What is fabric shrinkage? How to calculate shrinkage?

Fabrics are fibre fabrics. After the fibers absorb water, they will experience a certain degree of swelling, that is, a reduction in length and an increase in diameter. The percentage difference between the length of a fabric before and after it is washed and its original length is usually referred to as the shrinkage rate. That is, shrinkage rate = (pre washing size - post washing size) / pre washing size x 100%. Generally, fabric shrinkage is measured in both warp and weft directions.

The stronger the water absorption capacity, the more severe the swelling; the higher the shrinkage rate, and the worse the dimensional stability of the fabric. In the dyeing and finishing process, in order to reduce the shrinkage rate of fabrics, pre-shrinkage finishing is often used to increase the weft density and increase the weaving shrinkage rate in advance, thus reducing the shrinkage rate of fabrics.

In terms of fabrics shrinkage, the smallest is synthetic fibres and blended textiles, followed by woolen fabrics, linen fabrics, cotton fabrics in the middle, silk fabrics with larger shrinkage, while the largest is viscose fibre, rayon, artificial wool fabrics.

The general fabric shrinkage rate is: