gsm calculate

[vikram singh rathore]

sir,
please solve my problem and give formulla to calculate gsm of fabric if i know count and construction
2/20x2/20 40x36 cotton flex- how can we calculate gsm 48"?

[vikram singh rathore]

Originally Posted by vikram singh rathore

sir,
please solve my problem and give formulla to calculate gsm of fabric if i know count and construction
2/20x2/20 40x36 cotton flex- how can we calculate gsm 48"?

can u do answer for me

[vikram singh rathore]

no bodies is ther

[JohnS]

I don't know if there is a formula that calculates it with sufficient accuracy. If there is, I don't know it. It would be easier to just weigh a finished piece of known area. DFetermine weight in grams, divide by area in square meters.

Originally Posted by vikram singh rathore

sir,
please solve my problem and give formulla to calculate gsm of fabric if i know count and construction
2/20x2/20 40x36 cotton flex- how can we calculate gsm 48"?

Sir,

How do calculate count & construction of woven fabric.

(warp ct/ EPI + weft ct/ PPI)*25.14 = gsm

Originally Posted by unregistered

(warp ct/ epi + weft ct/ ppi)*25.14 = gsm

how do we derive constant 25.14?

[Robert Fogt]

Originally Posted by Unregistered

how do we derive constant 25.14?

I found two formulas here.
http://www.onlineclothingstudy.com/2...en-fabric.html

Fabric GSM = (EPI/warp count + PPI/Weft count) x (100+crimp %) X 0.2327

and this one:
Fabric GSM= ((EPI/warp count X 1.1) + (PPI/weft count x 1.04)) x 23.5

Notice that for a source they use this website. Normally that is fine but it points to a forum post so its only as accurate as the original poster.
http://forum.onlineconversion.com/ar...hp?t-7064.html

[JohnS]

Originally Posted by Robert Fogt

I found two formulas here.
http://www.onlineclothingstudy.com/2...en-fabric.html

Fabric GSM = (EPI/warp count + PPI/Weft count) x (100+crimp %) X 0.2327

and this one:
Fabric GSM= ((EPI/warp count X 1.1) + (PPI/weft count x 1.04)) x 23.5

Notice that for a source they use this website. Normally that is fine but it points to a forum post so its only as accurate as the original poster.
http://forum.onlineconversion.com/ar...hp?t-7064.html

I think the formula is reasonable as I can "almost" derive it from basic principles.

In a square meter of cloth, 1 m on each side, the total numbers of ends and picks is the EPI and PPI divided by 0.0254 m/in.

Because of the over and under-weaving, the threads in each direction have to be slightly over 1 m in length. I am assuming that the 1.1 and 1.04 factors are experiential factors that make this correction. Therefore 1.1*EPI/0.0254 and 1.04*PPI/0.0254 give us the total length of thread in each direction in meters.

For cotton, a warp or weft count of n means that 840 yd of thread weighs (1/n) pounds. To convert this to g/m, multiply by 453.59237 g/lb, divide by 840 yd, and divide by 0.9144 m/yd.

All of these conversion factors may be moved outside the parentheses, resulting in
453.59237/(0.0254 * 0.9144 * 840) = 23.25.

The first formula uses the corrections as a percent, if they were a decimal fraction, the constant would be 23.27. The 2nd formula uses 23.5. I believe the correct constant is 23.25 based on conversion, but any minor errors may be covered up by adjusting the two correction factors.