Woven Fabric GSM Calculation - WOVEN SACKS PLANNING FORMULA

 

GSM stands for Gram per Square Meter. In simple words, it is the calculation of the weight in grams for one square meter fabric. In most cases, we need these calculations while we are in the preproduction phase. It helps us to precisely compute what denier we should run in our flat yarn tape line plant. Polypropylene Woven Fabric GSM Calculation can be done by various methods when different factors are given for calculation. We can calculate GSM of Polypropylene Woven Fabric when combinations of the following factors are given;
1.     Sack Weight and area is given
2.     Mesh Size and Denier is given
3.     GPM (Gram Per Meter) and Width of the woven fabric is given
We will explain each method step by step to perfectly and accurately calculate the Woven Fabric GSM with examples.

 

Polypropylene Woven Fabric GSM Calculation by various methods

 

1. When Sack Weight and Area is Given

This is the most common method to calculate the fabric GSM. Mostly in preproduction planning, this information is available from the client as the base requirements however in other cases, the provisioning of the sample sack can make life easier.

GSM=Weight of the sack (Gram)/Area of the sack (m2)

 

Example 1

For instance, if the weight of the sack is 90 grams and the area is 1.020 square meters, hence the Woven Fabric GSM Calculation will be;

GSM = 90/1.020 = 88.235

 

Example 2

If the bag width and length are given then we can calculate area by the following simple formula.

Area of sack cm2 = width(cm) X Length (cm) X 2 Ply (Circular fabric two sides)

For instance;

Area of Sack cm2=60cm X 85cm X 2 = 10,200cm2

to compute GSM by the given formula above, we need the area in the square meter as follows;

Area in m2 = Area in cm2/(100 X 100) = 10,200/10,000 = 1.020m2

 

Example 3

Sack Weight 125 grams, Width 62cm, Height 96cm

First, we need to calculate area in meters square, for instance;

Area in cm2 = 62cm X 96cm X 2ply = 11,904cm2 

Area in m2 = 11,904/(100X100) = 11,904/10,000 = 1.190m2

 

Therefore Woven Fabric GSM Calculation of the sack is;

GSM = 125/1.190 = 105.00

 

2. When Mesh Size and Denier is Given

This is the second most common method for the Polypropylene Woven Fabric GSM Calculation.

A separate article elaborating about denier and Polypropylene Yarn Denier Calculation is available for more information.

In this method, we simply multiply WEFT Mesh with WEFT Denier and WARP Mesh with WARP Denier the calculate the sum of both. Then we divide the total with a constant value, for instance;

GSM = (WEFT Mesh X WEFT Denier + WARP Mesh X WARP) / Denier Constant

Example 1

If we say that the sample sack mesh is 10X10 mesh and the denier is 1200, therefore the GSM will be as follows;

GSM = (10 X 1200 + 10 X 1200) / 228.6 = 105.00

 

Example 2

In this example, we take sack mesh as 12X12 and the denier is 840.44, hence the Woven Fabric GSM Calculation will be;

GSM = (12 X 840.44 + 12 X 840.44) / 228.6 = 88.235

 

Example 3

In some cases the mesh size of the sack different for the WARP and WEFT. For instance, the mesh of the WEFT is 8  and the mesh of the WARP is 12 while denier of the WEFT is 1000 and the denier is the WARP is 900. In this case, thus the GSM shall be;

GSM = (8 X 1000 + 12 X 900) / 228.6 = 82.240

 

3. When GPM and the width of the Woven Fabric is given

This is the least common method for Polypropylene Woven Fabric GSM Calculation.

For more information on GPM, an article on Polypropylene Woven Fabric GPM Calculation elaborates on how to obtain Gram Per Meter of the fabric, however, in the following examples we will describe obtaining the GSM when GPM and width of the fabric are given.

The formula is;

GSM = GPM X 100 / (Width of the Fabric * 2ply)

Example 1

If the GPM is 105.88 and the width of the fabric is 60cm, therefore  the GSM will be;

GSM = 105.88 X 100 / (60 X 2) = 88.235

 

Example 2

In this example, the GPM is 130.208 and the width of the fabric is 62cm, hence the GSM will be;

GSM = 130.208 X 100/ (62 X 2) = 105.00

 

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