Common textile fabrics shrink
Cause of shrinkage
1, fiber during spinning, or yarn in weaving and dyeing and finishing, the fabric of the yarn fiber elongation by external force or deformation, stress in fiber yarn and fabric structure at the same time, in the static dry relaxation state, or static wet relaxation condition, or in a dynamic wet relaxation condition, total relaxation condition, different degree of internal stress release, make the yarn fiber and fabric back to its original state.
2, different fiber and its fabric, its shrinkage degree is different, mainly depends on the characteristics of the fiber - hydrophilic fiber shrinkage degree, such as cotton, hemp, viscose and other fibers; Hydrophobic fibers shrink less, such as synthetic fibers.
3. In the wetting state, the fiber expands under the action of immersion, resulting in a larger fiber diameter. For example, on the fabric, the curvature radius of the fiber at the interleaving point of the fabric increases, resulting in a shorter fabric length. For example, cotton fiber expanded under the action of water, the cross-sectional area increased by 40~50%, and the length increased by 1~2%, while the synthetic fiber contracted to heat, such as boiling water, generally about 5%.
4. Under the condition of heating, the shape and size of the textile fiber change and shrink, and it can not return to the initial state after cooling, which is called thermal shrinkage of the fiber. The percentage of the length before and after thermal shrinkage is called thermal shrinkage, which is generally measured in boiling water. In boiling water at 100℃, the percentage of fiber length shrinkage is expressed. It is also useful to measure the percentage of contraction in hot air over 100 ° c, or in steam over 100 ° c.
The fiber behaves differently under different conditions, such as internal structure, heating temperature and time, etc. For example, the boiling water shrinkage of polyester staple fiber is 1%, the boiling water shrinkage of vinylon is 5%, and the hot air shrinkage of chlorofiber is 50%. There is a close relationship between the dimensional stability of fiber in textile processing and its fabric, which provides some basis for the design of the later process.
Shrinkage rate of general fabric
Cotton 4%--10%, chemical fiber 4%--8%, cotton-polyester 3.5%-- 5%, natural white cloth 3%, wool blue cloth 3-4%, poplin 3-4.5%, printed cloth 3-3.5%, twill 4%, denim 10%, rayon 10%.
source:Hua Xian Tou Tiao