Presentation on theme: "Woven Fabric Analysis Dr. Jimmy Lam Institute of Textiles & Clothing."— Presentation transcript:
Woven Fabric Analysis Dr. Jimmy Lam Institute of Textiles & Clothing
What you can find from a woven fabric n Believe it or not, you can find at least ten items from a piece of fabric. n What are they?
Information from a woven fabric 1. Weave (structure) 2. Order of coloring in warp and weft (if applicable) 3. Sett – ends (warp) and picks (weft) per cm 4. Yarn particulars –Counts (tex) –Twist per cm –S or Z twist –Single or fold yarn
Information from a woven fabric (2) 5. Crimp% in warp and weft 6. Width of warp in reed 7. Warp length for a given finished fabric length (m) 8. Weight of fabric per unit area (gm/sq. m) 9. Type of material for both warp and weft 10. Type of finishing applied 11. Other factors: tensile strength, resistance to abrasion, drape, shower resistance, color fastness
ItemsUnits Weave, drawing-in and lifting plan - Fabric width Cm Warp density Ends/cm Weft density Picks/cm Warping (Colour pattern) - Wefting (Colour pattern) - Warp crimp % Weft crimp % Warp count & material Tex Weft count & material Tex Fabric weight Gm/sq. m
Face and back of woven fabric n 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 weave –It is always with higher warp float proportion of fabric –Fabric with special effects, the effects usually appears on the face.
WarpWeft With reed mark No reed mark End spacing is more uniform Pick spacing is more irregular Higher tension Lower tension Parallel to selvedge - Higher sett (ends/cm) Lower sett (picks/cm) Higher strength Lower strength than warp If folded yarn is used, warp is always with fold yarn Weft is single yarn Distinguish of warp and weft (1)
WarpWeft If both are with same yarn, warp is finer, higher twist, with longer staple yarn Weft is coarser, lower in twist, shorter in staple Usually sized No sizing Warp is Z twist Weft is S twist Usually lower crimp% Higher crimp% For stripes of fancy yarn, introduced in warp - For leno (selvedge), threads are warp - For cotton twill, twill run up from left to right when warp is vertical - Distinguish of warp and weft (2)
Finding crimp% and yarn count n Crimp%=[(extended length) – (sample length) x100%] ÷ (sample length) n For yarn count, it is determined through the weight of specific length and then calculate the count. n Yarn count (tex) = yarn weight (gm) per 1000 meter.
Yarn count (tex) Calculation n Total length= no. of yarn sample x length of each sample n Weight of these samples=by directed weight and unit in gm. n Weight of 1 km in length = by calculation in gm n Yarn count= weight in 1 km in length and unit in tex n Example: –No of yarn sample taken=12 –Length of each yarn sample=6 cm –Total yarn length=(12x6)÷100 m =0.72m –Weight of these samples =0.060gm –Weight of 1 km in length=(1000 x 0.06)÷0.72 =83.3gm –Therefore, yarn count =83.3 tex
Fabric Weight Calculation n This is done by calculation of fabric size 1 m x 1 m. n The formula for warp weight: –Warp weight (gm/sq m.) = [ends/cm x 100 x tex x (1+warp crimp%)] ÷ 1000 n The formula for weft weight: –Weft weight (gm/sq m.) = [picks/cm x 100 x tex x (1+weft crimp%)] ÷ 1000 n Fabric Weight (gm/sq. m) = warp weight + weft weight
Satin & Sateen Weaves n In these weaves, the warp faced ones are termed as “satin” and those of weft faced are termed as “sateen” weave. n 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. n The results with a maximum degree of lustre and smoothness of no prominent weave features. n 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
Sateen of repeat number of 8 Which moves number is not possible, why?
Sateen Weave n For M=1 and 7, weaves of opposite twill lines are formed n For M=2,4, and 6, some threads are without any interlacing points n For M=3 and 5, regular sateen weaves, with the above mentioned features are formed.
Rules for the Move Number of Sateen Weave n Some rules should be followed in the construction of regular satin or sateen weaves: n 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
Examples of Sateen Move Number Repeat No Move no. excluded Possible move no. 51,42,3 61,2,3,4,5None 71,62,3,4,5 81,2,4,6,73,5 91,3,6,82,4,5,7 101,2,4,5,6,8,93,7 111,102,3,4,5,6,7,8,9 151,3,5,6,9,10,12,142,4,8,11,13
Sateen Repeat Number Possible Move Number Repeat =5, Possible M=2 and3 Repeat =7, Possible move M=2,3,4 or 5
Sateen Repeat Number Possible Move Number Repeat=9, M=2, 4 or 5 Repeat=10, M=3 or 7 Repeat=11, M=3 or 7