The physical and mechanical properties of chemical staple fiber generally include: breaking strength, breaking elongation, fineness deviation, length deviation, super long fiber ratio and double long fiber ratio, crimp number, moisture regain, etc. Due to the variety of chemical fibers, the classification standard adds some other indexes according to the characteristics of different varieties, such as wet fracture strength of viscose fiber, crocheted fracture strength and residual sulfur, polyester fiber increases boiling water shrinkage, etc.
