Nonwoven Shrinkage Test

(1) Shrinkage rate test

After the non-woven fabric is immersed in water at room temperature or washed and dried, the degree of dimensional shrinkage in the vertical and horizontal directions is called shrinkage. Generally, the fabric will shrink to a certain extent if it falls into the water or after washing, especially for thin non-woven fabrics. If the shrinkage rate is too high, it will affect the performance.

The test of shrinkage has two methods: dipping method and washing machine method. Among them, the immersion method is static, and the washing machine method is dynamic. Impregnation method is commonly used in non-woven testing. Before the test, cut out three samples with a size of 250mmx2s0mm, and use a pen to draw a 200mx200m and center orthogonal mark line on the sample, and mark the vertical and horizontal directions. Afterwards, the sample was dehumidified under standard atmospheric conditions for 24 hours, and then the lengths of the three marked lines of the sample were measured vertically and horizontally, with an accuracy of 0.5 mm.

During the test, soak the sample in water at a temperature of 25°C and 2°C, take it out after immersion for 20 minutes, put it on the platform, and let it dry naturally. The sample can also be immersed in a neutral soap solution with a temperature of 50°C 1°C and 0.5% (the bath ratio is 1:50), soaked for 20 minutes and taken out, and rinsed at a temperature of 50°C ± 1°C for 20 minutes. Take it out and lay it on the platform to dry naturally. Then, after 24h of humidity control treatment, the length of the three marked lines in the vertical and horizontal directions of the sample was measured again, and the length was also accurate to 0.5mm. Calculated as follows:

Shrinkageu003d(L-L')/L*100%