一本一道人人妻人人妻αV,亚洲欭美日韩颜射在线,一区二区三区av波多野结衣,亚洲欧洲无码在线国产

"The scientific name of nylon is polyamide, which is also a general term for thermoplastic resins. There are many kinds of nylon, with large production capacity and wide application. And its molecular structure is nylon fiber.

Nylon has good comprehensive properties, and its fiber strength is 1-2 times higher than that of cotton. It has the significant advantage of replacing steel, iron, copper and other metals with plastics in production and manufacturing, and is an important engineering plastic.