Change of Fabric Gsm With Yarn Count

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Change of fabric GSM vary with yarn count


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GENERAL INTRODUCTION Fabric is a manufactured assembly of fibres and yarns that has substantial surface

area in relation to its thickness and sufficient cohesion to give the assembly

useful mechanical strength. Fabrics are most commonly woven or knitted but theterm includes assemblies produced by felting, lace making, net making, non wovenprocesses and tufting. Our project basically is on knitted fabric specification andmachines which are related to knitted fabric production.

The title of our project work is Analysis of knitted fabric specification and otherrelated machine specification. There are problem in our industries to produce

knitted fabrics of required G.S.M. Other specification like fabric width, fabricthickness is generally maintained in industries by previous data sheet. For thisreason there are problem if any order comes which didntproduced in previous.

Our target is to find out the easy process to get decision about yarn count selection,loop length selection, machine Diameter selection & machine gauge selection.

We strongly think that by this process we can get decision about yarn count, looplength, machine gauge, and machine diameter for the single jersey, Rib andinterlock fabric.

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Aim of the project work

Find out relation between yarn count and

GSM.

Find out the logic of selection of stitch length

selection.

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LITERATURE REVIEW

What is yarn

Yarn is a long continuous length of interlocked fibers,

suitable for use in the production of textiles, sewing,

crocheting, knitting, weaving, embroidery and rope

making. What is Fabric

Fabric or cloth is a flexible artificial material that is made

by a network of natural or artificial fibers. The example is

thread or yarn which is formed by weavingor knittingasin textiles. Cloth is mostly used in the manufacturing of

clothing and household furnishings etc.

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Weaving

Weaving is a method offabric production in whichtwo distinct sets of yarns orthreads are interlaced at rightangles to form a fabric or

cloth. The longitudinalthreads are called the warpand the lateral threads arethe weft or filling. The

method in which thesethreads are inter wovenaffects the characteristics ofthe cloth.

Fig. Interlacement of

warp & weft6


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Knitting

Knitting is a method bywhich thread or yarn may

be turned into cloth or

other fine crafts. Knitted

fabric consists of

consecutive rows of loops,called stitches. As each

row progresses, a new

loop is pulled through an

existing loop. The active

stitches are held on aneedle until another loop

can be passed through

them. This process

eventually results in a

final product.

Fig. Looping diagram

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Course: A course is predominantly

horizontal row of needle loops

produced y adjacent needles during

the same knitting cycle.

Wales: A wale is a predominantly

vertical column of intermeshed needle

loops produced by the same needle

knitting at successive knitting cycle. A

wale commences as soon as an empty

needle starts to knit.

Stitch length: Is theoretically a singlelength of yarn which includes one

needle loop and

adjacent needle loops on either side of

it

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GSM= Grams per Square Meter. A measurement system more

commonly seen in paper, but also seen in t-shirts, it measures

the weight of the sheet (of fabric, paper, etc.), which will give

you some indication of its thickness. There are two formulas

for calculating the GSM of knitted fabric:-

GSM =

Course per inch x Stitch

length x 39.37 x 39.37 x Tex

=1000 x 1000

GSM =

WPI x CPI x SL (mm) x 0.9155

=

Count (Ne)

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SOME MEASUREMENT NEED FOR

GSM CALCULATION

CALCULATION OF WALES PER INCH:

We calculated the number of wales in 10 inch fabric unraveling the

yarn. Then we divide the no. of total wales by 10 inch to getting the

wales per inch.

CALCULATION OF COURSE PER INCH:

We calculated the number of course in five inch with the help of

counting glass and needle. Then we divide the total no. of course by

five inch to getting the course per inch.

MEASUREMENT OF STITCH LENGTH:

In order to determine the stitch length, we count 100 no wales or

stitch and count its length by hanging the yarn on the stitch counter.

The reading is found in mm unit.

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MEASUREMENT OF YARN COUNT:

We have fallowed a different way to find out the count ofthe yarn. At first we unravel a considerable no yarn from thefabric. Then we measured the total length of the yarn andmeasured the weight of that no of yarn. From these weights,we find out the count of the yarn. The equation we followedis as follow:-

n-1 x 453.6

Count =

Wt x 36 x 840

Where, n= number of yarn in bundle.L= length of yarn.

Wt= weight of yarn.

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Yarn count is calculated in two systems:a. Direct system

b. Indirect system

Direct system:

In this system the the weight per unit length is the yarn count. This is use

for thrown silk, artificial silk, jute etc and count calculation formula is the

following

W x lCount =

L

Here, W = weight of sample.

L = length of sample.

l = unit length in system.

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Indirect system:In this system the count of yarn express the no of unit length per unit

weight. In this system higher the yarn count finer the yarn. It is generally

used for cotton, worsted, woolen, linen etc and the yarn count calculationformula is the following:

L x w

Count=

W x l

Here, W = weight of sample.

L = length of sample.

w = unit weight in system.l = unit length in system.

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GSM DEPENDS ONThe main material for knitting process is yarn. The quality of knitted yarn should be like as

follows:Parameter 30/1 Cotton Combed 30/1 Cotton Carded 30/1 Poly Cotton

Best Acceptable

limit

Best Acceptable

limit

Best Acceptable

limit

Uniformity % 99.5 9.710.2 11.5-12.1 12.8-13.5 9.5-9.8 10.4-10.7

Thin (-50%) 0 3 - 5 16-22 50-60 2-3 7-10

Thick (+50%) 7 - 12 32-43 75-90 250-300 15-20 34-42

Neps (+200%) 38 - 47 73 - 88 140-175 300-380 30-45 48-58

Hairiness 4.04.4 4.6 - 4.9 4.75-5.1 5.5-5.8 4-4.44 4.45-4.8

Tenacity

(CN/tex)

21.822.6 18.4 - 18.9 16.7-17.6 16.2-15.4 25.5-24 23.4-22.1

Elongation 6.76.9 6.2 - 6.4 7.3-7.08 6.6-6.4 14.7-13.7 11.8-11.2 14


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YARN COUNT

The following counts of yarn that are widely used for knitting

process are given:

a) Cotton: 20/1, 24/1, 26/1, 28/1, 30/1, 34/1, 40/1 Ne.

b) Terylene cotton: 20/1, 24/1, 26/1, 28/1, 30/1 Ne. c) CVC: 26/1, 28/1, 30/1, 34/1 Ne.

d) Melange: 20/1, 22/1, 26/1, 30/1 Ne.

e) Spandex: 40D, 70D.

f) Polyester: 75D, 150D. g) Sewing thread: 40/2, 150D etc.

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RELATIONSHIP BETWEEN

KNITTING PARAMETERS

1. Stitch length increase with the decrease of GSM.

2. If stitch length increase then fabric width increaseand WPI decrease.

3. If machine gauge increase then fabric widthdecrease.

4. If yarn count increase then fabric width increase.

5. If shrinkage increases then fabric width decrease

but GSM and WPI increase.6. For finer gauge, finer count yarn should use.

7. Grey GSM should be less than finish GSM.

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The following equations for

the selection of yarn count to

get required G.S.M.

equations vary for fabric

types, fabric construction.

List of equations are

tabulated below:

Single jersey

Yarn count = - 0.141 GSM + 50.22

Pique

Yarn count = - 0.146 GSM + 57.16

Double lacoste

Yarn count = - 0.167 GSM + 64.36

1 x 1 Rib

Yarn count = - 0.123 GSM + 54.57

Lycra 1 x 1 RibYarn count = - 0.119 GSM + 59.12

Lycra 2 x 2 Rib

Yarn count = - 0.108 GSM + 56.62

Interlock

Yarn count = - 0.206 GSM + 80.56

Single jersey

GSM = -6.879yarn count + 350.4

Lycra Single jersey

GSM = -4.9716 yarn count + 354.56

Pique

GSM = -6.6737 yarn count + 386.44

1 x 1 Rib

GSM = -7.9731 yarn count + 437.66

Lycra 1 x 1 Rib

GSM = -8.2839 yarn count + 494.08 Lycra 2 x 2 Rib

GSM = -8.2839 yarn count + 494.08

Interlock

GSM = -4.778 yarn count + 388

EQUATIONS FOR GETTING

REQUIRED GSM FROM THE

SPECIFIC YARN COUNT:

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Relation among GSM, stitch length and yarn count can be

derived from the following equation

1

GSM (When Yarn count and Stitch length both

Yarn count x Stitch length are variable)

Different properties were found in Different knit structures according to stitch

length, stitch density that means wales per inch, course per inch. Loose structure

that means higher loop length gives less GSM on fabric & compact structurethat means shorter loop length gives high GSM on fabric.

In our project analysis, we observed that single jersey plain structure & 11

plain rib structure variation of calculated GSM with respect to actual GSM is

too small. But in single lacoste & polo-pique structure variation of calculated

GSM with respect to actual GSM is high. Because single lacoste & polo-pique

structure are made by combination of knit & tuck loops. They also analyzed that

one knit loop consumes 30% more yarn than tuck loop. So calculated GSM is

higher in single lacoste & polo-pique structure than single jersey plain structure

& 11 plain rib structure.

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SOME FABRICS GSM IS SHOWED WITH

CHANGING YARN COUNTSI. No. Fabric Type Yarn Count SL (mm) GSM

1. Strip S/J 26/1 2.86 1602. S/J 30/1 2.80 150

3. Double Pique 32/1 2.58 165

4. 1/1 Rib 30/1 2.60 220

5. 1/1 Rib 20/1 3.20 270

6. 1/1 Rib 24/1 2.90 220

7. 1/1 Rib 28/1 2.67 2008. 1/1 Rib 32/1 2.45 200

9. S/J 28/1 2.78 155

10. S/J 40/1 2.45 110

11. S/J 28/1 2.75 160

12. Full Feeder Lycra S/J 34/1 2.90 180


14 Full Feeder Lycra S/J 28/1 2.80 160


16. 1/1 Rib 24/1 3.00 270

17. 1/1 Rib 40/1 cvc 2.80 250

18. 2/2 Rib 30/1 2.78 22019. 1/1 Lycra Rib 30/1 + 40D 2.90 230

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RESULT DISCUSSION

From our project work we manage to find the following equations for the

selection of yarn count to get required G.S.M. equations vary for fabric

types, fabric construction. The equations are tabulated below:

Relation between the fabric GSM and the yarn count:

If the GSM of the fabric is x and the count of yarn is y, then the

equation for determining GSM and the Yarn count is as follows:

GSM, x = 332 - 5.88y &

Yarn count (Ne), y = 56 - 0.17x

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CONCLUSION

About this project learning thing is that fabric GSM change

during production. Different type of yarn and Yarn count has

vary the fabric GSM. It is also vary with stitch length, dyeing

and VDQ pulley. These parameters are responsible for GSM

change. From this project try to input some information forhow GSM depends on any other parameters.

So these things are should learn well to avoiding upcoming

problem and increase productivity.

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Change of Fabric Gsm With Yarn Count