Fabric Weight Calculation in GSM
Fabric Weight Calculation in GSM (Woven Fabric)
GSM calculation of fabric
Fabric is the basic raw material to produce any particular garments . Before going to bulk production , it is quite essential to know and test the GSM of the supplied fabric by the supplier. This GSM can directly be got through GSM cutter .
But the GSM can be theoretically evaluated via some calculations . We will discuss here that process.
What is GSM?
Fabric GSM means the weight of fabric in grams in per square meter area. So the higher the GSM , the higher bulkier will be the fabric and vice versa , even they can be of same construction
Fabric Construction is a term in which some fabric detailing are available such as
EPI (Ends per inch –warp)
PPI (Picks per inch – weft)
fabric width (in inches) .Some Examples :
Calculation of GSM :
Warp weight calculation :
Here , EPI = 92
So total number of ends = 92×39.37
(as we have to go to meter cause EPI is in inches but GSM is in meter unit and 1 meter=39.37 inches )
Length of each 1 meter yarn allowing the crimp % = 1m + 1m x 3% ( Let, warp crimp = 3%)
= 1m + 1m x 0.03
= 1m + 0.03 m
= 1.03 m
(this is necessary to find out 1 meter yarn length because when we take 1 meter in both warp and weft , it’s covered area will be 1m x 1m =1 m2 which is identical to GSM unit that is – Grmas per Square Meter)
So . total length of warp yarn = 3622.04×1.03
= 3730.71 m
( Here , L = Length found , w=1 lb = 453.6 gm , W= Weight found/needed , l = 840×0.9144 meter)
[ As from the above formula , 453.6 gm means 1lb and 0 .9144 meter means 1 yd which came from the definition of Ne where weight unit is fixed to 1lb and length unit to 840 yds as a constant in the formula]
The number of hanks required of each having 840yds (1 hank) of yarn that can make 1 lb weight is called the count (Ne) of that yarn.
Weft weight calculation :
Here , PPI = 104
So total number of ends = 104×39.37 = 4094.48
Length of each 1 meter yarn allowing the crimp % = 1m + 1m x 5% ( Let, warp crimp = 5%)
= 1m + 1m x 0.05
= 1m + 0.05 m
= 1.05 m
So . total length of weft yarn = 4094.48×1.05
= 4299.21 m
= 31.74 gm
So the GSM of the fabric will be = 27.54 + 31.74
Here is a screenshot of a GSM calculator giving the same input and the result is correct !
Link to download the excel file of Fabric weight calculator for woven fabric :