The term nylon refers to a family of plastics. The two most common grades of nylon are Nylon 6 and Nylon 66. The numbers refers to the numbers of methyl groups. The term polyamide, another name for nylon, reflects the presence of these amide groups on the polymer chain. Nylon fiber are very good heat resistant, chemical resistant, have good strength and can be processed easily. In textiles, nylon fiber can be used in fabrics, carpeting, sportswear.