Shrinkage is a parameter of testing textile fabrics to measure changes in length and width after washing, shrinkage failing materials are dimensionally unstable and they can cause de shaping and deforming of the garments or products made out of those materials, it is tested at various stages but important is to before cutting the fabric into further sewn products and after cutting and sewing prior to supplying the products to buyers and end users.
The moisture absorption of fiber is the direct factor of fabric shrinkage. The tightness of yarn and fabric structure is the indirect factor of shrinkage. The tighter the structure, the expansion of the fiber cause the yarn to swell, then the warp height of the yarn in the fabric increases and the length of the yarn in the buckling state becomes shorter, so the fabric shrinks. Therefore, the higher twist and volume fraction of the yarn, the greater shrinkage of the fabric.
The processing tension of the fabric also has an effect on fabric shrinkage. If the processing tension increases, the fiber deformation increases, the internal stress and the slow elastic deformation increase, then the relaxation and retraction degree of the fabric increases after soaking, which make the shrinkage rate of the fabric increases obviously. Besides, temperature also has a great effect on fabric shrinkage, because the high temperature has the effect of relaxation and expansion, and even heat shrinkage.
Different raw materials of fabrics will affect shrinkage rate and heat shrinkage rate. Under normal circumstance, fabrics with minimum shrinkage rate are synthetic fibers and blended fabrics; secondary is linen fabrics; middle is cotton fabrics; the maximum is viscose fabrics. In addition to this, the shrinkage rate varies from fabrics density, the thickness of yarns, weaving, dyeing and finishing process. Different kinds of fabrics have been prescribed standard of shrinkage rate. In the process of dyeing and finishing, some processes like mercerization and preshrunk can reduce shrinkage rate. Synthetic fiber is easy to deform when heated, especially nylon fabrics, it shrinks more easily when heated, but it can improve its dimensional stability by hot setting.
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·website:http://www.qinsun-lab.com/
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The processing tension of the fabric also has an effect on fabric shrinkage. If the processing tension increases, the fiber deformation increases, the internal stress and the slow elastic deformation increase, then the relaxation and retraction degree of the fabric increases after soaking, which make the shrinkage rate of the fabric increases obviously. Besides, temperature also has a great effect on fabric shrinkage, because the high temperature has the effect of relaxation and expansion, and even heat shrinkage.
Different raw materials of fabrics will affect shrinkage rate and heat shrinkage rate. Under normal circumstance, fabrics with minimum shrinkage rate are synthetic fibers and blended fabrics; secondary is linen fabrics; middle is cotton fabrics; the maximum is viscose fabrics. In addition to this, the shrinkage rate varies from fabrics density, the thickness of yarns, weaving, dyeing and finishing process. Different kinds of fabrics have been prescribed standard of shrinkage rate. In the process of dyeing and finishing, some processes like mercerization and preshrunk can reduce shrinkage rate. Synthetic fiber is easy to deform when heated, especially nylon fabrics, it shrinks more easily when heated, but it can improve its dimensional stability by hot setting.
-------------------------------------------------------------------
For more information about our testing instrument, please contact
·website:http://www.qinsun-lab.com/
· +86-21-6780 0179
· info@qinsun-lab.com
· or leave your comments below
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