Polyamide is mainly used in synthetic fibers, its most outstanding advantage is that its wear resistance is higher than all other fibers, 10 times higher than cotton, 20 times higher than wool. A little polyamide fibers can greatly improve its wear resistance in blended fabrics; when stretched to 3-6%, the elastic recovery rate can reach 100%; it can withstand tens of thousands of times of bending without breaking.
The strength of polyamide fibers is 1-2 times higher than that of cotton, 4-5 times higher than that of wool and 3 times higher than that of viscose fibers. However, the heat and light resistance of polyamide fibers are poor, and the retention is not good. The clothes made of polyamide fibers are not as crisp as polyester fibers. In addition, both nylon-66 and nylon-6 used for clothing have the disadvantages of poor hygroscopicity and dyeability. Therefore, a new type of polyamide fibers, nylon-3 and nylon-4, has been developed. They have the characteristics of light weight, good wrinkle resistance, good air permeability, good durability, dyeability and heat setting. Therefore, they are considered to be very promising.