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Transcript of ,Loom Timing
Teaching Plan
(授课教案)
WEAVING
(机织学-双语教学)
Total teaching hours: 4×16=64
1st week
Chapter 1 Overview of the Weaving Process
(2 hrs)
Teaching r equirements of Chapter 1 This chapter will provide the basic knowledge of woven fabric formation
and the development of weaving technologies. Through the contents of this chapter, the students are required to be familiar with the interlacing structures of woven fabrics, their possible applications, and the processing technologies.
In addition, the students are asked to learn the vocabularies and some basic technical terms of weaving in English.
Teaching hours for the chapter: 2 hrs
ContentsGeneral introductionWoven fabric- Formation- Materials- Types of fabrics
Development of woven fabricsWeaving process
Key points Definition of woven fabric Flow chart of weaving process
Vocabulariesweaving, weaving preparation, weaving machine, warp yarn, filling yarn, woven fabric, gray fabric, dyed yarn fabric
Chapter 2 Winding (1)
(2 hrs)
Teaching requirements of Chapter 2 Winding is the first processing of weaving and an important processing
stage to ensure a success weaving. Through this chapter, the students are required to understand the objectives and the technical requirements of the process, to be familiar with the working principles of winding machine, and typical technical parameters. To provide them a theoretical background, they are asked to understand the built-up of the winding package.
In addition, the students are asked to learn the vocabularies and basic technical terms of winding in English.
Teaching hours for the chapter: 8 hrs
ContentsObjectives and requirementsDescription to winding processThree regions in winding- Unwinding
Methods of yarn withdrawal Tension and tension variation Balloon and balloon breaker
Key point s The path of the yarn in winding process Yarn tension variation and influencing factors
Vocabularieswinding, unwinding, side withdrawal, over-end withdrawal, yarn package, bobbin, cone, grooved drum, tension, tensioner, yarn clearer, balloon
2nd week
Chapter 2 Winding (2)
(2 hrs)
ContentsThree regions in winding (Cont.)- Tensioning and clearing
Tension device Clearing device Yarn defects Splicing device
- Winding Types of package drives Types of wound package
Key point s Working principle of tensioner Package drives and their features
Vocabulariessplicing, yarn hairiness, spindle drive, friction drive, cross wound package, parallel wound package
Chapter 2 Winding (3)
(2 hrs)
Contents - Winding (Cont.)
Winding angle Winding speed Winding methods
Key point s Formation of winding angle Winding method and the package built-up
Vocabularieswinding angle, constant angle of winding, constant pitch of winding, precision winding, step precision winding,
3rd week
Chapter 2 Winding (4)
(2 hrs)
Contents - Winding (cont.)
Cone winding (inc. driving radius, driving point, driving ratio, winding density)
Patterning and anti-patterning (inc formation of winding pattern, results problems, anti-pattern methods)
Key point s Parameters determining the built-up of the cone package Problems associate with the winding pattern Anti-pattern methods
Vocabulariesdriving radius, driving point, driving ratio, winding density, winding pattern, anti-patterning, driving radius, driving point
Practice 1
(2 hrs)
General descriptionYarn is the basic building block in weaving. In practice, the condition of
yarn produced on the spinning machine is not always good enough to be used directly for fabric formation. Package size, yarn surface characteristics, and other factors make it necessary for both filling yarn and warp yarn to be further processed for efficient fabric formation. Winding is the first processing of weaving and an important processing stage to ensure a success weaving.
R equirements In this practice, through a number of select questions, the key points and
possible difficulties during lecturing are reviewed to promote further understanding of the contents. The students are required to answer the questions.
In addition, the students are encouraged to ask questions of their own and try to make commons.
Question s Refer to “Questions” in the section of “Winding”
4th week
Test 1
(2 hrs)
The test is in written form and includes three parts, vocabularies involved in winding process, working principle of the processing equipment and the processing technologies. The students are asked to finish the test within 2 hours.
The score of this test will account for 10 % of the final examination.
Chapter 3 Warping (1)
(2 hrs)
Teaching requirements of Chapter 3 In this chapter warping process is introduced. The key point in this chapter
is the control of warping tension. Through this chapter, the students are required to understand the objectives and the technical requirements of the process, to be familiar with the working principles of warping machine, and typical technical parameters. They are asked to understand the reasons causing the variation of warping tension and the possible measures to ensure a uniform warp tension.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 4 hrs
ContentsObjectives and requirementsWarping methods- Direct warping- Section warping
Warping processCreel- Types- Tensioner and other devices
Key point s Path of yarn in warping process Features of different warp methods
Vocabularieswarping, direct warping, section warping, creel, single end creel, magazine creel, parallel creel, V-creel, headstock, extensible reed, warp beam, beaming, static eliminator, stop motion
5th week
Chapter 3 Warping (2)
(2 hrs)
ContentsWarping tension- Tension variation when yarn withdrawal from the package- Other factors influencing the variation of warping tension- Measures for a uniform warp sheet tension
Technical information in warp winding- Direct warping- Section warping
Key point s Factors influencing the tension variation in high speed warping Methods for a uniform warping tension
Vocabularieswarping tension, tension washer, surface friction drive, direct drive, warp band, pattern drum, warp separation, separation reed
Chapter 4 Slashing (1)
(2 hrs)
Teaching requirements of Chapter 4 The contents of this chapter include two parts, slashing processing and
size materials. Through this chapter, the students are required to understand the objectives and the technical requirements of the process, to be familiar with the working principles of slashing machine, and typical technical parameters. Tor size materials, the students are required to know the chemical structure and basic properties of major size film formers, i.e. starch, polyvinyl alcohol, and polyacrylic acid based sizes. Also, they are asked to know various types of additives. By select examples of size formula, the students are taught to understand how to chose the film former and additives according to the types of fiber, yarn and fabric to be processed.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 12 hrs
ContentsObjectives and requirementsSlashing process- Principle
Size penetration and encapsulation How yarn are sized
Key point s Path of yarn in slashing process Size penetration and encapsulation
Vocabulariesslashing, sizing, weavability, beam creel, size box, drying uint, lease rod, size penetration, size encapsulation, size solution
6th week
Chapter 4 Slashing (2)
(2 hrs)
ContentsSlashing process (Cont.)- Controlling parameters
General description to controlling parameters Size take-up How to control the size take-up
Key point s Size take-up and its controlling factors
Vocabulariessize take-up, size add-on, size concentration, sizing roller, squeezing roller, squeeze pressure, immersion roller, cover coefficient, desizing
Chapter 4 Slashing (3)
(2 hrs)
ContentsSlashing process (Cont.)- Controlling parameters
Elongation rate How to control the elongation rate Moisture regain How to control the moisture regain
Key point s Yarn elongation and its controlling factors Moisture regain of the sized yarns and the controlling factors
Vocabulariesmoisture regain, elongation rate, hot air dryer, cylinder drying chamber, withdraw tension, immersion tension, wet tension, drying tension, winding tension, desizing
7th week
Chapter 4 Slashing (4)
(2 hrs)
ContentsSize materials- - Film formers
Starch Modified starches Polyvinyl alcohol (PVA) Polyacrylic acid based sizes
Key point s Feature of starch as a film former and its modifications Degree of hydrolysis of PVA
Vocabulariessizing film, film former, adhesive, starch, modified starch, derivatives of cellulose, polyvinyl alcohol, polyacrylic acid based sizes, acrylate, acrylamide, viscosity, hydrophilic, hydrophobic
Chapter 4 Slashing (5)
(2 hrs)
ContentsSize materials (Cont.)- Additives
General description of additives Categories of additives
- Size formulation Factors determining the selection of size ingredients Selection of additives according to the film former
Key point s Principle of size formulation: The size materials (esp. the film formers) should be similar in construction to the fibers to enhance adhesion.
Vocabulariesadditive, thinning agent, surface active agent, surfactant, lubricant, Anti-static agents, preservative, humectant, anti-foam agent
8th week
Chapter 4 Slashing (6)
(2 hrs)
ContentsFilament sizingNew slashing technologies- High pressure sizing- Pre-wet sizing- Solvent sizing- Foam sizing- Hot melt sizing- Cold sizing
Key point s The technique of high pressure sizing and the features The technique of pre-set sizing and the features
Vocabularieshigh-pressure sizing, pre-wet sizing, solvent sizing, foam sizing, hot melt sizing, cold sizing
Chapter 5 Drawing-In and Tying-In
(2 hrs)
Teaching requirements of Chapter 5 Through this chapter, the students are required to understand the
objectives and the technical requirements of the process, to be familiar with the working principles of the process, and typical technical parameters. They are asked to understand the relationship between the interlacing structure of yarns and drawing-in process.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 2 hrs
ContentsDrawing-InTying-InDropper, heald frame and reed
Key point s The tasks of the processes
Vocabularies
drawing-in, tying-in, splitting, dropper, heald shaft, heddle, heald frame, harness, heald eye, heald wire, reed
9th week
Practice 2
(2 hrs)
General descriptionWarp preparation involves winding, warping, slashing and drawing-in or
typing-in. Modern weaving machines have placed increased demands on warp preparation due to faster weaving speeds and the use of insertion devices other than the traditional shuttle weaving. Warp yarn must have uniform properties with sufficient strength to withstand stress and frictional abrasion during weaving.
R equirements The practice of “Winding” has already been conducted in Practice 1. In this
practice, the rest processes of warp preparation are involved. Through a number of select questions, the key points and possible difficulties during lecturing are reviewed to promote further understanding of the contents. The students are required to answer the questions.
In addition, the students are encouraged to ask questions of their own and try to make commons.
Question s Refer to “Questions” in the sections of “Warping”, “Slashing” and “Drawing-
in”.
Test 2
(2 hrs)
The test is in written form and includes three parts, vocabularies involved in winding process, working principle of the processing equipment and the processing technologies. The students are asked to finish the test within 2 hours.
The score of this test will account for 20 % of the final examination.
10th week
Chapter 6 Weaving Fundamentals
(2 hrs)
Teaching requirements of Chapter 6 In this chapter the fundamental motions in a weaving machine is
introduced. Through this chapter, the students are required to understand the reason why modern shuttleless weaving machines are gradually replacing traditional shuttle weaving machine. They are asked to know various types of shuttleless filling insertion systems.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 2 hrs
ContentsPresentation of woven fabricWeaving processBasic motions in weavingClassification of weaving machineProblems of shuttle weavingFeatures of shuttleless weaving
Key point s Path of warp and filling yarn in a weaving machine Features of shuttle and shuttleless weaving
Vocabulariesshuttle, shuttleless, projectile weaving, rapier weaving, air-jet weaving, water-jet weaving
Chapter 7 Shedding (1)
(2 hrs)
Teaching requirements of Chapter 7 In this chapter shedding process is introduced. Through this chapter, the
students are required to understand the formation of shed geometry, the shed geometry and warp yarn stress, timing synchronization of shedding and other motions in a weaving machine. The students are asked to be familiar with the working principles of three shedding mechanisms, i.e. cam shedding mechanism, dobby shedding mechanism and Jacquard shedding mechanism. The working principles of modern electronic dobby and electronic Jacquard are also introduced.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 6 hrs
ContentsShed openingShedding and yarn stressShed geometry- Terms and definition- Warp yarn stress- Clear shed and unclear shed
Key point s Shedding motion and warp yarn stress Shed geometry and warp tension
Vocabulariesshedding, shed, front shed, back shed, top shed, bottom shed, clear shed, unclear shed, back rest, front beam, weave’s beam
11th week
Chapter 7 Shedding (2)
(2 hrs)
ContentsShedding motion- Stages of shedding motion- Timing of weaving process- Shed timing
Key point s Timing diagram Shedding motion and shed timing
Vocabulariesshed timing, shed level, warp line, period of shed opening, period of dwell, period of shed closing, diagram of loom timing
Chapter 7 Shedding (3)
(2 hrs)
ContentsShedding mechanism- Cam shedding- Dobby shedding- Jacquard shedding
Key point s Description of shedding motions Features of different shedding mechanisms
VocabulariesCam shedding, dobby shedding, Jacquard shedding
12th week
Chapter 8 Filling Insertion (1)
(2 hrs)
Teaching requirements of Chapter 8 In this chapter filling insertion process is introduced. Through this chapter,
the students are required to understand the timing synchronization of filling insertion and other motions in a weaving machine. Various filling insertion systems are explained, together with their technical details. The students are asked to be familiar with working principles of the typical shuttleless weaving machines.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 8 hrs
ContentsTiming of filling insertionShuttle weaving- Tasks of the shuttle- Picking mechanism- Timing synchronization- Controlling parameters- Average velocity of the shuttle- Selvedges of woven fabrics
Key point s Timing synchronization of filling insertion with shedding and beating up Picking principle and shuttle motion
Vocabulariesfilling insertion, filling insertion rate, picking device, picking stick, picker, shuttle box, checking device, picking time
Chapter 8 Filling Insertion (2)
(2 hrs)
ContentsProjectile weaving- Processing description- Picking process
picking energy generation and release- Features of projectile filling insertion
Selvedges in shuttleless weaving
Key point s Torsion rod and picking principle
Vocabulariesgriper projectile, torsion rod, projectile guide, tacked-in selvage, fringe selvage, leno selvage, melt selvage
13th week
Chapter 8 Filling Insertion (3)
(2 hrs)
ContentsRapier weaving- Processing description- Forms of rapier- Transfer of filling yarn- Features of rapier filling insertion
Filling yarn accumulator
Key point s Positive control of filling yarn in rapier weaving
Vocabulariesrigid rapier, flexible rapier, weft storage unit, prewinder, selvedge, filling feeder
Chapter 8 Filling Insertion (4)
(2 hrs)
ContentsAir-jet weaving- Processing description- Filling insertion system- Principle of Air-jet filling insertion
Air flow Yarn tension Dynamics of yarn insertion with air
- Performance of yarns in air-jet insertion Effect of yarn structure Effect of yarn count, twist and ply
- Features of air-jet filling insertionWater-jet Weaving- Processing description- Major characteristics of water-jet machines
Key point s Interaction between air flow and yarn structure Filling yarn tension in air-jet weaving
Vocabulariesnozzle, main nozzle, relay nozzle, supplementary nozzle, profile reed, confusor guide
14th week
Chapter 9 Beating-Up (1)
(2 hrs)
Teaching requirements of Chapter 9 In this chapter the process of beating up is introduced. Through this
chapter, the students are required to understand the formation of fabric by beat-up mechanism. The relationship between warp tension, cloth tension and weaving resistance is explained. The students are asked to be familiar with the working principles of beating up mechanisms. The timing synchronization of beating up, shedding and filling insertion is emphasized. Some parameters, such as the basic warp tension, position of the back rest and the shed timing, are introduced, together with their effects on fabric formation.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 6 hrs
ContentsTasks and requirementsBeat-up mechanismFabric formation- The cloth formation zone- Contract of cloth at the cloth fell
Key point s Movement of filling yarn at the cloth fell
Vocabulariesbeating up, reed, cloth formation zone, yarn crimping, pick spacing
Chapter 9 Beating-Up (2)
(2 hrs)
ContentsFabric formation (Cont.)- The weaving resistance- Bumping condition- Beating up strip
Key point s Beat-up force and weaving resistance Variation of warp tension and fabric tension during beat-up
Vocabularies
weaving resistance, beat-up force, beating up strip, bumping, pick spacing
15h week
Chapter 9 Beating-Up (3)
(2 hrs)
ContentsFabric formation (Cont.)- Parameters influencing fabric formation
Basic warp tension Vertical position of the back rest Shed timing
Key point s Warp tension and weaving resistance Position of back rest and shed asymmetry Shed timing and shed unbalance
Vocabulariesbeating up strip, basic warp tension, position of back rest, reed mark, shed asymmetry, shed unbalancing
Chapter 10 Take-Up and Let-Off (1)
(2 hrs)
Teaching requirements of Chapter 10 In this chapter working principles of various mechanisms of fabric take-up
and warp let-off are introduced. Through this chapter, the students are required to understand the principle of warp tension regulation, formation of fabric and pick spacing regulation in weaving machines.
In addition, the students are asked to learn the vocabularies and basic technical terms of warping in English.
Teaching hours for the chapter: 4 hrs
ContentsFabric Take-Up- Take -up mechanism- Operating principles- Filling density
Key point s Take-up rate and the control of pick spacing
Vocabulariestake-up mechanism, negative take-up, positive take-up, on-loom filling density, off-loom filling density
16th week
Chapter 10 Take-Up and Let-Off (2)
(2 hrs)
ContentsWarp Let-off- Let-off mechanism- Operating principles- Warp tension regulating device
Key point s Warp tension regulation in a weaving machine
Vocabularieslet-off mechanism, positive let-off, negative let-off, warp tension regulating device
Practice 3
(2 hrs)
General descriptionAlthough there are many mechanisms on a modern weaving machine for
various purposes, there are five basic mechanisms that are essential for continuous weaving: shedding, filling insertion, beat-up, warp let-off and fabric take-up. Shedding is the movement of some warp yarns up and some down to make an angled opening for the filling yarn to be inserted through. After each shed change, the filling yarn is inserted through the shed by means of carriers of various types. The newly inserted filling yarn needs to be brought to its final position by beating up. Warp let-off mechanism releases the warp yarn from the warp beam and applies tension to the warp yarns by controlling the rate of flow of warp yarns and the take-up mechanism removes cloth at a rate that controls filling density.
R equirements In this practice, the weaving process is involved. Through a number of
select questions, the key points and possible difficulties during lecturing are reviewed to promote further understanding of the contents. The students are required to answer the questions.
In addition, the students are encouraged to ask questions of their own and try to make commons.
Question s Refer to “Questions” in the sections of “Weaving”.