3.1 INTRODUCTION - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/18790/11/11_chapter3.pdf ·...

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CHAPTER 3

MATERIALS AND METHODS

3.1 INTRODUCTION

This chapter provides details of cotton fibers, yarns, fabrics used in the

study. The work done in this thesis is presented in the following figure3.1

Figure 3.1

Flow chart for the methodology

The following figure 3.1 gives the overall methodology adopted in the

present study

Physical Properties

Yarn Tenacity

Elongation

Evenness

Hairiness

Imperfections

Tested for tenacity and elongation at gauge lengths of 12.7mm, 25.4mm, 76.2mm, 127.0mm and 254.0mm respectively for Weibull modeling

Conventional yarn50Ne

Compact yarn 50Ne(Suessen Elite)

Cotton Fiber-Type A

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L1 L2 L3 L1 L2 L3 L1 L2 L3

Com Con Com Con Com Con Com Con Com Con Com Con Com Con Com Con Com con

Com-compact, Con-conventional (18 Samples)

Production of weft- knitted fabrics using conventional and compact yarns of 50Ne

Single Jersey Rib Interlock

Scouring

Bleaching

Dyeing

Bio polishing

Wicking-Linear Regression analysis,

Slope,

Intercept

Correlation coefficient,

Spirality

1. Manual method

2. Scanning method

ANOVA &Correlation

coefficient

Total 72 Samples




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Testing of doubled yarn

Conventional yarn50Ne

Compact yarn 50Ne (Suessen Elite)

Doubling

Conventional

+

Conventional

Conventional

+

Compact

Compact

+

Compact

Five Levels of Twist per inch

16.5, 18.0, 20.5, 22, 24

Yarn tenacity, elongation,

hairiness ,imperfections

Analysis of Variance

Cotton Fiber-Type B




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Materials

The materials used in the current research work are discussed below:

3.2 SELECTION OF MATERIAL

The experiments were conducted on two Indian cotton varieties (Mcu5 and

Mcu5). The fiber parameters are measured with HVI. Both were spun to Ne

50(11.8tex). As seen from Table 3.1 the two cottons differ widely in their

characteristics so that they cover a fairly wide spectrum of cottons generally used

for spinning.

The cotton raw material was considered to produce 50s Ne combed

conventional yarn and compact yarn in Suessen Elite Spinning.

Type A cotton yarns have been chosen for knitted fabrics and processing of

them like, scouring, bleaching, dyeing and biopolishing and the fabric properties

have been analyzed. Type B yarns have been doubled (conventional-conventional,

compact-conventional, compact-compact) using TFO machine at five levels of

twist in S direction and their yarn properties were tested and analyzed.

Details of the cotton mixings used for the production of 50s combed yarns

are given in Table 3.1. It may be noted that two different types of cottons were

used for the production of 50s Ne yarns.

Table 3.1

Details of the Cotton Fiber Properties

Fiber parameters Unit Mcu5 Mcu5 2.5%Span Length mm 30.72 30.9

Fiber strength gm/tex 23.08 25.1 Micronaire - 3.7 4.3

Uniformity ratio - 46.89 47




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Methods

3.3 YARN PRODUCTION

3.3.1 Spinning Process parameters for producing Type A yarns

The sequence of process followed for producing 50s combed yarns is given

below.

1. BLOW ROOM

Hcc ventricular speed 1500 rpm

Vario cleaner // Mono speed 650

Grid bar setting 4/6/ 4/6

Hcc ventricular speed 1500 rpm

Vario cleaner // Mono speed 650

Hcc ventricular speed 1500rpm

2. UNIMIX

Unimix beater speed 630

Lattice speed 60mm

Feed roller speed 4.0mm

Feed roller to beat setting 3mm

Grid bar setting 5mm

Waste plate setting 2,2,3,4,4

3. FLEXI CLEANER

Flexi cleaner beater speed- -rpm

425

Feed roller speed 7.0mm

Grid bar setting 5mm

Feed roller to beater 3mm

Waste plate setting 2,2,3,4,4




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4. CARDING

Chute beater speed-rpm 980

Chute wall distance 130mm

Feed plate to lickerin 0.75

Cylinder to flats setting-mm 0.25, 0.25, 0.20, 0.20, 0.20

Cylinder to doffer -mm 0.125

Licker- in speed-rpm 900

Cylinder speed-rpm 500

Flats speed -m/min 13.3 / 24T

Cylinder to SFL C- cleaner 0.375

Cylinder to SFD C- cleaner 0.225

5. LDO/6

Speed hank 0.11

Delivery hank 0.115

Total draft 5.16

Bottom roll setting 40 // 42

Break draft .51

Speed-rpm 350

6. LH-10

No. of ends 20

Break draft 1.43

GMS / MTR 69

Total draft 1.042

Speed-rpm 85

7. COMBER

Table trumpet 4.5mm

Top comb index 1




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Waste% 21%

Deliver hank 0.14

Feed length 4.71

Speed(rpm) 300

8. RSB

Speed-rpm 400

Delivery hank 0.14

Break draft 7.875

Bottom roll setting 39 // 43

Trumpet size 6.2 / 3.5

Scanning roll size 6.4 / 6.7

Scanning roll punnel 6.5mm

Draw off roller 4.8

Web tension tube 7 / 7

Count 50 – BTS2

Speed 950

Break draft 1.095

Total draft 10.02

TPI 1.43 / 1.21

Spacer Green

9. CONDENSOR

Inlet Green

Middle Green

Floating Red

Bottom roll setting 35 / 47 / 48

Top roll setting 37 / 49 / 46

Creel draft 1.034




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10. SPINNING

Total Draft 38.12

Break draft 1.136

Average speed 18.000

Spacer 2.5mm

Traveler 11/OU1UM UDR MAXIMA

3.3.2 Spinning Process for producing Type B yarns

The sequence of process followed for producing 50s combed yarns is given

below.

Process Parameters

1. BLOW ROOM

Lap weight in Kgs 200 gms 22.0

gms / mtr. 336.66

Lap Hank 0.0016

2. SPEED

MFC Speed 440

MPM Speed 720

RK Speed 560

3. SETTING IN MM

Pedal to Beater setting 8.0 mm

Pedal to feed roller 0.125 mm

Beater to stripping plate 1.5 mm




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4. CARDING

Sliver Hank 0.005 0.15

Total Draft 5% 88

Tension Draft 1.71

Waste % 2% 7.0

4.1 Carding Setting

Feed Plate to licker in 1.016

Lickerin to cylinder 0.175

Cylinder to flats 0.20

4.2 Speed in RPM ( 10%)

Licker-in-rpm 960

Cylinder 420

Flat inches/min 7.3

5. DRAWING

Sliver Hank 0.001 0.15

No. of doubling 6

Total Draft 6

Roller setting in mm 38/42

Breaking Draft 1.5

6. COMBER

Total Draft 12.04

Noils 1% 19.0

Type of feed Forward

Feed Length in mm 4.3

Piecing setting +0.2

Draw Box setting in mm 471.56




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7. SIMPLEX

Break Draft 1.21

Total Draft 9.76

Tpi /Tm 1.39/1.2

Spacer size in mm 5.0 mm

Roller Setting in mm 44/50/45 3.3.3 Doubling and twisting of yarn The 50s count yarns both conventional and compact produced from Type B

mixing were doubled in TFO (Two for one twister) employing five levels of twist

(16.5, 18, 20.5, 22.0, 24.0) in S direction. Three levels of doubled yarn were made

with three combinations, conventional and conventional, compact and compact

and conventional and compact (hybrid).This has developed to study the potential

of these yarns.

3.4 YARN TESTING

The skein (lea) count and strength measurements to compute count strength

product were carried out on automated testers. The lea is produced on a wrap reel

by wrapping 120 yards of yarn on a 1.5 yard girth reel. As the yarn counts vary

from the nominal count spun corrections to the CSP were made using the

following formula

Corrected CSP=

countyarn Nominalcountyarn Actual2SPCActual

This measurements of lea strength is a rapid test and is very useful in the

production environment. Both single and doubled yarn were tested for count,

tenacity, elongation, hairiness, imperfections and evenness. The following

Table 3.2 gives details of the Yarn tests




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Table 3.2

Yarn Testing and standards

Nature of the test Instrument Testing Standard

Yarn Count and Count CV% Statex yarn Count system

ASTM D-1907-01

Yarn strength and elongation Ustertensojet Uster standard test method

Yarn evenness, imperfections, hairiness

Uster-5 ASTM D 1425-96

Single yarn strength at different gauge lengths

Instron ASTM D 2256-97

3.4.1 Measurements of yarn count:

Yarn count and count CV% were measured on Statex yarn count system

which is a combination of electronic balance and computer, Using this system,

readings were taken from the yarn samples and the mean value was calculated.

3.4.2 Measurements of yarn Strength and elongation:

All the tensile properties of yarn, (breaking strength and elongation) were

measured on the UsterTensojet using the single strand method .This instrument

works on the CRE principle.

3.4.3 Measurements of yarn hairiness, evenness and imperfections:

The evenness of yarn is one of main indexes to measure the quality of

yarns. The unevenness of yarns will deteriorate the mightiness of yarns, and

increase the end breakage rate in the spinning, and the increase of the end

breakage rate will directly limit the speed of the machines and reduce the

productivity. In addition, the unevenness of yarns will seriously influence the




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appearance quality of textiles. Yarn hairiness and evenness were measured on

Uster Tester 5.

3.4.4 Measurements of single yarn strength at different gauge Length:

The gauge length is the distance between the grips. The conventional and

compact spun yarn having 50’s count and constructed of 100% cotton were tensile

tested using INSTRON tensile tester to determine how their strength varies as a

function of gauge length. Twenty tests were performed at each gauge length of

254.0mm, 127mm, 76.2mm, 25.4mm and 12.7mm.

3.5 FABRIC PRODUCTION

In this work conventional and compact yarns were used to produce Single

jersey, rib and interlock structures with three different loop lengths. The details of

machine type and selection of loop length are given in following

Tables 3.3 to 3.5.

Table – 3.3

Knitting Machinery Details

Particulars Single Jersey Rib Interlock

Machine Falmac Singapore Falmac Singapore Shinta Taiwan

Model FSB 3XSK PN1.6XRB DBR4

Diameter 24 18 20

Gauge 28 18 28

Number of feeders 72 48 40




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Table – 3.4 Loop Length Calculation for the Selected Knit Structures

Knit Structures Samples Tightness Factor Tex0.5cm-1 Loop Length(cm)

Single Jersey R1, C1 14 0.245 R2, C2 15.5 0.221 R3, C3 17 0.206

Rib R4, C4 12 0.286 R5, C5 12.5 0.272 R6, C6 13 0.262

Interlock R7, C7 12 0.286 R8, C8 12.5 0.272 R9, C9 13 0.262

Table – 3.5

Nomenclature of the samples

S.No Samples Yarn Used Knit Structure Loop

Length (in cm)

1 R1 Conventional yarns Single jersey 0.245 2 R2 Conventional yarns Single jersey 0.221 3 R3 Conventional yarns Single jersey 0.206 4 R4 Conventional yarns Rib 0.286 5 R5 Conventional yarns Rib 0.272 6 R6 Conventional yarns Rib 0.262 7 R7 Conventional yarns Interlock 0.286 8 R8 Conventional yarns Interlock 0.272 9 R9 Conventional yarns Interlock 0.262 10 C1 Compact yarns Single jersey 0.245 11 C2 Compact yarns Single jersey 0.221 12 C3 Compact yarns Single jersey 0.206 13 C4 Compact yarns Rib 0.286 14 C5 Compact yarns Rib 0.272 15 C6 Compact yarns Rib 0.262 16 C7 Compact yarns Interlock 0.286 17 C8 Compact yarns Interlock 0.272 18 C9 Compact yarns Interlock 0.262




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3.6 CHEMICAL TREATMENTS

With a view to investigating the effects of chemical treatments on the

properties of knitted fabrics, they were subjected to chemical treatments and these

are described below. Commercially obtained chemicals were used in all treatments

The investigator has subjected the conventional and compact spun knitted

fabrics to scouring, bleaching, dyeing and finishing processes.

The processes were carried out under normal industrial parameters.

3.6.1 Scouring

Scouring is the process in which natural as well as artificial impurities are

removed. The ultimate aim of the scouring is to make the material uniformly and

highly absorbent in a cost-effective manner so that there are no difficulties in the

later processes of dyeing, printing and finishing

The scouring solution contained the following ingredients

Scouring Recipe:

Sodium hydroxide : 3.0 %

Sodium Silicate : 0.1%

Material: Liquor Ratio : 1: 20

Wetting Agent : 0.1%

Reaction Time : 1 Hour

Temperature : Boiling

The weighed amount of sodium hydroxide was wetted with wetting agent

followed by sodium silicate. The calculated amount of water was added to it. The

temperature was raised to 100 ºC and was kept for an hour. Then the fabrics were




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taken out and thoroughly washed followed by flat drying for two days. The fabrics

were then dried in oven for not more than 70 ºC. After 12 hours, the fabrics were

ready for wickability testing.

3.6.2 Bleaching

Bleaching is the process in which we remove the color pigments in order to

achieve the degree of whiteness. The bleaching of textile fibers with hydrogen

peroxide is certainly the most popular process today because it is

1. Environmental friendly. (Potentially it can decompose into oxygen and Water).

2. It is versatile (it can used hot or cold batch wise and continuous)

Bleaching Recipe:

Hydrogen peroxide : 3 %

Sodium Silicate : 3%

Soda Ash : 1 %

Sodium hydroxide : 0.5%


Reaction time : 1 Hour

Temperature : 70 ºC

The weighed amount of hydrogen peroxide, sodium silicate and soda ash

were mixed with the required amount of water and the temperature of the bath was

raised to the boiling point and kept for an hour. Then the samples were taken out

and after thorough washing and drying, they were ready for testing.

3.6.3 Dyeing

The reactive dyes offer a wide range of dyes with varying shades, fastness,

with high brilliancy, easy applicability and reproducibility. In addition to giving




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high wash fastness on cotton, reactive dyes usually give bright shade. Reactive

dyes have moderate to good light fastness and fair- to- poor chlorine fastness.

Hence the reactive dyes for dyeing the bleached knitted fabrics were

selected

Dyeing Recipe:

Machine : Soft Flow Machine

Dye : Reactive Dye (Yellow-0.08Gpl, Red-

0.05Gpl, Blue-0.2Gpl)

Salt : 50gpl (Time- 30 Minutes)

SodaAsh : 10gpl (Time- 45 Minutes)



The dyeing was carried out in industry under normal industrial practices.

3.6.4 Bio Polishing Finish

Biopolishing result in smooth fabrics with enhanced appearance and handle

.As mechanical force is involved in scouring, bleaching, it increases the fuzz on

cottons knit fabrics. The hairiness or fuzz that produced in the last stage can be

reduced when bio polishing is introduced with cellulase enzyme. Acid cellulases

enzyme is concentrated, non-GMO based biopolishing enzyme, can achieve

desired results at lesser dosage and less processing time.

Biopolishing Recipe:

Machine : Winch and Tumble Dryer

Enzymes : Acid cellulases (Ezysoft GM3)




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Reaction time : 1 Hour


The biopolishing requires equipment such as washing machine or winch

machine. The machine was filled with water, material liquor ratio was taken as

1:15, then bio wash liquid and softener was added to the winch. The pH was

maintained between 4.5 and 5.5; the bio wash was carried out for 1 hour. Cold

rinse for 5 – 10 minutes was followed by hydro extraction and tumble dry.

3.7 FULL RELAXATION

In order to achieve the fully relaxed state, all the treated knitted samples

were subjected to static wetting in water containing wetting agent for 24h at room

temperature, followed by gentle agitation in water heated up to 70oC which is

maintained for 30 min (laundering). The sample were then tumble dried at 80o c

for about 1 hr, The cycle of laundering, hydro extraction and tumble drying was

carried out for five times. This method was considered to fully relax the samples

in view of the results of Knapton et al. (1985).The desired fabric parameters were

subsequently measured and recorded after conditioning the samples at 25o

C,65%RH for several days.

3.8 FABRIC TESTING

After full relaxation, the properties of the processed fabrics were analyzed

at standard atmosphere conditions of 65% relative humidity and at 27± 2° C. The

geometrical fabric properties tested were loop length, wales per cm, courses per

cm, area density and thickness. Bursting strength, spirality and wickability were

also tested.




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3.8.1 Measurement of wales per cm

The samples of 10 cm x 10 cm size were marked at ten different places in

the fabric, using the pick glass, the numbers of wales were counted and the result

was divided by 10 to determine the number of wales in 1 cm.

Number of wales in 10 cm. Wales per cm = ----------------------------------- 10

3.8.2 Measurement of Courses per cm

The samples of 10 cm x 10 cm size were marked at ten different places in

the fabric. Using the pick glass, the numbers of courses were counted and the

result was divided by 10 to determine the number of course in 1 cm.

Number of course in 10 cm. Course per cm = ----------------------------------- 10 3.8.3. Stitch density: (ASTM D 3887)

Stitch density is the number of loops per unit area, which can be obtained

by multiplying the number of Wales and courses per unit length;

Stitch density in sq. cm = Wales per cm x Course per cm.

3.8.4 . Measurement of Loop length

The loop length is the length of yarn used in one knitted loop.100 Wales are

counted from each dry relaxed knitting sample. 10 courses were unraveled from

these samples and every course average length was measured using a scale. These

average lengths were divided by 100, which is the total wale number and the loop

length is calculated.




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3.8.5. Measurement of fabric weight (ASTM 3776)

Calculating the mass per unit area and expressing as g/m2 (GSM) is

customary for knitted fabric. A circular specimen of size 100 cm2 was cut rapidly

and accurately by using sample cutter. Sample cutter for GSM is a specialized

instrument to determine the GSM of the fabric.

GSM states the determination of weight per unit area, which is exactly

1/100th of a sq. meter. The results in grams, multiplied by 100 gives the GSM.

GSM = Specimen weight in grams x 100

3.8.6Measurement of Wickability

Sample size

The sample size for wicking measurement was 1" Wide and 10 " long. The

samples were cut in both wales wise and course wise directions in conventional

spun and compact spun scoured, bleached, dyed and finished single jersey, rib and

interlock structures.

Wicking instrument

The wicking instrument was developed which is made of wood. It consists

of two pillars on either side with a flat rod at the top for easy hanging of the

sample and the bottom edge of the sample is faced towards the beakers containing

distilled water, acidic solution and alkaline solution. (Plate I)




72




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Wicking measurement

The wicking behaviour of all the samples was analyzed by the vertical

wicking strip test. Measurements were taken out by ordinary capillary rise method

on all the samples. On all fabric strips (scoured, bleached, dyed and finished),

three lines after each cm were made to indicate the height of the capillary

ascension. To initiate the test, end of the samples were immersed into the beakers

containing distilled water, acidic solution and alkali solution. Wicking property

was tested according to the rise in the level of the water and other solutions. Lesser

the time taken to climb, better the wicking property of the fabric. Every time the

front liquid reaches a line, time is recorded. The tests were carried out at the same

atmospheric conditions (65 % ± 2 % Relative humidity and 27 ºC ± 2 ºC

Temperature) on all the samples. (Plate II)

3.8.7 Measurement of spirality

Several standards are available for determining the spirality of knitted

fabrics, eg. ASTM D3882-88-1997. British standard 2819 (1990) IWS test method

No. 276, AATCC test method 179-2004.

The spirality was measured according to the IWS 276 standard test method

(Degirmenci and Topalbekiroglu, 2010). According to this method, 5 different

places are chosen for each sample. First a wale is marked by pen, and the course

linked wale is then marked, as seen in Figure 3.2. By using a protractor, the angle

different from the normal of the wale is measured.




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QP B

AA’

180 180

90

3.8.7.1.Determination of angle of wale spirality: Manual method

The following steps were included to determine the spirality

The fabric samples were relaxed at room temperature for 72 hours to test

the spirality. The specimen was spread on a flat surface without any

tension.

Place the protractor along the course line PQ so that the line AB is

perpendicular to PQ.

Determine accurately the path of the wale line A’ that intersects with the

bottom of 90º line on the protractor.

The angle between the 90º line and wale line <ie AA’> is measured and

direction of spirality (right – left) is recorded.

Repeat this process 10 times. Finally the mean is calculated. The

percentage of spirality is calculated with the following equation.

PS% = AB-BA’ =

Where x is the angle of spirality.

Figure 3.2

Measurement of spirality by manual method

100XABx




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3.8.7.2 Determining the spirality by CorelDraw software

Tools used

- Pick Tool

- Pen Tool

- Zoom Tool

- Dimension Tool

The cotton-plain-knitted fabric samples used in this study have been dry

relaxed and prepared as 5”x5” square. Image of the sample have been acquired via

a scanner with 1200 resolution.

Image was opened with corel draw graphics suite 12 version. The following

steps were framed to measure the angle of spirality.

Step: 1

The first step is to magnify the knitted structure to 3-5 times larger using

zoom tool. After magnifying the knitted structure of single jersey fabric with wale

and course is clearly shown.

Step: 2

In the second step the pen tool is selected to draw a horizontal line and then

the angular dimension tool is used to measure the angle of spirality. The

dimension tool is dragged from bottom of the horizontal line to draw a vertical line

upto 2” and then it is dragged towards the direction of wale line that intersects the

course line. The angle is automatically displayed on the screen which periodically




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represents the wale’s angle (Figure 3.3) and it is to be recorded. The percentage of

spirality was calculated with the following equation:

PS% = 90-MV =

Where MV is the mean value

x is the percentage of spirality.

Figure 3.3

Knitted fabric sample showing spirality

10090

Xx




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3.8.8 Measurement of bursting strength (ASTM D 3786)

The bursting strength of the single jersey, rib, and interlock knitted fabrics

was tested with hydraulic bursting strength tester. The fabric specimen was

clamped by a ring over a thin flexible rubber diaphragm which itself was clamped

over a circular hole in the upper face of a reservoir. The pressure in the liquid was

increased by valves and due to increase in pressure the diaphragm bulges and the

fabric bursts and the pressure at that point was indicated by the pressure gauge.

The tests were carried according to ASTM standard. The readings were noted in

kg/cm 2.

3.8.9. Measurement of thickness (ASTM D 1777)

Thickness is the distance between one surface to its opposite in textiles, the

distance between the upper and lower surface of the material, measured under a

specified pressure.

Thickness is one of the basic physical properties of textile materials. Bulk

and warmth properties of textile materials are often estimated from their thickness

values, and thickness is also useful in measuring some performance

characteristics, such as before and after abrasion and shrinkage. The thickness

value of most textile materials will vary considerably depending on the pressure

applied to the specimen at the time the thickness measurement is taken.

MAG Thickness tester was used to measure thickness. The pressure foot

was lifted with the help of the lifting lever fixed on the top of the dial gauge. Then

the specimen was placed on the anvil and the pressure foot was lowered down

gently onto the specimen. Then the readings were noted on the dial gauge to get

the thickness of the specimen. The above procedure was repeated to obtain the

value of thickness and the average thickness was reported.




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3.9 STATISTICAL ANALYSIS

Weibull software was used to obtain the values of shape and scale

parameters for tenacity and elongation at different Gauge length of 12.7mm,

25.4mm, 76.2mm, 127.0mm and 254.0mm.

The doubled yarn with three combinations, (conventional and conventional,

compact and compact and conventional and compact) were analyzed statistically

by Analysis of Variance.

The test results were analyzed statistically, with the view to finding out the

samples having better wicking. Correlation is a statistical device which helps us

in analyzing the association of two or more variables, says Gupta (2008). The

slope is the vertical distance divided by horizontal distance between any two

points on the line, which is the rate of change along the regression line. Intercept

calculates the point at which a line will intersect the y-axis by using existing x-

values and y- values. The standard error is the measure of the amount of error in

the prediction of y for an individual x. Confidence intervals display 95%

confidence intervals for each regression coefficient tests.

Analysis of variance and correlation coefficient were applied to find out

if there is statistically significant difference between conventional and compact

single jersey fabric data obtained from two methods (Manual method and

CorelDraw method) of measuring spirality.




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