## Tuesday, October 27, 2020

### WARP CRIMP CALCULATION IN THE WOVEN FABRIC WITHOUT SWATCH

Warp crimp (regain) is the ratio of the difference between warp length and fabric length to fabric length in the term of % is called warp regain.

If we have the fabric swatch, we can determine the warp crimp ( regain) by using below formula:

This practice is useful and gives accurate results if you have physical fabric swatch. If you don't have fabric swatch how will you determine the warp crimp ? I am discussing with you the procedure with examples and formulas. You can easily calculate the warp crimp in the fabric without physical fabric swatch.

The three fabric constructions are being given below:

We have taken three fabric constructions. The side views of each fabric is illustrated in the picture.

You compare fabric- 1 and fabric - 2, you find difference. Yarn count for both fabrics are similar. EPI of both fabrics are same. There is only difference between PPI of Fabrics. The increased PPI results in the increase in warp crimp in fabric - 2. You can see clearly in above picture. When the PPI of the fabric gets increased, the pick to pick spacing gets reduced. This the warp crimp in the fabric is increased.

Now we compare fabric - 1, and fabric - 3. The EPI and PPI of both fabrics are identical. The warp count of both the fabrics are also same. There is difference between weft count of two fabrics. In fabric - 3, we have used 12s in place of 10s weft yarn. You can see in illustrated picture how the weft count affects the warp crimp. 12s is finer than 10s . You can see clearly how the decrease in weft diameter reduces the warp crimp?.

We are giving below the calculations of warp crimp of all three fabric:

,In these calculations, there may be little bit deviation. The beam tension during weaving also affects the warp crimp in the fabric. The fabric woven on shuttle less loom has less warp crimp than the fabric woven on powerloom.