Definition | Tools for GSM checking_Calculation of GSM

GSM means the weight in gram per square meter of fabric. GSM is a parameter used for specified a certain quality of knitted fabric. The production of knitted fabric is calculated in weight. For this process the GSM cutter is used. The construction of this cutter is simple. It is circular in shape with 100 square cm area with sharp blade attached to its edge. So 100 square cm of fabric can easily cut by it and weighted at the electric balance to get GSM.

Tools for GSM checking

1. GSM cutter
2. Finished Fabric
3. Electrical Balance

 GSM Calculation

 

There are two formulas for calculating GSM

First formula

               Course per inch X Stitch length X 39.37 X 39.37 X Tex

GSM =    ----------------------------------------------------------

                                               1000 X 1000

and,

                WPI X CPI X SL(mm)

GSM =    ----------------------------- X 0.9155

                         Count(Ne)

WPI:  WPI means 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.

CPI: CPI means COURSE PER INCH. We calculated the number of course in 5 inch with the help of counting glass and needle. Then we divide the total no of course by 5 inch to getting the course per inch.

SL: SL means STITCH LENGTH. It is measured in mm unit. Stitch length is theoretically a single length of yarn which includes one needle loop and adjacent needle loops on either side of it. Loop exits in course in course length and it is that which influence fabric dimension and other properties including weight.

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.


MEASUREMENT OF YARN COUNT :

There are many ways to find out the count of the yarn. At first we unravel a considerable no yarn from the fabric. Then we measured the total length of the yarn and measured the weight of that no of yarn. From these weights, we find out the count of the yarn.

The equation we followed is as follow:

                 N x L x 453.6

Count =   ----------------

                 Wt x 36 x 840

Where,

N   = number of yarn in bundle.

L    = length of yarn.

Wt  = weight of yarn.

Second formula:

                    Ks x Tex

GSM =   ---------------------

              Stitch length (mm)

Where, Ks is a constant. Its value is different for different fabric structure and fabric type. Ks is calculated and estimated as below:

              GSM x Stitch length

Ks =     -----------------------------

                          Tex