulfill these conditions in order to measure all thick and thin places correctly. The determined values have to correlate to the size of the visual impression. Long thick and thin places can hardly be seen on the yarn itself, but are disturbing in the fabric. They require optimized calculation methods. These demands are fulfilled ideally with the USTER® QUANTUM 3. It is based on the calculation method already used in previous generations of the USTER® clearers and was proven to be best. Depending on the sensor type, the cross-section (iMH-C) or the diameter (iMH-O) are measured con-tinuously with a repetition rate of 2 mm. This means: the clearer calculates the mass or the diameter of the yarn continuously every 2 mm length and determines the mass or the diameter of these sec-tions. The fault determination starts, it is exceeding the mean value.

Positivethreshold

2 mm pieces

Mean value (0%)

- 100%

Negativethreshold

Fig. 3-11 Yarn signal with threshold Fig. 3-11 shows a yarn signal, for which a next test value is determined every 2 mm. Fig. 3-12 shows the yarn signal of a cotton yarn with two distinctive thick places and the deviation in percent. The first yarn fault has an increase of about 330%. In addition, one distinctive thin place is represented.

Fig. 3-12 Yarn signal of a cotton yarn with a clearing limit of 130% above the mean (0%)



In Fig. 3-13, the signal of the first fault is enlarged.

Fig. 3-13 Enlarged yarn fault, first significant thick place, Fig. 3-13 All the displayed yarn faults of Fig. 3-14 show a classification length of 16 mm and were classified with a thickness between 260 and 300%. This picture is taken from the library of USTER® QUANTUM EXPERT for winding.

Fig. 3-14 Yarn faults with 260 – 300% and a length of 16 mm The shown yarn faults (Fig. 3-14) serve as examples for the previously described fault. The example in Fig. 3-15 shows a long thick place with the classification 74% and 63 cm. If this clas-sification point is entered into the classification matrix, it can be seen that the fault is situated above the clearing limit.



Fig. 3-15 Example for a long thick place in the display window of the Control Unit Long thick places starting at a length of 8 cm are classified as L-faults. The length of the L-faults is limited at 200 cm. 3.5 Clearing limits for thick places The clearing limit is defined as a line which separates disturbing/cut faults from the non-disturbing/remaining faults. The course of the clearing limit is defined by setting parameters (see Fig. 3-16).

Fig. 3-16 Clearing limit of N, S and L by means of max 8 set points For a good overview, the clearing limit is shown in the classification matrix. The classification matrix corresponds always to the set parameters.

74%

63 cm



3.5.1 Standard way of optimizing clearing limits: Manual clearing limits entry Fig. 3-17 shows the clearing limit as shown in the setting window of the Control Unit. At the previous generations of the USTER® QUANTUM, besides the clearing limit (NSL), the settings for the thick place clearing with the auxiliary setting points (H1…H6) is possible. Now the USTER® QUANTUM 3 gives us the chance of determining clearing limits by placing a maximum of 8 set points NSL1 to NSL8. In Fig. 3-17, we can see 4 setting points (red rectangle) and the clearing limit for NSL thick places. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we enter the values for NSL1, set point NSL2 will appear and it will continue the same way.

Fig. 3-17 Clearing limits on the screen of the control unit Set points have two parameters. These are: sensitivity (%) and reference length (cm). Sensitivity The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensi-tivity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive). (NSL1 = 300%, Fig. 3-17). Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive) (NSL1 = 1.0 cm, Fig. 3-17).



3.5.2 Setting a smart clearing limit for disturbing thick places (NSL) As we mentioned before, the yarn body is used for a better understanding of thick places, thin places and it shows the nominal yarn with its tolerable, frequent yarn faults. The aim of yarn clearing is to follow the course of the yarn body and to eliminate the thick and thin places which are disturbing in a fabric and which are outside the yarn body. Since the yarn body is clearly visible, clearing can follow the yarn body to minimize the number of cuts and to optimize the removal of disturbing faults. It also prevents from cutting into the yarn body and removal of defects that don't add value to the yarn but simply need additional splices which then could potentially break in the weaving process. In other words the default smart limit based on the yarn body is a nearly optimal clearing limit from a quality point of view (Fig. 3-18).

Pressing key presents • The yarn body. • Scatter plot of the cut faults and

remaining events. • Number of expected fault cuts /

100 km. Clearing limit

Red dots = cut yarn faults. Green dots = remaining events. =Yarn body variation =Yarn body

= Proposes the starting point for the clearing limits based on the yarn body.

Fig. 3-18 Display of the yarn body and the actual clearing limit (thick places, NSL) with the forecasted cut val-ues

The conventional way of optimizing the clearing limits is checking the existing ones by looking at the yarn test results and entering the new ones manually based on the customer’s own experience. How-ever this procedure is time consuming, especially for a new user, and needs some experience. With the USTER® QUANTUM 3, we have a very useful and smart tool to find the right starting point for the new clearing limits. The Smart Limit function proposes a starting point for the clearing limits based on the yarn body and also provides a cut forecast to facilitate faster setup of clearing limits. Fig. 3-20 shows the selection of the optimum clearing curve for thick places. For a few seconds or minutes the yarn runs with a pre-defined clearing curve (default value). After this period the operator can see the yarn body on the screen. Now the clearing curve can be optimized either by moving the clearing curve up or down. The setting can be fixed by pressing the “confirm” button.



The setting of USTER® QUANTUM 3 can be done simply in one step:

Fig. 3-19 Start with standard setting Fig. 3-20 Only one step / Press Smart Limit button

and get a proposed setting including the cut forecast based on the yarn running

After pressing the Smart Limit key, a small window with the two appropriate keys to adapt and opti-mize the smart limit for NSL thick places appears. The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by open and close keys to optimize the settings according to the individual quality requirements and productivity. Every change of setting will automatically initiate a new calculation of the cut forecast. It is recom-mended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound. Of course all settings recommended by smart limit can also be altered manually. Even in this case the new cut forecast is calculated.

= The new setting point proposals

= Smart Limit 1 step less sensitive.

= Smart Limit 1 step more

sensitive.

= Show yarn body, scatter plot and re-calculate the ex-pected cuts / 100 km.

= confirm and activate

optimized clearing limit.

= Cancel all modifications

Fig. 3-21 Proposed setting is a starting point for optimization



Cuts/100km

Total yarn fault counts /100 km in this class

Besides the smart limit function, of course the thick places (NSL) classes are still a very powerful tool where we can base our last decision.

Fig. 3-22 NSLT online classification NSLT yarn faults are displayed together with all other yarn faults of the machine, a group or a winding position.

Fig. 3-23 NSLT yarn fault registration



3.6 Disturbing thin places Thin places, as long as they don't lead to yarn breaks, are only disturbing starting from a certain length. The reason for disturbing thin places is a missing number of fibers in the cross-section as a result of a non-optimal drawing process. 3.6.1 Classification matrix As already described in the introduction of this application handbook, seldom-occurring yarn faults are classified in the classification matrix of the USTER® CLASSIMAT. The thin places are shown in the classification matrix, Fig. 3-24.

Fig. 3-24 Area of thin places in the classification matrix (red square) 3.7 Clearing limits for thin places The evaluation of a thin place is similar to NSL

Fig. 3-25 Clearing limit for the T-channel



Fig. 3-26 shows a long thin place with the classification -32% and 65 cm. This classification point, as shown in the classification matrix, is located outside the clearing limit (Fig. 3-26).

Fig. 3-26 Example of a long thin place in the setting window of the control unit 3.7.1 Standard way of optimizing clearing limits: Manual clearing limits entry Fig. 3-17 shows the clearing limit as shown in the setting window of the control unit. The USTER® QUANTUM 3 gives us the chance of determining our clearing limits by placing a maximum of 8 set points T1 to T8. In Fig. 3-17, we can see 5 setting points (red rectangle) and the clearing limit for T thin places. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we enter the values for T1, set point T2 will appear and it will continue the same way.

-32%

65 cm



Fig. 3-27 Clearing limits on the screen of the control unit Set points have two parameters. These are: sensitivity (%) and reference length (cm). Sensitivity The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensi-tivity setting shifts the clearing limit from the zero line away (less sensitive) or towards zero (more sensitive). (T1= -45%, Fig. 3-27). Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive) (T1 = 2.6 cm, Fig. 3-27).



3.7.2 Setting a smart clearing limit for disturbing thin places (T) Fig. 3-28 shows the selection of the optimum clearing curve for thin places. For a few seconds or minutes the yarn runs with an automatically selected clearing curve (default value). After this period the operator can see the yarn body on the screen. Now the clearing curve can be optimized either by moving the clearing curve up or down. The setting can be fixed by pressing the “confirm” button (, Fig. 3-30).

Pressing key presents • The yarn body. • Scatter plot of the cut faults and

remaining events. • Number of expected fault cuts /

100 km.

Red dots = cut yarn faults. Green dots = remaining events. =Yarn body variation =Yarn body


Fig. 3-28 Display of the yarn body and the actual clearing limit (thin places, T) with the forecasted cut values. With the USTER® QUANTUM 3, the user has a very smart tool to find the right starting point for the new clearing limits. The Smart Limit function proposes a starting point for the clearing limits based on the yarn body and also provides a cut forecast to facilitate faster setup of clearing limits. The setting of USTER® QUANTUM 3 can be done simply in one step:

Fig. 3-29 Start with standard setting Fig. 3-30 Only one step / Press smart limit button

and get a proposed setting including the cut forecast based on the yarn running



Cuts/100km Total yarn fault counts /100 km in this class

After pressing the smart limit key, a small window with the two appropriate keys to adapt and optimize the smart limit for T thin places appears. The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by open and close keys to optimize the settings according the individual quality requirements and productivity. Every change of setting will automatically initiate a new calculation of the cut forecast. It is recommended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound (Fig. 3-29 and Fig. 3-30). Of course all settings recommended by smart limit can also be altered manually. Even in this case the new cut forecast is calculated automatically.



= Smart Limit 1 step more sensi-tive.

= Show yarn body, scatter plot and recalculate the expected cuts / 100 km.

= confirm and activate optimized clearing limit.

= Cancel all modifications

Fig. 3-31 Proposed setting is a starting point for optimization Besides the smart limit function, of course the thin place (T) classification is still a very powerful tool where we can verify our last decision.

Fig. 3-32 NSL T online classification



3.8 The effect of thick and thin places on the fabric appearance 3.8.1 Thick places In Fig. 3-33, we see the ring spinning areas of faults and their descriptions.

Ring Spinning Areas of Faults Description

Fig. 3-33 Formation of faults on the ring spinning machine

S1 – Spun in fly waste

S2 – Loose fly

S3 – Long collections of fly waste

S4 – Faults caused by static charges or damaged aprons

S5 – Collections of fly waste pushed together at the ring trav-eller

S1 Spun in fly

This refers to free fibers which fall into the drafting elements or onto the roving being fed into the drawing unit. These fibers are then twisted into the yarn along their entire length




S2 Loose fly

This refers to free fibers which are collected by the yarn at a position after the front roller and, in most cases, are only spun-in at one end.

S3 Long collections of fly

These are fibers which stick together on aprons or rollers and from time to time are collected and carried along by the yarn.

S4 Fish (corkscrew-type faults)

Faults caused by static charging or damaged aprons

These faults occur due to static charging or are a result of un-suitable drafting aprons or draft-ing aprons which have cracked surfaces.




S5 Pushed-together collections of fly

These are faults resulting from fibers which are held back, and occur primarily at the ring travel-er.

S6 Chains of faults S1, S2, and S3

These are combinations of the faults S1, S2, and possibly also S3 which occur in short succes-sion, one after the other, along the length of the yarn.

S7 Crackers

This is due to extra long fibers which disturb the drafting pro-cess and, for a short instant of time, stop the passage of the yarn.

Table 3-1 Spinning faults In Fig. 3-34 to Fig. 3-43, there are various examples of thick place faults resulting from the spinning process. Thick places in a woven fabric are given in Fig. 3-34 to Fig. 3-35. Here we can see a spun-in fly failure (Table 3-1). This refers to free fibers which fall into the drafting elements or onto the roving which is being fed into the drawing unit and are then twisted into the yarn along their entire length.



Fig. 3-34 Flying fibers which fall onto the roving or

into the drafting elements and are then twisted into the yarn

Fig. 3-35 Thick place in woven fabric, type S4 (see Fig. 3-33, Table 3-1)

Fig. 3-36 to Fig. 3-38 show a red colored, 100% polyester T-shirt. Unless examined closely, the fault would go unnoticed. However, we have discovered a disturbing thick place fault in the following zoomed pictures (Fig. 3-37 and Fig. 3-38).

Fig. 3-36 Thick place in a T-shirt / 100% polyester

Fig. 3-37 Thick place in a T-shirt Fig. 3-38 Thick place in a T-shirt, magnified

In Fig. 3-39 Fig. 3-40, a pair of 100% cotton jeans is shown as an example. We can see the long non-periodic thick places in the weft yarn in the zoomed picture.



There are two disturbing thick places in the white area (Fig. 3-40).

Fig. 3-39 Thick place in jeans / 100% cotton, Nec

18 (33 tex), OE rotor yarn Fig. 3-40 Thick place in jeans, zoomed

Fig. 3-41 to Fig. 3-43 show ladies’ pants, produced from 100% cotton, OE rotor yarn. In the previous example (Fig. 3-39 and Fig. 3-40) the weft yarn has a long non-periodic thick place. But in the exam-ple in Fig. 3-41, the warp yarn has a long non-periodic thick place which can easily be noticed. In Fig. 3-42 and Fig. 3-43, the fault is magnified and indicated by an arrow.

Fig. 3-41 Thick place, ladies pants / 100% cotton, OE rotor yarn

Fig. 3-42 Thick place, ladies pants Fig. 3-43 Thick place, ladies pants, zoomed



3.8.2 Reasons and measures to minimize seldom-occurring thick places In Table 3-2 and Table 3-3 the origin of the faults related to seldom-occurring events / thick places is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented.

SELDOM-OCCURRING EVENTS / Thick Places

Origin of Faults Possible Reasons and Preventive Actions

Drawframe Improper function of the autolevelling at finisher drawframe can cause long thin and thick places in the slivers which will results in long thin and thick places in the yarns or even in wrong yarn count

Comber High short fiber content in sliver or roving Optimize comber settings (comber noil) in order to achieve the maximum short fiber removal

Roving frame Spun-in fly waste from roving and spinning / Reduce flies in mill Improper draft distributions in drawing, roving, and spinning Wrong twist level in the roving Tension problems at roving frame Improper top roller pressure on roving frame

Ring spinning frame Contamination too high / Cleaning of ring spinning machine regularly Improper distance settings of a traveler cleaner at the ring spinning machine Air condition system performance in spinning not under control Avoid high amount of end breaks because it will result in a high number of outlier bobbins and excessive fly formation Optimize previous process stages to avoid or minimize slubs Avoid poor yarn joints Avoid eccentric front rollers in roving and spinning Avoid fiber accumulations on rollers and aprons Avoid false draft in ring spinning machine creel or improper spinning draft distributions Aprons worn out or damaged Rings and ring travelers worn out Wrong settings of the travelling overhead cleaner Improper apron settings Incorrect choice of the traveler profile and weight Lint accumulation by rollers

Winding machine Winding speed too high

Table 3-2 Preventive measures and tools for the management of seldom-occurring events / thick places



SELDOM-OCCURRING EVENTS / Thick Places / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Constant sliver quality and yarn quality

USTER® Testing on-line Adjustment of autolevellers

USTER® QUANTUM CLEARER Proper settings of the clearing limits

Monitor long-term quality level to secure consistency

Separate outlier bobbins with quality data

USTER® EXPERT SYSTEMS Monitor long-term variation of cut ratio and yarn quality

Table 3-3 Preventive measures and tools for the management of seldom-occurring events / thick places 3.8.3 Thin places Fig. 3-44 to Fig. 3-46 show two examples of thin places in knitted fabrics. Long thin places in yarns in the knitted fabric result in a severe defect. As illustrated in Fig. 3-45, the weak spots in the yarn gave in after five washing cycles and caused holes in the fabrics.

Fig. 3-44 Long thin places in yarns in the knitted fab-

ric result in a severe defect Fig. 3-45 Hole in a knitted fabric after five

washing cycles Fig. 3-46 shows a T-shirt with thin places. Although produced from 100 % combed cotton yarn, the thin places show up as horizontal lines.



Fig. 3-46 Thin places in knitted T-shirt / 100% cotton, combed

Fig. 3-47 and Fig. 3-48 show a T-shirt with two horizontal lines, produced from 100% carded cotton yarn. These lines, indicated by two black arrows, were produced by a yarn with a smaller diameter (long thin places) than the normal yarn which has then caused thin places in the T-shirt.

Fig. 3-47 Thin places in cotton T-shirt / 100% cotton,

carded, Ne 26 (22,5 tex) Fig. 3-48 Thin places in cotton T-shirt,

magnified



3.8.4 Reasons and measures to minimize seldom-occurring thin places In Table 3-4 and Table 3-5, the origin of the faults related to seldom-occurring events / thin places is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. SELDOM-OCCURRING EVENTS / Thin Places

Origin of Faults Possible Reasons

Drawing frame Improper function of autolevelling at finisher drawframe can cause long thin and thick places in the slivers which will re-sults in long thin and thick places in the yarns or even in wrong yarn count

Roving frame High unevenness of roving

Tension problems in roving

Weak roving

Eccentric front rollers

Aprons worn out

Ring spinning frame False draft in ring spinning machine creel

Eccentric front rollers

Aprons worn out

Blocked trumpets

Blocked drafting cages

Missing instruction and training of operators

Apron worn out or damaged

Winding High winding speed and winding tension

Table 3-4 Preventive measures and tools for the management of seldom-occurring events / thin places SELDOM-OCCURRING EVENTS / Thin Places / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Systematic quality control of sliver quality with the USTER® TESTER

USTER® Testing on-line Adjustment of autolevellers

USTER® QUANTUM CLEARER Proper setting of the clearing limits

Separate outlier bobbins with quality data software of the clearer


Table 3-5 Preventive measures and tools for the management of seldom-occurring events / thin places

Count variations 4


4 Count variations 4.1 Introduction Deviations of the yarn count within a yarn lot lead to high costs for complaints. The fact that the faulty yarn deviates from the nominal count can cause quality problems in the end product. The reasons for count variations are diverse:

• Deviations by mixing in wrong bobbins

• Peeled-off or uneven rovings can lead to significant count deviations within a bobbin

• Missing sliver from a finisher drawframe without an autolevelling system This demands a reliable monitoring of the yarn count on one side, but also its precise setting, which is in accordance with the quality requirements of the yarn. This can be done in many ways. In the follow-ing, two possibilities are described:

• The C-channel monitors the yarn count in the start-up phase after the splicing process. During this phase, mainly bobbins with the wrong count are registered, and the winding position must be stopped with the corresponding alarm functions. After the start-up phase, the C-channel is not ac-tive anymore. This procedure allows the choice of very sensitive settings, which are adjusted to the special circumstances of the start-up phase of the winding position.

• The CC-channel monitors the yarn count over the whole winding process. It is also possible to monitor very long yarn faults with the CC-channel dependent on the choice of the settings.

4.2 Definition of the yarn body for long-term variations (C and CC faults) The "yarn body" represents the nominal yarn with its tolerable, frequent yarn faults. Yarn body is a new yarn characteristic, and we know from the experience so far that the yarn body changes accord-ing to the raw material and the spinning process. By analyzing the shape of the yarn bodies out of different raw material varieties and process changes, we can discover patterns, and build up refer-ences. Based on the references, the operator can identify changes. The yarn body becomes always wider in the direction of the short yarn events, e.g. short faults occur more frequently. On the contrary, the yarn body becomes smaller in the direction of the long yarn events. The USTER® QUANTUM 3 interprets and displays the yarn characteristics with the help of the yarn body. The yarn body is a great tool to help finding the optimum clearing limits for thick places (NSL), thin places (T), yarn count deviations (C) and (CC). The yarn body for CC is composed of two parts:

• Dark green area representing the real yarn body

• Light green area representing yarn body variations

4 Count variations


The yarn body for C is composed of two parts (Fig. 4-1):

• Dark green line representing the real yarn body.

• Light green line representing yarn body variations.

Fig. 4-1 Yarn body display for C, defined from 2 to 12 m The vertical scale represents the yarn mass or diameter increase and decrease, and the horizontal axis represents the fault length in meter. Fig. 4-2 represents the yarn body for CC-fault. In Fig. 4-2 the green shaded area represents the yarn body for medium and long-term variations (2 to 12 m).

Fig. 4-2 Yarn body display for medium and long-term variations (CC faults), defined from 2 to 12 m The vertical scale represents the yarn mass or diameter increase and decrease, and the horizontal axis represents the faults length in meter. Since both dark and light green areas together constitute the yarn body, it is recommended that the clearing curve should not touch the yarn body. If the clearing limit is laid within these green areas, the cuts will increase significantly and the productivity will drop.

Count variations 4


4.3 Count deviations 4.3.1 Determination of the mean value of a yarn The pre-condition for an exact monitoring of yarn count deviations is the correct determination of the nominal yarn count. With the command "Start article" the parameters of C and CC are switched to a less sensitive fixed value in order to avoid wrong cuts during the calibration process. After the start-up of the winding position, each sensor determines the mean value for the running yarn and forwards it to the Central Clearing Unit. The Central Clearing Unit (CCU) calculates the mean value from all the transmitted values and sends it back to the sensors. 4.3.2 Purpose of yarn count deviation monitoring Deviations of the yarn count within a yarn lot lead to high costs for complaints. The fact that the faulty yarn deviates over several meters or even longer from the nominal count can cause quality problems in the end product. This demands a reliable monitoring of the yarn count on one side, but also its precise setting, which is in accordance with the quality requirements of the yarn. Fig. 4-3 shows the possibilities for yarn fault monitoring, if the fault channels N, S, L, C and CC are active.

Fig. 4-3 Clearing limits N, S, L, T, C+, C-, CCp and CCm

4 Count variations


4.3.3 Monitoring of yarn count deviations during start-up in the C – channel Objective The recognition of count deviations after the splicing process must be carried out very quickly, before too much yarn is wound on the cone. The pre-conditions during the start-up phase are not always perfect for a very sensitive monitoring. Therefore the monitoring must be carried out over a certain yarn length, in order to avoid wrong cuts. All modern winding machines are able to remove detected count deviations by setting a reference length on the clearer. Count variations in the start-up phase must be monitored with the C-channel. The thresholds for the clearer are set with the following parameters:

• Cp sensitivity setting for the detection of yarn diameter or mass increases

• Cm sensitivity setting for the detection of yarn diameter or mass decreases

• Reference length The choice of the thresholds depends on different factors and must be adjusted to the conditions of the mill:

• the produced yarn counts of the spinning mill

• the evenness of the yarn

• the possibilities of the winding machine to determine the suction length Function With each start-up, the C-channel monitors the yarn over the set reference length. The sensor measures the mean value over this length. If the mean value exceeds the above limits, a cut follows. Yarn suction after a C-cut / Machines with fault-related yarn suction Up-to-date winding machines provide measurable, fault-related yarn suction. The sensor transmits the length of a Cp or Cm cut to the processor of each individual winding position and determines the length to be sucked-off. As deviations from the nominal count can be calculated more precisely over a larger reference length it is recommended to choose the cut length on machines with a fault related yarn suction as long as possible. However, one has to pay attention that no back-windings occur during the suctioning of the yarn. In practice, lengths of 6 to 8 meters proved to show the best results. For very critical applications lengths of 12 to 20 m are recommended.

Count variations 4


4.3.4 Monitoring of the yarn count while winding with the CC-channel Objective

• The reasons for deviations from the yarn count are numerous and vary from mill to mill. In the end product, such events are only disturbing because of their length.

• By the draft, a faulty deviation can consists of several short, subsequent deviations, which are only disturbing as a whole in the end product.

The recording of count variations and very long yarn faults takes place in the CC-channel, even when they are interrupted by normal pieces of yarn. The yarn is monitored with two independent clearing limits. The parameters for the clearer are given with the following settings:

• CCp sensitivity setting for the monitoring of mass and diameter increases

• CCm sensitivity setting for the monitoring of mass and diameter decreases

• Reference length is set for different length classes between 2.0 and 12.0 meters Function In contrast to the C-channel, the CC-channel is active over the whole winding length. Therefore, a different kind of signal evaluation is applied. A mean value is continuously calculated. Short drops of the yarn count have only a minor effect on the total result of the continuous mean value. If the contin-uous mean value exceeds the above set sensitivity, a CC-cut is triggered.

Fig. 4-4

4 Count variations


Yarn suction after a CC-cut / Machines with fault-related yarn suction Modern winding machines provide a measurable, fault related yarn suction. The winding position gets the information from the yarn clearer, how much yarn has to be sucked-off before the splice is carried out. 4.4 C and CC settings The C-channel monitors the yarn count in the start-up phase after the splicing process. After the start-up phase, the C-channel is not active anymore. As already known from USTER® QUANTUM 2, the C-channel can be set for one reference length and a plus (Cp) and minus (Cm) limit. The CC-channel monitors the yarn count during the whole winding process. Depending on the setting long yarn faults with a small mass or diameter increase can be detected. This new CC-channel is able to detect and remove count variations at different cut length between 2 m and 12 m. For the CC-channel a smart limit proposal is available to find a good setting taking the variation of the current production into consideration.

Fig. 4-5 Display of C setting, only one reference length to be set

Fig. 4-6 Display of CC setting. Smart limits avail-able for length classes from 2 – 12 me-ters.

4.4.1 Yarn count deviations at start up (C) settings The C-channel monitors the yarn count in the start-up phase after the splicing process. After the start-up phase, the C-channel is not active anymore. In the example of Fig. 4-7 the Cp (plus) setting is 10% and the Cm (minus) setting is -10%. The refer-ence length (C) is 6 m.

Count variations 4


Pressing key presents • The yarn body.

Clearing limit A rea of actual yarn count. Red dots = cut yarn faults

Fig. 4-7 Display of C setting, only one reference length to be set Scatter plot of yarn count monitoring at start-up / Practical example

Fig. 4-8 Yarn Ne 40, cotton 100%, combed, compact, capacitive sensor, 1010 km. Too short reference length (2m) adjustment and too many cuts. It is recommended changing the reference length to 6m or 8m

4 Count variations


Fig. 4-9 Yarn Ne 24, cotton 100%, carded,

capacitive sensor, 10035.2 km. Open settings, reference length is 10 m.

Fig. 4-10 Yarn Ne 24, cotton 100%, carded, capaci-tive sensor, 3067.9 km. Close settings, reference length is 10 m.

4.4.2 Setting a smart clearing limit for yarn count monitoring (CC) The CC-channel monitors the yarn count during the whole winding process. Depending on the setting, long yarn faults with a small mass or diameter increase can be detected. This new CC-channel is able to detect and remove count variations at different cut lengths between 2 m and 12 m. The setting points are:

• 2 Set points: CCp +% at 2 m and 12 m

• 2 Set points CCm -% at 2 m and 12 m. The lines between the set points represent the clearing limit. Fig. 4-11 shows the yarn body and the actual clearing limit for CC. For a few seconds or minutes the yarn runs with an automatically selected clearing curve (default value). After this period the operator can see the yarn body on the screen.

Count variations 4


Pressing key presents • The yarn body. • Scatter plot of the cut • Number of cuts / 100 km.

Clearing limit

Red dots = cut yarn faults.

=Yarn body variation =Yarn body


Fig. 4-11 Proposed setting is a starting point for optimization By pressing Smart Limit function a proposed starting point for the CC settings will be selected. Ac-cording to the need of the customer this proposal can be accepted or modified with the smart limit function or manually.

Fig. 4-12 Start with standard setting. Press Smart

Limit key Fig. 4-13 Only one step / Display of CC setting, smart

limits available for length classes from 2 – 12 meter

After pressing the Smart Limit key, a small window with the two appropriate keys to adapt and opti-mize the smart limit for CC appears. The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by up and down keys to optimize the settings according to the individual quality requirements and productivity. It is recom-mended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound.

4 Count variations


Of course all settings recommended by smart limit can also be altered manually. As soon as the button at the smart limit window is pressed, the yarn body and scatter plot is displayed on the setting page.


= Smart Limit 1, step less sen-sitive.

= Smart Limit 1, step more sensitive.

= Show yarn body and scatter plot

= confirm and activate opti-mized clearing limit.

= cancel all modifications

Fig. 4-14 Proposed setting is a starting point for optimization C and CC faults are displayed together with all other yarn faults of the machine, a group or a winding position.

Fig. 4-15 C and CC fault reports

Count variations 4


Scatter plot of medium-term deviations / Practical example

Fig. 4-16 Frequent medium-term deviation of the count. Analysis of the spinning process required.

Fig. 4-17 Yarn Ne 40, cotton 100%, carded, knit-

ting, capacitive sensor, 1582 km. Low number of count deviations within the range of 2 to 12 m, 0,8 + 0,2 = 1,0 per 100 km.

Fig. 4-18 Yarn Ne 32, cotton 100%, carded, knitting, capacitive sensor, 3496 km, wider yarn body, same clearing curve as seen on the left hand side. High number of count deviations between 2 and 12 m, 3,4 + 1,5 = 4,9 per 100 km.

4 Count variations


Fig. 4-19 Yarn Ne 12, cotton 100%, carded, weav-

ing, capacitive sensor, 771 km. High number of count deviations within the range of 2 to 12 m, 8,3 + 2,6 = 10,9 per 100 km.

Fig. 4-20 Yarn Ne 16, cotton 100%, carded, weav-ing, optical sensor, 492 km. Low number of count deviations within the range of 2 to 12 m, 4,1 + 2,0 = 6,1 per 100 m.

4.5 Calculation of yarn count deviations The determination of the setting parameters for the yarn count deviation monitoring must be carried out very carefully. Different aids are at disposal.

• Determination of count variations with the clearer installation

• Calculation of the count variations with formulas

• Determination of count variations with a diagram

• Determination of count variations with the USTER® Calculator 4.5.1 Determination of count deviations with the clearer installation As described before, the mean value of the yarn is determined from the single winding positions and is detectable as the ADMV-value at the Control Clearing Unit. This means, this value presents the 100% - value of the yarn. This value can also be used for the calculation of deviations between bob-bins. The ADMV takes factors like the material or the relative humidity already into account. It is possible to calculate the count deviation in percent according to the following formula: Formula 1:

%100( ADMV)Ayarn

( ADMV)Ayarn( ADMV)ByarnWrong( %)deviationMass ⋅−

=

ADMV = Yarn mean value / value which is generated by the sensor as an electrical signal when

inserting a yarn in the measuring slot.

Count variations 4


Example 1: Article A is mixed up with a coarser yarn, article B (capacitive measurement)

• Article A: Ne 30 ADMV: 776

• Article B: Ne 20 ADMV: 1204,2

100%( ADMV)Ayarn

( ADMV)Ayarn( ADMV)ByarnWrong( %)deviationMass ⋅−

= = 55,2%100776,0

776,01204,2=×

−

This means, that the difference between Ne 30 and Ne 20, measured with the capacitive sensor, re-sults in a mass increase of 54,6%. Example 2: Article A is mixed up with a coarser yarn, article B (optical measurement)

• Article A: Ne 30 ADMV: 4578,4

• Article B: Ne 20 ADMV: 5513,6

100%( ADMV)Ayarn

( ADMV)Ayarn( ADMV)ByarnWrong( %)deviationDiameter ⋅−

= = %4,201004578,4

4578,45513,6=×

−

This means, that the difference between Ne 30 and Ne 20, measured with the optical sensor, results in a diameter increase of 20%. The percentage differences are limits. They should only be used as a guideline for the C- and CC-settings. Experience has shown that a certain tolerance must be taken into account. This means, the selected settings should be lower than the calculated values. 4.5.2 Calculation of the count deviations of wrong bobbins (capacitive measurement) Count deviations between yarns of the same fiber material For the iMH-C count deviations can be determined according to formula 1 below: Formula 2:

100%( tex)Ayarn

( tex)Ayarn( tex)ByarnWrong( %)deviationMass ⋅−

=

Example 1: Article (yarn A) is mixed up with a finer yarn Yarn A (33,3 tex) is mixed up with yarn B (25 tex)

25%33,38,33100%

33,333,3)( 25100%

AA)( B( %)deviationMass −=

−=⋅

−=⋅

−=

4 Count variations


Example 2: Article (yarn A) is mixed up with a coarser yarn Yarn A (25 tex) is mixed up with yarn B (33,3 tex)

33%25

8,33100%25

25)( 33,3100%A

A)( B( %)deviationMass +==⋅−

=⋅−

=

Count deviations between yarns of different fiber material If count deviations between yarns of different fiber material in blended yarns should be monitored, the deviations can be calculated with formula 2 below. The different material factors have to be taken into account. Formula 3:

100factorA

factor)A( yarnByarnofvalue( %)deviationMass ⋅×

×−= %

Yarn material Factors Relative humidity

Cotton, wool, viscose 0,86

0,77

0,69

80%

65%

50%

Acetate, Acrylic, Polyamide 0,62 65%

Polypropylen, Polyethylene 0,56 65%

Polyester 0,50 65%

Polyvinylchloride 0,45 65%

Table 4-1 Factors of the yarn material Example 3: Article A made out of Polyester is mixed up with article B made out of cotton

Yarn A: 20 tex: 20 x factor 0,5 = 10 Yarn B: 20 tex: 20 x factor 0,77 = 15,4

54%100%10

1015,4deviationMass +=⋅−

=

Example 4: Article A made out of cotton is mixed up with article B made out of Polyamide

Yarn A: 27, 8 tex: 27,8 x factor 0,77 = 21,4 Yarn B: 23,8 tex: 23,8 x factor 0,62 = 14,8

31%100%21,4

21,414,8( %)deviationMass −=⋅−

=

If the wrong bobbins deviate from the nominal yarn with respect to yarn material and yarn count, then the mass deviation has to be calculated according to formula 3:

Count variations 4


Example 5: Article A made out of cotton (20 tex) is mixed up with blended yarn B PES/CO 67/33% (19,2 tex)

Yarn A: 20 tex: 20 x factor 0,77 = 15,4 Yarn B: 19,2 tex: (B x factor PE x %-share) + (B x factor CO x %-share) = (19,2 x 0,5 x 0,67) + (19,2 x 0,77 x 0,33) = 11,3

%27100%15,4

15,411,3( %)deviationMass −=⋅−

=

In order to compensate the variation of the yarn count, the channels C and CC should be set to an about 5% more sensitive value than the calculated value. 4.5.3 Calculation of count variations of wrong bobbins – optical measurement As the iMH-O measures the yarn diameter, the count deviations must be converted in differences of the yarn count. This can be done quite easily with the aid of the USTER® Calculator (see section 4.5.5).

• Determination of the mass deviation according to the following examples 1 and 2.

• Conversion of the mass deviation to diameter deviations with the help of the USTER® Calculator. Example 1: Article A (33,3 tex) is mixed up with bobbins B (25 tex)

%25100%33,38,33100%

AAB( %)deviationMass −=⋅

−=⋅

−=

-25% mass deviation -13% diameter deviation Example 2: Article A (25 tex) is mixed up with bobbins B (33,3 tex)

%33100%258,33100%

AAB( %)deviationMass +=⋅

+=⋅

−=

+33% mass deviation +16% diameter deviation It has to be taken into account that with the optical monitoring of wrong bobbins, the diameter devia-tions are percentage-wise smaller than mass deviations. In order to compensate the variation of the yarn count, the channels C and CC should also be set about 5% more sensitive than the calculated values.

4 Count variations


4.5.4 Calculation of count variation of wrong bobbins with a diagram The following diagram can only be used for the calculation of count variations when the capacitive measuring head is used.

Nm/NecB

-50 -45 -40 -35 -30 -25 -20 -15 -10 -5

130

120

110

100

90

80

70

60

50

40

30

20

10

10 20 30 40 50 60 70 80 90 100 110 120 130 140

+5

+10

+25+20+15

+50+45+40+35+30

1

2

%

%

Nm/NecA

Fig. 4-21 Determination of the mass deviation of yarns made out of the same material, but with a different count

Fig. 4-21 shows two examples for the calculation of mixed-up bobbins:

Example 1: article A, Ne 68 is mixed with yarn B, Ne 80 → deviation = -15%

Example 2: article A, Ne 50 is mixed with yarn B, Ne 40 → deviation = +25% → When this calculation is carried out in tex, the values A and B must be reversed.

Count variations 4


4.5.5 Relationship between the mass and diameter deviation with the USTER® Calculator In this section, only the relationship between the mass and diameter deviations will be explained, which can be calculated with the aid of the USTER® Calculator. Scales ± and ″ of the calculator serve for this purpose.

Fig. 4-22 Conversion of mass and diameter deviations with the USTER® Calculator (6 = diameter scale, 7 = mass scale)

Depending on the measuring method and the unit which is used, the sliding tongue must be adjusted. Example from Fig. 4-22: A mass deviation of 50% (7) corresponds to a diameter increase of only about 22% (7). Determination of the yarn count deviation with the USTER® Calculator For the setting of the C- and the CC-channel, the value, which a wrong yarn must deviate in order to be recognized, must be entered in percent. Example: 1. First, the correct yarn count must be set with the vertical line of the Calculator. In case of Fig.

4-23, it is Nm 20 and 50 tex, respectively. 2. Furthermore, depending on the measuring method (capacitive or optical) the sliding tongue of the

Calculator must be moved so that the tongue for the spun yarn is on the "0" mark.

4 Count variations


Fig. 4-23 Setting of the USTER® Calculator (1) 3. If a wrong yarn with the count Nm 18,5 (54 tex) should be detected, the sliding tongue must be set

on this count (see Fig. 4-24). 4. Then, in the middle of the Calculator (area marked red), the corresponding deviation in percent

can be read on the scale. In this case, Fig. 4-24, for the optical sensor it is 4%, for the capacitive sensor it is 8%. The same procedure must be carried out for negative deviations.

Fig. 4-24 Settings of the USTER® Calculator (2) 4.6 Example for the setting of the C-channel For the choice of the right setting of the C- and CC-channel, the scatter plot serves as a helpful tool. The scatter plot shows the unevenness of a yarn, even for longer yarn pieces, very well. For the correct setting of the channels it is necessary to know which faults were defined as not tolera-ble by customers. It is also necessary to know the possibilities of the winding machine regarding the setting of the suction length.

Count variations 4


From all this information, the settings for the clearer can be derived. An example for a correct setting is explained in the following: A spinning mill produces three different cotton yarns: Ne 20, Ne 30 and Ne 40. It is possible with a normal unevenness of yarns to distinguish mixed up bobbins of these 3 yarn counts. The setting of outlier or mixed-up bobbins is: • iMH-C Cp: +24% Cm: -20% Reference length: min. 2 m or adjusted to the winding machine type • iMH-O Cp: +12% Cm: -10% Reference length: min. 2 m or adjusted to the winding machine type Due to the normal unevenness of a cotton yarn, it can be predicted that a more sensitive setting of Cp/Cm can lead to unjustified cuts. It can also be said that the detection of counts anywhere between Ne 20, Ne 30 and Ne 40 (e.g. Ne 24 out of a Ne 20) cannot be guaranteed anymore. Rule of thumb for iMH-C: The setting for the C-channel with a reference length of 2 to 4 m should not be set more sensitive than the CVm of the yarn. Rule of thumb for iMH-O: The setting for the C-channel with a reference length of 2 to 4 m should not be set more sensitive than 70% of the CVm of the yarn. 4.7 The effect of count deviations on the fabric appearance 4.7.1 Mixing two different yarn counts Bobbins with different yarn counts can be accidentally mixed up during yarn production, or there can be count deviations within a cone. These count deviations can cause long stripes in the fabrics which are visible to the naked eye. In this example, we have knitted ten rows of reference yarn (Nec 30, 20 tex) and ten rows of a finer yarn (Nec 34, 17,5 tex) spun from the rovings produced by using the same cotton blend, using the ring spinning method. We can observe horizontal dark and light colored lines in both the grey (Fig. 4-25 and Fig. 4-26) and the dyed samples (Fig. 4-27 and Fig. 4-28). These horizontal lines are the result of yarn count differences. There is also a difference between the diameter 2DØ values of these two yarns (Table 4-2).

4 Count variations


Yarn Count (Ne)

Twist 1/m

Twist direc-tion

CVm %

Thin -50%

Thick +50%

Neps +200%

H 2DØ mm

CV2D (8mm)

D (abs) g/cm3

Reference 30 830 Z 12.7 0.5 34.5 66 4.6 0.22 9.6 0.5 USP07 61 29 71 73 22 18

Wrong count 34 883 Z 13.5 6.0 52.5 90 4.5 0.20 10.3 0.5 USP07 77 >95 82 77 25 27

Table 4-2 Yarn quality results

USP07 = USTER® STATISTICS 2007

2DØ = Optically measured diameter with the USTER® TESTER 5 / Measurement of the yarn di-ameter with 2 light beams of 90 degrees

D = Density measured with the USTER® TESTER 5

Fig. 4-25 Reference fabric (grey) Fig. 4-26 Defective fabric (mix-up of reference

yarn with a finer count yarn) (grey)

Count variations 4


Fig. 4-27 Reference fabric Fig. 4-28 Defective fabric (mix-up of reference

yarn with a finer count yarn) In a similar trial, we have used ten rows of a coarser yarn (Nec 26, 22,5 tex) and ten rows of refer-ence yarn (Nec 30, 20 tex) and produced knitted fabric samples. Again in both the grey and the dyed samples, we can observe horizontal dark and light colored lines. As mentioned previously, these hori-zontal lines are the result of yarn count differences. There is also a difference between 2D-diameter values of these two yarns (Table 4-3). The pictures are not shown here, as the appearance of the previous sample (with finer yarn) and this one are very similar.

Yarn Count (Ne)

Twist 1/m

Twist direction

CVm %

Thin -50%

Thick +50%

Neps +200%

H 2DØ mm

CV2D (8mm)

D (abs) g/cm3

Reference 30 830 Z 12.7 0.5 34.5 66 4.6 0.22 9.6 0.5 USP07 61 29 71 73 22 18

Wrong count 26 770 Z 12.0 0.0 22.0 32.5 4.9 0.24 9.5 0.5 USP07 50 < 5 60 54 32 27

Table 4-3 Yarn quality results In another example, we have knitted 10 rows of reference yarn (Nec 36, 16,5 tex) and 10 rows of a coarser yarn (Nec 30, 20 tex) spun from the rovings produced by using the same cotton blend.

4 Count variations


Then the knitted fabrics were dyed and T-shirt samples were produced. In the fabric and the T-shirt sample, we can observe horizontal dark and light colored lines (Fig. 4-29 to Fig. 4-32). These horizon-tal lines are the result of yarn count difference (Table 4-4). Both yarns have the same evenness, but as a result of different counts the diameter is different.

Yarn Count (Ne)

CVm %

Thin -50%

Thick +50%

Neps +200%

H 2DØ mm

CV2D (8mm)

D (abs) g/cm3

Reference 36 12.6 0.6 33.1 71.7 5.2 0.20 9.6 0.5 USP07 48 19 61 65 76 40

Wrong count 30 12.6 0.90 33.8 52.3 5.6 0.23 9.8 0.5 USP07 50 32 62 52 90 55


Fig. 4-29 Reference T-shirt Fig. 4-30 Defective T-shirt (mix-up of reference

yarn with a coarser count yarn). Stripes in the direction of the arrow (see also Fig. 4-32).

Fig. 4-31 Reference fabric Fig. 4-32 Defective fabric (mix-up of reference

yarn with a coarser count yarn)

Count variations 4


4.7.2 Reasons and measures to minimize count variations In Table 4-5 and Table 4-6, the origin of faults related to long-term mass variations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. Yarn Count Variation


Drawing frame Use autoleveller on finisher drawframe

Roving frame Weight variation of rovings

Check roving trumpet hole diameter and cleanliness at the trumpet input

Use different color of roving tubes to avoid roving count mix-ups

Ring spinning frame Improper roller weightings

Spinning creel alignments

Dragging bobbin holders

Blocked spinning trumpet

False draft in ring spinning machine creel

Instruction and training of operators

Use of different colors of spinning tubes to avoid count mix-ups

Table 4-5 Preventive measures and tools for the management of long-term mass variations Yarn Count Variation / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Constant quality control of sliver and yarn quality with the USTER® TESTER

USTER® Testing on-line Adjustment of autolevelling system

USTER® QUANTUM CLEARER Separation of outlier bobbins with quality data software of the yarn clearer

Correct settings of C and CC channel

Use C and CC alarm settings for eliminating wrong spinning bobbins


Table 4-6 Preventive measures and tools for the management of long-term mass variations

4 Count variations


Splice Clearing 5


5. Splice Clearing 5.1 Introduction A splice, also called yarn joint, has the purpose to join two ends of a yarn as a result of yarn fault re-moval on OE rotor and winding machines and bobbin changes during the winding process. This means: when a detected fault is eliminated, the resulting yarn ends are pieced together by an auto-matic splicing device [1]. In the past, it was common practice to knot yarns together, but the knots were a source of weakness and could also lead to problems in subsequent processes. Nowadays, yarns are spliced using mechanical splicers, air-jet splicers, water-jet splicers, thermo-splicers, etc. which produce a joint that is usually at least 70% of the strength of the mean yarn strength, and gen-erally less than 130% of the thickness of the parent yarn. The splice efficiency is used as a measure of the spliced part of the yarn, expressed as percentage strength of the reference yarn. The adoption of splicing has greatly reduced problems in weaving, knitting, and dyeing [2]. A yarn must have a certain minimum tensile strength and a minimum elongation in order to stand up to the processes subsequent to spinning. This is also and especially valid for splices that join together two ends of a yarn. Since an average count ring-spun yarn can have more than 100 splices over a length of 100 km, it is important to monitor the parameters of the splices carefully. Besides the quality aspect that needs to be fulfilled by the yarn, its processing quality depends to a certain extent also on the quality of the splices. Today, approximately one splice per kilometer has to be expected in a cone. Considering the costs for a yarn break in knitting, warping, sizing or weaving, the splices play an important role in this respect as well. The number of splices must be kept at a low level, but the potential weak places must have the highest strength possible. This is only possible by checking the strength of the splices regularly by means of an instrument. 5.2 Scatter plot of splices The USTER® QUANTUM 3 interprets and displays the splice characteristics with the help of a scatter plot. It is the graphic representation of the thickness and length within a classification matrix. Each splice is marked with one dot. The vertical scale represents the yarn mass or diameter increase and decrease of a splice and the horizontal axis represents the splice length in cm. Fig. 5-1 shows a scat-ter plot with splices as seen by the USTER® QUANTUM 3, with all the splice recorded (green dots), the actual clearing limit and the area of the disturbing splices (red dots) which exceed the maximum and minimum admissible splices. The scatter plots are used to visualize the optimum clearing limits for both the Splice Clearing (Jp/Jm), and for such events the graphical display of a scatter plot matches the demands of the customers best. The scatter plot for Splice Clearing (Jp/Jm) represents the classified splices. The USTER® QUANTUM 3 classifies the thickest (Jp, Fig. 5-1, red circle) and thinnest (Jm, Fig. 5-1, blue circle) event for every splice and show them on the scatter plot. The active clearing limit of the Jp splice clearing limit is highlighted with red color on the setting page (Jp = joint, positive).

5 Splice Clearing


Fig. 5-1 Splice distribution. Measured yarn length: 216 km In the display main menu, it is possible to display either scatter plot of splices alone (Fig. 5-2) or to-gether with the scatter plot of disturbing thick and thick places (NSLT) (Fig. 5-3). Fig. 5-3 shows a regular distribution of splices (dark green dots) together with the scatter plot of the thick and thick places (light green dots). This combined scatter plot is a very helpful tool to show the localization and the distribution of splices compared to the remaining thick and thin places in the yarn. With the help of this combined graph, it is very easy to compare the splices to the natural events in the yarn and to avoid unnecessary splices because it makes no sense to replace a small fault by a bigger splice.

Fig. 5-2 Scatter plot of splices with the

clearing curves for thick/thin places and splices

Fig. 5-3 Scatter plot of splices and thick/thin places together

The scatter plot of splices demonstrates the performance of the splicer and shows the position of the outliers.

Splice Clearing 5


Examples of various scatter plots for splices.

Fig. 5-4 Optimum clearing curve for splices Fig. 5-5 Clearing curve for splices too wide

Fig. 5-6 Clearing curve for splices too narrow in

the domain of thick places Fig. 5-7 Clearing curve for splices too wide

Splices beyond the clearing curves (red dots) have to be repeated. The scatter plots show the popula-tion of the splices. Based on the scatter plot it is easy to recognize the outliers and to set the clearing curve for splices. 5.3 Splices 5.3.1 Visual appearance Splices are almost invisible in contrast to knots which used to be yarn joints in the past. Various inves-tigations have shown that the strength of the splices is critical in order to obtain a suitable splice in terms of size, a compromise may need to be reached between splice strength and appearance. A well spliced joint has a mass which is 20 to 30% higher than the yarn over a length of approximately 15 to 80 mm, and an average strength of around 80% of the mean yarn strength [1]. The variation of strength should also be low. Fig. 5-8 shows pictures of several splices.

5 Splice Clearing


Fig. 5-8 Picture of several splices 5.3.2 Practical example In a spinning mill the splices of 20 positions of a winding machine were tested. On each position, five splices were tested. The yarn type was Ne 30, carded, 100% cotton. Fig. 5-9 and Fig. 5-10 show the results of this trial. The blue dots indicate the test results of the splices, whereas the colored lines show the test results (minimum, maximum and average values) of the same yarn without a splice measured also on the USTER® ZWEIGLE SPLICE TESTER as the reference (ten measurements of the reference yarn). The minimum breaking force of the reference yarn was 222 cN, the average breaking force was 261 cN and the maximum breaking force was 302 cN. In regard to the elongation, the reference yarn had a minimum breaking elongation of 3.95%, an average breaking elongation of 4.66% and a maximum breaking elongation of 5.28% (Fig. 5-10).

0

50

100

150

200

250

300

350

400

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Forc

e [c

N]

Force of splices Minimum Reference Maximum Reference Average Reference

Fig. 5-9 Breaking force of splices, ring-spun yarn, compared with the mean strength of the yarn

Splice Clearing 5


0

1

2

3

4

5

6

7

8

9

10

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Elon

gatio

n [%

]

Elongation splice Minimum Reference Maximum Reference Average Reference

Fig. 5-10 Breaking elongation of splices, ring-spun yarn The numeric test results were as follows: Reference yarn Splice

Yarn type Ne 30, 100% CO, carded Ne 30, 100% CO, carded

Strength [cN] 261 200

Variation of the strength [%] 9.91 23.0

Elongation [%] 4.66 4.87

Variation of the elongation [%] 10.16 16.88

Table 5-1 Out of this data, the following conclusions can be drawn. The splices only reach an average breaking force of 76% compared to the regular (reference) yarn. As a rule of thumb, the strength of a splice should reach at least 70% of the strength compared of a regular yarn. The breaking elongation, on the other hand, improved slightly. Regarding the variation of the strength and the variation of the elonga-tion it can be observed that it is much higher compared to the reference yarn. This is an important quality parameter, as the high variation of the breaking force will lead to problems later on in subse-quent processing. The lowermost breaking force of a splice was measured at 83 cN, and the strong-est splice was measured with 295 cN. This is a huge difference that must be put under control. Therefore, it is recommended to check the splice mechanism of this winding machine and to modify the settings in order to reach higher strength values and lower variations from winding position to winding position.

5 Splice Clearing


5.3.3 Basic principles of splicing For a satisfactory splice, the two yarn ends have first to be prepared to make them properly tapered. Also, the fibers must be adequately separated and paralleled so that they are capable of intermingling when the splice is made. Fig. 5-11 illustrates the basic principle of the splicing process [1 and 2]: Time 1: Positioning of the yarns and cutting the unwanted yarn ends: The winding process was stopped in order to cut out the fault. The ends of the yarn are now parallel and face opposite direc-tions. The scissors are ready to cut the unwanted yarn ends after the two yarns have been laid in place. Time 2: Conditioning the yarn ends: The clamps grasp the yarn at the appropriate places before the main splicing procedure begins. The free ends of the two yarns are sucked into end-conditioning noz-zles and air blasts are provided to condition them before joining. Time 3: Forming loops to retract the yarn ends: Splicing is carried out after the two conditioned yarn ends are laid inside the splicing chamber so they are parallel, facing opposite directions and appropri-ately spaced without the tips of the conditioned ends protruding. The both lengths are drawn back until there is a certain length of overlap of the untwisted ends within the splicing chamber. Time 4: Splicing ends: A pulse of compressed air is injected through the nozzles into the chamber; the air blast intermingles the fibers and then causes the newly made joint to rotate to produce false twist. Time 5: Removing spliced yarn. The yarn is then removed from the splicer and the winding process continues.

Fig. 5-11 Stages in splicing [2]

Splice Clearing 5


Fig. 5-12 [1] shows the twist directions and twist distribution during the splicing operation. The splicing chamber in Fig. 5-12 (a) designed for use Z-twist yarns. The twist in the splice gives the joint a similar appearance to that of the parent yarn and also strengthens the joint. When the splice occurs, the ends have to be in the proper relative positions. In order to avoid a thick splice, it is necessary to taper then ends to be spliced so that the joint is not obvious. In Fig. 5-12 (b), the tapered ends are misplaced to give a thin spot. This is an undesirable weak spot. When the yarns overlapped two much, there would be a thick spot and two undesirable splice-tails (Fig. 5-12 (c)). These tails are mostly the subject of customer complaints during the knitting and weaving process. The splicer should be set to avoid these tails, sometimes at the expense of a slight loss in splice strength [2].

Fig. 5-12 Splice structure [2] 5.3.4 Wet Splicing The USTER® QUANTUM 3 optical clearer can be used with wet splicer without any restrictions. The capacitive clearer can be used with restrictions depending on the amount of water sprayed. Please contact USTER® for support. For the capacitive clearer the combination with Foreign Matter option, i.e. either C15/F30 or C20/F30, is required. There is a special setting for these clearers (Fig. 5-13) and the splice will be cleared opti-cally and needs an optical setting.

5 Splice Clearing


Fig. 5-13 Wet splice 5.4 Splice classification of the USTER® QUANTUM 3 The USTER® QUANTUM offers a unique feature, which is the splice classification. Each splice is measured, classified, and marked with a green or red square in the scatter plot depending on the splice settings. Thus, it is possible to check every winding position of a winding machine in order to see if the splices fulfill the requirements with regard to the appearance (Fig. 5-14).

Fig. 5-14 Display of splices (left) and splice classification (right) Meaning of the red rectangles: The size of the splice or mass increase has exceeded the set splice limits. The splice formation has to be repeated. The USTER® QUANTUM 3 classifies the thickest (Jp) and thinnest (Jm) event for every splice.

Splice Clearing 5


The splice channel J checks the yarn joint when passing the clearer just after it has been made by the splicer device. The evaluation of J is similar to the NSLT thick and thin places evaluations. Splice check Jp /Jm detects yarn joints which are “too thick” or “too thin”. 5.5 Clearing limits for splice clearing (Jp and Jm) 5.5.1 Standard way of optimizing clearing limits: Manual clearing limits entry Fig. 5-15 shows the clearing limit as shown in the setting window of the Control Clearing Unit. The USTER® QUANTUM 3 allows the determination of the splice clearing limits by placing a maximum of 8 set points Jp1 to Jp8 /Jm1 to Jm8. In Fig. 5-15, we can see 5 setting points (red rectangle) and the clearing limit for splices. By this setting method the effects of a change of the parameters on the clear-ing limit can be demonstrated directly. As soon as we enter new values at set point, the next set point will appear until we reach the 8th set point. This means after we enter the values for Jp1 (or Jm1), set point Jp2 (or Jm2) will appear and it will continue the same way.

Fig. 5-15 Clearing limits on the screen of the Control Clearing Unit, manual entry Set points have two parameters. These are: sensitivity (%) and reference length (cm). Sensitivity

The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensi-tivity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive, Jp1 = 300%, Fig. 5-15).

5 Splice Clearing


Reference length

The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive, Jp1 = 0.6 cm, Fig. 5-15). 5.5.2 Setting a smart clearing limit for splices (Jp/Jm) With the USTER® QUANTUM 3 splice clearing became much easier. A smart possibility offered by the system is to synchronize the splice settings to the thick and thin place (NSLT) settings to avoid bad splices being passed. The splice clearing curve could be selected ideally as same as the NSLT clearing limits. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the scatter plot and the events will appear. In order to see the scatter plot, the user should press the scatter plot key (Fig. 5-16). Besides the scatter plot, also the scatter plot of the cut faults and remaining events, and the number of expected fault cuts per 100 km together with the used setting limits will appear directly on the same setting page (Fig. 5-16). It is recommended to have at least 100 splices before making any fine tuning in the splice clearings settings.

Pressing key presents

• Scatter plot of the cut faults and re-maining events.

• Number of expected fault cuts / 100 km

Clearing limit

Red dots = cut yarn faults.

Green dots = remaining events

Fig. 5-16 Jp settings adjustment to the scatter plot, thick places For highest quality requirements the Jp, Jm setting can even be set up to 5 to 10% below the NSLT clearing limit (red circle). Good splices set the Jp splice clearing curve below the NSL thick places clearing curve (more sensitive setting) and on the contrary bad splices set the Jp splice clearing curve above the NSL thick places clearing curve (less sensitive setting, Fig. 5-16). The same rule is also valid for Jm splice clearing curve; there the Jm clearing curve will be set below or above the T thin places clearing curve according to the good or bad results. If this will result in too many Jp or Jm cuts then the rogue splicers should be identified and fixed. F and PP faults are also detected during splice check (Fig. 5-17).

Splice Clearing 5


Fig. 5-17 Jm settings adjustment to the scatter plot, thin places Splices are displayed together with all the other yarn faults of the machine, of a group or of a winding position. It can be switched from absolute values to values per 100 km.

Fig. 5-18 Jp/Jm yarn fault classification per winding position

5 Splice Clearing


Recommendations:

The new setting possibilities will help to ensure that the splice should always be better than the re-moved yarn fault. Depending on the mechanical settings of the splicer, we recommend to start with the splice adjusted to the thick place (NSL) and thin place (T) limits. For high quality requirements we also can use a setting closer than the clearing limits. This depends on the accepted Jp/Jm cut level / 100 km and of course of the splice quality possible. Splices are displayed together with all the other yarn faults of the machine, of a group or of a winding position (Fig. 5-19, red rectangle). In Fig. 5-19, the splice failure ratio (JR) has also been shown (Blue rectangle). Splice failure ratio (JR) measures the number of cut joints compared to the passed ones. It is the relation between total splices and splice cuts (Jp+Jm). In this example, the splice failure ratio is equal to 3.4.

Fig. 5-19 Jp/Jm yarn fault registration In order to find rogue splicers, the user should check the machine summary report to find the bad splicer. In the following example it is winding position no. 9 with a splice failure ratio of 33.3%. The mean value is 12.44% (Fig. 5-20).

Splice Clearing 5


Fig. 5-20 Machine summary display /JR Splice failure ratio 5.6 Upper yarn detection (U) The “upper yarn” feature avoids that a double threat is accidentally taken from the package above the clearer (Please consult Chapter 11). Settings (Fig. 5-21):

For capacitive clearers: 80%

For optical clearers: 60%

Fig. 5-21 Upper yarn detection (U)

5 Splice Clearing


5.7 Minimizing the number of splices 5.7.1 Critical items which affect the number of splices The number of splices depends on the selected number of cuts to eliminate disturbing faults and the number of joints necessary to process bobbins into a cone. There are experience values available for yarn clearers on winding machines to understand the re-placement of disturbing faults by splices. The relationship between the bobbin size, the number of cuts and the yarn count is explained in Fig. 5-22. This figure shows the number of splices required if the yarn clearer cuts 20 disturbing thick and thin places, 20 colored foreign fibers and 2 polypropylene fibers.

6 20 60 120 Nectex100 30 10 5

92g

57g

40g

1250

3020

0

20

40

60

80

100

120

140

Disturbing thick and thin places

“Natural end breaks”

Bobbin changes

Polypropylene fibers

Colored foreign fibers

No. of splices per 100 km

Fig. 5-22 Number of splices for a given number of cuts The average yarn mass of a fine yarn bobbin is 40 g. The mass of a bobbin in the medium count range is approximately 57 g and 92 g within the coarse count range. Fig. 5-22 shows that the number of splices required per 100 km also depends on the count and the weight of the bobbin. As already mentioned, the disturbing yarn faults have to be eliminated on the winding machine and replaced by a splice. The splice, however, should no longer be disturbing for the human eye. There-fore, the splice can be checked by the yarn clearer (Fig. 23) and should be below the clearing curve.

Splice Clearing 5


Fig. 23 Monitoring of splices with the USTER® QUANTUM 3 5.7.2 Mean time between two splices It is not only the number of splices which needs our attention, but also the mean time between two splices. If we are not careful in selecting the optimum clearing curve, the efficiency of the winding ma-chine may collapse. Table 5-2 shows the conditions on a winding machine when processing a 100% cotton yarn, Nec 30, carded, winding speed 1400 m/min. Figures per 100 km of yarn.

Bobbin changes 20

Table 5-2 Mean time between two splices

‘Natural’ end breaks 2

Thin and thick places 21

Colored foreign fibers 18

Polypropylene fibers 2

Total number of splices 63

Mean time between 2 splices per winding position 1.13 min The total run time of the machine to produce a yarn length of 100 km is 71.4 min at a winding speed of 1400 m. With a total number of 63 splices, the mean time between 2 splices is only 1.13 minutes. With a higher number of cuts, the mean time between splices would drop below one minute. This, however, can be considered as a critical limit. Therefore, it is beneficial for the mill to select the clear-ing curves carefully for disturbing thick places, thin places and foreign fibers.

5 Splice Clearing


5.7.3 Field test The USTER® QUANTUM 3 has to fulfill more and more tasks. On one hand the spinning mill has to eliminate disturbing thin places, thick places, colored foreign fibers and polypropylene fibers and has to replace them by a splice. In addition, the splicer of the winding machine has to produce splices at the end of each bobbin. On the other hand the clearer should not influence the efficiency of the wind-ing machine too much. The following is a study to demonstrate the critical cut rates of a clearer by means of the mean time between splices MTBS. Conditions:

Yarn Ne 30 (20 tex), yarn weight per bobbin 57 g, yarn length per bobbin 2850 m Winding speeds: 800 / 1000 / 1200 / 1400 / 1600 m/min Number of splices according to Table 5-3.

Reasons for splices Conditions

1 2 3 4 5 6 7 8

Bobbin changes 34 34 34 34 34 34 34 34

"Natural" end breaks 4 4 4 4 4 4 4 4

Thick and thin places 10 20 30 40 50 60 70 80

Colored foreign fibers 10 20 30 40 50 60 70 80

Polypropylene fibers 5 5 5 5 5 5 5 5

Number of splices 63 83 103 133 153 173 193 213

Table 5-3 Number of splices, conditions 1 to 8

Winding speed Winding time Mean time between splices MTBS

(under the conditions mentioned above)

1 2 3 4 5 6 7 8

800 m/min 125 min/100 km 2.08 1.51 1.21 0.94 0.82 0.72 0.65 0.59

1000 m/min 100 min/100 km 1.59 1.20 0.97 0.75 0.65 0.58 0.52 0.47

1200 m/min 83 min/100 km 1.32 1.00 0.81 0.62 0.54 0.48 0.43 0.39

1400 m/min 71.4 min/100 km 1.13 0.86 0.69 0.54 0.47 0.41 0.37 0.34

1600 m/min 62.5 min/100 km 0.99 0.75 0.61 0.47 0.41 0.36 0.32 0.29

Table 5-4 Mean time between splices MTBS at conditions 1 to 8

Splice Clearing 5


Fig. 5-24 Mean time between splices Reading example, Fig. 5-24: At condition 2 the mean time between splices already drops below 1 minute if the yarn speed exceeds 1200 m/min. 5.7.4 Relationship between the productivity on winding machines and splices The adjustment of the clearing limits is not only improving the quality level of the yarn. But in all cases the clearer should only remove the disturbing faults. The result is: optimum quality with less number of cuts and splices. By only making the right cuts one can optimize quality and productivity. It has been proven that the performance of the clearer (amount of cuts) is responsible for changing drastically the winding machine productivity. In Fig. 5-25, the relationship between the productivity on winding machines and splices can be seen. The red line is for yarn count Nec 50 and the blue line is for yarn count Nec 30. Fig. 5-25 shows that 70 splices per 100 km means a productivity level of 79% for yarn count Nec 30 and a productivity level of 81% for yarn count Nec 50. Speed: 1400 m/min.

5 Splice Clearing


Table 5-5 shows an example of a winding productivity calculation.

Winding speed

[m/min]

Count [tex]

Bob-bin

weight [g]

Fault cuts [1/100km]

Bobbin changes

[1/100km]

Winding time for 100 km without splices [min]

Formation of a splice

[min]

Bobbin change duration

[min]

Total duration for fault elimina-

tion [min]

Total duration for

bobbin changes

[min]

Total duration for stops

[m]

Winding efficiency

[%]

1400 12 tex (Ne 50) 60 20 20 71,43 0,18 0,22 3,6 4,40 8,0 88,8

1400 12 tex (Ne 50) 60 70 20 71,43 0,18 0,22 12,6 4,40 17,0 76,2

1400 20 tex (Ne 30) 60 20 33,3 71,43 0,18 0,22 3,6 7,33 10,9 84,7

1400 20 tex (Ne 30) 60 70 33,3 71,43 0,18 0,22 12,6 7,33 19,9 72,1

Table 5-5 Example of a winding productivity calculation Fig. 5-25 is a graphical evaluation of Table 5-5.

Fig. 5-25 Relationship between yarn clearing and productivity: splices and winding machine efficiency

Periodic yarn faults 6


6 Periodic yarn faults 6.1 Introduction Periodic yarn faults are thick places, which always occur with the same distance to each other. Such faults are caused in the spinning process, when yarn guiding elements are defective. An eccentric front roller of the ring spinning machine leads to a periodic fault with a wavelength of 8 cm, because the diameter of these rollers are 1 inch or 2,54 cm, and such a roller always causes faulty drafts in the draw-box within the same time intervals. The size of each individual fault is mostly not disturbing. But as a series of yarn faults, they can very well be disturbing. Disturbing patterns on a taper board due to periodic yarn faults can be seen in Fig. 6-1.

Fig. 6-1 Periodic fault in cotton yarn resulting in a moiré pattern The USTER® QUANTUM 3 has a new periodic faults channel (PF), and with minimal settings and by using only two parameters, the system can determine periodic faults of all wavelengths in parallel.

Fig. 6-2 New periodic fault channel (PF) of the USTER® QUANTUM 3

6 Periodic yarn faults


6.2 Influence of the yarn speed on the winding machine On an automatic winding machine, the yarn speed is not constant. The yarn speed depends on the position of the yarn during the reversal movement on the drum. Therefore, the yarn signal of a strictly periodic yarn fault does not appear as a strictly period fault in a spectrogram (Fig. 6-3), but it also in-fluences some adjacent lines. In order to detect such kind of periodic faults in bobbins on winding machines a new feature was in-troduced, called PF (Periodic Fault). Bobbins with periodic mass variations have to be ejected by the winding machine, because such faults are present throughout the entire bobbin. Fig. 6-3 shows graphically the difference of a strictly periodic fault in a spectrogram if the speed is not constant.

Strictly-periodic faults detected by the yarn clearer if the yarn speed is constant

Same faults detected by the yarn clearer because the yarn speed on the winder is not constant

Fig. 6-3 Difference between strictly-periodic faults at constant speed and variable speed There is a more intensive effect of the drum on the variation of the periodicities in the short wave-length range. 6.3 Further reasons for periodic defects In most cases, disturbing periodic faults are formed at the ring-spinning machine. Widely known are defects caused by cuts and pressure marks on the front rollers. By this, the continuous distribution of the fibers is disturbed, which results in thin and thick places. The size of the fault corresponds to an alteration/shift of all fibers of about 30 – 50%. The fault length depends on the dimension of the defec-tive machine part. The distance between the single events corresponds to the circumference of the roller.



If a spinning position or the whole spinning frame is stopped and the pressure is not taken from the top roller, it can lead to pressure marks on the top rollers after longer stops and thus to periodic de-fects in the yarn. The distance between the single events corresponds to the circumference of the rollers. Defective aprons of the drawbox also result in periodic yarn faults. For regular ring spun yarns, the reasons are mostly pure mechanical problems, which lead to periodic faults in the yarn. For compact yarns, the reasons can be found in the contamination with fibers and dirt. This dirt can build up for an uncertain time, which makes it much more difficult to find the rea-sons. Therefore, the monitoring of periodic defects in compact yarns is essential. 6.4 Periodic fault registration with the PF Periodic yarn defects cannot be detected with the normal settings of a yarn clearer, as the size of each individual fault lies far below the adequate clearing limits. With the USTER® QUANTUM 3 such periods can be detected with the Periodic Fault (PF) channel. This periodic fault option (PF) allows a quick and easy way of setting, and the system can scan the yarn for periodic faults of all wavelengths simultaneously. 6.4.1 Setting for Periodic Faults (PF / Optional Q Data) The periodic yarn faults always occur with the same distance from each other as already mentioned. The thick places which are created by the periodic alteration of the fibers in the cross-section, serve as the threshold in the PF-option. The recommended setting for FP (Periodic Faults) is:

• Period regularity: 75%

• Number of periods: 30

• PF-Alarm: 3 per 1 km For long periods (< 1 m) it is also possible to set 90% regularity and 15 events. After reaching the given number of faults ("number of periods"), a cut follows or a PF-alarm is trig-gered.



Fig. 6-4 PF settings for detecting periodic defects Fig. 6-5 Disturbing defects (so-called periodic defects)

When the value of the period regularity is 100%, then the channel will detect only strictly periodic yarn faults after a certain distance (Fig. 6-5). A setting of 100% means the periodicity is absolute. However, on the winding machine a defect is never strictly periodic as already mentioned due to the varying yarn speed.

Fig. 6-6 PF settings for detecting periodic defects



The checking of the settings is only possible with a defective yarn. There is also the option to choose a very sensitive setting, in order to make corrections according to the results. This is only possible with the sensitivity settings. For fault free yarn set 30 events and adjust the regularity until you get ∼0,1 … 0,2 cuts/100 km Furthermore, it is recommended to produce a taper board with the defective yarn for a visual evalua-tion of the defect.

Fig. 6-7 Taper board / Periodic fault on the left hand side The detection of periodic yarn faults is displayed together with all the other yarn faults of the machine, a group or a winding position. All cuts and alarms are displayed in absolute and relative values.

Fig. 6-8 PF yarn fault report with PF faults



6.5 The effect of periodic faults on the fabric appearance Mix-up of reference yarn with a yarn having periodic mass variation

Periodic mass variations in the yarn result in disturbing patterns in woven and knitted fabric. They are never caused by the raw material, but are due to faults during fiber processing. Such faults must be detected as early as possible. This type of fault is, however, extremely common. Mechanical parts such as defective card clothing, eccentric rollers of drawing elements, defective aprons, etc., can all produce periodic mass variations. Thick or thin places can appear at regular intervals in woven and knitted fabrics according to the width of the woven or knitted material and according to the wavelength of the periodic fault. These thick or thin places result in unacceptable patterning and, in most of the cases, downgrade the finished fabric. Fig. 6-9 shows two possible fault patterns and one optimum distribution in a woven or knitted material caused by periodic mass variations.

Moiré Stripiness Optimum distribution

Fig. 6-9 Fault patterns The fault pattern referred to as moiré is the most frequent, whereas the pattern on the right hand side is an exceptional case. Nearly all periodic faults result in an uneven appearance in the finished fabric. The type of disturbance, whether it is in a woven or knitted fabric, depends mainly on the wave-length λ of the fault. In this respect one differentiates between short, medium and long-term periodic mass variations. Another example of a yarn with periodic faults:

The condition of the rollers and the degree of ageing of the rollers affect the spinning performance. Occasionally, cotton fiber producers suffer from infestations of aphids and other insects, which even-tually produce contaminations such as sugars (honeydew) on cottons. Cotton fibers become sticky and difficult to handle during processing due to these contaminations and cause fiber lapping problem during processing [2]. Carelessness in cleaning lapped fibers on the rollers, especially during the cleaning process when metal knives are used, can cause defects which leads to high unevenness. The result will be an uneven fabric appearance. In our example, we have knitted ten rows of reference yarn and ten rows of a yarn spun using defective top rollers to produce a periodic fault. There is a significant difference between the CVm values, the thin places, thick places and neps values of the two yarns (Table 6-1). When we compare the USTER® STATISTICS values of the two yarns; the CVm value of the reference yarn is equivalent to 61% of the USTER® STATISTICS, the CVm value of the defective yarn is more than 95% of the USTER® STATISTICS. There is also a significant differ-ence between the USTER® STATISTICS values of thin places, thick places and neps of the two yarns.



Yarn Count (Ne)

Twist 1/m

Twist direc-tion

CVm %

Thin -50%

Thick +50%

Neps +200%

H 2DØ mm

CV 2D%

(8mm)

D (abs) g/cm3

Reference 30 830 Z 12.7 0.5 34.5 66 4.6 0.22 9.6 0.5 USP07 61 29 71 73 22 18 Fault 30 830 Z 17.5 118 1030 151 4.7 0.22 13.1 0.5

USP07 >95 >95 >95 >95 30 28

Table 6-1 Yarn quality results The result of the defective top roller can also be seen as red peaks in the mass spectrogram (Fig. 6-11) and periodicities in the conical taper simulation (Fig. 6-1). Because of the periodicities in the defective yarn, thick places can be observed as dark-colored, periodic areas in the grey and the dyed samples Fig. 6-12 and Fig. 6-13). Fig. 6-10 shows the spectrograms of the reference yarn.

Fig. 6-10 Spectrogram of the reference yarn measured with the USTER® TESTER

Fig. 6-11 Spectrogram of the defective yarn (defective top rollers) measured with the USTER® TESTER



Fig. 6-12 Reference fabric Fig. 6-13 Defective fabric (defective top rollers)

Periodic thick places have more fibers in the cross-section and absorb more dyestuff. Therefore, such thick places appear darker in the fabric. 6.5.1 Reasons and measures to minimize periodic mass variations In Table 6-2 and Table 6-3, the origin of the faults related to periodic mass variations is given. Possi-ble reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. PERIODIC MASS VARIATIONS


Comber, Drawframe,

Roving frame,

Ring spinning frame

Incorrect setting of the piecing process (Comber)

Eccentricity or defects of front top rollers

Eccentric or defects front bottom rollers

Contaminated front rollers (honeydew, etc)

Table 6-2



PERIODIC MASS VARIATIONS / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Systematic Quality Control with the USTER® TESTER

USTER® QUANTUM CLEARER Use “Periodic Faults” option to separate bobbins with periodic mass varia-tions

Monitor bobbins with periodic faults with the quality data software


Table 6-3 Preventive measures and tools for the management of periodic mass variations

Quality parameters of a yarn 7


7. Quality parameters of a yarn 7.1 Introduction In the previous chapters we have dealt with seldom-occurring yarn faults which can be eliminated and replaced by a splice. This chapter deals with frequent yarn faults which cannot be replaced by a splice anymore. If frequent yarn faults exceed preset quality limits, the bobbin has to be ejected by the wind-ing machine. Such yarns, if wound on a cone, would affect fabrics significantly (“cloudy appearance”, to many thick places, thin places and neps, high hairiness, etc.).

Fig. 7-1 Frequent yarn faults and seldom-occurring yarn faults

Fig. 7-2 Disturbing yarn faults were discussed in chapters 3 to 6. This chapter deals with frequent yarn faults.

In order to meet the increasing quality requirements for the products and to cope with the high pro-duction costs, yarn manufacturers have to optimize the individual production stages at shorter inter-vals today. With the optimization, it is important to fulfill the quality requirements of the customers completely and reliably. The reaction time for an optimization or the adjustments is an important factor. Any quality which is higher than actually required will result in an unnecessary increase of the manufacturing costs. Off-quality, however, leads to significant quality costs and to a loss of customers. Uncompromising quality management in all production stages guarantees a constant quality of the product and, at the same time, a cost optimization. In order to react immediately to changes of the yarn quality, it is important to monitor the quality pa-rameters during the production.

7 Quality parameters of a yarn


The determination of the frequent yarn faults is an option of the USTER® QUANTUM 3 and consists of:

• yarn evenness (CV)

• imperfections (frequent thick places, thin places and neps)

• class alarm

• hairiness

Fig. 7-3 Overview of quality characteristics The values of the yarn evenness, of the hairiness and of the imperfections are important information about the quality of a yarn. Through their results, it is possible to control the complete course of pro-duction. The analysis of the single value makes it possible to carry out countermeasures without any time delay. The following differences between the off-line measurement (laboratory) and the on-line measure-ment (production) must be considered: Off-line measurement

• The main purpose of the off-line measurement is the correct determination of the quality parame-ters.

• The results are reproducible, as the measurement is always carried out under the same condi-tions, i.e. a standard climate, the same sensor, and with the same testing speeds.

• The results can be used for comparison purposes, like e.g. the USTER® STATISTICS.

• The results are based on random samples.



On-line measurement

• The main purpose of the on-line measurement is a 100% monitoring of the yarn and its quality parameters.

• The results are determined at different speeds.

• The measurements are carried out with different sensors (measuring field width, capacitive or optical).

• The measurements are carried out on different machines. The environmental conditions such as climate, yarn course, dust, fly, and temperature are not constant in the winding room.

• If limits are exceeded, actions can be taken in order to remove the faulty yarn from the production process.

The on-line monitoring of quality parameters cannot replace the off-line measurement, because dif-ferent requirements have to be fulfilled. This makes it clear, that the absolute values of the on-line measurement cannot be compared exactly with those of the off-line measurement. However, the on-line measured deviations from the nominal value match within certain tolerances with the measurements of the off-line tests. With the USTER® QUANTUM 3 all the features of a yarn, which determine its quality, can be meas-ured individually. This delivers detailed information. Besides the values of the yarn evenness, the hair-iness and the imperfections have to be taken into account. Practical tests have shown clearly, that with a careful decision regarding the setting of alarms and the consequent tracking of fault reasons, the quality level can be kept within narrow limits, and this can be realized without excessive costs. In the following, different possibilities for the monitoring of the yarn structure are described. The set-ting of the alarms of the different monitoring possibilities must also be carried out. This is described in chapter 7.6. 7.2 Yarn evenness The coefficient of variation CV is a well-known value for the determination of the evenness of slivers, rovings and yarns. Each process in a spinning mill contributes a part to the unevenness. The continuous determination of the quality parameters guarantees that all spinning positions produce the same quality. For the calculation of the yarn evenness CV, it is possible to select 2 measure-ments:

• Continuous, over the whole bobbin length with selectable reference lengths or

• Starting from a bobbin change with selectable reference lengths When a preset limit is exceeded, the system can provide an alarm for the respective winding position and another one for the mean value of a quality parameter derived from all winding positions.



7.2.1 Definition of the coefficient of variation CV The coefficient of variation is given in percent; it is a measure of the yarn unevenness and is defined as follows:

100xsCV ×= %

Mass/diameter

Length

+s

-s

x_

Fig. 7-4 Graphical representation of the CV With the help of the coefficient of variation, CVm as well as CVd, winding positions which deviate with respect to quality, can be monitored. CVm = Coefficient of variation based on the measurement of the yarn mass (capacitive sensor) CVd = Coefficient of variation based on the yarn diameter (optical sensor) 7.2.2 Reasons and effects of the yarn irregularity The reason for yarn irregularity is based on the fact that it is not possible for staple fiber yarns to keep a constant number of fibers in the cross-section. Reasons can be divided into:

• raw-material related faults, like e.g. the variation of the fiber length, fiber adhesion, short fiber con-tent, stickiness

• process-related faults, caused by defective machine parts, like draw-box defects or the kind of roller coats

From these points it can be derived that the coefficient of variation is used as an efficient method for quality and process monitoring. In general it can be said: the lower the CV-value, the more even is the material and the more even it will look in the end-product. It is known, that the evenness is not constant over the whole bobbin length. It usually decreases from the tip to the base of a bobbin. This circumstance has to be taken into account when evaluating the setting of the alarm limits.



Fig. 7-5 to Fig. 7-7 show a mercerized cotton T-shirt. In the zoomed pictures (Fig. 7-6, Fig. 7-7) we can observe an uneven appearance of the knitted fabric because of thin places and thick places even though it is an expensive mercerized T-shirt.

Fig. 7-5 High unevenness / mercerized / 100% cotton, combed, Nec 50

Fig. 7-6 High unevenness / mercerized cotton Fig. 7-7 High unevenness / mercerized cotton,

magnified 7.2.3 Deviation of the CV mean value of a group of clearers (CV–MV) The CV mean value of the group (CV-MV) is determined from all winding positions. As it is based on a large population, it does not show any erratic deviations. Erratic deviations can occur with individual winding positions. The upper alarm limit “CV-MV upper” and the lower alarm limit “CV-MV lower” can be set independent of each other. Compared to the CV of the winding position, this "alarm band" is set to a relatively high sensitivity because a mean value CV-MV which exceeds preset limits is usually an indication of serious problems (Fig. 7-8). The CV-MV indicates important changes and trends of the yarn. In an initial test cycle, the settings of this alarm band should not be selected too sensitive. After the CV mean value of the group has been determined over a certain time span (e.g. one shift or several doffings), then the upper and lower alarm limits can be set.



If the upper or lower alarm limits are exceeded, then this will be indicated by an alarm. After a period of observation, the setting can then be adjusted according to the specific application. This is illustrated by Fig. 7-8.

Fig. 7-8 Schematic representation of the deviation behavior of the CV mean value of the group 7.2.4 Deviation of the CV of a single winding position (CV-SP) The mean of the CV of an entire machine (CV-MV) is used as a reference for the CV value of a single winding position. The monitoring of the CV of the spinning position is carried out in relation to the cur-rent CV mean value of the machine. As with the CV-MV, an "alarm band" can be set for the CV-SP value. The set value is effective in both the positive and the negative direction. If an alarm limit is ex-ceeded, then this will be indicated by an alarm. Depending on the settings, the winding position can be blocked. Example:

The percentage deviation (CV-SP), which is defined as the alarm limit, is calculated by means of the CV-MW, as shown in the following example, Fig. 7-9: With a CV-MV of 14% and an alarm limit of ± 20%, the effective range is between 11.2% and 16.8%. The deviation behavior of the CV of the sin-gle winding position is shown schematically in Fig. 7-9.

Fig. 7-9 Schematic representation of the deviation behavior of the CV of an individual winding position



7.2.5 Settings In the window "Q-Parameter" of the Control Unit, the following settings can be adjusted:

Fig. 7-10 Setting window for the coefficient of variation at the Control Unit Reference length:

It is possible to set the reference length between 50 – 10'000 m. In winding, a reference length of 100 m has been accepted as the standard. This is a length which is necessary for a reliable CV-value. However, the setting of the reference length also depends on the objective when monitoring the coef-ficient of variation.

• For data acquisition: For the monitoring of the CV it is recommended to select the reference length of 100 m starting

from the bobbin tip (see "measurement"). As the yarn evenness increases from bobbin tip to bobbin base, it is guaranteed that results measured under the same circumstances (same yarn length) can better be compared with each other. A longer reference length is not recommended as the number of faults increases at the bottom part of the bobbin and thus, the CV-value is influ-enced.

For pure data collection, no action is taken in case of exceeding limits. • For the selection of bad bobbins:

The selection of the reference length depends on the quality requirements. The reference length must be derived from the possible CV-deviation in the yarn. The monitoring of faulty yarn must be carried out continuously. This guarantees that bobbins which do not meet the quality requirements will be monitored and can be taken out of the winding process (action: block). Mainly in the pro-duction of compact yarns, faults which are formed in the compacting zone can influence the CV-value. Such faults can occur over the whole bobbin length.



Measurement:

The measurement can be carried out:

• continuously • at bobbin change The following winding machines provide a bobbin change signal. This means that the winding position informs the clearer when a bobbin change is carried out:

• Murata Process Coner PC 21

• Savio Orion

• Savio Polar

• Schlafhorst Autoconer 338

• Schlafhorst Autoconer AC5, ACX 5

Alarm limit MV-monitoring

This is an absolute monitoring of the CV of a group. The CV mean value (CV-MV) alarm can only be deleted by increasing the alarm limits or when the CV-MV decreases below the alarm limit. As no ac-tion is carried out in case of an exceeding limit, the alarm must be considered as a warning. If the alarm limit is set to 0, the monitoring is inactive. Monitoring of individual winding positions

With the monitoring of the CV of a winding position, a relative deviation of the single bobbin (SP-MV) from the mean (CV-MV) is set. The setting of the percent value must be determined for each individu-al application. Due to the diverse causes for the changes of the yarn evenness, it is not possible to give any recommendations for the settings. • The setting of an upper CV alarm limit which serves for the monitoring and detection of:

- a high CV, caused by diverse faults in the production process - a rough ring - slow spindles caused by loose or contaminated drive belts or spindles drive belts

• The setting of a lower CV alarm limit serves for monitoring and the detection of yarns, which have

too much twist caused by:

- heavy ring travellers - 2 ring travellers on one ring with different operating hours, i.e. the old traveller was not re-

moved - twisted drive belts for spindles

If the yarn evenness of a bobbin deviates from the spindle ALARM LIMIT, a CVp- or CVm alarm is triggered. At the same time, this deviation from the mean value can be found on the window for "tex-tile alarms" at the control unit. If the information on the yarn evenness is desired only, there is the possibility to set the alarm limit, but without selecting any actions. In this case, the number of alarms is indicated in the shift report. If the alarm limit is set to 0, the monitoring of the alarms is inactive.



Action

If the unevenness CV of a winding position exceeds the upper or lower alarm limits, the sensor reacts according to the selected alarm, setting column ACTION. An entry is made in the logbook in all cases. There are four different possibilities:

• register

• cut

• block

• block +suck If the action “register” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maxi-mum possible length of the winding position. The action block can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the sensor lamp lights up. The alarm will be counted as Q Block-ing. The behavior of the winding position depends on the machine type. For this, trained personnel are necessary. Depending on the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually. The action block + suck can be recommended, if it is desired to take a bad bobbin out of the pro-cess. The winding position will be blocked and the sensor lamp lights up. The alarm will be counted as Q Blocking. The Reference length or evaluation length of the quality parameters CV, H or IP has a fixed maximum length of 64 m if the action at alarm is set to "block + suck". After the blocked winding position has been reset, 64 m yarn will be sucked off from the cone. 7.2.6 Display of the CV values Fig. 7-11 shows the results of the CV-measurement of each winding position as well as the CV-mean value of the group and the absolute CV-alarm at the control unit.



Fig. 7-11 Display of the CV-value • SP UPPER LIMIT

The upper absolute CV-limit is calculated from the CV-mean value of the group and the set rela-tive upper CV-alarm limit.

• SP LOWER LIMIT The lower absolute CV-limit is calculated from the CV-mean value of the group and the set rela-tive lower CV-alarm limit.

If the CV of a winding position lies above or below the absolute SP ALARM LIMIT, a CVp- or CVm-alarm is triggered. 7.3 Imperfections "Imperfections" are frequent thick and thin places as well as neps, which are formed when processing fibers into yarns. They can be raw material related as well as process related. The frequency and the size of imperfections influence considerably the further processing and the quality of a yarn and thus the textile fabric. The frequency and the size of these events can provide information about the quality of a produced yarn. Furthermore, the data serve for monitoring and the optimization of the processes in spinning preparation. Fig. 7-12 shows a T-shirt with a high number of thick places, thin places and neps under reflective and transmitting light. It shows the irregularity caused by imperfections on the surface of the garment. The reflective light shows particularly the amount of neps. The same garment shows particularly the effect of the short thick places and thin places on the appearance of the fabric in transmitting light.



Fig. 7-12 Garment Reflective light Transmitting light 7.3.1 Definition of imperfections Imperfections are divided in three fault groups and four classes. This can be seen in Table 7-1.

Fault group Class

Neps shorter than 4 mm 140% 200% 280% 400%

Thick place length: about fiber length 35% 50% 70% 100%

Thin place length: about fiber length -30% -40% -50% -60%

Table 7-1 Imperfections, fault groups and classes Thick and thin places

Thick and thin places have a relationship to the yarn evenness. The size and frequency of thick and thin places has an influence on the yarn evenness. The higher the unevenness, the more frequent the occurrence of thick and thin places. An increase of the number of thick and thin places affects the quality of a yarn and has a disturbing effect on the textile fabric. At the same time the increase is a textile-technological indicator for a dete-riorating raw material quality, for worn-out card clothing in spinning preparation and worn-out key components of the spinning machine. If such an increase occurs, the spinner can optimize the spin-ning preparation based on these data. The occurrence of thick and thin places can of course not be prevented, but it is possible to reduce the frequency and size of these faults.



Neps

Neps have an enormous influence on the appearance of a textile fabric. Neps are defined as follows: "Dense tangle of intertwined fibers with a core of fibers or with seeds or seed coat fragment slightly enclosed in fibers. Usually spherical. Diameter approximately 1 mm." We differentiate between raw material-related and process-related neps. Raw material-related neps

Raw material-related neps which usually consist of dead and immature fibers often cause problems due to different dye absorption in the dyeing process.

Nep, enlarged 44fold Nep, enlarged 360fold

Fig. 7-13 Nep in a knitted fabric, scanning electron microscope photography Fig. 7-13 shows an enlarged image of a knitted fabric made with a scanning electron microscope. It shows the effect of these so-called shiny neps. The neps, which in part consist of dead and immature fibers, have not absorbed any dyestuff at all. They remain in the fabric as small white spots. Seed-coat fragments, which also contain fibers, are also known as raw-material related neps. Process-related neps

Process-related neps are actually produced in the opening/cleaning lines and in spinning preparation. Due to the fact that cotton is being cleaned at very high speeds, this also results in a loss of quality. The consequences of higher cleaning speeds are a higher content of short fibers and neps. The initial increase of the number of neps occurs already during the ginning process, and additional neps are produced in the cleaning lines of the spinning mills. Carding may result in a significant reduction in the number of neps but, depending on the condition of the clothing, it also produces new neps. The effect of an increased number of neps is becoming noticeable especially in fine knitted or woven fabrics. An increased number of neps also causes problems while processing fabrics in the knitting mill (breaking of needles, loops are not properly taken up, formation of holes).



7.3.2 Settings The determination of the alarm limits requires some basic knowledge of statistics first, the mean value of the number of imperfections over at least 10 producing winding positions has to be determined. The mean value indicates the arithmetic mean of the single values. It is the sum of all single values, divided by the number of the single values. The standard deviation is the variation of single values and can be calculated according to the rules of statistics. The standard deviation, therefore, is used for setting the alarm limits. Recommendation for the alarm limits of the imperfections: An insensitive setting is: Mean value (MV) of the imperfection classes + 5 × standard deviation (s). A sensitive setting is: Mean value (MV) of the imperfection classes + 3 × standard deviation (s).

Fig. 7-14 Setting of the alarm limits for imperfections Evaluation length

Setting: 100 m to 2000 m. After this length the alarm condition is checked and a new measurement started. It is recommended to select an evaluation length of 1000 m. Neps

The limit for neps of all classes can be set between 0 – 64000. If 0 is selected, the monitoring is inac-tive. For neps, the operator can select between several sensitivity levels.



Thick places

The limit for thick places can be set between 0 – 64000. If 0 is selected, the monitoring is inactive. For thick places, the operator can select between several sensitivity levels. Thin places

The limit for thin places can be set between 0 – 64000. If 0 is selected, the monitoring is inactive. For thin places, the operator can select between several sensitivity levels. Action

If the class limit is reached on a winding position, the sensor reacts according to the setting ACTION at the ALARM window. An entry is made in the logbook in all cases. There are four possibilities:

• register

• cut

• block

• block +suck If the action “register” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maxi-mum length of 64 meter. This setting should not be chosen, as a pure cut does not make much sense. The action block is recommended, if it is desired to take an off-quality bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained per-sonnel are necessary. Depending on the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually. The action block + suck can be recommended, if it is desired to take an off-quality bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The reference length or evaluation length of the Q parameters CV, H or IP has a fixed maximum length of 64 m if the action at alarm is set to "block + suck". After the blocked winding position has been reset, 64 m yarn will be sucked off from the cone.



7.3.3 Display of the imperfection results Fig. 7-15 displays the last measurement over the evaluation length with date and time of:

• neps of all sensitivity levels per winding position • thick places of all sensitivity levels per winding position

• thin places of all sensitivity levels per winding position Furthermore, it displays the group mean value of all imperfection classes.

Fig. 7-15 Display of the imperfection counts The results of the sensitivity levels will be marked in color in case of set alarm limits for certain clas-ses.

• green Alarm limit set but no alarm

• red Alarm, the set limit has been exceeded 7.4 Class-Alarm This alarm deals with yarn faults which are classified in the USTER® CLASSIMAT matrix, Fig. 7-17. If one wants to monitor repeatedly occurring yarn faults which are not disturbing as a single event but as a group of faults the winding position can be stopped with the class-alarm. A single D1 fault might not be disturbing, but a series of several D1 faults shortly after each other cannot be accepted in the end product. With the setting of an alarm in this class, e.g. 3 faults per kilometer, the winding position will be stopped when the alarm limit is reached. The bobbin must be removed by the personnel.



With the USTER® QUANTUM 3 class-alarm, according to the USTER® CLASSIMAT criteria, the user has a tool which operates according to the same criteria as the USTER® CLASSIMAT for the laborato-ry. Seldom-occurring yarn faults are detected, assessed and classified within the well-known CLAS-SIMAT matrix according to length and mass deviations. This provides the user with complete information on the yarn quality and allows him to make a fore-cast for the subsequent process stages. Based on this information about the quality parameters, the user can then apply that knowledge to specifically use the yarn according to the customer's require-ment profile. The yarn fault classification is carried out simultaneously at all winding positions according to the USTER® CLASSIMAT: Short thick places with a mass or diameter increase of at least 75%, 45 long thick places with a mass or diameter increase of at least 30% and thin places with a mass or diameter decrease of at least –20% are classified within the CLASSIMAT matrix in 45 thick and thin place clas-ses. This allows the user to quickly identify any outlier winding positions. The CLASSIMAT matrix is shown in the following Fig. 7-17.

Fig. 7-16 Classification matrix at the Control Unit The user can select between displays of the detected yarn faults or of all remaining yarn faults. The yarn fault classification is permanently active and cannot be switched off. In addition, there is the pos-sibility of displaying the data of individual winding positions or the complete machine, which also can be printed out via a function key. 7.4.1 Definition of the classes Fig. 7-17 shows the fault channels of the CLASSIMAT matrix with the fault length (cm) and the fault size (%).



Fig. 7-17 CLASSIMAT matrix with the fault classes 7.4.2 Reasons and effects of the faults The increase of the yarn faults can have different causes:

• raw material related, i.e. a change in the raw material quality

• process related changes, i.e. worn-out machine parts, like e.g. card cloth, defect regulation of the draw box, fly, dirty machines, etc.

The rising of yarn faults is an indicator for a negative change in the textile process, which has to be looked at carefully. 7.4.3 Settings

Fig. 7-18 Setting of the class-alarm at the Control Unit



Evaluation length

It is possible to set the evaluation length between 1 – 6000 km per winding position. This means, that the alarm condition is checked referred to this length. It is recommended to set the evaluation length to 1 km. Class

One out of 23 classes. It is possible to set limits for up to 5 classes. Alarm limit

The alarm limit can be set between 0 and 64000 events until an alarm is triggered. Action

If the alarm limit is reached on a winding position in one out of 5 classes, the iMK reacts according to the setting ACTION at the ALARM window. An entry is made in the logbook in all cases. There are three different action settings:

• register

• cut

• block If the action “register” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maxi-mum by the winding position supported length. The action block can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained per-sonnel are necessary. Depending to the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually. 7.4.4 Display of the class alarms The class alarm can be triggered for the channels: N/S and L/T. It can be selected between the re-sults of the machine, the group or individual winding positions. The results can be displayed absolute or per 100 km.



In the upper part of the result window of the individual classes, the status of the measurement is dis-played:

• OK: The set alarm was not reached.

• ALARM: The set alarm was exceeded. In the lower part of the result window, the overall number of events corresponding to the chosen ref-erence length is given.

Fig. 7-19 Display of the class alarms The result of the class will be marked in color in case a set alarm limit was exceeded.

• green Alarm limit set, but no alarm

• red Alarm, the set limit has been exceeded 7.5 Tailored classes (Option Advanced Classes) The tailored classes offer the possibility to define customer classes or group classes together for spe-cial purposes. It is also useful to inspect yarn faults and foreign fibers within the customized class. The aim is to define tailored classes for NSL, T and FD (Fig. 7-20 and Fig. 7-21). The settings can be done by defining sensitivity in % and cm of the upper right and lower left corner for the tailored class for NSL, T or FD. In order to inspect faults within the tailored class the user should use the LED func-tion of the sensor. The tailored class will be shown in the classification matrix of the related clearing function. The tailored classes offer the possibility to define custom classes or group classes together for special purposes. Tailored classes are used only for information and will not influence the cut ratio. After changing the tailored class, the data should be cleared (clear counters) otherwise the tailored class values are mixed up with the former settings.



7.5.1 Settings

Fig. 7-20 Setting of the fault class Tailored classes for NSL, T and FD can be defined. The settings are: Sensitivity (%) and the length (cm) values of the upper right and lower left corner for the tailored classes NSL, T and FD.

Fig. 7-21 Setting of tailored the fault class



7.5.2 Display of the tailored classes The tailored class will be shown in the classification matrix of the related clearing function (Fig. 7-22, right side). “Tailored class” can be used for the LED function.

Fig. 7-22 Classification matrix at the Control Unit (at the “Displays” main menu) To better understand defects Uster Technologies always recommends to put the fault on a black board (disturbing thick and thin places) and on a white board (foreign fibers). To make this easier the iMH-LED function and the display of defect length, percentage and classification can be displayed on the event report on the CCU (Fig. 7-23). The iMH-LED is turned on, when a tailored class cut is trig-gered.

Fig. 7-23 iMH LED Display Function for tailored classes



7.6 Adjustment of the individual alarm possibilities On new winding machines, the textile alarms are shown on the man-machine interface of the ma-chine. A reset of the textile alarm is carried out by the machine. Depending on the machine type, the reset of the alarm is carried out at a bobbin change. By this, the alarm of the sensor is also deleted. Especially by selecting the same reference length for different quality parameters, it can happen that two different alarms are triggered at the same time. As an example the following event is described: The yarn evenness and the hairiness are monitored over a reference length of 400 m. For both moni-toring parameters, the respective limits are set and the action "block" is selected. It is possible, that an off-limit bobbin shows a higher hairiness as well as a higher unevenness. In this case, both alarms can be triggered, i.e. an alarm for CVp and an alarm for Hp. 7.7 Hairiness Hairiness plays an important role in the textile industry. Hairiness variations in yarns can substantially affect the appearance and the hand of woven and knitted fabrics. Furthermore, hairiness can be dis-turbing in subsequent processes. With the introduction of compact spinning, the hairiness monitoring on the machine became more and more a must. Since the hairiness of compact yarns is very low, it is important that bobbins which de-viate in hairiness can be recognized immediately. Otherwise the fabrics have to be downgraded. Statistical surveys (USTER® STATISTICS) have shown that yarns have become more even. There-fore, variations of the quality characteristics of conventional yarns from bobbin to bobbin have be-come more disturbing than several years ago. This is also valid for the hairiness. 7.7.1 Principles of operation of the hairiness measuring systems The oldest hairiness monitoring system represents the counting of the number of protruding fibers at a distance of 3 mm from the yarn body. (Fig. 7-24).

Fig. 7-24



A testing method with high reproducibility was introduced in the market by Uster Technologies in 1988 with the USTER® TESTER 3. The method is based on a dark field optics (Fig. 7-25 and Fig. 7-26).

Fig. 7-25 Fig. 7-26

Fig. 7-25 and Fig. 7-26 represent the hairiness of yarns from the point of view of the optical receiver. The yarn body is dark, but all the loose and protruding fibers are bright and contribute to the hairiness measurement. The light intensity along the yarn is permanently measured by the receiver. Since the yarn body is dark, it does not contribute to the hairiness monitoring. It is possible to evaluate hairiness and to calculate the absolute hairiness, the hairiness variation and to print out a diagram and a spectrogram of hairiness with this measuring principle. It could be proved in various interlaboratory trials that this measuring method is the most accurate hairiness monitoring system in the industry. Uster Technologies has been publishing USTER® STA-TISTICS for hairiness since 1989. The conditions for the clearer are different. Therefore, a suitable solution had to be found, which pro-duced comparable results, even with the limited space conditions which are available for the clearer. Fig. 73 and Fig. 74 show a 100% cotton, yellow colored garment. In the zoomed picture (right) it is obvious that the hairiness is rather high.



Fig. 7-27 Yarn hairiness in garment / 100% cot-

ton, combed, Nec 32 (18,5 tex) Fig. 7-28 Yarn hairiness in garment, zoomed

picture The following 100% bleached cotton T-shirt (Fig. 75 and Fig. 76) also shows excessive hairiness.

Fig. 7-29 Yarn hairiness in cotton T-shirt / 95% cotton / 5% polyurethane, Nec 34 (17,4 tex)

Fig. 7-30 Yarn hairiness in cotton T-shirt

Measuring method of the USTER® QUANTUM 3

For the USTER® QUANTUM 3, a similar measuring method as for the USTER® TESTER 4 was cho-sen. The prerequisites for the hairiness measurement are given by the foreign fiber measuring field. However, the evaluation of the signal had to be adjusted. The highest attention was put on the repro-ducibility of the deviations from the mean value to detect outlier bobbins.



7.7.2 Settings

Fig. 7-31 Setting of the hairiness parameters at the Control Unit Reference length

It is possible to set the reference length between 50 and 10000 m at the Control Unit. After the length setting the alarm condition is checked and a new measurement is started. As already mentioned for the monitoring of the yarn evenness, it is necessary to adapt the reference length to the respective quality demands. Depending whether changes of the hairiness should be monitored or only regis-tered, the reference length will be different. • For data collection:

For the monitoring of the hairiness, it is recommended to select a reference length of 400 m start-ing from the bobbin tip (see "measurement"). As the yarn hairiness increases over the bobbin length, it is guaranteed that results measured under the same circumstances can be compared with each other. A longer reference length is not recommended, as the hairiness increases at the bottom part of the bobbin. For pure data collection, no action is taken in case of exceeding limits.

• For the selection of bad bobbins:

The selection of the reference length depends on the quality requirements. The reference length must be derived from the expected hairiness deviations of the yarn. The monitoring of faulty yarn must be carried out continuously (see section "Measurement" below). This guarantees that bob-bins, which do not meet the quality requirements, can be taken out of the winding process (action: block). In case of compact spinning it is particularly the compacting zone in the case of compact spinning which can considerably influence the hairiness. Such faults can affect the hairiness over the whole bobbin length.



Measurement

The measurement can be carried out:

• continuously • at bobbin change The following winding machines provide a bobbin change signal. This means that the winding position transmits a trigger signal to the clearer, when a bobbin change is carried out:

• Murata PC 21

• Savio Orion

• Savio Polar

• Schlafhorst Autoconer 338

• Schlafhorst Autoconer AC5

MV-monitoring (group mean value)

Upper alarm limit H MV: 0,1 – 20.0 Lower alarm limit H MV: 0,1 – 20.0 SP-monitoring (winding position)

Deviation of the SP-monitoring from the group mean value. Upper alarm limit SP: 0,1 – 20.0 Lower alarm limit SP: 0,1 – 20.0 Action

If the hairiness of a winding position is exceeded on one of the alarm limits, the sensor will react ac-cording to the setting ACTION at the ALARM window. There are four different possibilities:

• register

• cut

• block

• block +suck If the action “register” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maxi-mum by the winding position supported length. This setting should not be chosen, as a pure cut does not make much sense. The action block can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained per-sonnel are necessary. Depending to the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually.



The action block + suck can be recommended, if it is desired to take a bad bobbin out of the pro-cess. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The Reference length or evaluation length of the Q parameters CV, H or IP has a fixed maximum length of 64 m if the action at alarm is set to "block + suck". After the blocked winding position has been reset, 64 m yarn will be sucked off from the cone. 7.7.3 Display of the hairiness values Fig. 7-32 shows the hairiness results per spinning position, the mean value of the hairiness per group as well as the upper and lower alarm limit.

Fig. 7-32 Display of the Hairiness value • SP UPPER ALARM LIMIT

The indicated upper absolute hairiness alarm limit is calculated from the hairiness mean value of the group and the preset upper hairiness alarm limit.

• SP LOWER ALARM LIMIT

The indicated lower absolute hairiness alarm limit is calculated from the hairiness mean value of the group and the preset lower hairiness alarm limit.

Any hairiness value of a winding position that is above or below the absolute SP ALARM LIMIT will trigger a Hp or Hm alarm. At the same time, it is possible to read the deviation from the mean value out of the display for Textile Alarms. As far as information on hairiness only is desired, there is the possibility to set the alarm limits without selecting any actions. In this case, the number of events exceeding the limits is indicated in the shift report.



7.7.4 How do hairiness variations affect woven and knitted fabrics? Uster Technologies has investigated various aspects of hairiness in order to clarify the effect of hairi-ness variations on fabrics. Patterns in the fabrics

First test: The effect of hairiness variation on woven fabrics was investigated after dyeing. Fig. 7-33 shows the consequences on a fabric consisting of 100% cotton in the weft. The yarns with various hairiness values were inserted in the weft. The four yarns were of the same count but had different hairiness values of 5.7, 6.9, 7.9 and 9.0.

Fig. 7-33 It is obvious in Fig. 7-33 that the human eye can recognize hairiness differences of H = 1. The same trials were carried out with a viscose yarn with the same result. Investigations on hairiness variations on fabrics made out of compact yarns have shown that differ-ences of H = 0,6 ... 0,7 could already be recognized . 7.7.5 Hairiness monitoring on the machine The textile industry is aware of the fact that the hairiness on all the spinning positions must be kept under control. Therefore, it is strongly required that the hairiness is measured on the machine so that 100% of the yarn is monitored. The following events have generated the need for such monitoring systems: • Since 1988 a highly reproducible hairiness testing system is available with the USTER® TESTERS

3 and 4. The experience with these systems and the consequences on fabrics have proven that hairiness deviations of only H = 1 can be seen in the fabrics after dyeing. Therefore, hairiness var-iations have to be avoided.



• Compact yarns have only very little hairiness. Therefore, compact yarns with only small deviations can easily be recognized in the fabric. Contamination and defects in the compacting zone can prevent the correct formation of compact yarns. This can lead to the production of a yarn with "normal" hairiness, instead of a yarn with only a little hairiness. After dyeing, such hairiness varia-tions become clearly visible.

7.7.6 On-line tests versus off-line tests The laboratory tests for hairiness can be regarded as benchmarks for the textile industry. The USTER® STATISTICS are also available for such tests. Fig. 7-34 shows the correlation of the USTER® off-line system with the on-line system. These tests were carried out by installing the USTER® on-line system in the thread-line of the USTER® TESTER.

0,00

2,00

4,00

6,00

8,00

10,00

12,00

0,00

2,00

4,00

6,00

8,00

10,0

0

12,0

0

14,0

0

Hairiness USTER TESTER 4

Com4 11.8TexCom4 11.8TexCom4 11.8TexRing gek. 14.7TexRing 24.6TexRing 16.4TexRing kard.19.7TexRing 50%PES 29.5TexCom4 gek.7.7TexCom4 11.8TexRing kard. 20TexComp Süssen 20TexRing 100Tex

Fig. 7-34 The correlation between the off-line and the on-line measurement in Fig. 7-34 is very good. However, practice has shown that such ideal conditions as shown in Fig. 7-34 are not always given on the wind-ing machine. As already mentioned, there are many factors which influence a correlation with the measurements in the laboratory. For this reason, as for the results of the yarn evenness, the absolute values of the hairiness will not exactly correlate with the results in the laboratory. However, there is a very good correlation regarding the relative deviations from the mean value.

Hairiness USTER TESTER 5



It must be taken into account, that the winding machine increases the hairiness. This applies mainly for the unwinding of the yarn from the bobbin with high speed, for yarn tensioners and deflection de-vices. 7.7.7 Basic hairiness differences between the different spinning methods Hairiness characteristics within a bobbin or a package depend on the spinning system. The knowledge of hairiness characteristics is important for comparison tests between the off-line and the on-line systems for reaching high accuracy and reproducibility. For conventional ring-spun yarns, the hairiness increases from the bobbin tip to the bobbin base. The increase is in the order of about 10% (Fig. 7-35). In comparison to ring-spun yarn, for compact yarns the increase of the hairiness from the bobbin tip to the bobbin base only reaches about 2 to 4%. The origin of these within-bobbin variations is the ring rail movement causing varying balloon sizes and varying angles of the yarn at the ring traveler.

Fig. 7-35 Hairiness variation of yarns produced by various spinning systems Fig. 7-35 shows the hairiness variation within a cross-wound cone. In the case of ring-spun yarn, the test was made after winding. Since the conditions on the OE rotor spinning machine are the same at any time, there is also a con-stant hairiness throughout the package. Therefore, if values of on-line systems have to be compared with off-line systems, it has to be taken into consideration that the laboratory results represent only 400 m of yarn from the bobbin tip. For comparison it is, therefore, recommended to measure the bobbin tip on the winding machine as well. The USTER® QUANTUM 3 allows this measurement for all winding machines which generate a bob-bin change signal.



Fig. 7-36 shows the hairiness from the tip of the bobbin to the base, each test representing 400 m of yarn. In Fig. 7-36, the bobbin tip is represented with blue color, the bobbin base in light red color.

4

4,2

4,4

4,6

4,8

5

1 2 3 4 5 6 7 8 9 10 blue: bobbin tip – red: bobbin base

Fig. 7-36 6 measurements, 400 m per bobbin, through the bobbins 7.7.8 Practical examples Hairiness monitoring on ring-spun yarns

On a winding machine, 460 bobbins were tested regarding the hairiness. Yarn: Nec 30, 100% cotton, combed, ring-spun yarn. Fig. 7-37 shows the results of a series of measurements of 460 bobbins. It can be clearly recognized that the hairiness results are scattered around the mean value of H = 4,8. Furthermore, there are 5 winding positions with a hairiness beyond the set limits.

4

4.2

4.4

4.6

4.8

5

5.2

5.4

5.6

5.8

1 21 41 61 81 101 121 141 161 181 201 221 241 261 281 301 321 341 361 381 401 421 441

Hai

rines

s H

H H-Mw limit Hm - 0.7 limit Hp + 0.7

Fig. 7-37 Measurement of the hairiness of a conventional ring-spun yarn

Outlier winding positions

Winding positions



Abbreviations H = Single value for the hairiness

H-MW = Mean value of the hairiness of the group

Limit Hp +0,7 = Positive limit (red) set to +0,7 with reference to the mean value

Limit Hm -0,7 = Negative limit (blue) set to –0,7 with reference to the mean value Hairiness monitoring of compact yarns

On a winding machine, 160 bobbins were tested regarding the hairiness. Yarn: Nec 50, 100% cotton, combed, compact yarn. Fig. 7-38 shows the results of a measurement of 160 bobbins of compact yarn. In comparison to the measurements of a ring-spun yarn shown in Fig. 7-37, the values are located much closer around the mean value. Furthermore it can be seen that the mean value of the hairiness is much lower than the mean value of conventional ring yarn. This was also experienced with off-line measurement.

2.02.12.22.32.42.52.62.72.82.93.03.13.23.33.4

1 21 41 61 81 101 121 141

Hai

rines

s H

H H-MW Hm-limit -0,5 Hp-limit +0,5

Fig. 7-38 Hairiness measurement of a compact yarn Abbreviation: H = Hairiness

MW-group = Hairiness mean value of the group

Hm-limit –0,5 = Negative limit (blue) is set to –0,5 with reference to the mean value

Hp-limit +0,5 = Positive limit (red) is set to +0,5 with reference to the mean value

Winding positions



7.8 Indication of ejected bobbins If the operator is interested in marking the alarmed bobbin in order to re-check them off-line in the laboratory, he can select the "continuous printout". For this purpose, it is possible to print out the Q-alarms by selecting the feature of the "continuous printout" at the Control Unit. After each stop, a printout follows. This printout provides information to the operator about the alarm reason and the deviation from the nominal value. This printout can be attached to the bobbin and further analyses of the bobbin can be carried out in the laboratory. 7.9 Criteria to select the limits for quality characteristics Bobbins which exceed the selected limits for quality characteristics have to be ejected at the winding machine. For this purpose, we have to discuss the characteristics which can be detected with a mod-ern yarn clearer:

• Unevenness • Hairiness

• Frequent thin places • Periodic faults (pearl chains)

• Frequent thick places • Excessive cuts

• Frequent neps • Clusters of faults In establishing a real quality management system, it is of utmost importance that selections made by the yarn clearer with respect to quality characteristics can be verified in the laboratory. The following examples to explain what this means. Fig. 7-39 shows the determination of hairiness on the machine.

4.15

4.25

4.35

4.45

0 3 6 9 12 15 18 21 24 27 30 33

Hairiness

Weeks

4.55

4.65

4.15

4.25

4.35

4.45

0 3 6 9 12 15 18 21 24 27 30 33

Hairiness

Weeks

4.55

4.65

Fig. 7-39 On-line monitoring of hairiness / Count: Nec 30, ring-spun yarn, cotton, combed In week 10 a massive increase in the hairiness can be noticed.



Fig. 7-40 shows the distribution of the hairiness on the winding machine. A selection criterion was set to select the bobbins which exceed the warning limit.

0

50

100

150

200

250

300

2.80

2.88

2.96

3.03

3.11

3.19

3.27

3.34

3.42

3.50

3.58

3.65

3.73

3.81

3.89

3.96

4.04

4.12

4.20

4.27

4.35

4.43

4.51

4.58

4.66

and

high

er

Selected limit forseparating bobbins

Hairiness

Frequency

0

50

100

150

200

250

300

2.80

2.88

2.96

3.03

3.11

3.19

3.27

3.34

3.42

3.50

3.58

3.65

3.73

3.81

3.89

3.96

4.04

4.12

4.20

4.27

4.35

4.43

4.51

4.58

4.66

and

high

er

Selected limit forseparating bobbins

Hairiness

Frequency

Fig. 7-40 On-line hairiness measurement / Count: Nec 40, ring-spun yarn, cotton, combed Fig. 7-40 shows the distribution of the hairiness measured on a winding machine on 2500 bobbins. A limit was set to separate and eject bobbins which will lead to visual disturbances in a fabric. 7.9.1 Installation of a quality management system to eliminate outliers In the previous chapters, it was explained in detail how modern quality management tools can con-tribute to the improvement of the performance of a spinning mill. However, we identified one major area where mill managers and quality managers still suffer. This is the area of outliers. Since one sin-gle thread in the warp on a weaving machine can downgrade the entire woven fabric, it is of utmost interest to get rid of outliers. An average ring spinning mill has a size of 20,000 to 30,000 spindles. In comparison with other indus-trial activities, the number of production positions in spinning mills is very high. Therefore, a well or-ganized spinning mill will have a repair crew which permanently improves outliers among the produc-tion positions. The repair crew, however, needs input from the laboratory where systematic quality analyses are made.



Fig. 7-41 shows the principles of operation in a modern spinning mill.

Fig. 7-41 The bobbins which are ejected by the winding machine are analyzed in the laboratory. Outliers are brought back to the normal distribution.

The bobbins of individual spinning machines are marked to identify the production positions where the ejected bobbins came from. The ejected bobbins are brought to the textile laboratory, where the quality problems are evaluated. The findings are listed on an instruction sheet for the repair crew. The intention to bring the outliers back within the normal distribution range (Fig. 7-41). The repair crew has to undertake the repair work at the machines (Fig. 7-42). Successful repairs are reported back to the laboratory.

Fig. 7-42 Recommendations for a systematic quality management Bobbins which are recognized as having tolerated quality characteristics will go back to the yarn batch. The outlier bobbins will be handled as second-grade bobbins.



7.9.2 Tracing back outlier bobbins to the source Bobbin identification method

The easiest way to trace back outlier bobbins is the designation of each bobbin with the number of the spinning position. This identification can be realized for one ring spinning machine within 20 minutes. Fig. 7-43 shows the identification of the bobbins.

Entry of marked spindle in action planLaboratory

Action plan for repair crewMarking of spindle

position

Ejected bobbins from winding machine

Fig. 7-43 Identification of spinning positions for one doff If the winding machine ejects a bobbin from this ring spinning machine, it is easy to find the spinning position where the bobbin was produced. Therefore, it is recommended, particularly in low cost countries, to designate the bobbins of one doff and one machine every day. In a medium size spinning mill of 20’000 to 30’000 spindles it will last approximately 20 to 30 day to check and trace back all the outlier bobbins in a mill. Identification process:

• The spinning mill establishes a test plan which ring spinning machine has to be tested at what day.

• All the bobbins of this machine are identified for one doff so that the laboratory operators know where the ejected bobbin came from.

• The production position which produced the ejected bobbin is entered into the action plan for the maintenance and repair crew.

• The maintenance and repair crew receives an action plan from the laboratory. Fig. 7-44 shows part of an action plan for the maintenance and repair crew. The yellow part is filled in by the laboratory staff. This part also has a column where the laboratory operators insert the expected source of the fault. The green part of the action plan is filled in by the repair crew. They also confirm if the expected source proposed by the laboratory staff was correct. If the crew finds another fault, the technical prob-lem is described in detail.



The action plan goes back to the laboratory the same day when all the actions are finished.

June 25, 2007

10 minCleaned drawbox of finisher drawframe

SameConta-mination of drawbox of finisher drawframe

Periodicity at 28 m

3Finisher

drawframe

June 25, 2007

5 minReplaced ring travellers

Ring travellerworn out

Ring traveller

High periodic hairiness

28414RSM

June 25, 2007

10 minCleaned front roller

Contamination of front roller due to honeydew

Damage on front roller, ring spinning

Peak in spectrogram at 8 cm

23114RSM

DateSignatureTime for repair

Action taken

Source found by repair crew

Expected source

Detection in laboratory

Spinning position

Machine

June 25, 2007

10 minCleaned drawbox of finisher drawframe

SameConta-mination of drawbox of finisher drawframe

Periodicity at 28 m

3Finisher

drawframe

June 25, 2007

5 minReplaced ring travellers

Ring travellerworn out

Ring traveller

High periodic hairiness

28414RSM

June 25, 2007

10 minCleaned front roller

Contamination of front roller due to honeydew

Damage on front roller, ring spinning

Peak in spectrogram at 8 cm

23114RSM

DateSignatureTime for repair

Action taken

Source found by repair crew

Expected source

Detection in laboratory

Spinning position

Machine

Fig. 7-44 Systematic repair of defective production positions Lessons learned with the first systems in mills:

• The yarn monitoring system on the last machine in the spinning process also has to check the quality characteristics.

• The monitoring of the quality characteristics on the winding machines offers new opportunities to considerably lower the daily outlier bobbins.

• Modern on-line systems support spinners to keep the quality of every yarn package within pre-set limits.

Outlier bobbins produced by non-identified spinning positions

As has been mentioned above, the bobbins of all spinning positions are identified once in 20 to 30 days. This method allows a precise tracing back of outlier bobbins to the source of the problem. However, in a spinning mill with 25 ring spinning machines there are 24 machines which deliver non-identified outlier bobbins to the laboratory via the winder at a certain date. If there is a clear assign-ment in the mill what kind of bobbins were processed on what winding machines, it also allows the assignment of the type of problems at least to a specific spinning machine. If a spinning mill uses link systems, the back tracing of the bobbins to the ring spinning machine is easy. In spinning mills with stand alone winders it depends on the organization of the mill. Example: If more and more non-marked bobbins exceed the hairiness thresholds, it may be time to replace the ring travelers.



7.9.3 Examples from the industry The closed loop system was tested in the industry with considerable success. If the clearer really can detect quality deviations from established benchmarks, it will also be possible for the quality special-ists to trace back the yarn faults to the origin. The following are a few examples where faults could be traced back to the ring spinning machine. Examples 1 and 2

A bobbin was ejected by the automatic winding machine as an outlier, because the evenness (CVm) was too high. In the laboratory the high evenness could be confirmed. Since the bobbin was identified with the spinning position at which the yarn was produced, the repair crew found that the top roller of the respective drawbox was contaminated with honeydew (Fig. 7-45).

Fig. 7-45 Honeydew deposit Fig. 7-46 Defective apron

Another outlier bobbin was ejected at the winding machine because the number of S-faults was too high. A check at the spinning machine could clarify that a defective apron with a hole has caused this alarm at the yarn clearer (Fig. 7-46).



Examples 3 and 4

Another outlier bobbin was ejected because of a high number of S-faults. After having confirmed this in the laboratoary as well, the check at the respective spindle at the ring spinning machine has shown that the apron of the drawbox moved in the wrong direction, and, therefore, the joint was defective (Fig. 7-47).

Fig. 7-47 Wrong direction of apron, bad joint Fig. 7-48 Intensive contamination at output of

drawbox A bobbin was identified as outlier by the yarn clearer because the number of imperfections was too high. The check at the ring spinning machine has shown an accumulation of fiber fragments at the locations indicated by yellow arrows in Fig. 7-48. 7.9.4 Recommendations for a sampling plan There are some limitations on the winding machine to reach the same accuracy as spinners reach in the laboratory. The reasons for these limitations are:

• Long maintenance cycles for clearers

• Contamination of the measuring zones of on-line systems as a result of a permanent monitoring, 24 hours a day, 7 days per week

• The yarn speed is not constant on a winding machine. Therefore, periodic mass variations cannot be measured directly on the winding machine. Periodic events have to be measured by indirect measurements such as the higher evenness or the frequent occurrence of thick and thin places. However, in the laboratory the operator can measure the yarns at constant speed and, conse-quently, an accurate spectrogram can be determined. With this precise information of specific pe-riodicities the textile laboratory can elaborate a detailed action plan.

• The microclimate on the winding machine near the yarn clearer is given by various variables such as the environmental conditions in the winding room, the heat produced by the winder, etc. In the laboratory the environmental conditions are defined by international standards.

As a result of this it is strongly recommended to check the bobbins in the laboratory which are ejected at the winding machine due to quality problems. Table 7-2 is a recommended test procedure for a textile laboratory in a mill with 27’000 spindles, cot-ton 100%, combed, count range Ne 30 to Ne 50.



Machine No. of ma-chines or positions

Quality characteristics

Test inter-vals

Test speed

Test length

Required test time per day *

Card 12

Evenness Diagram Spectrogram Variance-length curve

2 per day 100 m/min 250 m 8 min

First draw-frame 2



Comber 12



Finisher drawframe 4



Roving frame 600


5 roving bobbins per day

100 m/min 250 m 16 min

Ring frame 27’000

Evenness Diagram Spectrogram Imperfections Hairiness Yarn diameter Density Trash

10 bobbins per machine every third day

(90 bobbins daily)

800 m/min 1000 m 169 min

Winder ** 600

Evenness Diagram Spectrogram Imperfections Hairiness Yarn diameter Density Trash

60 ejected bobbins from winding ma-chine daily

800 m/min 1000 m 113 min

20 cones per day

800 m/min 1000 m 39 min

Total 401 min

Table 7-2 Total test time required in the laboratory per day for this example * Time required also includes setting of instrument and sample preparation ** The amount of 60 ejected bobbins per day is equivalent to 0,022% of the daily production or 3,5 kg of yarn (Basis: Nec

30).



The total test time per day is equivalent to 401 minutes or 6 hours and 41 minutes. This indicates that the tests can be managed in one shift. The total test time is based on an average work load in the laboratory. However, the slivers of the cards, drawframe, combers, etc., can also be measured at the same day. As a measure for corrections at machines with non-identified bobbins we recommend to study the action plan once per day, to check the analysis of the outlier bobbins, to walk along each machine and to check the spinning positions. 7.9.5 Conclusion Most of the spinning mills have an established quality management system based on sample testing. With such a quality system, however, it may last year or more to get rid of outliers. This paper describes a method with which outlier bobbins can permanently be separated on the wind-ing machine with the help of yarn clearers and traced back to the faulty spinning position. The method which is described in this paper also allows the daily elimination of outlier bobbins. The described system is used by various mills with considerable success. 7.10 Yarn evenness (CV), hairiness and imperfections and their effect on the fabric

appearance 7.10.1 Reasons and measures to minimize random mass variations In Table 7-3, the origin of faults related to random mass variations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. RANDOM MASS VARIATIONS


Card Regular maintenance

Draw-ing frame

Apply autoleveller at finisher drawframe / Regular maintenance of drawing elements

Roving frame

Incorrect setting of the roving traverse

Ring spinning frame Incorrect break drafts

Dimension of apron

Aprons change schedule and quality of aprons

Excessively worn aprons



RANDOM MASS VARIATIONS


Top roller grinding schedule

Top roller hardness

Cot condition and hardness

Roll chatter

Top roller minimum diameter

Dimension of spacers

Training of operators (avoid cutting top roller)

Yarn diameter differences

Excessive balloon tensions

Incorrect roller settings

Top front rollers are out of position

Pigtail centering

Worn rings

Periodic mass variation from previous processes

Roller weightings

Improper apron spacing

RANDOM MASS VARIATIONS / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Constant quality control of sliver and yarn quality with the USTER® TESTER (spec-trogram)

USTER® Testing on-line Adjustment of autoleveller

USTER® QUANTUM CLEARER Proper setting of the “pearl chain” option for alarms

Separate bobbins with high CVm with quality data option

The quality data setting for CVm can be used to separate bobbins with high CVm


Table 7-3 Preventive measures and tools for the management of random mass variations



7.10.2 Reasons and measures to minimize imperfections Uneven fabric appearance is the result of too many thin places, thick places and neps. There are var-ious reasons for an excessive formation of imperfections. In this section, some of these reasons will be explained with the help of pictures of the knitted samples and their yarn quality results. Mix-up of a reference yarn with a yarn of a high imperfection level

During compact yarn production, the air suction area in the compacting zone can become clogged for a variety of reasons. This affects the spinning process in a negative way and can increase the number of imperfections and especially neps. In our example, we have tested a reference compact yarn and a defective compact yarn arising from a clogged compacting zone. If we check the CVm values, thin places (-50%), thick places (+50%) and neps (+200%) of the two yarns, we can see a significant dif-ference. In particular, the number of thin places (-40%), thick places (+35%) and small neps (+140%) have increased significantly (Table 7-4).

Yarn Count (Ne)

Twist 1/m

Twist direc-tion

CVm %

Thin -50%

Thick +50%

Neps +200%

H 2DØ mm

CV2D (8mm)

D (abs) g/cm3

Refer-encecom-pact yarn

30 770 Z 10.1 0.0 6.0 8.0 3.7 0.20 7.5 0.6

USP07 < 5 < 5 11 < 5 62 34 Defective-compact yarn

30 770 Z 10.5 1.0 12.0 19.0 4.0 0.21 7.9 0.6

USP07 < 5 51 23 80 52

Thin -40% Thin -50% Thick +35% Thick +50% Neps +140 Neps +200

Reference compact yarn 3.0 0.0 45.0 6.0 46.0 8.0

USP07 < 5 < 5 < 5 11 < 5 < 5 Defective compact yarn

13.0 1.0 76.0 12.0 100.0 19.0

USP07 28 24 51 34 23

Table 7-4 Yarn quality results, well maintained and badly maintained compact spinning machine We made fabric simulations for these two yarns using the USTER® TESTER 5 fabric simulation pro-gram and the results are given in Fig. 7-49 and Fig. 7-50. The increase in the number of the small neps can be seen in the right hand picture. The neps (+200) are shown as white points and indicated by white arrows.



Fig. 7-49 Fabric simulation of reference com-

pact yarn Fig. 7-50 Fabric simulation of defective compact

yarn In Table 7-5 the origin of faults related to imperfections is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are present-ed. YARN IMPERFECTIONS


Thick places & Thin places

Comber Excessive short fiber content

Roving frame Lint or fly on roving

Ring spinning frame

Lint build up on drafting rolls

Blown in lint

Apron and cot conditions

Apron spacing

Out of position top front roll

Incorrect roving traverse

High balloon tensions

Loaded travelers

Draft distributions (break draft)



YARN IMPERFECTIONS


Roller spacing

Condition and hardness of top cots

Eccentric or damaged front rolls (top or bottom)

Too coarse fiber

Wrong drafting zone settings

Bad conditions of top rollers

Bad operation of the overhead cleaner

Extreme air conditions

Neps Nep levels in roving

Apron worn out

Tensor pin opening

Ring and traveler worn out

Improperly set traveler clearers

Balloon control ring worn out

Raw material: Length uniformity

Short fiber content

High micronaire variations

High level of neps

YARN IMPERFECTIONS / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Proper bale management and laydown management

Systematic quality control of sliver and yarn quality with USTER® TEST-ER / imperfection counts and comparison with USTER® STATISTICS

USTER® QUANTUM CLEARER Use the imperfections block function form the Q DATA option and sepa-rate those bobbins with excessive counts

USTER® EXPERT SYSTEMS Monitor long-term variations of cut ratio and yarn quality

Table 7-5 Preventive measures and tools for the management of yarn imperfections



7.10.3 Reasons and measures to minimize excessive hairiness and hairiness variations There are various reasons for the formation of excessive hairiness and hairiness variations. In this section, some of these reasons will be explained with the help of pictures of the knitted samples and their yarn quality results. Different ring spinning techniques

In this trial, two different ring spinning techniques were compared on the same T-shirt sample: con-ventional ring spinning and the compact spinning technique. We have knitted 10 rows of reference yarn (conventional, Nec 36, 16,5 tex) and 10 rows of a compact yarn (compact Nec 36, 16,5 tex) spun from rovings produced from the same cotton blend. We can observe horizontal dark and light colored lines in the T-shirt sample. These horizontal lines are the result of yarn hairiness difference (Fig. 7-51 to Fig. 7-54). This significant difference can also be observed in Table 7-6.

Yarn Count (Ne)

CVm %

Thin -50%

Thick +50%

Neps +200%

H sh 2DØ mm

CV 2D%

(8mm)

D (abs) g/cm3

Reference 36 12.6 0.6 33.1 71.7 5.2 1.30 0.20 9.6 0.5

USP07 48 19 61 65 76 >95 40

Compact 36 12.2 0.20 30.2 76.4 4.0 0.93 0.19 9.4 0.6

USP07 37 <5 57 67 <5 19 <5


Fig. 7-51 Reference T-shirt Fig. 7-52 Defective T-shirt

Fig. 7-53 Reference Fabric Fig. 7-54 Defective fabric (mix-up of compact

yarn)



Less twist

The twist of the yarn has a decisive effect on the hairiness: the lower the twist, the higher the hairi-ness, and thus the hairiness decreases with increasing yarn twist. This correlation can be explained by the fact that, in cases of a high twist, the number of protruding fibers decreases because most of these fibers are embedded into the yarn body. The spindles of the ring frame are driven by one or more belts which engage the whorls (pulleys) that project from the bottom of the spindle. Slippage of the belts can lead to twist losses, which vary from spindle to spindle. These variations can cause barré and stripping problems when the yarn is assem-bled into the finished fabric [2]. Eccentric rings/spindles

As is well-known, both eccentric spindles and rings can increase the hairiness of the yarn as well as influence its strength and elongation, especially at high eccentricities. Additionally, the life of an ec-centric spindle is shorter than a normal one and it has a higher noise level. An eccentric spindle, or a displaced guide or ring, can also increase the end-breakage rate remarkably, because of the periodic tension variation at each revolution. In Table 7-7, the origin of faults related to excessive hairiness and hairiness variations is given. Pos-sible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. EXCESSIVE HAIRINESS Origin of Faults Possible Reasons Raw material Fiber length

Length uniformity

Excessive short fiber content

Spinning preparation, spinning and winding Roving twist

Age and type of rings & ring travelers (ring spinning)

Spinning tension (ring spinning)

Yarn twist

Slipping spindle belts

Damaged pigtail guides

High winding speed

Condition of rings

Eccentricity of spindles & rings

Traveler changes

Full bobbin diameter

Yarn twist

Damaged or worn travelers

Separator slap

Improperly positioned or missing anti-balloon rings

Spindle speed



EXCESSIVE HAIRINESS Origin of Faults Possible Reasons

Spindle speed curve

Improper traveler weights

Damaged cots

Improperly centered pigtail guides

Variation of spinning climate

EXCESSIVE HAIRINESS / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Systematic quality control of sliver and yarn quality with USTER® AFIS system (short fiber content) and USTER® TESTER, hairiness sensor

USTER® QUANTUM CLEARER Use quality data settings for hairiness to separate spin-ning bobbins with excessive hairiness


Table 7-7 Preventive measures and tools for the management of excessive hairiness and hairiness variations

Foreign fibers 8


8 Foreign fibers 8.1 Introduction Foreign fibers are one of the major problems in spinning mills. The global ITMF [3] survey on cotton contamination in 2009 showed that, in the perception of spinners from around the world, contamina-tion remains a serious problem. During the past 20 years the degree of significantly contaminated cotton bales has been increasing steadily from 14% to 22%. Organic matter is still the main contami-nant, followed by fabrics of cotton and plastic film, strings of jute and plastic [3]. These fibers can be of different origin, character, structure or color. There are distinct benefits to early detection and re-moval of unwanted fibrous material, since subsequent processing stages open up and spread out these “foreign fibers.” This can result in the contamination of many yarn packages [1]. Fabrics con-taining foreign fibers cannot be dyed homogeneously, and these fibers can cause many quality prob-lems, especially after finishing [4]. Foreign fibers and materials adversely affect processing, produce end breaks and also affect the dye uptake, fiber reflectance and the appearance of the final product [2]. It is obvious that foreign matter in textile fabrics can no longer be accepted. Therefore, the fight against foreign material in cotton has to cover all the areas where this type of contamination can oc-cur. Many foreign fiber problems are detected only after finishing, and the spinner is ultimately held re-sponsible for the damage. Therefore, the costs for such claims can be considerable, and provisions have to be made to absorb such claims if the spinning mill does not have a quality management system to eliminate or minimize the number of foreign fibers in yarns. The following is a collection of experience with foreign matter removal systems prior and after the card. Fig. 8-1 and Fig. 8-2 show separated foreign material in cotton.

Fig. 8-1 Separated foreign material in cotton Fig. 8-2 Separated foreign material in cotton

8 Foreign fibers


In Fig. 8-3 and Fig. 8-4 we can see the result of a large blue plastic part which was cut into individual fibers by the card. As can be seen the cotton fibers are contaminated with blue colored plastic fibers. The plastic fiber cluster (Fig. 8-3 and Fig. 8-4) will result in foreign fibers in yarns.

Fig. 8-3 Plastic fibers in card sliver Fig. 8-4 Plastic fibers in card sliver

Fig. 8-5 Various foreign fibers in yarns at different magnification / inorganic material

Foreign fibers 8


8.2 Dense Area Another new, innovative and unique feature of the USTER® QUANTUM 3 is the “Dense Area”. The dense area in the scatter plot (appearance versus length) is the display of the range where foreign fibers are occurring very frequently but which can hardly be recognized in a fabric because they are very small (Fig. 8-6). This display of the dense area helps the user to set a clearing limit easier with an optimal balance between quality and productivity. The dense area depends on the raw material. If a yarn is produced from cotton having a lot of foreign matter or vegetables, then the dense area will be wider and a high number of cuts have to be expected. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the dense area and the significant foreign fibers will appear. The blue colored dense area is used to visualize the distribution and frequency of clearing limits for the Foreign Matter (FD). By this means a quality analysis of the degree of contamination for different yarns can be easily done. With multicolored light sources the new FM sensor can see all colored foreign fibers and enables the classification of vegetables separately. Having detected all the defects, the USTER® QUANTUM 3 smartly splits the foreign matter into two pools, disturbing colored foreign fibers and mostly non dis-turbing vegetable foreign matter (see chapter 9). Separate limits for foreign fibers and vegetable mat-ter can be defined. Fig. 8-6, shows a dense area with yarn faults as seen by the USTER® QUANTUM 3, with all the fre-quent remaining events recorded in the yarn (blue dots), and with the marked area of the yarn body (blue area) and the area of the disturbing yarn faults (red dots). The vertical scale represents the visual appearance or intensity and the horizontal axis represents the FD faults length in cm.

Fig. 8-6 Display of the dense area and the scatter plot for foreign matter

8 Foreign fibers


Examples of various dense areas:

Fig. 8-7 Display of the dense area and the scatter plot for foreign matter Examples of various dense areas:

Fig. 8-8 Display of the dense area and the scatter plot for foreign matter

Foreign fibers 8


8.3 Foreign fibers 8.3.1 Types of foreign material in cotton There are various spinning mills which permanently eliminate foreign matter manually from the bales. However, this method only allows the elimination of larger particles. Small foreign fibers such as hu-man or animal hair cannot be eliminated with such methods because they cannot be detected. The International Textile Manufacturers Federation ITMF investigates the contamination of cotton bales on a global scale. The classification of foreign material in bales leads to Table 8-1. [5] Type of contamination Designation Origin

Cotton-related contamination honeydew insects

leaf cotton plant

stem cotton plant

bark cotton plant

trash cotton plant

seed coat fragments cotton boll

Contamination of natural and man-made origin

woven plastic packing material

jute packing material

plastic fragments foreign matter blown into the fields

strings for cotton bags

bird feathers natural contamination

grass contamination during harvesting

paper contamination of cotton fields

leather contamination during harvesting

human and animal hair contacts with humans and animals

rust machines or transportation trucks

metal plates / wires contamination during harvesting

oil / grease machines or transportation trucks

rubber contamination during harvesting

stamp colorant identification of bales

tar contamination during harvesting

Table 8-1 Contaminations found in cotton (Source: ITMF 2009 [5]) Depending on the growth area and the harvesting methods the type and number of foreign material can change considerably.

8 Foreign fibers


Foreign fibers

Foreign fibers are all kinds of fiber type materials, which cling to the yarn. They can be of different origin, composition, structure and color. They occur as single fibers as well as in fiber bundles. The length of foreign fibers can vary considerably, but hardly exceeds a length of 7 cm. Packing material

Cotton bales are often packed in polypropylene bags or other synthetic material after ginning. Other kind of packing material made of natural fibers will not be discussed here. Foreign fibers consisting of polypropylene are often white and therefore hardly detectable by electron-ic means. These fibers do not protrude and are not detected before dyeing or finishing. Thus, they first become visible in the dyed woven or knitted fabric.

Fig. 8-9 Examples of packing material / Single fiber of a colored polypropylene string for packing the cot-ton fibers / Distance between black lines: 1 cm

Dirtiness

Dirtiness is caused of substances, which adhere to, are spun into or have penetrated into the yarn body. The contamination of bales is usually attributed to transport damage, improper storage and print color. In the spinning mill, dirtiness as a foreign matter can be caused by

• lubricant residue on machine parts (grease or oil)

• a messy working environment with dust and dirt

• dust or very small particles from rubberized machine parts (e.g. press rollers) or drive belts, which adhere to the yarn

• Transport vehicles which were not cleaned when moving cotton. In the yarn, dirtiness appears mostly as dark, brown or gray contaminants. In contrast to many foreign fibers or packing materials, such faults are often very long, for example 5 cm or more. Due to the length and the missing fibrous structure, these faults can usually be clearly identified.

Foreign fibers 8


Fig. 8-10 Example of grease in the yarn Vegetable matter

With vegetable matter, it is necessary to clearly differentiate between two categories

• pieces of vegetables

• vegetable packing material Pieces of vegetables

Under this term, it is commonly understood some fragments of:

• leaves

• stems

• bark

• seed-coat fragments The color is light to dark brown and the shape is irregular. The foreign matter adheres to or, in some cases, is embedded in the yarn. The frequency of such foreign matter depends on the degree of contamination of the fiber material and on the efficiency of the blowroom equipment. In general, it can be said that the relative percent-age of such foreign matter is usually very high.

Foreign matter in the form of vegetable frag-ments is normally brightened up almost com-pletely in the bleaching process. But the effec-tiveness of the bleaching process depends on the recipe and on the applied technology. Un-der normal conditions, this type of foreign mat-ter is considered as non-disturbing after correct bleaching. However, aggressive bleaching agents are not allowed anymore. Experience has shown that vegetables deriving from weeds might remain as dark spots in the yarn after bleaching. The monitoring of such faults is recommended.

Fig. 8-11 Examples of seed-coat fragments

8 Foreign fibers


Vegetable packing material Foreign matter made out of vegetable packing materials is e.g.:

• jute fabric or jute-/hemp strings

• chemical components based on cellulosic material The structure of the material is clearly fibrous. The color is usually light to dark-brown and the length is in a short to medium range of approx. 1 to 2 cm. The fibers are extremely rigid and brittle, so that they often protrude from the yarn and rarely cling tightly to the yarn body. Due to the chemical similarity to the vegetable components of the fiber material, e.g. cotton, vegetable packing materials are also affected by the bleaching process, whereby the recipe and the process technology again play an important role.

Fig. 8-12 Examples for vegetables in the yarn 8.3.2 Degree of contamination of bales The investigation of ITMF every second year in the past has shown that the degree of contamination of cotton bales depends very much on the growth area. Fig. 8-13 shows the growth areas with the most contaminated bales.

Foreign fibers 8


Fig. 8-13 Growth areas with the highest foreign fiber contamination in cotton bales (Source: ITMF 2009) Fig. 8-14 shows the growth areas with the least contaminated cotton bales.

Fig. 8-14 Growth areas with the lowest foreign fiber contamination in cotton bales (Source: ITMF 2009) It has to be taken into consideration that those growth areas where cotton is harvested with machines are less affected by inorganic matter because there is less contact between workers and cotton, but the amount of vegetable can be higher.

8 Foreign fibers


It is evident that while a distinction between “most contaminated” and “least contaminated” cotton can be made, there are no cotton varieties produced which have zero contamination. As can be seen above, at least 5% of the produced bales from even the least contaminated origins have significant levels of contamination. 8.3.3 Size and appearance of foreign matter in spinning mills If foreign material cannot be eliminated prior to the card the foreign material is cut into pieces by the card. A piece of plastic can result in a number of individual foreign fibers after the card. As these fi-bers are mostly colored, the cluster of foreign fibers can easily be recognized in the card sliver. These clusters of foreign fibers will lead to human interventions, consequently loss of production effi-ciency and labor costs, because the clearers on the winding machines will trigger foreign fiber alarm due to the higher amount of foreign fibers within a short period. Often in some spinning mills some of the foreign fibers are added accidentally through human igno-rance, waste recycling etc. which contaminate the cotton fibers during the spinning process. For such fibers the clearer as a monitoring system at the last stage of the spinning process is the only tool which can eliminate such fibers.

Opening &CleaningLine

Card Draw-frame

Spinningmachine

Removed foreign material in bale

Cardsliver

Yarn

Fig. 8-15 Foreign material at various stages of the spinning process The foreign fibers which cannot be eliminated during the spinning process will show up in the yarn and have to be eliminated by the yarn clearer on the winding.

Foreign fibers 8


8.3.4 Frequency of foreign fibers in spinning mills In order to understand the frequency of foreign fibers in spinning mills we have to consider that for-eign fibers which exist as clusters in the card sliver are drawn several times in the spinning process until they show up in the yarn. The more steps in the spinning process the more increases the dis-tance from foreign fiber to foreign fiber in the yarn. Therefore, the distance between two foreign fibers is longer in a ring spinning operation with combers than in an OE rotor operation. Assumption: Plastic film prior to card of 2 cm2. Resulting cluster: 400 individual foreign fibers in the card sliver (Fig. 8-15).

OE rotor spinning

OE rotor spinningmachines

Ring spinningcombed process

Ring spinningmachines

Cards

Drawframes

Cards

Drawframes

Roving frames

Ribbon lapmachines

Combers

Drawframes

Winding machines

Ring spinningcarded process

Cards

Drawframes

Roving frames

Ring spinningmachines

Winding machines

Drawingratio3000

to30'000

Drawingratio1200

to10'000

Drawingratio

300'000to

1'000'000

*0,2 to 1,5 m *1 to 10 m

*100 to 300 m

* Average distance between 2 foreign fibers

Fig. 8-16 Effect of drafting on foreign fiber distribution in yarns In Fig. 8-16 the processing steps and the drawing ratios are shown for the 3 most important spinning processes. It can be seen in the figure that the distance between two foreign fibers is short for short spinning processes and long for spinning processes with many steps.

8 Foreign fibers


8.3.5 Foreign fiber risk calculated for a spinning mill Fig. 8-17 shows the risk of a spinning mill which has the foreign fiber challenge not under control.

3840

34800

1320600

7320

18000

0

4000

8000

12000

16000

20000

24000

28000

32000

36000

Bale Yarn (Nec 30,combed)

Raw fabric Finished fabric(bleached)

Shirts Retailer

Sale

s pr

ices

in U

SD

Fig. 8-17 Foreign fiber risk calculated for a spinning mill The calculation is based on a bale of 480 lbs (217 kg). The price for the bale was USD 600. The spin-ner’s sales price for yarns made of this bale was USD 1’320. The raw fabric was sold for USD 3’840. The finished fabric was sold for USD 7’320. The foreign fibers were only detected after bleaching. The finishing plant did not send the complaint to the cotton trader, but to the spinner. Therefore, the finishing plant had a damage of USD 7’320 per bale which had to be paid by the spinner, but the spinner only earned USD 600 for the processing of the entire bale. Therefore, a reliable foreign fiber elimination system has to be installed in the spinning mill if the spin-ner wants to be the master of his destiny. Any claims to the spinner are much higher than the actual cost of spinning since there is a significant value addition along the chain. 8.4 Classification matrix of foreign fibers with the USTER® QUANTUM 3 Uster Technologies has developed a classification matrix for foreign fibers and vegetable matters. Fig. 8-18 shows the structure of the classification matrix for foreign fibers, which represents the appear-ance (in %) and length (in cm). The appearance corresponds to the visibility of a fault.

Foreign fibers 8


Fig. 8-18 Classifying system for foreign fibers (Standard F classes (left) and extended F classes(right)) This matrix was developed in a similar way as Uster Technologies designed the matrix for thick plac-es and thin places. A considerable amount of foreign fibers are located in the B1 class. Therefore, the B1 class (B11 to B14) serves as a benchmark for recognizing the degree of contamina-tion of the raw material. The experience values are the following:

Yarn type Low degree of contami-nation per 100 km

Heavily contaminated per 100 km

Table 8-2 Benchmarks for foreign fibers

Combed yarns, 100% cotton 10 150

Carded yarns, 100% cotton 20 300

Worsted yarns, 100% wool 20 100

8.5 Clearing limits The setting of the foreign fiber channels depends highly on the application profile of the yarn and the amount of foreign fibers in the raw material. Basically, it can be said: the longer a foreign fiber and the higher its color intensity:

• the more disturbing are the consequences in the fabric

• the lower is the number of this kind of faults in the yarn As for regular yarn clearing, it is also valid for foreign fiber clearing:

• More sensitive setting: more splices, but less remaining faults in the yarn

• Less sensitive setting: many remaining faults, but less splices As for normal yarn clearing, it can also be said that foreign fiber clearing is a compromise between quality and productivity.

8 Foreign fibers


8.5.1 General references for foreign fiber clearing Fig. 8-19 illustrates the relationship between the visual appearance and the length of foreign fibers. The normal position for typical foreign fibers in a cotton yarn is shown. The limit between the diverse foreign fibers cannot be drawn clearly and they also overlap partly.

Fig. 8-19 Distribution of foreign fibers in a cotton yarn

• Vegetables: - are mainly in short length ranges - occur in the whole intensity spectrum from low to high - should not be cleared, if possible, as they are possibly removed or neutralized in the follow-

ing processes, particularly during the bleaching process

• Foreign fibers: - are mostly shorter than 7 cm, but thinner than vegetables - must be cleared when exceeding the clearing limit

8.5.2 Clearing limits for dark foreign fibers in light yarn The FD-channel (Foreign matter Dark) is responsible for the clearing of dark foreign fibers in light yarn. A dark foreign fiber has a low light reflection and, therefore, appears darker than the yarn.

Foreign fibers 8


8.5.3 Standard way of optimizing clearing limits: Manual clearing limits entry Analogous to the optimization of the thick and thin places, the setting for the foreign fiber clearing must also be started with the standard settings. According to the results, further adjustments have to be carried out. Fig. 8-20 describes this standard procedure when starting foreign fiber clearing with unknown cotton:

Fig. 8-20 Diagram for the optimization of foreign fiber clearing

8 Foreign fibers


Foreign fibers of different origin, composition, structure and color can be detected with foreign fiber clearing. By selecting a limit only the disturbing foreign fibers are removed from the yarn. By using FD, dark foreign fibers in light yarn are detected during production. The setting of foreign material is mainly driven by the production lines in a mill; of course also in blended or synthetic yarn the foreign material caused by fly or mix up can be eliminated. Fig. 8-21 shows the clearing limit as shown in the setting window of the control unit. The USTER® QUANTUM 3 gives us the chance of determining our clearing limits by placing a maximum of 8 set points FD1 to FD8. In Fig. 8-21, we can see 3 setting points (red rectangle) and the clearing limit for FD foreign fibers. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we entered the values for FD1, set point FD2 will appear and it will continue the same way.

Fig. 8-21 Clearing limits on the screen of the control unit Set points have two parameters. These are: sensitivity (%) and reference length (cm). Intensity

The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensi-tivity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive). (FD1= 40%, Fig. 8-21). Reference length

The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive) (FD1 = 0.6 cm, Fig. 8-21).

Foreign fibers 8


8.5.4 Setting a smart clearing limit for dark foreign matter (FD) As we mentioned in the previous chapter, the dense area is the display of the range where foreign fibers are occurring very frequently. This display of the dense area helps the user to set a clearing limit easier with an optimal balance between quality and productivity (Fig. 8-22). Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the dense area and the events will appear. In order to see the dense area, the user should press the dense area key (Fig. 8-23). Besides the dense area, also the scatter plot of the cut faults and remaining events, and the number of expected fault cuts per 100 km together with the used setting limits will appear directly on the same setting page (Fig. 8-24).

Pressing key presents • The dense area. • Scatter plot of the cut faults

and remaining events. • Number of expected fault cuts

/ 100 km.

Clearing limit

Red dots = cut yarn faults. Blue dots are remaining events Dense area

= Proposes the starting point

for the clearing limits based on the dense area.

Fig. 8-22 Display of the dense area With the USTER® QUANTUM 3, we have a very useful and smart tool to find the right starting point for the new clearing limits. The Smart Limit function proposes a starting point for the clearing limits based on the yarn body and also provides a cut forecast to facilitate faster setup of clearing limits. The setting of USTER® QUANTUM 3 can be done simply in one step (Fig. 8-23, Fig. 8-24):

Fig. 8-23 Setting page for FD manual setting or setting by smart limits available

Fig. 8-24 Display of dense area

8 Foreign fibers


Cuts/100km Total yarn events /100km

After pressing the smart limit key, a small window with the two appropriate keys to adapt and optimize the smart limit for foreign fibers appears (Fig. 8-25). The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by up and down keys to optimize the settings according to the individual quality requirements and productivity. Every change of setting will automatically initiate a new calculation of the cut forecast. It is recom-mended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound. This length includes all the clearers of the machine.

The new setting point proposals


= Smart Limit 1 step more sensitive.

= Show dense area and scatter plot

= confirm and activate optimized

clearing limit.


Fig. 8-25 Proposed setting is a starting point for optimization Besides the smart limit function, of course the foreign fiber (FD) and vegetable matter clearing (VEG) classification is still a very powerful tool where we can refer our last decision (Fig. 8-26).

Fig. 8-26 FD online classification

Foreign fibers 8


The red figure in each class indicates how many foreign fibers were eliminated by the clearer within this class and the black figure represents the number of foreign fibers which were detected in the class. 8.6 Foreign fibers and their effect on the various production processes What is understood by foreign fiber detection?

Commonly, under the term “foreign fiber detection”, textile specialists understand the elimination of all foreign matter in a yarn, which exhibits a contrast to the yarn. With the existing technology, a real col-or measurement is not possible. Therefore, the evaluation of the light/dark contrast was chosen. Very short foreign fibers with the same extension like seed coat fragments must be left in the yarn as they are not disturbing and because of the high number of cuts that has to be expected and because such fibers can hardly be recognized in a fabric. The decision for the respective clearing limit must derive from the principle that no long foreign fibers should remain in the yarn. The maximum admissible length of the foreign fibers which may remain in the yarn depends on the final purpose of the yarn. Particularly critical are unicolored large fabric such as bed sheets, table sheets, etc. Measuring principle and evaluation

For the monitoring of foreign fibers, an optical measuring system is used. For this, a comparison be-tween the reflection deviation of the foreign fiber and the normal yarn color is measured. This means, that a very dark foreign fiber in a very light yarn produces a higher contrast than the same foreign fiber in a yarn made out of gray fibers. The difference between the actual yarn color and the contrast of a foreign fiber and its length, over which the color change occurs, is measured. These two values (reflection in % and length in cm) are compared with the set clearing limits. Are both values above the clearing limit, a cut is carried out. Foreign fibers which do not exceed the clearing limit are entered in the classification matrix. Structure of the classification matrix

Fig. 8-27 shows the structure of the classification matrix for foreign fibers. The foreign fibers are clas-sified by the parameters reflection (%) and length (cm).

8 Foreign fibers


Fig. 8-27 Structure of the classification matrix for foreign fibers Fig. 8-28 shows a practical example for a classification matrix of a carded cotton yarn.

Fig. 8-28 Practical example for a foreign fiber matrix Foreign fiber grades

The graphical representation of disturbing foreign fibers and their classification cannot be done the same way as for disturbing thick and thin places, i.e. as generally accepted grades. Depending on the degree of contamination of the raw material, certain colors and frequencies can dominate in the cot-ton from certain growth areas, whereas other growing regions have completely different foreign fibers. Therefore, it is recommended to generate such grades depending on the respective fiber blend inter-nally, in order to obtain certain standards for the existing foreign fibers.

Foreign fibers 8


8.6.1 Methods to eliminate foreign material and frequency of foreign material A comparison of frequency of foreign material and elimination methods

Fig. 8-29 shows the domains of foreign material removal systems and the frequency of foreign mate-rial. It is obvious that the frequency of foreign material increases considerably in the area of fine for-eign matter (human and animal hair, plastic fibers, fragments of strings, seed coat fragments).

Size of foreignmaterial

0,001(diameter 10µm)


0,1 1,0 10 cm2

Domain of manual removal

Domain of automatic removal systems prior to card

Domain of yarn clearers

Frequency offoreign material

Size of foreignmaterial



0,1 1,0 10 cm2

Domain of manual removal

Domain of automatic removal systems prior to card

Domain of yarn clearers

Frequency offoreign material

Fig. 8-29 Methods to eliminate foreign material in cotton and foreign material frequency It is evident that the type and frequency of foreign matter require an effective system to combat this problem. Over the years spinning mills used the following methods to eliminate disturbing foreign mat-ter in order to keep the defects within acceptable limits:

• Selection of cotton with small amount of foreign fibers

• manual labor to pick foreign matter in cotton prior to the opening

• foreign matter removal systems prior to the card

• foreign fiber clearers on winding machines In some cases, especially in vertically integrated textile mills, the mending of defects after finishing the fabric is also common practice, but only part of the foreign fibers can be extracted from the fabric. Cotton selection

It makes sense in a spinning mill to know the growth areas with low foreign material contamination. It must be the aim to order cotton from areas with a low number of foreign material content to keep the risk of remaining foreign fibers low and to improve the efficiency of the removal systems both human and electronic. Further, they help to keep the number of foreign fiber cuts with the clearer on a low level. This is especially valid for end customers who ask for “zero foreign fibers” as a mandatory require-ment, and where a significant premium is paid for such a high value addition. If the premium which the spinner can realize is not significant, choosing low contamination cotton can often lead to other issues seriously affecting profit margins.

8 Foreign fibers


This may be cotton with higher nep content, higher short fiber content and higher cotton prices. Fur-ther, cotton supply contracts in general do not include contamination level as a dispute clause, with the result that losses cannot be recovered in case contamination expectations are not met. Manual labor

In developing countries, low labor costs allow use of manual inspection of cotton to remove the major defects. Typically mills use manual labor to open bales, inspect for contamination and repack them again. The number of people or the work load employed varies from mill to mill and the end use. Es-timates from spinning mills in China show between 1 person per 1 to 3 bales per day depending on the quality demand. Therefore, in an average size spinning mill with 30’000 spindles the number of employees who do these jobs vary from 60 to 180 people.

Fig. 8-30 Manual removal of foreign material in a Chinese spinning mill Foreign material removal systems prior to the card

There are various foreign material removal systems available today prior to the card. In general such devices are important to eliminate the foreign matter of a size greater than 0.5 cm2 to avoid further disintegration into finer fibers which would increase the cuts in the final inspection by the yarn clear-ers. However, such systems do not fully meet the quality targets of the end user since the size and the number of ejections make it practically impossible to eliminate the single foreign fibers which consti-tute the highest amount of disturbing defects in the final yarn or fabric. Further, the location of the sys-tem and the size of the tuft play a decisive role for the detection efficiency. Similar to manual elimina-tion, the electronic removal systems help in reducing major contaminations, finally reducing cuts and human intervention in winding. This helps to maintain consistency in cuts. Foreign fiber clearers in winding

Foreign fiber clearers are by far the most efficient systems to solve the contamination problems. With the improvement of the detection rate by the USTER® QUANTUM 3, the solution has become more and more popular. Today about 75% of delivered clearers are with foreign fiber functionality for cotton yarn measurement.

Foreign fibers 8


Since the clearers are integrated in the automatic winder, they are in a position to make the final in-spection and monitor every millimeter of yarn. Further, the clearers are today capable of detecting the finest defects not clearly visible to the naked eye. However, many of these very fine fibers may be visible after subsequent processes such as bleaching, dyeing, etc. This includes white and transpar-ent polypropylene defects. The clearer can replace each disturbing defect with a splice, thereby elimi-nating the defect from the final package to the weaver or knitter. Fig. 8-29 is, therefore, a very important figure to understand the mechanism of foreign material. This figure also shows that the foreign material removal systems prior to the card have little influence on the cut rate of the clearers, because most of the foreign fibers which are eliminated by the clearers cannot be recognized by systems prior to the card. It also has to be taken into consideration that the automatic foreign material elimination systems prior to the card eject a considerable amount of cotton together with the foreign materials which must be separated manually from the “real” foreign materials to keep the waste on a reasonable level.

Fig. 8-31 Contaminations found in cotton Calculation of a practical example: Assumption: Spinning mill with 30‘000 spindles Production per day: 15’000 kg Yarn count: Nec 30 Subject Calculation method Result

Ejections prior to card per opening/cleaning line 1200/24 hours

Efficiency 80%

960 foreign items

Ejections prior to card 2 opening/cleaning lines 1920 foreign items

Number of foreign fiber cuts on the winding machine 1/100 km 25 per 100 km of yarn

Winding speed: 1400 m/min Winding duration per 100 km: 100’000 / 1’400

71,43 min

Foreign fiber cuts per winding position and per day 25 • 1440 / 71,43 504 cuts

Number of foreign fiber cuts with 600 winding positions 600 • 504 302’400 cuts

Table 8-3 Calculation of foreign material detection

8 Foreign fibers


Conclusion per 24 hours, entire mill: Ejection of real foreign matter: 1920

Number of foreign fiber cuts: 302’400 This calculation clearly indicates that the number of foreign fiber cuts by the clearer is more than 100 times higher than the number of ejections by the foreign fiber removal system prior to the card. This also explains that the number of small foreign items is much higher than the number of large particles which can be eliminated prior to the card. If the foreign material removal system prior to the card is switched off, it does hardly affect the number of clearer cuts for the same reason. However, the foreign matter removal systems prior to the card can avoid that large foreign particles are cut in hundreds of fibers which later requires a human intervention to eliminate the foreign fiber clusters in the card sliver or to replace the affected roving in case of a foreign fiber alarm of the clearer. Mending of defects in weaving/knitting

Mending of the woven fabric by removing the disturbing foreign fibers is also a common practice, es-pecially in composite mills. However, as a practice this is possible only if the defect frequency is low. Further, this also results in costs and claims to the spinner. Some estimates mention USD 6 to 10 / 100 m as mending costs in low cost countries depending on the amount of defects. For knitted fabrics, mending is not recommended since they damage the fabric. Defects that have a higher defect rate or mending requirement are often sold for other low end applications, e.g. printed furnishing. 8.6.2 Effect of large foreign particles on the spinning process If the foreign material removal system prior to the card is not in a position to eliminate larger foreign particles because the particles are embedded in a tuft, the card will produce a large number of indi-vidual foreign fibers which form a cluster in the card sliver as mentioned above. After various drawing processes they will end in the yarn. The frequency depends on the number of drawing processes as mentioned above in Fig. 8-16. 8.6.3 Alarm options for frequent foreign fibers in yarns with clearers The following are the methods to eliminate clusters of foreign fibers: Ring spinning

Recognition with foreign fiber alarm. If the number of foreign fiber counts oversteps a preset threshold the winding machine triggers the red light at the critical winding position which also needs a human intervention or the winder automatically ejects the contaminated bobbin.

Foreign fibers 8


8.6.4 Limits of foreign fiber elimination Ring spun yarn

Table 8-4 shows an average number of splices in a ring spinning operation. This mill eliminates 30 foreign fibers per 100 km. The total number of splices is 92,5 per kilometer. At a winding speed of 1200 m/min the mean time between 2 splices per winding position is 0,9 minutes. Assumption: Count Nec 30, combed cotton, bobbin size 70 g, winding speed 1200 m/min. All figures calculated per 100 km.

Bobbin changes 28,5

Table 8-4 Limits of foreign fiber elimination on winders

"Natural" end breaks 4,0

Thin and thick places 30,0

Foreign fibers 30,0

Total number of splices 92,5

Mean time between 2 splices per winding position 0,9 min

With 0,9 minutes between two splices we are approaching the limit of admissible stops on the winding machine. It is not recommended to process heavily contaminated cotton and expect afterwards that the clearer can produce a yarn which is completely free of foreign fibers. 8.6.5 Process disturbances while beaming, weaving and knitting caused by foreign matter Table 8-5 shows the influence of remaining foreign fibers in yarns on subsequent processing stages in the textile chain.

Process Benchmarks for end breaks (Central Europe)

End breaks caused by foreign matter (experience values)

Table 8-5 Experience values / end breaks in beaming, weav-ing, knitting caused by foreign matter

Beaming 0.2 to 0.3 per 1'000'000 meters up to 50%

Weaving 1 to 2 per 100'000 picks up to 50%

Knitting 1 to 2 per hour up to 40%

8.6.6 Recommended approach to eliminate foreign fibers Based on the discussions in this paper, the following approach is recommended for elimination of foreign fibers:

• Foreign fiber clearers are mandatory to eliminate foreign fibers, to fulfill the end user quality needs and to assess the overall cotton quality (using classification figures)

8 Foreign fibers


• Installing automatic detection systems prior to the card helps in reducing manpower, eliminating major defects to reduce stoppages, to reduce human intervention and to maintain consistency in FF clearing

• Random manual inspection of cotton batches helps to identify and track the type and amount of defects in order to optimize purchase decisions

• Importing cleaner cotton helps to fulfill demands for a cotton yarn with small amount of foreign fibers

To prove the above approach Uster Technologies conducted a trial in a Chinese Spinning Mill. The following is the description and results of the field trials. 8.6.7 Field tests in China Test procedure

A field test was carried out in a quality oriented Chinese spinning mill, where the following foreign matter removal systems were available:

• Electronic foreign material elimination system prior to the card

• Visual elimination of foreign material prior to the card (70 employees)

• Yarn clearer (USTER® QUANTUM 3) with foreign fiber feature. The mills had the following standards:

• Knitted fabric - 10 defects/ 20 kg

• Woven fabric – 28 defects / 100 square yards Four tests were carried out to check the efficiency of the three above mentioned elimination systems. The final packages were sent for weaving (as weft) and knitting (circular knitting machine). The tests were carried out in a mill where the yarn was woven and knitted. Afterwards, textile experts checked each of the trial fabrics and counted the remaining foreign fibers in the fabrics. All defects that were disturbing were counted. This means that very short defects were included as well, though they were beyond the clearing limits. Dirt was not considered since it disappears in sub-sequent processes. The yarn produced was a Ne 32/1 (18,7tex), produced from mainly Xinjian province, but also included some imported cotton from Benin, Zimbabwe and Uzbekistan. The daily production of this mill is about 22 tons of ring spun yarn.

Foreign fibers 8


Knitted fabrics

This mill sells knitted fabrics as first grade if the number of foreign fibers in a knitted fabric of 20 kg weight is less than 10. The weight of 20 kg is equivalent to a length of the knitted fabric of 120 m. A first test was made without any foreign material elimination systems. The fabric was knitted on a 30” circular knitting machine, 96 feeders, fabric weight 125g/ 75cm. The fabric inspection experts could find 49 foreign fibers in the grey knitted fabric of 20 kg (Fig. 8-33).

Fig. 8-32 Fabric inspection for foreign fibers at Litay A second test was carried out with a visual check of the raw material and simultaneously with an elec-tronic elimination system prior to the card. With these two elimination methods, the amount of foreign fibers which the experts counted in the knitted fabric dropped from 49 (without any elimination sys-tem) to 38 (Fig. 8-33).

Number of foreign fibers

Tolerated limit: 10 foreign fibers

50

0

40

30

20

10

Without removal systems

Visual check and removal system prior to card

49

38



50

0

40

30

20

10


Visual check and removal system prior to card

49

38

Fig. 8-33 Test result with knitted fabrics, Litai Ne 32, 1st grade < 10 defects / 20 kg of knitted fabric A third test was made by using the USTER® QUANTUM clearer only. The number of foreign fiber cuts of the clearer was 30 to 35 per 100 km. The visual check of the grey knitted fabric has resulted in 8 foreign fibers remaining (Fig. 8-34).

8 Foreign fibers


50

0


40

30

20

10



With yarn clearer only

49

8

50

0


40

30

20

10




49

8

Fig. 8-34 Comparison with the efficiency of the yarn clearer only A fourth test was undertaken with all the elimination systems. After knitting of a roll with 20 kg, the experts counted 6 remaining foreign fibers (Fig. 8-35).

50

0


40

30

20

10



With removal systems prior to card and yarn clearer

49

6

50

0


40

30

20

10




49

6

Fig. 8-35 Application of all elimination systems Conclusion

It was only possible to reduce the amount of foreign fibers below the given threshold of 10 per 20 kg of knitting with the USTER® QUANTUM clearer because the clearer is the only tool which can also detect and eliminate small foreign fibers. If this figure has to be improved, the number of foreign fiber cuts of the clearer per 100 km has to be increased.

Foreign fibers 8


Woven fabrics

This mill also sells woven fabrics as first grade if the number of visually counted foreign fibers in a woven fabric of 100 square yards is below 28. A first test was made without any foreign material elimination systems (Fig. 8-36). The experts could find 56 foreign fibers in the grey woven fabric of 100 square yards. A second test was carried out with a visual check and simultaneously with an electronic elimination system prior to the card. With these two elimination methods the amount of foreign fibers which the experts counted in the woven fabric dropped from 56 (without any elimination system) to 52 (Fig. 8-36).

Fig. 8-36 Test results with woven fabrics, Litai Ne 32, 1st grade < 28 defects / 100 square yards A third test was made by using the USTER® QUANTUM only. The number of foreign fiber cuts of the clearer was 30 to 35 per 100 km. The visual check of the grey woven fabric has resulted in 26 foreign fibers (Fig. 8-37).



50

0

40

30

20

10



56

26

60



50

0

40

30

20

10



56

26

60

Fig. 8-37 Comparison with the efficiency of the yarn clearer only

8 Foreign fibers


A fourth test was undertaken with all the elimination systems. The experts counted 16 remaining for-eign fibers per 100 square yards (Fig. 8-38).



50

0

40

30

20

10



56

16

60



50

0

40

30

20

10



56

16

60

Fig. 8-38 Application of all elimination systems Conclusion

It was only possible to reduce the amount of foreign fibers below the threshold of 28 per 100 square yards with the USTER® QUANTUM clearer because the clearer is the only tool which can also detect and eliminate small foreign fibers. If this figure has to be improved, the number of foreign fiber cuts of the clearer per 100 km has to be increased. 8.7 Foreign fibers and their effect on the fabric appearance Depending on the application of the yarn, a foreign fiber can have different effects on the woven or knitted fabric. In knitting, the loop formation causes a shortening of the yarn, including the foreign fi-ber, which leads to a concentration of the color contrast. This means, that short foreign fibers have a more disturbing effect than in a knitted fabric. Short foreign fibers protrude from the woven fabric, un-less it exhibits a high density and stiffness. Only a combination of the intensity and the length of a foreign fiber have a disturbing effect on the eye. In the following figures (Fig. 8-39 and Fig. 8-40) examples for foreign fiber in a woven and in a knitted fabric are shown.

Foreign fibers 8


Fig. 8-39 Example of a foreign fiber in a woven fabric

Fig. 8-40 Example of foreign fibers in a knitted fabric

8 Foreign fibers


In general, 4 – 5 disturbing foreign fibers are accepted in a piece of knitted fabric (about 80 – 120 m) today. As disturbing are regarded:

• Short, clearly visible colored foreign fibers in a range of 2 to 3 loops

• Longer, light foreign fibers starting in a range of 8 to 10 loops Fig. 8-41 to Fig. 8-46 show foreign fibers in various garments. The zoomed pictures show different colored foreign fibers. In Fig. 8-41 and Fig. 8-42, a blue colored foreign fiber can be observed. The garment was produced with 100% cotton and, after the bleaching process, it had a uniform white col-or. But the blue colored foreign fiber disturbs the knitted fabric appearance.

Fig. 8-41 Foreign fiber in knitted garment / 100%

cotton, combed, Nec 46 (13 tex) Fig. 8-42 Foreign fiber in knitted garment / 100%

cotton, combed, Nec 46 (13 tex) In Fig. 8-43 and Fig. 8-44, a red colored foreign fiber can be observed. The garment is produced with 100% cotton, and, after bleaching process, it had a white color. But the red colored foreign fiber dis-turbs the knitted fabric appearance.

Fig. 8-43 Foreign fiber in knitted garment / 100%

cotton, combed, Nec 46 (13 tex) Fig. 8-44 Foreign fiber in knitted garment / 100%

cotton, combed, Nec 46 (13 tex)

Foreign fibers 8


Fig. 8-45 and Fig. 8-46 show a blue colored foreign fiber in men’s cardigan. The product was pro-duced with 100% combed cotton.

Fig. 8-45 Foreign fiber in men’s cardigan / 100%

cotton, combed, Nec 28 (21 tex) Fig. 8-46 Foreign fiber in men’s cardigan / 100%

cotton, combed, Nec 28 (21 tex) 8.7.1 Reasons and measures to minimize foreign fibers in yarns In Table 8-6 and Table 8-7, the origin of the faults related to yarn contaminations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. CONTAMINATION


Bale management Prefer – when possible – to use cotton with low content of foreign fibers.

Sometimes spinning mills tend to create or intensify the contamination problem. A popular mistake is the use of plastic bags for the waste collec-tion and transportation inside the spinning mill.

Blowroom Controlled recycling of waste

Cards Efficient carding and combing

Drawing frame Proper blending at all drawframes

Combing Optimize comber settings (comber noil, processing speed) in order to achieve the maximum foreign fiber reduction.

Table 8-6

8 Foreign fibers


CONTAMINATION / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Quality control of foreign fibers with USTER® TESTER when dealing with new raw material

USTER® QUANTUM CLEARER Proper setting of foreign fiber detection

Separate outlier bobbins with too many foreign fibers with quality alarm settings

USTER® EXPERT SYSTEMS Long-term control of quality level

Table 8-7 Preventive measures and tools for the management of foreign fibers

Vegetable Matter Clearing 9


9 Vegetable Matter Clearing 9.1 Introduction Uster Technologies has now many years of foreign fiber experience with USTER® QUANTUM. This experience helped us to recognize opportunities to improve the features of the USTER® QUANTUM 3. Some of the customers are also interested to eliminate vegetables, but many customers are eager to only remove real foreign fibers because they can prove that the vegetables are not visible anymore after bleaching. The elimination of inorganic foreign fibers only and keeping as much vegetables in the yarn as possi-ble can be applied for the following purposes:

• Reduction of cuts while keeping the eliminated number of disturbing foreign fibers constant

• Keeping the number of cuts constant but eliminating more and finer foreign fibers with the same machineefficiency.

Uster Technologies has developed a tool for the USTER® QUANTUM 3 to separate foreign fibers and vegetables. This feature is named Vegetable Clearing. The new foreign matter (FM) sensor of the USTER® QUANTUM 3 has multicolored light sources and can detect various colored foreign fibers and also enables the classification of vegetables separately. The USTER® QUANTUM 3 smartly splits the foreign matter into two populations, disturbing colored inorganic foreign fibers and non disturbing vegetable foreign matter. Separate limits for foreign fibers and vegetable matter can be defined.

Fig. 9-1 Various vegetable matters in yarns at different magnification. The distance between the black lines is 10 mm

9 Vegetable Matter Clearing


9.1.1 Vegetable matter With vegetable matter, it is necessary to clearly differentiate between two categories

• pieces of vegetables

• vegetable packing material Pieces of vegetables

Under this term, it is commonly understood:

• leaf fragments

• stem fragments

• bark fragments

• seed-coat fragments The color is light to dark brown and the shape is irregular. The foreign matter adheres to or, in some cases, is embedded in the yarn.

The frequency of such foreign matter depends on the degree of contamination of the fiber material and on the efficiency of the blow-room equipment. In general, it can be said that the relative percent-age of such foreign matter is usually high. Foreign matter in the form of vegetables is normally brightened up almost completely in the bleaching process. But the effectiveness of the bleaching process depends on the recipe and on the applied technology. Under normal conditions, this type of foreign matter is considered as non-disturbing. Experience has shown that vegetables deriving from some weeds might remain as dark spots in the yarn after bleaching. The monitoring of such faults is aspired.

Fig. 9-2 Examples for seed-coat fragments (left) and short vegetables (right) in yarns Vegetable packing material

Foreign matter made out of vegetable packing materials is e.g.:

• jute fabric or jute or hemp strings

• chemical components based on cellulosic material



The structure of the material is clearly fibrous. The color is usually light to dark-brown and the length is in a short to medium range of approx. 1 to 2 cm. The fibers are extremely rigid and brittle, so that they often protrude from the yarn and rarely cling tightly to the yarn body (Fig. 9-3). Due to the chemical similarity to the vegetable components of the fiber material, e.g. cotton, vegetable packing materials are also affected by the bleaching process, whereby the recipe and the process technology again play an important role. Usually, this type of foreign matter can only be partly bright-ened through bleaching.

Fig. 9-3 Examples for long vegetables in yarns 9.1.2 Distribution of vegetables and foreign fibers In order to differentiate between vegetables and foreign fibers, different possibilities were tested. The chosen approach was:

• A fine foreign fiber has a low reflection and a low mass

• A coarse foreign fiber or a bundle of foreign fibers has a high reflection and a considerable mass The vegetable matter clearing was developed only for the capacitive clearer. 9.2 Dense area for vegetable matter (VEG) The “Dense Area”, an innovative and unique feature of the USTER® QUANTUM 3 has already been explained for foreign matter in Chapter 8. The USTER® QUANTUM 3 has a similar dense area for vegetable matter clearing. The dense area for vegetable matter is also the display of the range where vegetable matters are occurring very frequently. The brown colored dense area is used to visualize the distribution and frequency of clearing limits for the vegetable matter.



The dense area depends on the raw material. If a yarn produced from cotton having a lot of foreign matter and vegetables, then the dense area will be wider, and a high number of cuts have to be ex-pected. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the dense area and the significant foreign fibers will appear. Fig. 9-4 shows a dense area for inorganic foreign matter with vegetable clearing and Fig. 9-5 shows a dense area for vegetable matter with larger vegetables shown as single dots as seen by the USTER® QUANTUM 3, with all the frequent events recorded in the yarn (brown dots), and with the dense area of insignificant events (brown area). The vertical scale represents the visual appearance or intensity and the horizontal axis represents the vegetable faults length in cm.

Fig. 9-4 Display of the dense area and the scatter

plot for foreign matter (inorganic matter only) Fig. 9-5 Display of the dense area and the scat-

ter plot for organic matter only As shown in Fig. 9-6, two separate limits for inorganic fibers and vegetable matter are shown on the vegetable clearing page. The brown dots between the FD and vegetable clearing curves represent in cuts savings.

Fig. 9-6 Separate limits for inorganic fibers and organic matter



Fig. 9-7 shows how the foreign matter can be separated into inorganic foreign fibers and vegetable matter.

Scatter plot containing inorganic and vegetable matter (FD Clearing)

Scatter plot containing only inorganic fibers (VEG Clearing)

Scatter plot containing only vegetable matter (VEG Clearing)

Matrix of foreign matter showing clearing curve for inor-ganic matter (VEG Clearing)

Matrix of vegetable matter showing both clearing curves for inorganic and vegetable matter (VEG Clearing)

Fig. 9-7 Separation of inorganic and vegetable matter



9.3 Classification matrix of vegetable matters with the USTER® QUANTUM 3 Uster Technologies has developed a classification matrix for foreign fibers and vegetable matters. Fig. 9-8 shows the structure of the classification matrix for foreign fibers, which represents the appearance (in %) and length (in cm).

Fig. 9-8 Classifying system for vegetables (Standard vegetable classes (left) and extended vegetable clas-ses (right))

9.4 Clearing limits As a result of intensive field tests, the vegetable clearing was defined. Vegetables are part of foreign matter. However with most common bleaching processes, vegetables become invisible after bleach-ing. Therefore mostly it is not necessary to remove them. Since the proportion of vegetables is rather high in cottons of some growth areas this results in a substantial drop in production if all the larger vegetables have to be removed and at the same time limits the ability to remove inorganic disturbing fibers. The USTER® QUANTUM 3 separates vegetables from other foreign matter. This offers better selec-tivity in foreign matter clearing and save cuts significantly. The reduction of cuts is reached by allow-ing vegetables which will not disturb the downstream process to pass (they will not be cut). The fea-ture is used for articles that will undergo a bleaching process. In most situations vegetables are not disturbing. However long and thick vegetables have to be re-moved since they can cause breaks in downstream processes. The Vegetable Clearing is a very use-ful tool to distinguish between organic and inorganic fibers. Since vegetables are not visible after the bleaching process, they can often remain in the yarn. The result is a reduction of foreign fiber cuts. There might be a need to cut long or intense vegetables to avoid warping or knitting breaks in subse-quent processes.



Fig. 9-9 Cut savings with vegetable clearing. The colored area between the two clearing curves shows the

cut savings when applying Vegetable Clearing (right). In applications where the bleaching agents are milder, vegetables do not completely disappear for the human eye after bleaching and need to be treated like colored foreign fibers. Therefore they have to be removed according to the quality needs. 9.4.1 Setting a clearing limit for vegetable matter (VEG) The built-in intelligence of USTER® QUANTUM 3 divides the vegetables into more or less disturbing events according to the end product requirements. This is expressed by the way of choosing close, medium and open setting. The USTER® QUANTUM 3 has a vegetable Clearing feature displaying a dense area and four differ-ent setting possibilities. These are named FD switched off, close, medium and open. The USTER® QUANTUM 3 also provides vegetable classification. Three clearing limit possibilities (close, medium, open) are always synchronized to the FD clearing limit. The difference between the FD and vegetable clearing results in cut savings.

• As FD: The vegetable clearing is switched off. (All the vegetables are classified as foreign matter and they are removed by using FD clearing limit.)

• Close: Only small vegetables remain in the yarn. Of course this will only result in a small saving of FD cuts.

• Medium: Small to medium vegetables remain in the yarn. This will reduce the number of FD cuts to a large extend.

• Open: Most of the vegetables remain in the yarn and the highest savings of cuts will be reached. The Vegetable Clearing is only available when using the capacitive clearer. The USTER® QUANTUM 3 provides Vegetable Clearing with a dense area and three setting possibili-ties.



Fig. 9-10 FD setting only

Fig. 9-11 Vegetable settings “close”

Fig. 9-12 Vegetable settings “medium”

Fig. 9-13 Vegetable settings “open”

Fig. 9-14 Vegetable settings “close”

Fig. 9-15 Vegetable settings “medium”

Fig. 9-16 Vegetable settings “open”

For each group or winding position the VEG events are displayed as individual dots on the classifica-tion matrix.

VEG clearing limit

Brown dots are remaining vegetables.

Dense area

Fig. 9-17 Display of the dense area and Vegetable Clearing curve. In the top right corner of the matrix the FD cuts saved are displayed.



Recommendations:

Generally, we are recommending using “medium” level, if the used raw material (cotton) contains vegetables. If the user is sure that the used raw material does not contain any vegetables, then the vegetable clearing feature should not be used. For other raw material types like synthetics or worsted yarns the use of this function is not recommended. Besides the clearing limit function, of course the foreign fiber (FD) and vegetable matter clearing (VEG) classification is a very powerful tool to minimize the number of cuts.

Fig. 9-18 Display of the limits for Vegetable Clearing. This Vegetable Clearing allows the saving of 15,2 cuts per 100 km.

9.5 Vegetable matters and their effect on the fabric appearance 9.5.1 Field test In this field test, an investigation about the contamination and its impact on yarns has been done. In order to realize the effect of the contamination on the final product, the after treatment processes of the yarn were simulated. For this field test, 100% medium staple Greek cotton was used. The contamination from the blow-room over a lot of seasons was collected and classified into categories according to their frequency and appearance characteristics. Then the contaminated samples together with cotton yarn were pre-bleached and bleached. The material after the treatment was analyzed under a microscope and pictures were taken.



The results of the survey had shown that more than 70% of the foreign material that had been found in the blow-room was decolorized with pre-bleaching including feathers, cotton plant residuals, col-ored cotton due to infection. The plastics or wool was not affected by bleaching. The vegetable resid-uals were not fully always decolorized but some of them remain of a yellowish shade after pre-bleaching. The majority of the colored contaminants were from the strings which have been used for cotton transportation and ginning and from fabrics (cloths).The non-affected material was inorganic material (Fig. 9-19 and Fig. 9-20).

Fig. 9-19 Effect of bleaching on foreign fibers. The inorganic foreign fibers hardly change the color.

Fig. 9-20 Effect of pre-bleaching on vegetable matter. Already after pre-bleaching most the vegetable fibers do not differ in color from normal cotton.



9.5.2 Reasons and measures to minimize vegetable matter in yarns In Table 9-1 and Table 9-2, the origin of the faults related to yarn contaminations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented.

VEGETABLE MATTER CONTAMINATION


Bale management Prefer – when possible – to use cotton with low content of foreign fibers and vegetable matter.


Optimize and control the settings and maintenance of the blowroom ma-chines

Cards Efficient carding and combing

Drawing frame Proper blending at all drawframes


Table 9-1

CONTAMINATION / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Quality control of foreign fibers and vegetable matter with USTER® TESTER when dealing with new raw material

USTER® QUANTUM CLEARER Proper setting of foreign fiber and vegetable matter detection



Table 9-2 Preventive measures and tools for the management of foreign fibers and vegetable matter

Detection of polypropylene fibers with USTER® QUANTUM 3 10


10 Detection of polypropylene fibers with USTER® QUANTUM 3 10.1 Introduction With the foreign fiber measuring method, only colored foreign fibers can be detected in a yarn. For-eign fibers consisting of polypropylene, however, are often white or without any color and are there-fore, hardly detectable with the foreign fiber detection principle because there is no color difference to cotton. Therefore, a new measuring principle was developed to find these foreign fibers. Polypropylene fibers are mostly stiff, ribbon-like fibers which often protrude from the yarn body (refer to Fig. 10-1). Polypropylene is used as a package material for cotton bales and as such the source of the contamination of cotton.

Fig. 10-1 Examples of PP fibers taken with a scanning electron microscope / OE rotor yarn As they are not found with the conventional foreign fiber detection, they are only detected after dyeing or finishing. Thus they first become visible in the finished woven or knitted fabric. A polypropylene fiber is shown in a raw fabric (Fig. 10-3) and after dyeing (Fig. 10-4). There are more and more complaints in the textile chain because of polypropylene fibers remaining in the fabric. The damages are enormous since many polypropylene fibers can only be detected in fin-ishing.

10 Detection of polypropylene fibers with USTER® QUANTUM 3


Fig. 10-2 Examples of polypropylene fibers / Optical microscope photography

Fig. 10-3 Polypropylene fiber in a knitted fabric before dyeing



Fig. 10-4 Polypropylene fibers in a knitted fabric after dyeing The fact that the PP fibers do not absorb dyestuff used for cotton will always lead to visible PP fibers in fabrics. The aim of the USTER polypropylene fiber detection development was not only to detect these white or translucent fibers, but also to be able to classify the length and the thickness reliably. A considerable part of cotton bales are embedded in polypropylene bags. If these bags are not han-dled carefully either after the ginning process, on transit or in the blow room of spinning mills, there is a high probability that polypropylene fibers contaminate the cotton. The USTER® QUANTUM 3 has a new, smart polypropylene (PP) clearing system. The clearer set-tings are very easy since the system proposes a smart limit which is a good starting point again at the touch of a button. This new smart clearing limit is different from the previous detection system. Fur-ther, the new USTER® QUANTUM 3 polypropylene clearing has no count, length or speed re-strictions. The system is also less affected by environmental conditions. The PP option is available for all capacitive clearers (C15 and C20). With the help of the USTER® QUANTUM 3 smart polypropyl-ene clearing, the user can detect very fine and short polypropylene fibers. 10.1.1 Configuration of a PP-clearer For polypropylene clearing the measuring head C15 or C20 can be used, with foreign fiber sensor and additional polypropylene feature. A software upgrade for PP clearing is not possible, as it requires hardware changes in the Central Clearing Unit (CCU) only.

Fig. 10-5

Configuration of a USTER® QUANTUM 3 with PP clearing / Required options / Clearer iMH C15F30 or C20F30



10.1.2 Frequency of PP fibers The PP fibers are much less common than colored foreign fibers. Trials have shown that the frequen-cy of PP fibers is about 5 – 20% compared to colored foreign fibers as a rough estimate. In the table below, there are experience values of the ratio of polypropylene cuts to the cuts of thin and thick places and conventional foreign fibers. It can be seen that even with additional cuts caused by the PP clearing, the clearing efficiency only changes insignificantly.

Reasons for splices Splices / 100 km

Table 10-1 Number of splices per 100 km, count Nec 30, 100% cotton, combed

Number of bobbin changes 34

Disturbing thin and thick places 30

Conventional foreign fibers 30

Polypropylene fibers 2

Total splices 96

Fig. 10-6 below shows the frequency of PP fibers taking into account the process (carded or combed) and the count of the yarn. It can be seen that the number of PP fibers decreases when a combing process is added and the yarn count becomes finer. In combing the stiff large PP fibers can be re-moved. The finer the count, the more short fibers are removed – thus more PP fibers can be eliminat-ed as well. On the ring spinning machine, PP fibers often lead to yarn breaks on medium and fine yarn counts since the PP fiber weakens the yarn. Furthermore, finer yarn counts have a smaller num-ber of fibers in the cross-section and, therefore, a PP fiber has a higher effect on the end break rate than on a coarse yarn. In a field trial carried out the number of detected PP fibers in carded yarns was by 38% higher compared to combed yarns (see Fig. 10-7 and Fig. 10-8). A PP fabric moving through the card shows up as a cluster of fine fibers in the card sliver. For a fine yarn the drawing ratio is much higher than for a coarse yarn. Therefore, the distance from PP fiber to PP fiber is higher and, therefore, the number of PP fibers in fine yarn is lower per unit length.

Fig. 10-6 Frequency of PP fibers in carded and combed cotton ring yarn (RSM = ring spinning machine)



To illustrate Fig. 10-6 above, the following trials were carried out in a 100% cotton spinning mill. PP fibers were extracted from a carded yarn, Nec 14, and from a combed yarn, Nec 20. For both materi-als the winding machine was running at the same speed of 1300 m/min. The same PP settings were used. In Fig. 10-7 one can see some of the big and stiff polypropylene fibers, which were removed on the winding machine from a carded yarn, Nec 14. Altogether 3.4 PP fibers were detected per 100 km.

Fig. 10-7 100% cotton, Nec 14, carded In Fig. 10-8 the polypropylene fibers, which were extracted from a combed yarn, Nec 20 can be seen. The PP clearer detected 2.1 PP fibers per 100 km.

Fig. 10-8 100% cotton, Nec 20, combed



It can also be observed that the PP fibers from the combed yarn are much finer than the PP fibers taken out of the carded yarn. This is due to the additional combing process which eliminates many coarse PP fibers. In Fig. 10-9, one can see PP fibers taken out of a compact yarn Nec 30. They are even finer than the ones shown in Fig. 10-7 and Fig. 10-8.

Fig. 10-9 100% cotton, Nec 30, compact yarn with PP fibers 10.1.3 Application range of PP-clearing, ring-spun yarn Yarn types At the moment, PP clearing can be used for 100% combed and carded cotton yarns, compact yarns included. iMH Types - All capacitive clearers C15 F30 and C20 F30 / The PP efficiency of C15F30 is higher

Count range – Same as the range for 100% cotton yarns for C15 and C20

Speed – No restriction

Length – No hard limit

Humidity range - No hard limit

Fig. 10-10 Count range of polypropylene detection



In Fig. 10-11, the yarn count frequency of ring-spun yarns produced worldwide is shown. It can be noticed that the entire count range is covered with PP clearing.

Fig. 10-11 Range of yarn counts produced worldwide, ring spun yarn. 10.2 Scatter plot The USTER® QUANTUM 3 interprets and displays the polypropylene characteristics with the help of a scatter plot. It is the graphic representation of the detected PP events within a classification matrix. Each event is marked with one dot. The vertical scale represents the visual appearance or intensity and the horizontal axis represents the vegetable fault length in cm. Fig. 10-12 shows a scatter plot with yarn faults as seen by the USTER® QUANTUM 3, with all the frequent events recorded (grey dots), the actual clearing limit and the area of the disturbing yarn faults (red dots).

Fig. 10-12 Frequent and seldom-occurring yarn faults. Measured yarn length: 2298 km The scatter plot also depends on the raw material. If a yarn is produced from cotton having a lot of polypropylene fibers the scatter plot will be denser with many dots, and a high number of cuts has to be expected.



Examples of various scatter plots

Fig. 10-13 Yarn Ne 40, 100% cotton, combed, knit-

ting, 1438 km. Low amount of PP fibers: 1,7 PP fibers per 100 km

Fig. 10-14 Yarn Ne 60, 100% cotton, combed, weaving, 1952 km. High amount of PP fibers: 7,2 PP fibers per 100 km

Fig. 10-15 Yarn Ne 40, 100% cotton, combed, com-

pact, 2298 km. Low amount of PP fibers: 3,2 PP fibers per 100 km

Fig. 10-16 Yarn Ne 60, 100% cotton, combed, compact, weaving, 2254 km. High amount of PP fibers: 6,6 PP fibers per 100 km



10.3 Clearing limits for polypropylene fibers 10.3.1 Standard way of optimizing clearing limits: Manual clearing limits entry Fig. 10-17 shows the clearing limit as shown in the setting window of the Central Clearing Unit (CCU). The USTER® QUANTUM 3 gives us the chance of determining our clearing limits by placing a maxi-mum of 8 set points PP1 to PP8. In Fig. 10-17, we can see 4 setting points (red rectangle) and the clearing limit for PP polypropylene. By this setting method the effects on the change of the parame-ters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we enter the values for PP1, set point PP2 will appear and it will continue the same way.

Fig. 10-17 Clearing limits on the screen of the control unit Set points have two parameters. These are: intensity (%) and reference length (cm). Intensity

The intensity (%) is a parameter for the clearing limits of the corresponding fault channel. The intensi-ty setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive). PP1 = 30%, Fig. 10-17. Reference length

The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive). PP1 = 0.4 cm, Fig. 10-17.



10.3.2 Setting a smart clearing limit for polypropylene fibers Polypropylene defects are very disturbing, especially in dark dyed fabric. With the PP option the USTER® QUANTUM 3 can detect white or colored polypropylene fibers coming from bale packing material and other sources. Polypropylene fiber contaminations are well visible as white fault after dyeing of the finished cloth because the polypropylene fiber doesn’t absorb cotton dyestuff. The PP feature detects polypropylene in cotton yarn during winding. But it is not just restricted to appearance issues. Similar to regular foreign fibers, polypropylene de-fects can also cause breaks in weaving preparation or on looms. Polypropylene elimination capability is slowly becoming a crucial flexibility for spinning mills to meet higher quality needs. Thanks to tech-nological improvements, the USTER® QUANTUM 3 has a high polypropylene detection rate and at the same time spends relatively less cuts to remove them. This has been proven with several field trials which have consistently shown a high removal efficiency of polypropylene including short and fine PP fibers with high cut efficiency. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the scatter plot and the events will appear. In order to see the scatter plot, the user should press the scatter plot key (Fig. 10-18). Besides the scatter plot, the cut faults and remaining events and the number of ex-pected fault cuts per 100 km can be seen on the screen. The used setting limits will appear directly on the same setting page (Fig. 10-18).

Pressing key presents • Scatter plot of the cut faults and re-

maining events. • Number of expected fault cuts / 100 km.

Clearing limit Red dots = cut yarn faults. Grey dots = remaining events.

= Proposes the starting point for

the clearing limits based on the body.

Fig. 10-18 Proposed setting is a starting point for optimization As soon as the button at the smart limit window is pressed, the yarn body and the expected cut figure per 100 km is displayed on the same setting page (Fig. 10-18). The sensitivity of the smart limit can be changed stepwise by pressing up and down keys, whereupon the limit moves away from or approaches the area of frequent events. At the same time, the new cal-culated setting point values appear in blue color. Every time this key is pressed, the limit moves fur-ther away or approaches the scatter plot, and the adapted setting limits are presented in blue color. Simultaneously, the expected cut figure is calculated based on the real yarn events.



The new setting point proposals

= Smart Limit 1 step less sensi-tive.

= Smart Limit 1 step more sensi-tive.

= Show scatter plot

= confirm and activate opti-mized clearing limit.


Fig. 10-19 Proposed setting is a starting point for optimization PP yarn faults are displayed together with all the other yarn faults of the machine, a group or a wind-ing position. It can be switched from absolute values to values per 100 km.

Fig. 10-20 PP yarn fault registration



10.4 Polypropylene fibers and their effect on the fabric appearance Polypropylene fibers can hardly be recognized in grey fabrics, because they cannot be distinguished from the point of view of color. However, they can easily be recognized after dyeing because polypro-pylene fibers do not absorb textile dyestuff. Polypropylene fibers cannot be recognized with sensors which need a difference in colour for a dis-tinction. Therefore, a particular sensor technology is used to eliminate polypropylene fibers. Fig. 10-21 and Fig. 10-22 show a white polypropylene fiber knitted into a turtleneck sweater. A con-siderable proportion of cotton bales are packed in white polypropylene bags. If these bags are not handled carefully, either after the ginning process, during transportation or in the blowroom of the spinning mill, there is a high probability that polypropylene fibers will contaminate the cotton. Such fibers are spun into yarns. White polypropylene fibers can hardly be recognized in grey fabrics, because they cannot be distin-guished from the point of view of color. However, they can easily be recognized after dyeing because polypropylene fibers do not absorb dyestuff (Fig. 10-21 and Fig. 10-22).

Fig. 10-21 White polypropylene fiber, turtleneck,

knitted / 100% cotton, combed, Nec 34 (17,5 tex)

Fig. 10-22 Magnified PP fiber in turtleneck



10.4.1 Reasons and measures to minimize foreign fibers in yarns In Table 10-2 and Table 10-3, the origin of the faults related to yarn contaminations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. CONTAMINATION

Origin of Faults Possible Reasons and Preventive Actions Bale management Prefer – when possible – to use cotton with low content of foreign fibers.

Sometimes spinning mills tend to create or intensify the contamination problem. A popular mistake is the use of plastic bags for the waste collec-tion and transportation inside the spinning mill. Particularly the use of polypropylene bags should be avoided.


Cards Efficient carding and combing Drawing frame Proper blending at all drawframes


Table 10-2 CONTAMINATION / USTER® Tools for Improvement

Tools Improvement

USTER® Testing off-line Quality control of foreign fibers with USTER® TESTER when dealing with new raw material

USTER® QUANTUM CLEARER Proper setting of foreign fiber detection



Table 10-3 Preventive measures and tools for the management of foreign fibers

Various settings and applications of USTER®QUANTUM 3 11


11 Various settings and applications of USTER®QUANTUM 3 Up to now, various smart features of the USTER® QUANTUM 3 have been explained with the help of different examples. At the beginning of this chapter, we would like to show the user some other smart and helpful applications which can be used in various comparisons and data evaluations. The last part of the chapter is focused on monitoring winding functions of the winding machine. 11.1 Comparison of different clearing limits and article settings 11.1.1 Comparison of various clearing limits The USTER® QUANTUM 3 gives the chance of comparing up to three different clearing limits on the same yarn body. These three limits are presented in Fig. 11-1, with different colours: Red = Active clearing limit for a yarn which is currently on the winder (Fig. 11-1)

C1, Dark blue = Clearing limit for a yarn which has a yarn count of Ne 34, Article name is Geneva (Curve 1 in Fig. 11-1)

C2, Light blue = Clearing limit for a yarn which has a yarn count of Ne 40, Article name is Sydney (Curve 2 in Fig. 11-1). As it can be seen in the example Fig. 11-1, the user can compare 2 various clearing limits with differ-ent names to his current clearing limit.

Article

Selection ofclearing channel

Display of theclearing limit from

2 other articles

Active clearing limit = redCurve 1 = dark blueCurve 2 = light blue

Selection of article

Fig. 11-1 Comparison of various clearing limits But there are also other usages. For example in Fig. 11-2, the comparison of two different settings of the same article is given. Before editing the current article setting (Changed-Training/Test/30.0 NeC), the user should make a copy of the article and give a different name. In this example, the new given name is “Training/Test/30.0 NeC” and can be seen in C1 area. After the modifications of the current article ' “Changed-Training/Test/30.0 NeC”, the user can detect the differences to the original settings (dark blue line, C1) very easily: With the help of this comparison the user will not use any production data and be switched to the original settings.

11 Various settings and applications of USTER®QUANTUM 3


Fig. 11-2 Comparison of current modified article settings to the original article settings Another application is the comparison of the current article to the chosen smart limit. In Fig. 11-3, the original article settings are given as Curve 1 with dark blue color.

Fig. 11-3 Comparison of the chosen smart limit to original article clearing limit



11.1.2 Recreate or recall of the factory settings of the default articles Up to version release 1.01.05, it is possible to recall the factory settings of the two default articles (ca-pacitive and optical default). To recreate the default article again, the user can select and copy any article by pressing 'Copy article' button. After that “create a new article” option should be chosen (Fig. 11-4, left) and confirmed. However it is also possible to reset an existing article to the factory default settings. For this, the user should choose the article that should be reset in the 'Copy to' selection box instead of creating a new article (Fig. 11-4, right).

Fig. 11-4 Recalling the factory settings of the default articles (capacitive (left)and optical (right)) 11.2 Display of Data and Alarms 11.2.1 Display of Data and Alarms with the help of bar graphs With the USTER® QUANTUM 3, it is possible to display the events occurring in the various evaluation channels by using data bar graphs. These are used for monitoring quality and finding the outliers and as aid for setting the clearing limits. There are various categories and related features and can be found under the “Display” main menu, in the machine summary page. These categories and features are given in Fig. 11-5.



Fig. 11-5 Machine summary categories and their features. Abbreviations: see Appendix, chapter 16.2.

Fig. 11-6 Machine summary submenu in the “Display” main menu



In Fig. 11-7, an example of these bar graphs is given. Here the category is “Yarn Faults YF” and fea-ture is YF (see Fig. 11-5). As it can be seen on Fig. 11-7, every group has its own mean value which is highlighted with a black horizontal line. The values can be displayed according to current data or last shift. The user can also select relative or absolute display values. By using these bar graphs it is very easy to compare various winding positions and find the outliers. However, because the scale is changing automatically, the user should also check both the actual value for a winding position and the mean value of the group before making decisions.

Red vertical line = selected winding position (here SP 6) SP = winding position (spindle) (Totally 50 winding positions are in production) Black horizontal line = average value of group (Mean value for group 1 = 146.06 /100 km)

Gr.no. = group in production (totally 3 groups are in production)

Fig. 11-7 Group settings of the winding machine 11.2.2 Display of Data and Alarms with the help of exception reports Another interesting and useful application is exception report. The user can define exception thresh-olds for the following event groups:

• Yarn fault total YF

• Yarn alarms YA

• Quality alarms QA

• Foreign fiber F

• Foreign fiber alarms FA

• Faulty splices J For the above mentioned event groups, the tolerances should be entered as +/- deviation in % of group average value and/or events per 100 km or absolute number of events as upper tolerance limit. In order to print out the values of all winding positions, “Print all SP” should be selected, otherwise only the values of the exception winding positions will be printed out. The lines in the report with all values = 0 will not be printed.



Fig. 11-8 Definition of exception report in the “Reports” main menu 11.2.3 Display of yarn faults with the help of textile alarms With the USTER® QUANTUM 3, it is possible to define and display textile alarm limits in the settings main menu. A textile alarm is triggered when the set number of yarn faults per reference length is reached. The winding position will be blocked and the iMH LED lights up continuously. The setting parameters are number of faults and the reference length in km.

Fig. 11-9 Definition of yarn fault alarms in the “Settings” main menu In the “textile alarms” submenu of the “Display” main menu, it is possible to display all yarn faults of the machine, a group or a winding position over the selected period. The values for the machine, for a group or for a winding position can be selected. Also various periods like current, current / last shift or current / last article can be chosen and displayed. The "current" counter is reset with

• Shift change

• Article change

• Clear counters of a group



Fig. 11-10 Textile alarms submenu in the “Display” main menu All textile and technical alarms which have occurred during operation are displayed in the “Alarms” function menu. In the textile alarms window (Fig. 11-11, left), consecutive winding positions with the same alarm are shown as a group. Textile alarms can be deleted either on the control unit or on the measuring head. In the technical alarms and warnings window (Fig. 11-11, right), each individual alarm is displayed with date and time and registered in the Service Logbook. Textile alarms and warnings can be deleted on the control unit.

Fig. 11-11 Textile alarms (left) and technical alarms and warnings (right) Explanation of textile alarm types:

Textile Alarm Quality Alarm Explanation of technical alarm and warning types:

Warning Technical Alarm



11.3 Collecting defects 11.3.1 Introduction To better understand defects Uster Technologies always recommends to put the fault on a black board (disturbing thick and thin places) and on a white board (foreign fibers). To make this easier the iMH-LED function can stop the winding position at a particular yarn defect type and the fault length, percentage and classification can be displayed on the event report of the Central Clearing Unit. 11.3.2 Event display by the red light at the sensor (iMH-LED) The two LEDs at the iMH are used for the display of textile and technical alarms. Furthermore, it is possible to show the status of the clearer installation, especially during a lot change or during start-up of the installation. In addition, the LED can be used for the display of cut events. This can be very helpful, when certain yarn faults should be removed for visual examination. After the setting of the corresponding function code at the Central Clearing Unit, the iMH-LED dis-plays the code as soon as the desired cut type is triggered. The LED can be deleted by pressing the iMH-button or it switches off automatically when the winding position is started again. On new winding machines, the winding position automatically switches to "test mode". This means, that the winding position will be stopped until it will be turned on again manually. This is valid for the following machine types:

• Schlafhorst AC-338

• Schlafhorst AC-5 and ACX5

• Murata PC-21

• Savio Espero

• Savio Orion

• Savio Polar

• Smaro The iMH LED display function can be assigned to the whole machine, one group or a range of wind-ing positions. When the programmed cut occurs:

• the iMH cuts

• iMH LED flashes according to the selection

• red winding position lamp lights up continuously. The user should enter the range and cut type for the 3 display variants. These are:



Fig. 11-12 iMH LED Display Function Explanation: The iMH-LED is turned on, when a N, FD or PP-cut is triggered. In the event report (Fig. 11-12, right), the yarn faults / cuts are also displayed showing the size / inten-sity in % and length in mm, as well as their classification. The events which should be displayed have to be selected in the Configuration Menu (Valid up to Release 1.01.05, for higher release numbers this will not be necessary anymore, Fig. 11-13, left). The selected events are displayed with date, time and winding position information (Fig. 11-13, right).

Fig. 11-13 Configuration menu (left) and Event Reports menu (right) 11.3.3 Yarn fault cards Yarn fault cards are an easy and very helpful instrument for the collection of yarn faults and their evaluation. The displayed yarn faults provide a very good impression about the existing faults. By means of the visualization the user can decide which faults can remain in the yarn and which faults have to be cut. This depends also on the final product.



Yarn fault cards have a white and a black side. For greige yarns the black side is used in order to document yarn faults like thick and thin places. The other side, i.e. the white side of the yarn fault card, is used for the documentation of foreign fibers and vegetable matter in the yarn. White polypro-pylene fibers should also be put on the black side. By this method, the yarn body disappears in the background and the foreign fibers and vegetables can easily be recognized. On top of the yarn fault card there is room for yarn, test and clearer identification. The information about the clearing limits are of special importance in order to be able to compare the results of future tests. Depending on the application, the following decisions can be made with the aid of yarn fault cards or they can serve to obtain more information:

• clearing limits can be better determined and optimized

• with every modification of the clearing limits the expected cuts can be determined in advance

• the quality of the current production can be controlled in accordance with textile aspects, i.e. with respect to the form of the yarn fault

To sum up, it can be said that yarn fault cards with documented faults together with the classification and the scatter plot serve as a basis to decide which clearer settings have to be chosen.

Fig. 11-14 USTER® yarn boards, thick places (left), foreign fibers (right) When collecting thick places (e.g. N and S defects) it is quite easy to see the defects in the yarn. For collecting the foreign fibers it is needed to use the white side of the board and make sure that there is enough light so that the defect can be seen in the yarn easily. Sometimes it appears that the defect, especially at low reflections e.g. 5 or 7% can hardly be seen under insufficient light conditions or even need the aid of a magnifying glass to see it. Therefore the yarn board always should be used as sup-port as shown in the examples, and, whenever possible, a magnifying glass. When the user has the advanced classification option, then tailored classes can also be used to inspect yarn fault within a length and amplitude range.

Yarn: Ne 30, 100% cotton, combed, bobbins Sensor: iMH C15F30 S-faults

Yarn: Ne 30, 100% cotton, combed, bobbins Sensor: iMH C15F30 FD-faults



11.4 Monitoring of winding functions On most modern winding machines, the monitoring of the yarn joint process is carried out by the yarn clearer. The functions of the clearer include the monitoring of the:

• Upper yarn (U)

• Splice (Joint, J)

• Yarn jump (JPM)

• Drum sensor (DSM)

• Drum wrap (DWM)

• Cut (CTM)

• Zero point (ZPM)

The display of the group settings can change according to the winding machine type. The following additional parameters can be seen on the display:

• Speed: manual winders only

• Startup time: manual winders only

• Don’t cut drum wrap (Orion (Polar only), Espero, Smaro, Spero

• DSM Drum Signal monitoring (most ma-chines)

• Don’t cut drum wrap (Orion (Polar only), Espero, Smaro, Spero

Fig. 11-15 Group settings of the winding machine Speed Setting of the winding speed (for manual winding machines only). Setting: Speed per group in m/min Length correction Correction factor to get correspondence between displayed and actual wound yarn length. Setting: The correction factor can be set for each group between 0.800 and 1.200 (+/- 20%). The correction factor has no influence on the set reference lengths of the clearing channels. Startup time The start-up time must be set to measure the fault length correctly on a manual winder during the start up acceleration. The start-up time represents the time between the winding position start until it has reached the nominal speed. Setting: 0.6, 1.2, 1.8, 2.4 and 3.0 s



JRA Splice failure rate alarm The splice failure rate in % is a relation between total splices and splice cuts (Jp + Jm). A textile alarm occurs and the LED of the sensor lights up if the relation exceeds the set JRA alarm limit. Setting: Alarm limit 0.0% to 100.0% Alarm limit: 0.0 = monitoring inactive Special monitoring functions Special monitoring can only be switched on and off using «Customer Service» access rights. If the special monitoring functions are activated they react as follows: ZPM Zero point monitoring (ZPM): If, during the splicing cycle, there is still yarn or fluff in the measuring zone despite the blow-out, then a ZPM event is counted but no zero adjustment made. Clean measur-ing zone. CTM Cut monitoring (CTM): If the iMH repeatedly detects running yarn after a cut then a technical alarm is triggered. Check cutting device. JPM Yarn jump monitoring (JPM): A cut is triggered if the yarn jumps out of the measuring zone for a mo-ment e.g. because of a large yarn fault. JPA Yarn jump alarm (JPA): A cut and an alarm is triggered if the yarn jumps out of the measuring zone 3 time per 1 km. The winding position is blocked and a textile alarm is displayed. Possible settings for JPM and JPA:

JPM JPA Effect at yarn jump

– – Yarn jumps are registered and counted.

X – A cut follows a yarn jump.

X X Cut, textile alarm with SP blocking (3 x JMP / 1 km).

Table 11-1 DSM Drum signal monitoring (DSM): A technical alarm is activated if the iMH does not receive a guide drum signal after the winding position starts up. Check guide drum sensor. DWM Drum wrap monitoring (DWM): DWM prevents the yarn from getting wrapped around the drum with a cut.



DWA Drum wrap alarm (DWA): DWA prevents the yarn from getting wrapped around the guide drum with a cut. At the same time a textile alarm is activated which blocks the winding position. “Don’t cut drum wrap” prevents loose pieces of yarn on ESPERO, ORION, POLAR, SMARO and SPERO winder.

DWM DWA Don’t cut DW Effect at danger of drum wrap

– – – Drum wraps are registered and counted.

X – – Cut at drum wrap

X – X Espero, Orion, Polar, Smaro and Spero: Wind-ing machine stops without cut. Other machines: not available.

X X – Cut, textile alarm with SP blocking

Table 11-2

Fig. 11-16 Display of the group setting of the winding machine



11.4.1 Monitoring of the yarn joint process with the USTER® QUANTUM 3 The monitoring of the yarn joint process by the clearer is carried out according to the splicing process of the winding position (Please see Chapter 5). The individual steps are: Monitoring of the upper thread (U)

If double or even multiple yarns are coming from the cone, the cutter has to be triggered. → U-channel with setting of U% U-channel for upper threads (U)

The monitoring of the upper thread is only possible on machines on which the upper thread runs through the clearer measuring field before splicing. The U-channel prevents that an upper thread (yarn end removed from the cone) is joined as a double thread or as a loop with the yarn which is drawn off from the bobbin. Therefore, the upper thread is checked when putting it into the measuring field. With a correct setting of the U-channel, any upper thread which is drawn in as a double or multi-ple thread, will be cut. 11.4.2 Monitoring of the settings All the settings should be adjusted according to the produced yarn, especially after putting into opera-tion of the machine. This coordination helps to avoid surprises afterwards. Monitoring of the settings for the upper yarn detection

With the chosen setting U, a double yarn removed from the cone must always be cut. This can be checked with a prepared cone with double yarn or with suctioning off an additional yarn from a bob-bin. The setting is correct, when all double yarns are cut. Single yarns should not be cut. Incorrect detection of single yarns as double threads should not be higher than 1 to 2%. Monitoring of the yarn joint setting

With the chosen setting Jp and the corresponding length a good quality joint should not be cut. The checking is done best with a double yarn from the cone side. During this procedure, the U-channel has to be switched off (U = 0%). Therefore, Jp has to be set rather sensitive. It has to be pointed out that the set length does not have to correspond with the actual yarn joint. 11.4.3 Splice classification Up until now, visual checks of the splice were carried out in periodic intervals with random samples. This is also recommended by the machine manufacturers. However, this check is very time-consuming.



In order to make this procedure of the splice control easier, the USTER® QUANTUM 3 splice classifi-cation was introduced. During the measurement, the values are recorded and displayed as a scatter plot in the classification matrix (Fig. 11-17). The classifications of each single winding position can be looked at separately, in order to be able to find the winding positions at which the splice formation does not meet the quality requirements.

Fig. 11-17 Scatter plot with splice classification 11.4.4 Yarn jump monitoring (JPM, JPA) JPM A hard yarn fault, like for example attached fiber balls or a yarn loop, can cause a significant increase of the yarn tension at a deflection point. The subsequent slackening of the yarn can cause the yarn to jump out of the clearer measuring field. With other words: a hard yarn fault can jump out of the meas-uring field and thus will not be monitored. With the yarn jump monitoring function a cut is triggered as soon as the yarn is out of the measuring field and a 100% monitoring cannot be guaranteed anymore. JPM-cuts are mainly caused by yarn faults. In principle, JPM-cuts should, therefore, be considered as yarn fault cuts. JPM-cuts can also be caused by a very unstable yarn movement. Our recommendation: Turn on function „Yarn jump monitoring“.



JPA If the function JPA is turned on, a textile alarm is triggered for every JPM-cut which blocks the respec-tive winding position 11.4.5 Drum signal monitoring (DSM) Winding machines with a guide drum signal generate a certain number of pulses per revolution of the drum. These pulses are used to calculate the yarn speed and the length of yarn faults. Without a guide drum signal, yarn clearing is not possible on those winding machines. If no guide drum signal is provided within approx. 5 seconds after the start of the winding position or if the clearer detects a failure of the guide drum signal, a DSM-cut and an alarm is triggered by the clearer. This means, that the clearer gets no yarn speed information. If the DSM monitoring is turned off, the drum signal will not be monitored and the yarn clearing might not be guaranteed. Our recommendation: Turn on function “Drum signal monitoring DSM“. 11.4.6 Drum wrap monitoring (DWM, DWA) DWM A drum wrap can occur, when the yarn breaks in the guide drum during traversing. After the break, the yarn usually stops briefly in the guide drum as well as in the measuring field. A drum wrap occurs when the yarn is subsequently wound onto the guide drum. The dynamic yarn detector (DYD) detects the brief stoppage of the yarn. The DYD is switched-off, which results in a DWM-cut and prevents a drum wrap. Practical experience has shown that this is mostly the case. But drum wraps can also happen for other reasons (sticking of the splice to the drum) and therefore, not all drum wraps can be avoided with this monitoring function. If the DWM monitoring is turned off, drum wraps cannot be avoided by the clearer. Some machine manufacturers also offer their own drum wrap monitoring. Our recommendation: Turn on function “Drum wrap monitoring DWM”. Don't cut drum wrap

If the function “Don't cut drum wrap” is activated (Espero, Orion, Polar, Smaro, Spero), the winding position will only be stopped, but no cut is triggered. This can avoid free flying yarn pieces. Our recommendation: Turn on function “Don't cut drum wrap”.



DWA The drum wrap alarm prevents the yarn wraps around the drum by a cut. At the same time, a textile alarm is triggered which will block the winding position. Our recommendation: Turn off function “Drum wrap alarm DWA”. 11.4.7 Cut monitoring CTM With CTM monitoring, it is checked, if the yarn has been separated after a cut. If the cut fails repeat-edly, a CTM alarm is triggered. If the CTM monitoring is turned off, the clearer cuts are not monitored. Our recommendation: Turn on the function “Cut monitoring”. 11.4.8 Zero point monitoring ZPM During splicing of a winding position, the clearer adjusts itself when the measuring field is empty. De-viations from zero are adjusted to zero again. The measuring field must be empty for this procedure. If this adjustment is carried out while the measuring field is not empty, the zero point would not be set correctly and wrong measurements could occur. With the zero point monitoring ZPM turned on, the condition of the measuring field is monitored during the zero point adjustment. In this case, the zero point adjustment is only carried out with an empty measuring field. If the ZPM is turned off, a zero point adjustment is carried out, even if the measuring field is not empty and also in case of a piece of yarn remaining in the measuring field. If the piece of yarn falls out of the measuring field during the adjustment cycle, the yarn clearer does not recognize the laid-in upper yarn. This can have the effect, that:

• a double yarn cannot be recognized as such and thus, will be wound on the cone

• a normal yarn cannot be recognized with the consequence, that a new cycle is started, although no yarn is laid into the measuring zone.

Our recommendation: Turn on the function “Zero point monitoring ZPM“.

Clearing of slub yarns 12


12. Clearing of special yarns 12.1 Introduction to fancy yarns Fancy yarns are used in the textile industry for various applications. Therefore, fancy yarn manufac-turing is not a niche market anymore. Up until now, it was not possible to determine the quality char-acteristics of fancy yarns in detail which are needed for a quality management. This can be done in the laboratory with the USTER® TESTER 5. An accurate determination of slub yarn characteristics is also required for negotiations and specifica-tions between fancy yarn spinners and weavers, knitters, traders and retailers. 12.2 Clearing of fancy yarns Slubs, neps, thick and thin places are noted as yarn faults and are considered as degrading features of yarn quality. During various processes, efforts are taken to minimize their occurrence. However, in fancy yarn production these features are introduced in the yarn in order to give visually attractive dif-ferences to the other fabrics [1]. Fancy Yarn is a yarn that differs from the normal construction of single and ply yarns by way of delib-erately produced irregularities from the normal construction. These irregularities relate to an increased input of one or more of its components, or to the inclusion of random effects, such as knops, loops, curls, slubs, or the like. [6] There are various names which are used to describe the different yarn effects. Table 12-1 shows eight basic profiles of fancy yarns. These yarn effects can be made by plying a number of yarns to-gether or, with modified spinning techniques, most can be spun from sliver or roving [1]. Basic yarn profile Designations

Spiral Mock spiral, mouline, jaspe

Gimp Frise, caterpillar, onde

Slub Ground slub, injected slub, injected flame (also called tear- off flame)

Knop Knot, nep, noppe, button, reverse caterpillar, flake

Loop Boucle, frotte, pong, mock-spun chenille

Cover Twisted flame

Chenille Woven chenille, plied chenille

Snarl

Table 12-1 Various fancy yarns [1]

12 Clearing of slub yarns


Fig. 12-1 Examples of effect twist fancy yarns [1] There are also several classifications for fancy yarns. Table 12-1 gives one of these classifications according to the employed production methods. Here mainly two production methods are employed: Produced effects are based on twisting or doubling of yarns together to create the fancy yarn effect from already spun yarns. Spun-effect yarns are fancy yarns spun directly from fibers fed to the spin-ning system [1].



Yarn (produced) effects Spun yarn effects

Regular effects Controlled discontinu-ous effect Regular effects Controlled

discontinuous effect

Spiral Reverse caterpillar Spiral Button

Mouline Neps Mouline Slub

Loop Knots Loop Caterpillar

Boucle Knop Boucle Combinations

Gimp Slub Gimp

Onde Onde

Snarl Chenille

Cover

Chenille

Table 12-2 Classification of fancy yarns [1] If fancy yarns have to be cleared on winding machines, the following recommendations have to be taken into consideration: All the fancy yarns have a regular pattern (pseudo-random formation). If faults occur, the regular pat-tern is disturbed and can be recognized in the scatter plot (Yarn Body Clearing). Such faults can be eliminated accordingly. In this chapter we will concentrate mainly on slub yarns. 12.3 Clearing of slub yarns A slub yarn is a yarn in which slubs may be created to produce a desired effect. Generally, slub yarns are divided into two classes: (i) spun slubs, and (ii) plucked (or inserted) slubs. Spun slubs may be produced by an intermittent acceleration of one pair of rollers during spinning or by the blending of fibers of different dimensions. Plucked slub yarns are composed of two foundation threads and short lengths of straight-fiber materials that have been plucked from a twistless roving by roller action [6]. As the range of applications is very wide for slub yarns, there are also different types of slub yarns. They are usually called slub yarns, multicount yarns and multitwist yarns.



Table 12-3 below explains the differences between these three yarn types. Term Twist αe Mass Slub length

Slub yarn constant variable variable Any length up to 2 meters

Multicount variable constant variable Any length over 2 meters

Multitwist variable variable constant any

Table 12-3 Definition of different slub yarn types It is also possible to distinguish between structured slub yarns and slub yarns with distinctive slubs. Structured yarns can be characterized as very uneven yarns without any clear slubs. Fig. 12-2 shows an example of a distinctive slub yarn on a blackboard.

Fig. 12-2 Slub yarn with short slubs on a blackboard Setting of a clearing limits for slub yarns

With the USTER® QUANTUM 3, there is a special setting for slub yarns. For this, we can use the ra-dio buttons to switch from NSL thick places to Slub Yarn settings window. The aim of this feature is to define the clearing limit to prevent the clearing of desired thick places in slub yarn. The events in the defined slub area should not be cut because this is a characteristic of the yarn. In order to clear slubs, instead of standard setting points P, we have the special setting points K1 to K3 to zone out areas where slubs should not be cut. For example: Set point K1 = 700% / from 10.0 cm to 25.0 cm. This means the slubs between 10.0 and 25.0 cm are not cut.



It is possible to assign up to 3 K areas where slubs should not be cut Fig. 12-3.

Fig. 12-3 Slub yarn setting. No clearer cuts up to +700% from 10 to 25 cm. Characteristic yarn faults in slub yarns

The clearing of slub yarns should achieve the following: Specifically generated "thick places" should remain in the yarn, disturbing yarn faults have to be cleared. Slub yarns consist of at least 2 single yarns, i.e. if one of them is missing, the yarn clearer has to de-tect this. The existence of each single yarn has to be monitored. Faults in the single yarns have to be eliminated, in order to avoid any unevenness in woven or knitted fabric. 12.4 Clearing of yarns with nep or loop effects Fundamentally, it can be said:

• The desired effect has to be monitored. If the effect is missing, a cut has to follow.

• Each single yarn of the ply yarn has to be monitored.

• Possible yarn faults in the single yarn must be monitored.

Fig. 12-4 Yarn fault in a bouclé yarn



In summary, it can be said, that all irregularities of the visual impression of the end product have to be monitored. 12.5 Melange yarns Melange yarns are produced by blending a certain percentage of fibers of different colors. Blending can be done in a very early stage of the process. This means, for example, mixing of multi-colored fibers in the opening line, feeding of slivers of different colors at the drawframe or directly at the spin-ning machine. Characteristic yarn faults in melange yarns

For melange yarns it is of particular importance that the blending effect, i.e. the blend of multicolored fibers is as regular as possible. If too many fibers of one component are missing, it is possible that stripes of a particular color occur in the end product.

Fig. 12-5 Melange yarn / Blending problems / Blend of black and white fibers 100% cot-ton, Ne 30 (20 tex), OE rotor

Fig. 12-6 Melange yarn / Blending problems

Choice of the measuring head

It is not possible to monitor uneven color effects with a capacitive measuring head. The increase or decrease of one fiber component is less than the normal mass unevenness of a yarn. With the USTER® QUANTUM 3 iMH-O30, it is possible to monitor the proportion of blending. For the clearing of long color deviations, it is necessary to set the CC-channel accordingly. The de-fined length must correlate with the expected fault length. If necessary, the set length must be short-ened and the diameter must be increased in 2%-steps.



12.6 Core yarn Core yarns are usually made of a filament core and a cover yarn made out of staple fibers. The main problem with core yarns (with respect to yarn clearing) is the detection of the missing core. When a core is missing, it causes a marginal change in diameter however it causes a higher change in mass. The capacitive clearer has, therefore, an advantage for this application. The change in mass is pro-portional to the fineness of the core. The USTER® QUANTUM 3 has a new capacitive sensor technology which has an even better signal ratio and therefore a higher possibility to detect the missing core. The detection is mainly possible when the change in mass due to the missing core is higher than 5-6%. Clearing of core yarns (CY)

Core yarn monitoring; detects the break of the core while yarn is running. A cut takes place if the cov-er thread is missing and at yarn break. The setting parameters are: Tolerated decrease in %. This setting is only active when the yarn type is core yarn. Sensitivity: 0% = Clearing channel inactive

Fig. 12-7 Core yarn setting (CY) A missing core can only be detected if the mass of the core is at least 13% of the entire yarn mass. Clearing of a yarn with missing cover

Besides normal thick places, a missing cover is also disturbing. Therefore, a partly or completely missing cover must be monitored. In case of sewing threads, a classification of short neps is required. Neps are considered as disturb-ing events if they are occurring in high numbers. The frequency of such neps is an indicator for the running behavior of the yarn on the sewing machine.

The first hour at the new clearer system 13


13 The first hour at the new clearer system 13.1 Introduction The USTER® QUANTUM 3 is the successor of the USTER® QUANTUM 2. With this new generation of yarn clearers, the user has various smart tools in finding the optimum solutions in yarn clearing. The new USTER® QUANTUM 3 is focused on simplifying the complexities of yarn clearing and there-by enables the user to easily and fully exploit all clearer capabilities and to optimize production costs every day. The USTER® QUANTUM 3 interprets and displays the yarn characteristics in minutes and proposes a starting position for clearing limits with a cut forecast by pressing a single button. We have prepared this chapter as a quick reference for the setting of the most important features of the USTER® QUANTUM 3. This chapter is targeted on the one hand at new and inexperienced users and, on the other hand, it is also relevant to everyone who is already experienced in yarn clearing and would like to learn the new features of USTER® QUANTUM 3. We believe that with the combination of Uster Technologies’ know-how with smart, reliable and mod-ern technology, the user will be able to deliver significantly better yarn quality and post spinning per-formance while most likely maintaining productivity. 13.2 Short description of the settings This chapter is a quick reference for the setting of the most important features of the USTER® QUAN-TUM 3. One page is dedicated for each feature (pages 13.4 to 13.16). The setting procedures are shown graphically. Create and start an article Whenever the article on the winding machine has to be changed, the designation of the article has to be made first. Page 13.3 shows what kind of steps have to be taken for a new article. Setting a smart clearing limit for disturbing thick places (NSL) and thin places (T) Page 13.4 shows the selection of the optimum clearing curve for thick and thin places. For a few se-conds or minutes the yarn runs with the default clearing curve. After this period the operator can see the yarn body on the screen. Now the clearing curve can be optimized either by moving the clearing curve up or down. The setting can be fixed by pressing the “confirm” button. Setting of Periodic Faults (PF) Page 13.5 shows the settings for periodic faults. Setting a smart clearing limit for dark foreign matter (FD) Page 13.6 shows the setting of the optimum clearing curve for the elimination of foreign matter.

13 The first hour at the new clearer system


Setting a clearing limit for foreign mater (FD) with Vegetable Clearing (VEG) Page 13.7 shows the setting of the clearing curve for the Vegetable Clearing curve. With the setting of the Vegetable Clearing curve there are opportunities to the lower number of cuts per unit length, be-cause most of the vegetables cannot be seen after bleaching. Setting a smart clearing limit for Polypropylene Clearing (PP) Page 13.8 shows the setting of the clearing curve for polypropylene clearing. Polypropylene detection is significantly more difficult than the detection of colored fibers in white yarns because the color of polypropylene hardly differs from the color of yarn. Setting a clearing limit for count deviation clearing (C) Page 13.9 shows the clearing of count variations in the length category 2 to 12 m. The count varia-tions particularly serve for the recognition of wrong bobbins. Setting a smart clearing limit for count monitoring clearing (CC) Page 13.10 shows the steps to be taken to monitor the count deviation of the yarn during the entire operation. The settings are also made between 2 and 12 m. Setting a clearing limit for Splice Clearing (Jm /Jp) Page 13.11 demonstrates how the clearing limits can be set for splices. If bad or faulty splice is locat-ed above the splice clearing limit, the splice is eliminated and replaced by a better splice. Setting of Q Parameters: Yarn Evenness (CV) The evenness CVm belongs to the most important quality characteristics of yarns. The reference length is selectable. Alarm limits are available for every single measurement as well as for the group average / mean value. The procedure is shown on page 13.12. Setting of Q Parameters: Hairiness (H) Page 13.13 shows the settings for hairiness. The reference length is selectable. Alarm limits are available for every single measurement as well as for the group average / mean value. Setting of Q Parameters: Imperfections (IP) Page 13.14 demonstrates the steps to be taken to set the sensitivity and the alarm limits for frequent thick places, thin places and neps. Outlier bobbins can also be detected and eliminated. Setting of Q Parameters: Class Alarm Page 13.15 explains the settings for class alarm. It is an option to set alarm limits for up to 5 individual class of the Classimat matrix. Setting of Q Parameters: Tailored Classes Page 13.16 shows how mill-specific classes can be selected, if required.

Frequently asked questions 14


14 Frequently asked questions This paper was written to answer the questions which are asked frequently by our customers. 14.1 Product related questions 14.1.1 What type of sensing principles does USTER® QUANTUM 3 offer? USTER® QUANTUM 3 offers the choice of optical and capacitive sensing technologies for basic clear-ing. The foreign matter option can be added on top of the basic capacitive or optical clearing. The available measuring head types are:

• Capacitive – C15, C20

• Optical – O30

• Foreign matter – C15 F30, C20 F30 or O30 F30 * *PP is an option to the C15F30, C20F30 and O30F30 measuring head see also 15-2. 14.1.2 How does the USTER® QUANTUM 3 differ from competing products? The USTER® QUANTUM 2 was until now the market leader and the benchmark for high performance yarn clearing. The USTER® QUANTUM 3, the successor, takes yarn clearing to a next level. The sys-tem was designed bearing the needs of a range of requirements starting from basic users to the most sophisticated demands. It incorporates futuristic technology while at the same time being robust to withstand the challenging mill environment. The core of the USTER® QUANTUM is its smart clearing technology. It helps to eliminate the basic and most important challenge for spinners which is the definition of the optimum clearing limit for a variety of yarns with differing quality needs. USTER® QUANTUM 3 has simplified the complexities of yarn clearing and enables valued users to easily and fully exploit all clearer capabilities, every day. The system learns and displays the yarn body (nominal yarn with its set of tolerable frequently occur-ring yarn faults) in minutes and at the press of a button proposes a starting point for clearing limits with a cut forecast. Practically this is equivalent to having an USTER® specialist always beside to achieve the optimum results out of any yarn application. The new USTER® QUANTUM 3 will also amaze you with its speed and ease of use. In just two minutes, it will learn everything it needs to know about your yarn. Then, applying USTER® knowhow it will suggest the best way to achieve the quality requirements you specify, by proposing suitable clearing limits. You now only need to approve and hit the START button The USTER® QUANTUM 3 with its new foreign matter clearing concept also sets a new benchmark for contamination control.

• The new sensor technology is able to see all colors of foreign fibers and separates them into dis-turbing foreign fibers and mostly non disturbing vegetables to enable maximum removal of foreign fibers with minimal cuts.

Polypropylene detection is another key highlight. Founded on the new capacitive sensor technology, USTER® QUANTUM 3 sets a new benchmark for PP removal.

14 Frequently asked questions


In summary the USTER® QUANTUM 3 is the most robust and technologically advanced knowledge integrated clearer ideally suited to today’s market needs, far ahead of any competing products. 14.1.3 What are the main new functions of the USTER® QUANTUM 3? USTER® QUANTUM 3 offers a host of new innovative features such as: Smart clearing

• Display of the real yarn body to ensure appropriate clearing limits at the lowest possible cuts

• Fast and easy setup of appropriate clearing limits - One button proposal for clearing limits con-sidering the yarn body and requirements as a starting point for optimization

• Easy selection of the appropriate clearing limit with open and close buttons

• Cut forecast for the selected clearing limit Smart count clearing

• Detection and elimination of bobbins with wrong counts

• Detection and elimination of short term mass/diameter variations of length ranging from 2 m to 12 m having a major negative impact on fabric appearance

Detection of periodic defects (spectrogram peaks) of multiple wavelengths Advanced splice clearing

• Synchronized to clearing limits to ensure safe quality

• Scatter plot and numeric classification of splices to identify and eliminate rogue splicers. JRA (splice failure ratio alarm) is a perfect feature to find rogue splicers.

Foreign Matter clearing

• Detection of all colors of foreign fibers using multiple light sources

• New foreign fiber clearing concept separating foreign matter into foreign fibers and vegetable matter. This allows the most effective and economic removal of disturbing foreign fibers ever.

Next generation of Polypropylene detection with a higher removal efficiency of PP including small PP at high cut efficiency. A new faster control clearing unit with the latest generation touch screen and an ergonomic interface The next generation Expert system with a host of smart features – The USTER® QUANTUM EXPERT 3.



14.1.4 What are the new quality parameters measured by the USTER® QUANTUM 3? The USTER® QUANTUM 3 detects short, fine thick and thin places in new classes – see picture be-low.

Fig. 14-1 Designation of the thick and thin places classes Short count variations (CC) of multiple cut lengths i.e. 2 m to 12 m (For comparison: USTER® QUAN-TUM 2 – only one cut length) Periodic faults of multiple wavelengths All colors of foreign fibers including those with very low contrast or reflectance

Fig. 14-2 Designation of the foreign fiber and vegetable classes Even small Polypropylene defects As always the quality data is on the same basis as the established Uster laboratory instruments



14.1.5 What is the yarn count range of USTER® QUANTUM 3 and which sensing method will fulfill the quality requirement?

The USTER® QUANTUM 3 yarn count range is extended compared to the USTER® QUANTUM 2 and can be used for all staple fiber yarns from Nec 3 – Nec 200 / Tex 200 – Tex 2.9. The choice of either an optical or a capacitive sensor gives the widest application range. USTER® will assist you in the choice of sensing method best for your quality requirements. 14.1.6 What is new with the USTER® QUANTUM 3 optical basic clearer? USTER® QUANTUM 3 comes with complete new sensor technology for all sensors including the opti-cal basic clearing. The new optical sensor is able to see the complete yarn body and suggest clearing limits for all applications. In addition to the advanced short thick place detection, the system has new algorithms for detection of long thick and thin places and also offers the new advanced count and CC channel to detect short term diameter variations from 2 m to 12 m. Splice clearing is taken to the next level with USTER® QUANTUM 3 and the classification (numeric and graphic) is offered with the new optical clearer. As with USTER® QUANTUM 2, Q Data monitors all quality parameters such as CV, Imperfections and classification on the same basis as a the laboratory. 14.1.7 What is the difference to UQC2 Vegetable Filter? The USTER® QUANTUM 3 separates foreign matter into three pools. It provides online classification of foreign fibers (FD and FL) as before and for the first time Vegetable Matter Classification. Users can see the amount of vegetables illustrated as dense areas or from the numeric vegetable classifica-tion matrix for different cotton varieties. Another innovation is that the system provides a choice of four different clearing limit possibilities for vegetables. With this the users can choose the level of vegetable clearing needed depending on the end use. 14.1.8 What is the advantage of the USTER® QUANTUM 3 for core yarns? The main problem with core yarns (with respect to yarn clearing) is the detection of the missing core. When a core is missing, it causes a marginal change in diameter however it causes a higher change in mass. The capacitive clearer has therefore an advantage for this application. The change in mass is proportional to the fineness of the core. The USTER® QUANTUM 3 has a new capacitive sensor technology which has an even better signal ratio and therefore a higher possibility to detect the missing core. The detection is mainly possible when the change in mass due to the missing core is greater than 5-6%.



14.1.9 What is the benefit of slub yarn setting in USTER® QUANTUM 3? The USTER® QUANTUM 3 clearing concept based on yarn body helps to easily define the bounda-ries for clearing disturbing defects in such yarns while retaining the slubs produced on purpose. The K-point setting will easily help to keep these purposely produced slubs away from clearing. All other defects, which might disturb the fabric appearance, can be taken out. 14.1.10 How is the PP performance of the new clearer? The USTER® QUANTUM 3 PP clearing is based on the newest sensor technology. The new PP sensor has high detection efficiency with a high cut accuracy resulting in reduction of disturbing PP in the fabric like never before. The illustration by means of the scatter plot enables to choose or fine tune the clearing limits in an easy and reliable way. 14.1.11 How are the repair costs of USTER® QUANTUM 3? USTER® products always offer high reliability and accuracy. The USTER® QUANTUM 3 also delivers on this promise. Building on the proven USTER® QUANTUM 2, the USTER® QUANTUM 3 is a tough, robust clearer which will need less maintenance and repairs and therefore lower running costs. 14.1.12 What are the advantages from a maintenance point of view? The USTER® QUANTUM 3 has a mechanical design that reduces maintenance. The foreign matter sensor is taller and wider with stable yarn path. This result in less dirt deposits and therefore needs far lower cleaning than conventional clearers. This has been proven in extensive tests in challenging environments. The electronic assembly is better shielded to prevent dust and dirt and is also better decompled from the vibrations of the cutter. This ensures higher performance stability and the enhanced lifecycle. As a result of the above, users can expect a long lasting, less maintenance demanding clearer with solid performance. 14.1.13 Can the USTER® QUANTUM 3 is installed be winders of previous generations? USTER® QUANTUM 3 with its versatile design can also be used for retrofits on older automatic wind-ers. Please refer to the Technical Data Sheet on www.uster.com to see the list of winder models. Our sales organization will be glad to assist you in all respects.



14.1.14 Why does the USTER® QUANTUM 3 have a bigger housing? USTER® QUANTUM 3 is USTER’s biggest clearer to date - quite simply to fit all new robust technolo-gy. Tough on the outside, it’s completely newly designed to stand up to the most demanding mill envi-ronments and provide a long life. Like a better sealed clearer core which keeps out dirt and dust, rein-forced sensors, which can cope with vibration, thermal stability etc. The new air blowing arrangements reduces dirt build-up of the sensor from both the yarn and the air supply. These QUANTUM 3’s innovations will help the clearer to work better, last longer and need less cleaning and maintenance. Another major reason is the new sensor design. The capacitive sensor; optical sensor and the foreign matter sensor all occupy more space for better performance. The foreign matter sensor for example is higher and wider than before, which reduces dirt deposits and therefore needs less cleaning and maintenance. 14.1.15 What is the purpose of the arrow LEDs on the measuring head? The LEDs as in the case of USTER® QUANTUM 2 are used to display textile or technical alarms. In case of a textile alarm – both arrows light up and in the case of a technical alarm both LEDs blink con-tinuously The arrow LEDs is also used in the test mode to collect defects. Each arrow LED can be programmed for a specific fault type. Please refer to the operating instructions for more details about the several possibilities with the test mode – called the iMH LED function. 14.2 Application related questions 14.2.1 What kind of yarn clearer do I need for my application? It depends on the type of application. Only Uster Technologies offers the knowledge and possibility of the best capacitive and optical clearer for the monitoring and elimination of seldom-occurring thick and thin places. Both types are available with the possibility of optical clearing for foreign fiber elimi-nation. The sales staff and specialists of Uster Technologies can help you to select the best option for your application. 14.2.2 How is it possible to simplify the definition of clearing limits? With the USTER® QUANTUM 3 Uster Technologies has developed a completely new, easy and cus-tomer oriented way of setting the clearing limits. At first the system can be started up with existing clearing limits. After a couple of minutes of produc-tion, the USTER® QUANTUM 3 analyzes the yarn and proposes smart clearing limits as a starting point for optimization . The smart limits proposed consider the yarn body and the limits. For each smart limit the system provides a forecast of the number of cuts to be expected.



In case the clearing limit proposal is not consistent with the end user requirements, users can choose to open or close the setting easily with the open/close buttons or of course manually enter the set-tings. 14.2.3 How can one find the optimal setting for basic clearing? Is it the same as before? With the USTER® QUANTUM 3, finding the optimal setting is easier and faster like never before. After evaluating the yarn over a few kilometers, the system proposes an optimum starting point for the clearing limits considering the yarn body, experience and requirements. At the same time the system predicts the number of cuts per 100 km to be expected for the defined limit. This is available at the touch of a button. In case the default starting point has to be changed for some reasons, users can simply choose from a range of closer or more open limits each time looking at the cuts that should be expected for the setting. Thus the optimum setting is based on the smart limits within a short time According to the quality level of the end user required, the settings can be selected more open or close. 14.2.4 What is the best basic setting for my yarn? The best setting is a compromise between quality and productivity. The USTER® QUANTUM 3 pro-poses an optimal starting point after a couple of minutes of production. This setting fulfils most end user needs. 14.2.5 How can one find the optimum setting for good fabric appearance and for optimum

productivity? The new unique feature of the yarn body display is showing the real characteristic of the yarn for the first time. After just 30 km of yarn running, the yarn body is illustrated and optimization can already be started. If higher accuracy of cut prediction is sought one can wait for 100 km. The smart limit proposal based on the yarn body analysis and USTER® experience will ensure that the clearing will result in no major defects left and good fabric appearance. 14.2.6 Which setting shall I use to make sure that no Classimat objectionable faults will re-

main? The scatter plot and the yarn body are displayed according to the classes. The USTER® QUANTUM 3 considers objectionable faults according to Classimat as a criterion when proposing clearing limits. Where needed, the clearing limits can be easily adopted manually to ensure that no major defects will remain in the yarn (to date).



14.2.7 What is the USTER® QUANTUM 3 advantage with respect to compact yarns? The USTER® QUANTUM 3 offers major advantages for compact spinners. Compact yarns are very even, and small defects can be disturbing in the fabric. USTER® QUANTUM 3 shows the complete yarn body and hence it is possible to clearly identify and remove the outliers even if they are small and fine. At the same time the unjustified cuts are minimized. Since yarn faults can easily be recog-nized by the human eye due to missing hairiness, the USTER® QUANTUM 3 is particularly suitable to detect small faults. Therefore the USTER® QUANTUM 3 is the most powerful clearer for compact yarns. Trials with different compact yarn producers have shown that the fabric produced out of USTER® QUANTUM 3 cleared yarn is the best. As known the monitoring of the quality parameters such as hairiness, evenness, imperfections and periodic faults is also crucial with compact yarns. The USTER® QUANTUM 3 with all these possibili-ties and the new periodic fault (PF) channel makes it much easier to find the fault reasons. The moni-toring of the hairiness must be especially emphasized, as a higher hairiness variation results in a de-crease of the yarn strength and cloudy fabric appearance. 14.2.8 When should I use the vegetable clearing? Vegetables are part of foreign matter. However with most common bleaching processes, vegetables disappear during bleaching. Therefore mostly it is not necessary to remove them. Imagine a clearer without a vegetable filter – in this clearer one would incur cuts for removing vegetables since the clearer is not able to distinguish between vegetable and other foreign matter. Since the proportion of vegetables are rather high in some cottons this results in a substantial drop in production and at the same time limit the ability to remove real disturbing foreign fibers. The USTER® QUANTUM 3 intelligently separates vegetables from other foreign matter. This offers better selectivity in F matter clearing and save cuts significantly. The reduction of cuts is reached by allowing vegetables which will not disturb the downstream process to pass (they will not be cut). The feature is used for articles that will go for bleached applications. 14.2.9 Why cannot all vegetables pass using Vegetable Matter Clearing when they are not

disturbing? In most situations vegetables are not disturbing. However long and thick vegetables have to be re-moved since they can cause breaks in downstream processes. In applications where the bleaching agents are milder, vegetables do not completely disappear after bleaching and need to be treated as colored foreign fibers. Therefore they have to be removed ac-cording to the quality needs. The built in intelligence of USTER® QUANTUM 3 divides the vegetables into more or less disturbing events according to the end product requirements. This is expressed by the way of setting close, me-dium and open setting.



14.2.10 We have an USTER® QUANTUM clearer or other clearer generations - can we copy the setting because it was acceptable until now?

The USTER® QUANTUM 3 has a new easy way of setting which is nevertheless different from previ-ous generations. Therefore, the same setting cannot be directly copied. However it is very easy to get to the same or better quality and productivity levels by following the procedure below. If the existing setting was fine until now, choose the smart limit in the USTER® QUANTUM 3 which offers the same level of cuts. This smart limit should normally be able to deliver the same or better quality. In a second step it is recommended to compare this setting with the yarn body itself to see if the set-ting follows the yarn body. If it does not follow the yarn body it is advantageous to choose a clearing limit that follows the yarn body. On the other hand if the setting cuts into the yarn body it is beneficial to stay away from the yarn body and save cuts. Verify the results according to the normal quality. Make yarn boards to verify that all cut faults need to be removed and that the not cut faults may remain. 14.2.11 What is different with the continuous count channel? Is the settings process easier? With the USTER® QUANTUM 3 the CC (continuous count) clearing has made a substantial jump. The CC setting is now possible for multiple length channels. To make settings easier the system displays the yarn body and an optimal starting point for the set-tings. In a standard application a cut level for CC with about under 2.0 /100km is common. If there is a problem occurring from side of the spinning process, e.g. sliver count deviations, the clearer will identify these deteriorations and increase the cuts to ensure that only the yarn within the given limits will be wound on the package. 14.2.12 How can one set up the splice clearing curve? With the USTER® QUANTUM 3 splice clearing also has made a substantial jump. A smart possibility offered by the system is to synchronize the splice settings to the NSL T settings to avoid bad splices being passed The splice clearing curve could be placed ideally as same as the NSLT clearing limits. For highest quality requirements the Jp, Jm setting can even be set up to -5 to -10% below the NSLT clearing limit. If this will results in too many JP or Jm cuts then the rogue splicers should be identified and fixed.



14.2.13 How can one find/identify rogue splicers?

• Use JR Splice failure ratio (miscellaneous, JR splice failure ratio)

• Use JRA splice failure ratio alarm (group setting) 14.2.14 What FD setting should I keep for a cotton yarn? (In case of no specific requirement

from the buyer) An attempt should still be made to understand the quality demand of the end user to prevent claims later. As a general rule longer and very dark foreign fibers should be removed on priority. We propose using the default smart limit setting of the USTER® QUANTUM 3 together with the medi-um setting of the Vegetable Clearing in such situations. Depending on the cuts and feedback from the buyer one might optimize the settings to more close or open settings. 14.2.15 USTER® QUANTUM 3 has more than 40 classes, but in USTER® QUANTUM 2, we only

have 23 classes- What is the purpose of these additional classifications in USTER® QUANTUM 3?

Fig. 14-3 Designation of the thick and thin places classes



Fig. 14-4 Designation of the foreign fiber and vegetable classes The USTER® QUANTUM 2 already offers extended classes in thick and thin places and extended classification in Foreign Fiber classification. USTER® QUANTUM 3 offers these classes and further newer classes in thick and thin places with the option Advanced Classification. The new classes were defined due to the reason that yarns have become more even and defects in these newly defined area have been seen to be causing quality claims. For the first time spinners can measure and therefore control these defects. 14.2.16 USTER® QUANTUM 3 has new sensor technology in basic and FM clearing – are the

results comparable to the old classification? The new sensor for the detection of thick places and thin places is able to better determine the length and size of short thick places and the small thin places than the previous sensor. This more accurate determination for short thick places does not affect the fault categories which have to be eliminated. Foreign matter is detected by a sensor with multiple light sources which is able to deter-mine all col-ors with the same sensitivity because of improvements of the optical measuring system. However, the counts per category remain within the statistical variations which have to be expected for seldom oc-curring events when comparing with the previous measuring systems. 14.2.17 Can I use the QUANTUM 3 for wet splicer applications? The USTER® QUANTUM 3 optical clearer can be used with wet splicer without any restrictions. The capacitive clearer can be used with restrictions on the amount of water sprayed. Please contact USTER® for support.



For the capacitive clearer the combination with Foreign Matter option i.e. either C15/F30 or C20/F30 is required. There is a special setting on these clearers particularly assigned for the wet spliced appli-cations. 14.2.18 Is it possible to classify foreign fibers? The USTER® QUANTUM 3 classifies foreign fibers and vegetables in the USTER® FOREIGN CLASS matrix. The faults are classified according to the reflection (%) and length (mm). The system also illus-trates the frequency of foreign fibers and vegetables as dense areas to facilitate easy settings. The system provides numeric classification and the scatter plot of foreign fibers and vegetables in-cluding the dense area display.

Fig. 14-5 Designation of the foreign fiber and vegetable classes 14.2.19 What are the experience values for cuts in ring spinning mills with foreign fiber

clearers? Cuts will depend on the degree of contamination of the raw material and the quality requirements. With medium degree of contamination of the raw material and non bleached fabrics end use it could be expected that the foreign fiber cuts range between 10 to 40 cuts per 100 km. In case of bleached knitted or woven fabrics FF clearing is more critical and even higher cuts should be expected. With the new FF clearing concept, The USTER® QUANTUM 3 ensures the highest possible quality with the lowest possible cuts. The smart way of setting the clearing limits of the yarn clearer will en-sure that the most disturbing fibers will always be eliminated first. Closer settings will eliminate finer and shorter faults.



14.2.20 Can we compare the classification of C15 on C20 in USTER® QUANTUM 3 The USTER® QUANTUM 3 new capacitive sensor has shorter guarded measuring fields (4mm). As a result of the new technology, the classification of C15 and C20 is comparable. This means the clearing limits can be similar between these clearer types and the cuts, clearing per-formance for C15 or C20 is comparable. Users can now choose the most appropriate iMH type for their application. 14.2.21 Is the USTER® QUANTUM 3 classification comparable to the USTER® STATISTICS? The Quality Data such as the coefficient of variation of the yarn evenness, the thick places, thin plac-es, classification results and hairiness can be compared with the USTER® STATISTICS. It has to be taken into consideration, however, that the environmental conditions are not the same on the machine and in the laboratory, and, therefore, we have to compare the figures with more tolerance than be-tween two laboratory systems.

Technical specifications 15


15 Technical specifications 15.1 Basics of USTER® QUANTUM 3

Fig. 15-1 15.1.1 Architecture The USTER® QUANTUM 3 is a yarn clearing and monitoring system for winding machines consisting of:

1. Central Clearing Unit 6 (CCU6). One control unit per winder. All settings and operational check of each position are made from the Central Clearing Unit - Standalone on all winders except Oerlikon Schlafhorst Autoconer 5 and X5 - Integrated with winder Informator on Oerlikon Schlafhorst Autoconer 5 and X5

2. Intelligent clearer measuring heads (iMH) for each winding position.

3. Interface to the winding positions and connecting cables.

15.1.2 Scope of application Yarn types: For all spun yarns consisting of natural fibers, blended fibers, syn-

thetic fibers and plyed yarns.

Languages: GB, CN, TR, VN, DE, FR, IT, ES, PT

Count range: Nec 3 to Nec 200 / Nm 5 to Nm 340 / 2.9 to 200 tex

Maximum speed: 2200 m/min

General Ambient conditions: - Temperature range +5 to 50°C / 41 to 122°F - Humidity up to 95%, not condensing 15.1.3 Scope of supply iMH for each position, Central Clearing Unit 6 (CCU6), Documentation, Tools, Yarn Boards, Yarn Grades

15 Technical specifications


15.1.4 Miscellaneous Printer: USB Printout or via an optional portable printer Access Rights: Controlled through programmable passwords Unit system: Nec, New, Nm, Tex 15.2 Structure of the USTER® QUANTUM 3 15.2.1 Features of USTER® QUANTUM 3 and options Table 15-1 shows the individual features of the options.


Basic clea-ring

Yarn Body (N, S, L, T, CC) Visualization of the yarn characteristics Smart limits (N, S, L, T, CC) A proposed starting point for clearing limits

Scatter plot (N, S, L, T, C, CC, J) Visualization of the thick and thin places, count deviations and splices.

N, S, L, T Elimination of the disturbing thick and thin places C, CC Count deviation clearing and monitoring Jp, Jm Splice Clearing Cut forecast A forecast of cut numbers per 100 km Technical alarms Alert for technical problems Textile alarms Alert for textile problems

Foreign matter

Vegetable Clearing

(Option)

Dense Area (FD, FL, VEG) Identification of range where foreign fibers are located

Smart limit (FD) A proposed starting point for foreign fiber clearing limits

Scatter plot (FD, FL) Visualization of dark and light foreign fibers

Dark foreign matter (FD) Light foreign matter (FL)

Elimination of dark and light foreign fibers

On-line foreign matter classification Classification of foreign fibers

Identification of vegetables Separation of vegetable matter

On-line vegetable classification Classification of vegetable matter

Polypropy-lene fibers (Option)

Smart limit (PP) A proposed starting point for polypropylene clearing limit

Scatter plot (PP) Visualization of polypropylene fibers

Q-Data (Op-tion)

Evenness (CV) Determination of the yarn evenness

Imperfections Determination of the frequent thick places, thin places and neps

Basic on-line classification (NSLT, FD, J and VEG)

Classification of disturbing thick and thin places, foreign fibers, splices and vegetables

Class alarms Triggering of alarm if the number of disturbing faults has exceed the selected number of faults

Periodic Faults (PF) Detection of periodic faults




Hairiness (Option)

Absolute hairiness measurement Determination of the hairiness value

Exception spindle detection Recognition of spindles with excessive hairiness

Expert (Op-tion) Expert

Access to the data output for Expert System and central-ized data collection and reporting

Advanced Classifica-tion (Opti-on)

Extended Classes Classification of additional classes in NSLT, F, VEG

Tailored classes Classes can be selected by customers

Lab On-line (Option) Software pack

Software pack consists of Hairiness, Advanced Classifica-tion and Expert

Table 15-1 Features of Basic Clearing and options 15.2.2 Features versus measuring head types Table 15-2 below describes what type of USTER® QUANTUM 3 sensor for each measuring head is appropriate for which kind of application.

USTER® QUANTUM 3 SENSORS

MEASURING HEAD TYPES Capacitive C15

Capacitive C20

Capacitive C15 F30

Capacitive C20 F30

Optical O30

Optical O30 F30

FEA

TUR

ES

BASIC X X X X X X

FOREIGN MATTER (Option) --- --- X X --- X

VEGETABLE (Option) --- --- X X --- ---

POLYPROPYLENE (Option) --- --- O* O* --- ---

Q-DATA (Option) O O X X O X

HAIRINESS (Option) --- --- O O --- O

USTER® QUANTUM EXPERT 3 O O O O O O

ADVANCED CLASSI-FICATION (Option) O O O O O O

LAB ONLINE (Option) --- --- O O --- O

Table 15-2 The USTER® QUANTUM 3 sensors and options



Key: X This feature is included in this version of the sensor

O Product Option Key (POK) is needed to have access to the feature mentioned in the header of this col-umn

O* Hardware upgrade required in the Central Clearing Unit 6 (CCU6) to have access to the feature

--- Not available with this iMH type 15.3 Comparison, capacitive versus optical measuring principle for basic clearing Table 15-3 shows the comparison capacitive versus optical measuring principle for basic clearing. In the following table there are a few remarks to the selection of the clearer type.

OPTIONS Capacitive principle Optical principle

Basic difference A capacitive measuring signal is proportional to the cross-section of a yarn

An optical measuring system is proportional to the diameter of a yarn

Sensitivity A thick place with 3 times more fibers in the cross-section than average produces a signal of +200%

A thick place with 3 times more fibers in the cross-section than average produces a signal of +73% (Exception: N, S faults)

Application range

For most of the yarns the capacitive principle can be utilized.

For all the yarns the optical principle can be uti-lized.

Contamination The capacitive system needs less cleaning of the measuring zone. Particularly useful in dirty environments

The optical system needs more cleaning of the measuring zone

Exception 1: Conductive fibers

The capacitive system is affected by conduc-tive fibers and should not be utilized for such yarns

The optical system is not affected by conductive fibers

Exception 2: Dyed yarn

The capacitive system is not affected by color variations

The optical system is affected by color variations

Exception 3: Wet splicing

It is recommended to minimize the amount of water used for splicing to protect the clearer and the machine.

The optical system is recommended

Exception 4: Wet spun linen

Not recommended The optical system is recommended

Table 15-3 Comparison capacitive versus optical measuring principle for basic clearing



15.4 Winding machines Table 15-4 shows the winding machines on which the USTER® QUANTUM 3 can be used:

Manufacturer New machines Retrofit

Murata Murata PC 21 Murata PC 21

Oerlikon Schlafhorst Oerlikon Schlafhorst Autocon-er AC5 and AC X5

Oerlikon Schlafhorst Autoconer 338

Oerlikon Schlafhorst Autoconer AC5 and AC X5

Savio Savio Orion

Savio Polar

Savio Espero

Savio Orion

Savio Polar

Qingdao Qingdao Smaro Qingdao Smaro

Table 15-4 15.5 Count range of the USTER® QUANTUM 3

Nec 3Nm 5200 tex

Nec 6Nm 10100 tex

Nec 12Nm 2050 tex

Nec 30Nm 5020 tex

Nec 60Nm 10010 tex

Nec 80Nm 1357,4 tex

Nec 100Nm 1705,9 tex

Option F30

Nec 200Nm 3402,9 tex

Option PP

iMH-C15

iMH-C20

iMH-O30

Fig. 15-2



15.6 Architecture, sensor principles and configuration

Subject Characteristics Technical specification Comment

Architecture of clearer

Intelligent measuring head

Signal processing unit integrated in each measuring head, no separate evaluation unit anymore, high interference suppression, high accuracy due to the self-check of the system.

Sensor prin-ciples for basic clearing

Mass variation Diameter variation

Length of measuring zone: Mass variation: 4 mm Diameter variation: 3 mm

Physical principles: Mass variation: capacitive Diameter variation: optical

Sensor prin-ciple for for-eign fiber detection and monitoring of the hairiness

Reflectance Length of measuring zone: 2 mm

Physical principle: optical

Sensor for polypropylene detection

Phase angle Measurement of phase shift of 2 different materials

Length measurement of polypropylene fibers is pos-sible.

Physical principle: capacitive

Sensor confi-gurations

Basic clearing: Ca-pacitive or optical

Basic and foreign fiber clearing: Capacitive and opti-cal; Optical and optical

Same measuring head dimensions for all sensor configurations

Table 15-5



15.7 Elimination of disturbing yarn faults

Subject Quality characteristics Abbreviation Sensitivity Reference

length Options needed Comment

Elimination of distur-bing thick and thin places

Short thick places

Long thick places

NSL 0*/1...900% 0…200 cm Basic The clearing curve can be optimized by means of 8 setting points for NSL faults.

Thin places T 0*/-1…-100% 0…200 cm Basic The clearing curve can be optimized by means of 8 setting points for T faults.

Elimination of wrong counts

Wrong bobbin (count variation during start up)

Cp

Cm

0*/+1...80%

0*/-1...-80% 2...100 m Basic

Long thick- and thin place (count variation during winding process)

CCp 1

CCp 2

CCm 1

CCm 2

0*/+1...+150%

0*/+1...+150%

0*/-1...- 80%

0*/-1...- 80%

2 m (default)

12 m (default)

2 m (default)

12 m (default)

Basic Monitoring of long thin- and thick places

Elimination of periodical faults

Periodical faults PF 0*/50...100% --- Q Furthermore, setting of the number of periods: 5 – 500

Elimination of foreign fibers

Dark foreign fibers in light yarns

FD 0*/3...100% 0...10 cm F There are 8 setting points each for the FD channel

Vegetable material VEG Close, medium, open

and ‘as FD’ F There are 4 different modes: Close, medium, open and ‘as FD’

Polypropylene fibers PP 0*/3 … 100% 0...10 cm PP Available with both C15F30PP

and C20F30PP clearers

Elimination of bad joints

Avoidance of thick joints Jp 0*/-20…+30% Basic Adjust to NSL

Avoidance of thin joints Jm 0*/-20…+30% Basic Adjust to T

Avoidance of thick joints Jp 0*/1…900% 0…10 cm Basic There are 8 setting points each

for Jp

Avoidance of thin joints Jm 0*/-1…-100% 0…10 cm Basic There are 8 setting points each

for Jm

Core missing

Core Yarn CY 0*/5…80% Basic

Table 15-6 Abbreviation: Q = Q-Data F = Foreign fibers PP = Polypropylene 0* = Inactive (off)



15.8 Supervision of the machine operations The supervision of the machine operations depends on the requirements of the machine manufactur-ers.

Subject Quality characteristics Abbreviation Sensitivity Reference

length Options needed Comment

Supervision of the splice failure ratio

Avoidance of splice failures JRA 0*/1…100% --- Basic

All winding machine types if needed

Supervision of upper yarn during joint opera-tion

Avoidance of double yarns from the cone side

U 0*/10...200% --- Basic

Supervision of the drum wrap

Avoidance of yarn wounds on the guide drum

DWM --- --- Basic

Table 15-7 0* = Inactive (off)



15.9 Determination of quality characteristics All quality characteristics are monitored continuously at every production position. These quality char-acteristics can be monitored at any time.

Subject Quality characteristics Abbreviation Technical

specifications Options needed Comment

Determi-nation of quality charac-teristics

Coefficient of variation, per group

CV-MV 50 ... 10'000 m, 0*/0.1…99%

Q No substantial variation when chang-ing the evaluation length. Measurement can be started at bob-bin change or can be done continu-ously.

Coefficient of variation per position

CV-SP 50 ... 10'000 m, 0*/1… 99%

Q No substantial variation when chang-ing the evaluation length.

Imperfections: IPI Evaluation length: 50…2000m

Setting thresholds

Alarm limit: 0*/1…64’000

• frequent thin places

-30/-40/-50/-60% Q

Imperfections are always displayed per 1000 m (reference length) • frequent thick

places 35/50/70/100% Q

• frequent neps 140/200/280/400% Q

Classification of thick and thin places

CMT

Length classes A to G: 0.2 – 1 cm, 1 – 2 cm 2 – 4 cm, 4 – 8 cm, 8 – 16 cm, 16 – 32 cm 32 – 64 cm, > 64 cm

Thick place classes: 30 – 45%, 45 – 75%, 75 – 100%, 100 – 150%, 150 – 250%, 250 – 400%, > 400%

Thin place classes: H0, H1, H2, I0, I1, I2, TB1, TB2, TC1, TC2, TD2, TD1, TD”: -20..-30%, -30...-45%, < -45%

Q, A

Total number of yarn faults per class (absolute) and relative per 100 km

30 thick place classes and 15 thin place classes.

Periodic faults PF As defined in chapter 15.7 Q Total number of yarn faults per class (absolute) and relative per 100 km

Number of dis-turbing thick and thin places

N, S, L, T As defined in chapter 15.7 Basic Total number of eliminated yarn faults per class (absolute) and rela-tive per 100 km

Wrong count Cp, Cm As defined in chapter 15.7 Basic Total number of eliminated yarn faults(absolute) and relative per 100 km



Subject Quality characteristics Abbreviation Technical

specifications Options needed Comment

Count deviation and monitoring of uneven long thick and thin places

CCp, CCm As defined in chapter 15.7 Q Total number of eliminated yarn faults (absolute) and relative per 100 km

Classification of foreign fibers FD

Length classes A to F: 0.1-0.6cm, 0.6-1cm, 1-1.4cm, 1.4-2cm, 2-3cm, 3-5cm, 5-7cm, >7cm

Reflectance classes: 5-7%, 7 – 10%, 10 – 20%, 20 – 30%, 30 – 100%

F

Total number of foreign fibers per class (absolute) and relative per 100 km

32 displayed foreign fiber classes.

1 table for FD,

Foreign fibers, grey or colored yarns

FD As defined in chapter 15.7 F Total number of eliminated yarn faults per class (absolute) and rela-tive per 100 km

Polypropylene fibers PP As defined in chapter 15.7 PP Available with both C15F30PP and

C20F30PP clearers

Vegetable clearing VEG

Length classes A to F: 0.1-0.6cm, 0.6-1cm, 1-1.4cm, 1.4-2cm, 2-3 cm, 3-5cm, 5-7 cm, >7cm

Reflectance classes: 5-7%, 7-10%, 10-20%, 20-30%, 30-100%

F

Total number of vegetable matter per class (absolute) and relative per 100 km

32 displayed vegetable matter clas-ses.

Hairiness per group H-MV/ 50 ... 10'000 m,

0*/0.1...20 H Measurement can be started at bob-bin change or can be done continu-ously. The test length per bobbin can be selected.

Hairiness per winding position H-SP 50 ... 10'000 m,

0*/0.1...20 H

Splice classifica-tion J 0...10 cm

-100…900% Q Deviation in length and percent from the nominal value are displayed.

J-Classes as NSLT

Table 15-8 Abbreviations: Q = Q-Data H = Hairiness A = Advanced Classification F = Foreign fibers PP = Polypropylene 0* = Inactive (off)



15.10 Cut alarms, Quality alarms, Special Counters and Logbook Choices Subject Abbre-

viation Settings Reference

length Options needed

Comment

Yarn fault alarms

(ALARM)

Short thick places NSA 0*/1...99 1...999 km Basic

Monitoring of the fault fre-quency

Long thick places LA 0*/1...99 1...999 km Basic

Thin places TA 0*/1...99 1...999 km Basic

Wrong count CA 0*/1...99 1...999 km Basic

Count deviation and uneven, long thick and thin places

CCA 0*/1...99

1...999 km Basic

Foreign matter FA 0*/1...99 1...999 km F

Polypropylene fibers PPA 0*/1...99 1...999 km PP iMH C15F30 and C20F30 with option PP

Periodic faults PFA 0*/1...99 1...999 km Q Monitoring of the fault fre-quency

Splice failure ratio alarm

JRA 0*/1…100% --- Basic Monitoring of the frequency

Q-Registration

Q-Blocking

Q-Cut (Ejec-tion)

Q-Blocking / Sucking

Coefficient of variation, mean of entire ma-chine or article

CV-MV upper: 0*/0.1...99%

lower: 0*/0.1...99%

0,05...10 km Q Absolute monitoring of the CV-MV; upper and lower limit.

Coefficient of variation per position

CV-SP upper: 0*/1...99%

lower: 0*/1...99%

0,05...10 km Q Relative deviation of the CV-MV value

Hairiness, mean value of the group

H-MV upper: 0*/0.1...20

lower: 0*/0.1...20

0,05...10 km H Absolute monitoring of the H-MV value; upper and lower limit.

Hairiness per winding position

H-SP upper: 0*/0.1...20%

lower: 0*/0.1...20%

0,05...10 km H Absolute deviation of the H-MV value

Class Alarm CMT Up to 5 clas-ses Alarm limit 0*/1...64'000

1...300 km Q 5 individual classes for alarm monitoring can be selected

Frequent neps IP 0*/1...64000 0.05...10 km Q Monitoring of the frequency

Frequent thick places IP 0*/1...64000 0.05...10 km Q Monitoring of the frequency

Frequent thin places IP 0*/1...64000 0.05...10 km Q Monitoring of the frequency

Tailored classes (NSL) tNSL 0*/5…900% 0.1…200 cm A Monitoring of the frequency

Tailored classes (T) tT 0*/-5…-100% 0.1…200 cm A Monitoring of the frequency

Tailored classes (FD) tFD 0*/5…100% 0.1…10 cm A Monitoring of the frequency

Tailored classes (FL) tFL 0*/5…100% 0.1…10 cm A Monitoring of the frequency

Special Counters

Upper yarn cuts U 0*/10...200% Basic Monitoring of the frequency

Machine-associated A --- --- Basic



Choices Subject Abbre-viation

Settings Reference length

Options needed

Comment

additional cuts

Yarn jump monitoring / registration/ alarm

JPM / JPM reg

/ JPA --- --- Basic

Drum wrap monitoring / registration/ alarm

DWM / DWM reg /DWA

--- --- Basic

Drum signal monitor-ing

DSM --- --- Basic

Special cuts SPC --- --- Basic

Logbook Recording of all changes and alarms Logbook --- --- Basic Monitoring of the logbook

entries

Table 15-9 Abbreviations: Q = Q-Data

F = Foreign fibers

H = Hairiness

PP = Polypropylene

A = Advanced Classification

0* = Inactive (off)



15.11 Reports Table 15-10 shows various reports. Reports can be transferred to an USB stick or to an optional printer.

Groups Feature Per position Per group Necessary

options Comment Display Printout Display Printout

Machine data

Winding speed --- --- --- Basic

List of reports:

Per shift, per day, per article

Intermediate report / present shift

Last shift (can also be config-ured as auto-matic report)

Produced yarn length * Basic

Settings Setting of the clearing- and alarm parameters --- --- Basic

Yarn Faults

Number of all yarn faults YF absolute --- Basic

Number of all yarn faults YF / 100 km * Basic

Number of all yarn joints YJ / absolute --- Basic

Number of all yarn joints YF / 100 km * Basic

Number of N, S, L, T, Cp, Cm, CCp, CCm absolute --- Basic

Number of N, S, L, T, Cp, Cm, CCp, CCm / 100 km * Basic

Periodic Faults absolute --- Q

Periodic Faults / 100 km * Q

Foreign fibers, grey or colored yarns, FL, FD absolute --- F

Foreign fibers, grey or colored yarns, FL, FD / 100 km * F

Polypropylene fibers PP, abso-lute --- PP

Polypropylene fibers PP / 100 km * PP

Faulty yarn joint Jp, Jm abso-lute --- Basic

Faulty yarn joint Jp, Jm / 100 km * Basic

Cuts U, JPM, SPC, DSM, DWM absolute --- Basic

Cuts U, JPM, SPC, DSM, DWM / 100 km * Basic

Yarn Fault Alarms

Yarn Fault Alarms

Yarn fault alarms NS, L, T, F, C, CC absolute --- Basic

Yarn fault alarms NS, LT, F, C, CC /100km * Basic

Periodic Faults alarm PF abso-lute --- Q

Periodic Faults alarm PF / 100 km * Q



Groups Feature Per position Per group Necessary

options Comment Display Printout Display Printout

Q Alarms Number of CV alarms CVp, CVm absolute --- Q

Number of CV alarms CVp, CVm / 100km * Q

Number of Hairiness alarms Hp, Hm absolute --- H

Number of Hairiness alarms Hp, Hm / 100km * H

Number of Class-alarms abso-lute --- Q

Number of Class-alarms / 100 km * Q

Number of Imperfection alarms absolute --- Q

Number of Imperfection alarms / 100 km * Q

Exceptions SP

Exceptions: yarn faults, textile alarms, J, JR, yarn length * --- --- Basic

Exceptions: F, VEG, PP * --- --- F

Exceptions: CV, IP, Class, (H) * --- --- Q

Q Data Coefficient of variation per group CV-MV --- --- Q

Coefficient of variation per position CV-SP * --- --- Q

Mean imperfection counts 12 in different classes / 1 km Q

Classification of NSLT faults / 100 km, absolute --- Q, A

Classification of FD-faults / 100 km, absolute --- Q, F

Classification of FL-faults / 100 km, absolute --- Q, F

Classification of VEG-faults / 100 km, absolute --- Q, F

Hairiness, mean value of the group H-MV --- --- H

Last value of the hairiness per winding position H-SP * --- --- H

Event reports

Yarn faults (N, S, L, T, C/CC, F, VEG, PP, PF) ** ** ** ** Basic, F, PP

Yarn faults are also displayed showing size, intensity and classification.

Textile alarms (NS, L, T, C/CC, F, Q, PF) Block-ings/Cuts/Registrations)

** ** ** ** Basic, F, Q, H, A

Other ** ** ** ** Basic

Table 15-10



Abbreviation:

Q = Q-Data F = Foreign fibers H = Hairiness PP = Polypropylene A = Advanced Classification

Available

* Available if exceptions are defined and “Print all SP (spindle positions)” is selected in the menu “Configu-ration- Exceptions”.

** Available if events are defined and selected in the menu “Configuration-Event report”.

--- Not available 15.12 Clearing of various yarn types Table 15-11 shows the application range of the clearer types according to various yarn types:

USTER® QUANTUM 3 SENSORS C

apac

itive

C

15,C

20

C15

/ F30

C

20/F

30

*PP

opti-

on

Opt

ical

, O

30

O30

/ F30

Cotton, carded, combed, compact ring X* X

Blended, short staple X X

Synthetics, short staple,100% X X

Cellulosics,100% X X

Woolen X X

Worsted X X

Blended, long staple X X

Synthetics, long staple,100% X X

Flax,linen, hemp X X

Wet spun linen X

Spun Silk X X

Technical yarns, non-conductive X X

Technical yarns, conductive X

Table 15-11 * For cotton yarns the polypropylene feature can be applied with clearer types C15/ F30 and C20/F30.



15.13 Recommendations how to use clearers 15.13.1 Sensor systems versus end use of yarn The following tables shall give some guidelines what kind of iMH should be recommended. The asterisks in the tables have the following significance:

***** Highly recommended

**** Recommended

*** Recommended. Limitations for some applications.

** Can be used for this application, but expertise of an Uster specialist recommended

* Should not be used for this application without the expertise of an Uster specialist

--- Should not be used for this application Important note:

Guidelines for selling USTER® QUANTUM 3: Most of our customers want to keep the type of sensors which are installed on their machines because they may have achieved the best results with this type of sensor. Therefore, it makes sense to continue with the same sensor principle.

Type of yarn Count range Ne

End use IMH-C IMH-O IMH with F Recommendation for sales engineers

1

Cotton yarns All yarn counts Weaving / Knitting ***** ***** *****

For all winders with wet splicers (ask Uster spe-cialists)

Ply yarns

Same color / 2 ply ***** ***** *** Detection of foreign fi-bers in ply yarns causes more ply-joints

Different colors / 2 ply ***** *** ---

3 ply and more ***** **** ---

2

Blended yarns

All yarn counts ***** ***** ***

100% Syn-thetic yarns ***** ***** ***

3

Worsted yarns worsted/ synthetics blended yarns

Grey ***** ***** ***

Dyed ***** *** ***



Type of yarn

Count range Ne

End use IMH-C IMH-O IMH with F Recommendation for sales engineers

4

Melange (Blended yarns with long staple fibers of dif-ferent colors)

All yarn counts and blends

Blending of col-ored fibers at drawframe

***** ***** ****

Short yarn defects are mostly of the same color and appear as small spots

Blending of col-ored fibers at spinning machine

** *** ****

The mass deviation of the missing colored fibers are very small but the visual impact can be significant

5 Core yarns All yarn counts

Sewing threads ***** ***** ***** Yarns for industrial use and with a core of more than 14 % of the total mass

***** --- ***

The biggest problem is the missing core since the yarn does not break. Such defects can only be detected with iMH-C.

With Lycra as core ***** *** *****

6 DREF yarns All yarn counts **** **** *** Challenges depend on

the end use

7 Slub yarns All yarn counts Fancy fabrics ***** ***** ***

Mostly the missing slubs are a problem and, there-fore, the visual appear-ance is most important.

8 Antistatic yarns, yarns containing metallic fibers

All yarn counts

Technical fabrics as well as safety cloth

--- **** ---

Capacitive sensors are unable to measure metal-lic fibers or highly con-ductive fibers correctly.

9

Linen, flax, hemp yarns *** ***** ---

Should customer already successfully use C-type clearers, iMH-C can be offered

Linen (wet spun) --- ***** ---- Use only optical clearer

for wet spun yarns 10 Spun silk **** **** *****

11 Filament yarns *** *** ---

Ask Uster specialists before offering and send samples for investigation

Table 15-12



15.13.2 Poor environmental conditions The demand for detecting yarn count deviations is raising constantly. The conditions for the clearers must be constant in order to guarantee the quality requirements. The choice of the correct measuring system is very important. Especially when using the USTER® QUANTUM 3 as a retrofit solution the environmental condition plays a key role in order to exploit all the features of this clearer. Take into consideration that the customer expects a better performance when changing to a new clearer. Room conditions IMH-C IMH-O IMH with F Recommendation for sales engineers

1 Bad or no air-conditioning **** ***** *****

When the winding room is separated from the spinning department the air humidity can fluctu-ate rapidly

2 Water spraying only ** ***** ***** The moisture of the yarn and the humidity can fluctuate rapidly

3 Floor watering only *** ***** ***** The humidity can fluctuate rapidly

Table 15-13

Appendix 16


16 Appendix 16.1 Standard settings The following standard settings should assist when setting clearer for short staple yarns and their blends. 16.1.1 Standard settings for the capacitive clearer – Capacitive Default

Fig. 16-1 Standard settings

16 Appendix


16.1.2 Standard settings for the optical clearer – Optical Default The following standard settings should assist when setting clearer for short staple yarns and their blends.

Fig. 16-2 Standard settings

Appendix 16


16.2 Abbreviations A Machine-related additional cut

A0...A4 Classimat classes

ADMV Analog Digital Mean Value

B0...B4 Classimat classes

BC Board Computer

BI Built in

C Yarn Count deviation during start-up (wrong bobbin)

C0...C4 Classimat classes

CA Yarn Count Alarm during start-up

CC Yarn count fault during operation (Continuous Count)

CCA Yarn count alarm during operation (Continuous Count Alarm)

CCm (CC-) Lower tolerance limit for yarn count faults during operation

CCp (CC+) Upper tolerance limit for yarn count deviations during operation

CCp1..2 Setting point for CC

CCU 6 Central Clearing Unit 6

Cm (C-) Lower tolerance limit for yarn count faults during start-up (m = minus)

CMT Yarn fault classification

CMTA (4 cm fault classification Alarm) named as “Class Alarm”

Cp (C+) Upper tolerance limit for yarn count faults during start-up (p = plus)

CSA Clearer Spindle Adapter (interface to machine)

CSG Communication central clearing unit (iMH bus connection)

CTM Cut Monitoring

CV Coefficient of Variation of yarn evenness

CVA Coefficient of Variation of yarn evenness Alarm

CV-MVAm CV Mean Value Alarm -

CV_MVAp CV Mean Value Alarm +

CY Core Yarn

D0...D4 Classimat classes

DEF Defined (Status of the article)

DSM Drum Signal Monitoring

DWA Drum Wrap Alarm

DWM Drum Wrap Monitoring

DYD Dynamic Yarn Detector

16 Appendix


E Classimat class

EHR Machine (unit) computer (Schlafhorst)

F Foreign matter

F, P21 .. 22 Classimat classes

FA Foreign matter Alarm

FD Foreign matter Dark (dark fiber in light yarn)

FD1... FD8 Setting Points for Foreign matter Dark (dark fiber in light yarn)

FL Foreign matter Light (light fiber in dark yarn)

FL1... FL8 Setting Points for Foreign matter Light (light fiber in dark yarn)

FMA Foreign matter sensor Monitor Alarm

G, GP21 .. 22 Classimat classes

GR Group

GUI Graphic user interface H Hairiness

HA Hairiness Alarm

H-MVAm H Mean Value Alarm -

H-MVAp H Mean Value Alarm +

H0...H2 Classimat classes

I0...I2 Classimat classes

iCSA Intelligent Clearer Spindle Adapter

iMH Intelligent Measuring Head

iMH-C Measuring head, Capacitive

iMH-F Measuring head with Foreign matter detection

iMH-O Measuring head, Optical

INF Informator (Schlafhorst)

IPI Imperfections

J (Splice Clearing), Joint (yarn splice/knot/piecing/connection)

Jm Lower tolerance limit for yarn joints

Jm1... Jm 8 Setting Points for Lower tolerance limit for yarn joints

Jp Upper tolerance limit for yarn joints

Jp1... Jp 8 Setting Points for Lower tolerance limit for yarn joints

JPA Jump Alarm (yarn)

JPM Jump Monitoring (yarn)

JR Splice failure Rate

JRA Splice failure Rate Alarm

K1...K3 Slub yarn auxiliary setting point

Appendix 16


L Long thick place ≥ 8 cm

LA Long thick place Alarm

LED Light Emitting Diode

...m Minus

MA Machine

MMI Man Machine Interface (keyboard, display, printer)

MV Mean Value

N Very short thick places (N) < 1 cm

NS Very short thick places (N) and Short thick places

NSA Very short thick places (N)and Short thick places Alarm

NSL Very short thick places (N) and Short thick places and Long thick places

NSL1... NSL 8 Setting points for very short thick places (N)and Short thick places (NSL)

...p Plus

P1...P8 Setting Points

PF Periodic yarn Fault

PFA Periodic yarn Fault Alarm

PP Polypropylene clearing POK Product Option Key

PPA Polypropylene Alarm

PP1... PP 8 Setting Points for Polypropylene clearing

PROD Production (State of the article)

Q-Data Quality data

S Short Thick place 1 cm, < 8 cm

SEED Seed coat fragments SP Spindle/Spinning Position/Winding position

SPC Special cut

SP-CTR Spindle controller (Savio)

STAT Status

SW Software SYD Static Yarn Detector

T Thin place

T1... T 8 Setting Points for Thin places

TA Thin place Alarm

TB1…2 Classimat classes TC1…2 Classimat classes TD0…2 Classimat classes

16 Appendix


TM Top Mounted

tNSL tailored class for NSL

tFD tailored class for FD

tFL tailored class for FL tT tailored class for T U Upper Yarn

UQC USTER® QUANTUM 3 VEG Vegetable matter clearing YA Yarn fault Alarm

YB Natural Yarn Breaks

YD Yarn Detector

YF Yarn Fault

YJ Yarn Joint (Splice)

ZPM Zero Point Monitoring

Nec English cotton count

Nm Metric cotton count

tex Metric cotton count (SI unit)

Appendix 16


16.3 Explanation of terms

Advanced classifi-cation

The option which includes extended classes and tailored classes.

Article The article is an identification of the yarn. It is identified by: Article number, article name and yarn count. From the point of view of the yarn clearer manufacturer, the article is also defined by the combination of all clearing settings.

Article change Operation-specific function, which involves one or several of the following items:

- delete the collected article data; set the counters to zero - adjust the basic sensitivity to the new yarn of the group - enter the new settings in the USTER® QUANTUM 3.

Board computer Computer of the winding machine.

Bobbin Type of yarn package used in ring spinning.

C-channel Fault channel for the detection of yarn count deviation.

Clearer Sensor and evaluation electronics of a winding position.

Clearer cut Cutting of the running yarn to eliminate a disturbing yarn fault or a disturb-ing foreign fiber.

Clearer cut blocking

A signal generated by the winder, which prevents a clearer cut, e.g.: - during the splicing/knotting cycle, - when the cone is full and being changed.

Clearer group See group

Clearing limit Separation line between yarn faults which may remain in the yarn and those which have to be cut by the clearer. The clearing limit is defined by the setting of the sensitivity and the reference length for the respective fault channel. For the setting of the fault channels, the clearing limit is shown in the dis-play of the USTER® QUANTUM 3 unit. For technical reasons, the clearing limit is subject to a certain tolerance.

CMT matrix Representation of the yarn faults in the 23 fault classes of the USTER® CLASSIMAT system.

Cone Cylindrical or conical yarn package produced at each winding position of a winding machine.

Central Clearing unit

Component of the yarn clearing installation. Some functions: - centralized operation of the installation - data exchange with the iMHs - output of information and results by display and USB-connection

Cross-sectional deviation

Deviation of the yarn cross-section from the mean yarn value.

Cut forecast A forecast of the number of cuts per 100 km.

16 Appendix


Dense Area Identification of range where foreign fibers are located.

Diameter deviation Deviation of the yarn diameter from the mean yarn diameter.

Display Display panel at the USTER® QUANTUM 3 central clearing unit. Shows the dialog between the user and the operating program.

Double thread Two single threads or a faulty yarn spun from two rovings with approxi-mately double the cross-section of the single thread.

Extended classes Classification of additional classes in NSLT, F, VEG

Evaluation unit - evaluation of the yarn signals for the yarn fault detection, provided by the measuring head

- issue of a cut command to the measuring head (or the winding ma-chine) in the event of a disturbing yarn fault

- signal exchange with the winding position, e.g.: cut blocking, elec-tronic yarn detector, etc.

Fault channel The yarn faults are detected according to the reference length and the sen-sitivity in different fault channels.

Group (setting group, clearer group) Consecutive number of spindles which have - the same measuring head type - producing the same yarn and use the same settings

Guide drum signal Electrical signal consisting of a pulse sequence. The pulse frequency is equivalent to a multiple of the circumferential speed of the guide drum. The guide drum signal is used, among other things, for the calculated adjust-ment of the fault reference length to the yarn count.

iMH intelligent measuring head

Part of the USTER® QUANTUM. Some of the functions are: - conversion of the yarn mass or yarn diameter in a proportional electri-

cal signal - evaluation of the yarn signals for the yarn fault detection, provided by

the measuring head - issue of a cut command to the cutter (or the winding machine) in the

event of a disturbing yarn fault - signal exchange with the winding position, e.g.: cut blocking, electronic

yarn detector, etc.

Interface Permits the exchange of data between different systems.

L-channel Fault channel for the detection of long thick places.

Lab On-Line Software pack consists of Hairiness, Advanced Classification and Expert.

Machine computer See board computer

Mass deviation Deviation of the yarn mass from the mean yarn value.

Material Raw material of the yarn. Material in pure form or as a blend of different materials used for the production of yarns.

Measuring field Part of the measuring head which converts the yarn measurement into an electrical signal.

Appendix 16


N-channel Fault channel for the detection of very short thick places or neps.

Nep Thick place which is shorter than 1 cm.

OEM OEM = Original Equipment Manufacturer The USTER® QUANTUM 3 installation is delivered to the customer by the machine manufacturer who acts as OEM partner for Uster Technologies.

Periodic Faults Detection of periodic faults at multiple wave length.

Reference length Set length over which a clearing feature is evaluated.

Release See software release

Reset Resetting an electronic circuit to a preset initial state.

Retrofit On a winding machine, an already existing clearer installation is exchanged by a new USTER® QUANTUM 3 installation.

Scatter plot Graphic representation of the detected events within a classification matrix. One event = 1 point.

S-channel Fault channel for the detection of short thick places.

Sensitivity Set %-value for the determination of the clearing limit.

Smart limits A proposed starting point for clearing limits.

Software pack A package consists of various software parts (see also Software release). Released USTER® QUANTUM 3 software package consisting of a CCU and an iMH software version.

Software release Is indicated by Rel and five digits (X.XX.XX, e.g. 1.01.05) and shows the level of development of the installed software.

Spinning cop See bobbin

Splice Yarn joint based on the interlacing of the two yarn ends.

Splice check Checking of a splice with regard to its mass or diameter increase and length in the splice channel of the installation.

T-channel Fault channel for the detection of thin places.

Tailored classes Classes can be selected by customers.

Thick place, long Faulty yarn mass increase which is at least than 8 cm.

Thick place, short Faulty yarn mass increase which is between 1 and shorter than 8 cm long.

Thick place, very short

Faulty yarn mass increase (nep) which is shorter than 1 cm.

Thin place, short Faulty thin yarn section

Upper yarn check Check the yarn drawn from the package during splice cycle. Prevent from joining two or more yarns from the package to the yarn from the bobbin (lower yarn).

Vegetable Clearing Separation of vegetable matter.

16 Appendix


Winding position Winding unit of a winding machine, which winds the yarn of several bobbins to a cone.

Yarn body The yarn body is defined as the nominal yarn with its tolerable, frequent yarn faults.

Yarn clearing The detection and removal of disturbing yarn faults.

Yarn fault Faulty yarn section which is detected by the yarn clearing. Collective term for all thick and thin places.

Yarn fault channel See fault channel.

Yarn fineness (Yarn count) System of units for yarn:

Nm, Nec, New Ratio: Length/mass

Tex Ratio: Mass/length

Yarn measurement value

Electrical signal, which is continuously determined from the yarn mass or the yarn diameter in the measuring field.

Yarn joint Joining of two yarn ends by a splice or knot.

Appendix 16


16.4 International Systems of units 16.4.1 International system During the last decades, most countries have revised the laws referring to measurement determina-tions. The motivation for this was the introduction of an internationally-recognized system of measur-ing units which is known under the name of "Système International d'Unités" (abbreviation: SI) or In-ternationale System of Units. In the European Commuity (EC), the deadline for introducing the SI-system was already reached at the end of 1977, and in Switzerland, this deadline ran until the end of 1982. Also in the East European countries, a forerunner to this SI-system, the MKSA-system was legally embodied quite early on, and in Eastern Germany, for instance, even as early as 1958. 16.4.2 'SI' system Confusion in the system of units during the last decades has often led to quite considerable difficulties in science and technology, and more particularly in commerce. This resulted, even many years ago, in various forward-thinking scientists suggesting a reorganization of the system of units. An important foundation stone, in this respect, was laid by the Italian physicist Giorgi as far back as the year 1901. His suggestion led, in 1948, to the international recognition of the MKSA-system (meter-kilogram-second-ampere). All physical units used in science and technology could be related to these four basic units. In the year 1960, at a general conference on weights and measures, the SI-system was officially ac-cepted. The SI-system differs from the MKSA-system in that the four referred to fundamental units of meters, kilograms, seconds and amperes were extended by the Kelvin (temperature), the Mol (amount of substance) and the Candela (intensity of light) as further basic units. Although, according to present-day knowledge, every physical size which can be measured can be related to a combination of these 7 basic units, it is quite frequent to find that certain used combina-tions have their own name. For instance, in the SI-system, the force unit of kg • m/s² is allowed to be referred to as the "Newton" [N]. For work done, which in the SI-system has the unit kg • m/s² • m, the reference Newton-meter [Nm] or Joule [J] can be used. As the physical sizes, in some cases, extend over a quite wide range of figures, it is allowed that, for a decimal multiple or a part of a basic unit, derived units such as milli, deci, kilo, etc., can be applied. Table 16-1 shows the seven base units of the SI System of Units. All the additional units are derived from these 7 base units. Physical parameter Unit Abrevation

Table 16-1 Seven base units

Length Meter m

Mass Kilogram kg

Time Second s

Electric current Ampere A

Temperature Kelvin K

Amount of substance Mole mole

Intensity of light Candela cd

16 Appendix


With the SI-system, there are two special properties which are to be given preference:

• In the SI-system, the derived units are coherent, i.e., all derived units are a combination of basic units in which only the numerical factor 1 is encountered.

• The SI-system is characterized by 'freedom from contradiction', i.e., every physical size can only be described in one manner with the help of the basic units.

The units allowed and those which are obsolete when applying the SI-system for fiber, sliver, roving and yarn testing are summarized in the following table: Physical para-meter

SI-units and other legally-allowed units Conversion Obsolete units Base unit Abbreviation Derived units

Length meter m km, cm, mm 1 m = 1,099 yard Inch, yard, mile

Length-related mass kilogram/meter kg/m

ktex, tex (1 ktex = 1 g/m) (1tex = 1 g/km)

1 tex = 1000/Nm 1 tex = 590,5/Nec

Nm, Nec, New, den, grains/yd,

etc.

Mass kilogram kg g, mg, µg 1 kg = 2,204624 lbs Grain (gr), ounce (oz), pound (lb)

Force Newton N mN, cN 1N = 0.102 kgf kg, kg*, kgf, gf, lb, lbf

Tenacity Newton/tex N/tex cN/tex 1 cN/tex = 0,9807 • Rkm g/tex, Rkm, CSP

Work done Newton • meter (Joule) N • m cN • cm 1 cN • cm = 0.9807 gf • cm

1 N • m = 0.09807 kgf • m g • cm, kg • m

Table 16-2 Unfortunately the textile industry still uses obsolete unit systems. The following tables are conversion tables.

Appendix 16


16.4.3 Conversion table for yarn count systems In the textile industry, it is often the case that in the same spinning mill both English and metric sys-tems of count determination are used with fiber assemblies. The following table enables the conver-sion into one or the other of the count systems. The use of this table is illustrated based on an example: For a particular yarn the English cotton count Nec = 32 is known. The yarn count in tex is to be deter-mined. One looks fist of all in the column "GIVEN" for the section Nec. In this section one moves downwards until one reaches tex in the "TO DETERMINE" column. Now one carries out the calcula-tion referred to in this field.

45.1832

590.5

cNe590.5tex ===

GIVEN →

tex dtex den yardgrains

inchgμ Nm Nec Nel New Y.S.W.

tex 1 dtex ⋅0.1 den ⋅ 0.111 yardgrains 70.86

4.25inch

gμ

Nm000'1

cNe5.590

lNe5.1653

wNe8.885 .W.S.Y

7.1937

dtex tex ⋅ 10 1 den ⋅1.11 yardgrains ⋅ 708.6

54.2inch

gμ

Nm000'10

cNe4.5905

lNe535'16

wNe8858 .W.S.Y

377'19

Metri

c

den tex⋅ 9 dtex ⋅ 0.9 1 yardgrains ⋅ 637.7

82.2inch

gμ

Nm000'9

cNe9.5314

lNe882'14

wNe3.7972 .W.S.Y

439'17

yardgrains

68.70

tex 6.708

dtex 7.637

den 1 4.1801

inchgμ

Nm1.14

cNe33.8

lNe33.23

wNe5.12 .W.S.Y

34.27

Engl

ish

inchgμ tex ⋅ 25.4 dtex ⋅ 2.54 den ⋅ 2.82 yard

grains ⋅ 1801.4 1 Nm

400'25 cNe

000'15 lNe

000'42 wNe

500'22 .W.S.Y218'49

Metri

c

Nm tex000'1

dtex10'000

den000'9

yardgrains

1.14

inchgμ400'25

1 Nec ⋅ 1.693 Nel ⋅ 0.605 New ⋅1.13 Y.S.W. • 0.516

Nec tex

5.590 dtex

5'905.4 den

9.5314 yard

grains33.8

inchgμ000'15

693.1Nm 1

8.2Nel 5.1

New 28.3.W.S.Y

Nel tex

5.653'1 dtex

16'535 den

882'14 yard

grains33.23

inchgμ000'42

6050Nm.

Nec ⋅ 2.8 1 New ⋅ 1.87 172.1.W.S.Y

New tex

8.885 dtex8'858

den7972.3

yardgrains

5.12

inchgμ500'22

13.1Nm Nec ⋅ 1.5

87.1Nel 1 187.2

.W.S.Y

←TO

DET

ERM

INE

Engl

ish

Y.S.W. tex

7.937'1 dtex

19'377 den

17'439 yard

grains34.27

inchgμ218'49

516.0Nm Nec ⋅ 3.28 Nel ⋅ 1.172 New ⋅ 2.187 1

Table 16-3

16 Appendix


Explanation of the abbreviations

dtex = Decitex Nec = Cotton hank number

den = Denier Nel = Linen lea number

μg/inch (ap-prox)

= Fiber count system (can be determined with Micronaire type instruments)

New = Worsted hank number

Nm = Metric count Y.S.W. = Yorkshire skeins woollens 16.4.4 Conversion of English units into metric units The units referred to in this handbook are primarily metric units In order to be able to convert all the figures into English units, the more important conversions as used in the textile industry are provided here.

Name of the unit Symbol Metric unit

Length units

1 inch in 2.54 cm

1 foot (= 12 in) ft 0.3048 m

1 yard (= 3 ft) yd 0.9144 m

1 mile mile 1609.344 m

1 lea (120 yds), cotton lea 109 m

1 hank (840 yds), cotton hank 768 m

Area units

1 square inch sq in 6.4516 cm2

1 square foot sq ft 929.030 cm2

1 square yard sq yd 0.836127 m2

1 square mile sq mile 2.58999 km2

Mass units

1 grain gr 0.064799 g

1 ounce oz 28.3495 g

1 pound lb 0.453592 kg

Force units

1 gram-force gf 0,0098 N

1 ounce-force ozf 0.278014 N

1 pound-force (=16 ozf) lbf 4.44822 N

Tenacity 1 kilogram-force • Nec 1 kgf • Nec 0.579 cN / tex

1 gram-force per denier 1 gf / den 8.838 cN /tex

Pressure units

1 pound-force per square inch (p.s.i)

lbf/in2 6894.76 N/m2

1 pound-force per square foot

lbf/ft2 47.8803 N/m2

Table 16-4

Appendix 16


16.5 Bibliography 1. Lawrence, C.,A., “Fundamentals of Spun Yarn Technology”, CRC Press LLC, 2003. 2. Lord, P. R., “Handbook of Yarn Production: Technology, Science and Economics”, Woodhead

Publishing Limited, 2005. 3. Schindler C., ITMF COTTON CONTAMINATION SURVEY 2007, 29th International Cotton Con-

ference, Proceedings, Bremen, April 2 - 5, 2008. 4. Ajgaonkar, D.B.,”Principles of Knitting XXXIII”, The Indian Textile Journal,163-170, October

1975.

5. ITMF COTTON CONTAMINATION SURVEY 2009

6. The Textile Institute Textile terms and definitions 8th Edition”, Manara Printing Services, London,

1986. 7. USTER® QUANTUM 3 Operational Handbook: “The yarn quality assurance system -Winding”,

316 052-10010, December 2010. 8. USTER® QUANTUM 2 Application Handbook: “On-line quality management on winding ma-

chines”, V2.2, 304 000-89720, December 2008. 9. USTER® TESTER 5 Application Handbook: “Laboratory system for the measurement of yarns,

rovings and slivers”, V1.3, 410 106-04020, December 2008. 10. USTER® News Bulletin No 47: “Origins of fabric defects – and ways to reduce them: Recom-

mendations for Spinning Mills”, July 2010. 11. USTER® News Bulletin No 45: “Think Quality: Opportunities to improve the quality in the textile

supply chain”, July 2008. 12. USTER® CLASSIMAT QUANTUM Application Handbook, “Classification of thick and thin plac-

es, classification of foreign fibers”, V1.1, 304 100-89720, May 2005. 13. USTER® CLASSIMAT QUANTUM Application Manual, “Analysis of yarns by a sophisticated

classifying system”, Se 620, May 2008. 14. USTER® ZWEIGLE SPLICE TESTER 4 Application Report: “Determination of the strength and

elongation of splices”, SE 633, February 2010.

15. USTER® ZWEIGLE SPLICE TESTER 4 Application Handbook, “Determination of the strength and elongation of splices”, V1.0, 623 106-04020, October 2009.

16. Behery H., Thomas, R.K.T., “Understanding the Short Staple Manufacturing Process and the

Sources of its Yarn Faults”.

16 Appendix


Uster Technologies AG Sonnenbergstrasse 10 CH-8610 Uster / Switzerland Phone +41 43 366 36 36 Fax +41 43 366 36 37 www.uster.com

Local sales and service organizations under: www.uster.com → USTER Support/Tools → Customer Support

SW 461 040-10020 Printed in Switzerland © Copyright 2011 Uster Technologies AG

http://www.uster.com/

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