1. Weaving Preparation , Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth.pdf

Cloth is usually woven on a loom, a device that holds the warp threads in place while filling threads are woven through them. A fabric band which meets this definition of cloth can also be made using other methods, including tablet weaving, back strap loom, or other techniques without looms.

1. Weaving: Introduction

2. Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 2
Reference Books
1.Weaving:Conversionofyarntofabric;P.R.Lord,M.H.Mohamed
2.Weavingmechanism;Prof.N.N.Banerjee
3.Understandingtextilesforamerchandiser;Engr.ShahAlimuzzamanBelal
4.WeavingPreparationTechnology;N.Gokarneshan
5.HandbookofWeaving;SabitAdanur

3. Weaving
Types of fabric:
1.Woven fabric: The fabrics which are produced by two sets of yarn by interlacing
are called woven fabric. The name of two sets yarn are-
a)Warp yarn/ends and
b)Weft yarn/Picks/filling yarn
2.Knitted fabric: The fabrics which are produced by one sets of yarn by
interloopingare called knitted fabric.
3.Non woven: Here fabrics are produced by connecting yarn with gummy or bonded
materials.
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 3

4. Weaving
▪Weaving is the process most used for the manufacture of textile fabrics.
▪In weaving two or more sets of yarns are interlaced at right angles to each other.
▪The warp yarns run in the lengthwise direction in a woven fabric also called as
ends.
▪The filling yarns run in the crosswise direction also called as picks.
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 4
Fig: Determination of warp & weft yarn

5. Weaving
Identification of warp and weft yarn in a woven fabric: The characteristics of warp
and weft yarn differ from each other. Followings are the main characteristics of warp
and weft yarn.
▪Warp count is better than weft count.
▪Warp yarn is more twisted than weft yarn
▪Yarn which contains size particles is warp yarn.
▪Normally stripe effect is done in warp direction (both woven and printed fabric).
▪Warp yarns are relatively hairy yarn.
▪Warp crimp is expected to be less than weft crimp due to high warp tension on the
loom.
▪In most cases, EPI/EPCmis more than PPI/PPCm.
▪The selvedge direction is warp.
Warp and weft yarn is used for interlacement for producing woven fabric.
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 5

6. Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 6

7. Weaving FLOW CHART OF WEAVING:

Yarn from spinning department



Warp yarn Weft yarn

Cone/cheese winding Pirn/cop winding

Warping

Sizing

Drawing in or tying in

Denting

Weaving

Fabric checking

Fabric folding

Bale of fabric or baling
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8. Continued…
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9. Continued…
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10. Weaving
YarnPreparation
Necessityofwarpyarnpreparation:
Yarnisthemainelementofweaving.Theyarncollectedfromspinningsection
cannotbeusedinloomdirectly.Beforeusingitinloomisprocessedbyvariousways.
Allofthoseactivitiesarecalledyarnpreparation.
Preparationofwarpyarnisnecessarybecause-
▪Imperfectionsofyarnneedtobecorrected.
▪Requirementtotransferthespunyarnsinaconvenientpackage.
▪Extratreatmenttomaketheyarnreadyforweaving.
▪Warpyarnmustbeabletowithstanddestructiveforcestowhichitissubjectedduring
theweavingprocess.
▪Yarnhairinessmustbedecreased.
▪Yarnsmustbealignedproperly.
▪Yarnelongationandflexibilitymustbesustained.
▪Desiredlengthonapackagetobegained.
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 10

11. Weaving
Necessityofweftyarnpreparation:
Onconventionalloomthefillingyarnisinsertedbymeansofashuttlecarrying
abobbin.Thisbobbinshouldbetaperedattheendsothattheyarnmaybepulled
withoutinterruptionthroughtheeyeoftheshuttleastheshuttletravelsfromonesideof
theloomtotheother.
Preparationofweftyarnisnecessarybecause-
▪Removalofslubs&weakplacesduringprocessingwhichotherwisewouldimpairthe
runningoftheloom.
▪Theproductionofthetighterpackageshavingmoreyardsperpirn.Thisreducesthe
numberofpirnchangesintheloom.This,inturn,reducesthepossibilitiesofflaws&
wastage.
▪Greateruniformityofpirnsusedontheloom.Thisimprovestheuniformityofthe
fabric.
▪Theeasyhandlingofthesmalllots.
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 11

12. Weaving
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 12

13. Weaving
Different Yarn Faults
Thick place:
It is a fault of length approximately the fiber staple length, having a cross section >50%
of the average value (+50% cross section).
Thin place:
It is a fault of length approximately the fiber staple
length, having a cross section <50% of the average
value (-50% cross section).
Both thick & thin places are produced due to drafting
irregularities.
Md. Abdul Alim, Lecturer, Dept. of Textile Engineering, KUET. 13

14. Weaving
Neps:
It is a fault length of 1 mm having a cross section of
200% of the average value.
Generated due to immature fibres in raw materials.
Slubs:
It is a fault of longer length than nepshaving a cross section >400% of the average
value.
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15. Weaving
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16. Weaving
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17. Weaving
Featuresofagoodwarp
Theessentialfeaturesofagoodwarpareasfollows:
▪Theyarnmustbeuniform,cleanandfreefromknotsasmuchaspossible.
▪Theyarnmustbesufficientstrongwithwithstandthestressandfrictionwithoutend
breakage.
▪Knotsshouldbeastandardsizeandtype.Sothattheycanpassthehealdeye,
dropper,reedeasily.
▪Thewarpmustbeuniformlysizedandsizecoatingshouldbethickenoughtoprotect
theyarnvariousfunction.
▪Theendsofwarpmustbeparallelandeachmustbewoundontoaweaversbeamat
anevenandequaltension.
▪Allwarpyarnshouldofsamesizeinlength.
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18. ❑Historical background of fabric manufacture