Presentation on theme: "Dr. Jimmy Lam Institute of Textiles & Clothing"— Presentation transcript:
1Dr. Jimmy Lam Institute of Textiles & Clothing Woven Fabric AnalysisDr. Jimmy LamInstitute of Textiles & Clothing
2What you can find from a woven fabric Believe it or not, you can find at least ten items from a piece of fabric.What are they?
3Information from a woven fabric Weave (structure)Order of coloring in warp and weft (if applicable)Sett – ends (warp) and picks (weft) per cmYarn particularsCounts (tex)Twist per cmS or Z twistSingle or fold yarn
4Information from a woven fabric (2) Crimp% in warp and weftWidth of warp in reedWarp length for a given finished fabric length (m)Weight of fabric per unit area (gm/sq. m)Type of material for both warp and weftType of finishing appliedOther factors: tensile strength, resistance to abrasion, drape, shower resistance, color fastness
6Face and back of woven fabric In defining which is the face or back of woven fabric, it is mainly accorded to type of material, yarn count, arranging of yarn, dyeing and printing, weave pattern, finishing effect. Typical for fabric surface are:Smoother;Soft handle;The face with solid jacquard pattern, pattern weave or printed weaveIt is always with higher warp float proportion of fabricFabric with special effects, the effects usually appears on the face.
7Distinguish of warp and weft (1) With reed markNo reed markEnd spacing is more uniformPick spacing is more irregularHigher tensionLower tensionParallel to selvedge-Higher sett (ends/cm)Lower sett (picks/cm)Higher strengthLower strength than warpIf folded yarn is used, warp is always with fold yarnWeft is single yarn
8Distinguish of warp and weft (2) Warp Weft If both are with same yarn, warp is finer, higher twist, with longer staple yarnWeft is coarser, lower in twist, shorter in stapleUsually sizedNo sizingWarp is Z twistWeft is S twistUsually lower crimp%Higher crimp%For stripes of fancy yarn, introduced in warp-For leno (selvedge), threads are warpFor cotton twill, twill run up from left to right when warp is vertical
9Finding crimp% and yarn count Crimp%=[(extended length) – (sample length) x100%] ÷ (sample length)For yarn count, it is determined through the weight of specific length and then calculate the count.Yarn count (tex) = yarn weight (gm) per 1000 meter.
10Yarn count (tex) Calculation Total length= no. of yarn sample x length of each sampleWeight of these samples=by directed weight and unit in gm.Weight of 1 km in length = by calculation in gmYarn count= weight in 1 km in length and unit in texExample:No of yarn sample taken=12Length of each yarn sample=6 cmTotal yarn length=(12x6)÷100 m =0.72mWeight of these samples =0.060gmWeight of 1 km in length=(1000 x 0.06)÷0.72 =83.3gmTherefore, yarn count =83.3 tex
11Fabric Weight Calculation This is done by calculation of fabric size 1 m x 1 m.The formula for warp weight:Warp weight (gm/sq m.) = [ends/cm x 100 x tex x (1+warp crimp%)] ÷ 1000The formula for weft weight:Weft weight (gm/sq m.) = [picks/cm x 100 x tex x (1+weft crimp%)] ÷ 1000Fabric Weight (gm/sq. m) = warp weight + weft weight
13Satin & Sateen WeavesIn these weaves, the warp faced ones are termed as “satin” and those of weft faced are termed as “sateen” weave.For either one, the interlacing points of two adjacent threads are so arranged that each only has one interlacing point and then floats across the width of the repeat.The results with a maximum degree of lustre and smoothness of no prominent weave features.Also, such arrangement of interlacing points of threads with each other lets them with much freedom, and therefore, more close packing of threads is possible
14Sateen of repeat number of 8 Which moves number is not possible, why?
15Sateen Weave For M=1 and 7, weaves of opposite twill lines are formed For M=2,4, and 6, some threads are without any interlacing pointsFor M=3 and 5, regular sateen weaves, with the above mentioned features are formed.
16Rules for the Move Number of Sateen Weave Some rules should be followed in the construction of regular satin or sateen weaves:The selected move number should not be either one or one less than repeat number of weave; or with a common factor of the repeat number
17Examples of Sateen Move Number Repeat NoMove no. excludedPossible move no.51,42,361,2,3,4,5None71,62,3,4,581,2,4,6,73,591,3,6,82,4,5,7101,2,4,5,6,8,93,7111,102,3,4,5,6,7,8,9151,3,5,6,9,10,12,142,4,8,11,13
18Sateen Repeat Number Possible Move Number Repeat =5, Possible M=2 and3Repeat =7, Possible move M=2,3,4 or 5
19Sateen Repeat Number Possible Move Number Repeat=9, M=2, 4 or 5Repeat=10, M=3 or 7Repeat=11, M=3 or 7