Polyamide, also known as nylon yarn, is mainly used for synthetic fibers. Its most prominent advantage is that its abrasion resistance is higher than that of all other fibers, 10 times higher than cotton, 20 times higher than wool, and a little added to the blended fabric Polyamide fiber can greatly improve its wear resistance; 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 fiber is 1-2 times higher than cotton, 4-5 times higher than wool, and 3 times stronger than viscose fiber. However, polyamide fibers have poor heat resistance and light resistance, and poor retention. The clothes made of polyamide are not as firm as polyester. In addition, nylon-66 and nylon-6 used for clothing have the disadvantages of poor hygroscopicity and dyeability. For this reason, new varieties of polyamide fibers-nylon-3 and nylon-4 new polyamide fibers have been developed, which have high quality Light weight, excellent wrinkle resistance, good air permeability, and good durability, dyeability and heat setting characteristics, so it is considered to be very promising.

Nylon yarn is the first synthetic fiber variety to be industrialized, and belongs to aliphatic polyamide fiber. Nylon yarn has a high output and a wide range of uses. It is the main synthetic fiber species second only to polyester. Nylon is mainly filament. In addition, there are a small amount of nylon staple fiber, nylon filament is mainly used to make strong yarn for the production of socks, underwear, sports shirts, etc. Nylon staple fiber is mainly blended with viscose, cotton, wool and other synthetic fibers to be used as clothing fabrics. Nylon can also be used as tire cords, parachutes, fishing nets, ropes, conveyor belts, etc. in industry.

Since the end groups of nylon macromolecules are more sensitive to light and heat, the nylon becomes yellow and brittle. Therefore, the light resistance and heat resistance of nylon is poor, and it is not suitable for making outdoor fabrics. In addition, nylon is resistant to corrosion, mildew, and insects.