How can I accurately test the shrinkage of textile fabrics?

The weaving shrinkage rate is one of the fabric process design parameters and refers to the difference between the original length of the warp (or weft) yarn in the fabric and the corresponding fabric length (or width), as a percentage of the original length of the warp (or weft) yarn. The warp yarn weaving shrinkage rate and the weft yarn weaving shrinkage rate are expressed respectively.

 

Weaving yarns are unisex materials, warp and weft yarns are not interwoven into the fabric before, can be under a certain tension in a straight state, but when weaving, warp and weft yarns interlocked floating, the yarn is changed from the original straight state into a waveform flexure state, the length is shortened, thus forming a different structure of the fabric, so that the length of the woven fabric is shorter than the original length of the yarn and the formation of weaving shrinkage.

Weaving shrinkage has an impact on the strength, thickness, density, weight, appearance and shrinkage of the finished product. As the warp and weft yarns of raw material thickness, density and fabric organization and on the machine process parameters, etc. different, warp and weft yarns can have a variety of cooperation between the relationship, therefore, the weaving shrinkage rate is also different.

 

Fabric weaving shrinkage rate is large, the use of raw materials, and vice versa, weaving shrinkage rate is small, the use of raw materials will be less.

 

Weaving shrinkage rate is generally measured and calculated by taking a certain length, width of the fabric specimen, and gently remove the warp, weft yarn, according to the above definition of measurement and calculation, but also through the relevant parameters of the weaving process with the empirical formula.

 

1. Calculation of warp yarn weaving shrinkage rate.

Formula.

a = (L1 - L2) / L1 * 100%

Formula: a - warp yarn weaving shrinkage rate.

L1 - after straightening (i.e. the original) warp yarn length;

L2 - the warp length of the cloth sample.

 

 

2. Calculation of the weft yarn weaving shrinkage rate

Formula.

b = (L3 - L4) / L3 * 100%

Formula: b - weft weaving shrinkage rate;

L3 - the length of the weft yarn after straightening.

L4 - weft length of the fabric sample