Textile Calculations

TD-4074, TEXTILE CALCULATIONS (Weaving Calculations)

Khubab Shaker Lecturer

Weaving Department National Textile University, Faisalabad

TD-4074, Textile Calculations (Weaving)

Khubab Shaker

Course Outlines Lectures 2

3

2

2

3

Module

Learning Outcomes

Fabric contraction

-Calculate warp contraction -Calculate weft contraction -Contraction in different weaves

Fabric Weight

-Determine GSM of fabric -Determine warp weight per linear meter (GLM) -Inter-conversion of GSM and GLM

Cover factor

-What is cover factor -Factors affecting cover factor -Calculate cover factor for different constructions

Reed calculations

-Determine reed space for a quality -Determine reed count for fabric -Determine total ends for fabric qualities

Yarn requirement

-Determine requirement of warp for particular quality. -Determine requirement of weft for particular quality. -Fabric produced from a certain amount of yarn

Reference Book

“Weaving Calculations” by R. Sen Gupta

th

7 Semester, Fall 2013

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Khubab Shaker

1. Fabric Contraction The woven fabric is produced by interlacement of two type of yarns, i.e. warp and weft. Contraction produced in the fabric is due to the undulations/crimp in the yarn. The contraction in fabric depends on the warp count, weft count, ends/inch, picks/inch and weave design. The plain woven fabric has the maximum contraction (due to more number of intersection), while the other weaves have less contraction. Contraction is also affected by loom settings and fiber type. F abri c Quality

Warp Contraction

Weft Contraction

W.F. = Weave Factor For 1/1=1 For 2/1= 1.16 For 3/1= 1.26 For 4/1= 1.34

Exercise 1: Problem 1.1: Determine the warp and weft contraction for quality Problem 1.2: Determine the warp and weft contraction of 2/1 twill for quality Problem 1.3: Determine the warp and weft contraction of 3/1 twill for quality Problem 1.4: Determine the warp and weft contraction for quality

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Khubab Shaker

2. Weight of Fabric The fabric weight is expressed in terms of grams per square meter (GSM), grams per linear 2 meter (GLM) or ounces per square yard (oz/yd ). The most commonly used term to compare different fabrics is GSM. It depends on the warp & weft count, thread density andcontraction in the fabric.

GLM It is the weight of one linear meter of the fabric, irrespective of the fabric width.

Exercise 2:

2

Problem 2.1: Calculate the weight/m and weight/linear meter with and without size for quality

. Warp & weft contraction are 8.5% and 3.5%. Size add on in warp is 9%.

Problem 2.2: Calculate the GSM and GLM with and without size for plain fabric quality , if size %age is 16% and warp & weft contraction are 8.5% & 6.85% respectively. Problem 2.3: Calculate the sized and un-sized GSM and GLM of 4/1 satin fabric

.

The warp is sized to 9.5%

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Khubab Shaker

3. Cover Factor The cover factor is represented by Kc, and is the sum of warp cover factor (K 1) and weft cover factor (K 2). It can be calculated by the following formula:

Another formula for GSM

4. Reed Calculation Reed is the part of loom responsible to beat the filling yarn to the fell of cloth. The reed consists of a number of small metallic strips called dents. Every reed has a specific reed count, which is expressed as number of dents/inch.

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Khubab Shaker

5. Yarn Requirement

Where,

Exercise 5: Problem 5.1: Calculate the amount of yarn required to produce 2000 meter fabric for quality . The warp & weft contraction are 8.5% and 3.5%. Problem 5.2: How much weft yarn is required to weave 5000 yards of a satin fabric quality , if warp & weft contractions are 8.5% & 6.85% respectively. Problem 5.3: Calculate the warp and weft yarn required in grams to weave

4/1

satin. The order quantity is 300 meters.

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Textile Calculations

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