Nylon 6-6: The Polyamide Fiber

The term "nylon" refers to a group of related chemical compounds classified as 'polyamides'. It is manufactured from hydrogen, nitrogen, oxygen and carbon in controlled proportions and structures. According to the Federal Trade Commission(FTC), nylon " is a long-chain synthetic polyamide in which less than 85% of the amide linkages are attached to two aromatic rings" There are many varieties of nylon that have their own characteristic properties. Nylon plastics are used for making such products as combs, brushes and gears. Nylon yarns, on the other hand, are used for making nylon fabrics. When talking about nylon textile, there are two types that are mostly prevalent in the market- nylon 6-6 (also written as nylon 6,6) and nylon 6.

Spinning of Nylon 6-6

Nylon 6-6 is made from hexamethylene diamine and adipic acid, which are, in turn, obtained from such raw materials as coal, petroleum or from cereal byproducts like oat, hulls or corncobs. Hexamethylene diamine and adipic acid are combined to form nylon salt which is dissolved in water. In the spinning mill, salt is heated in evaporators to obtain a concentrated solution. This solution then goes to reaction vessels where the heat combines the molucules of the two chemicals into large chainlike molucules known as 'linear superpolymers'. These superpolymers move onto a slowly revolving casting wheel from the vessel. The molten nylon goes through the spinning process. Through this polymer processing, nylon 6,6 is extruded through a spinneret and then air-cooled to form filaments.

Characteristics of Nylon

Strength: Nylon has high-tenacity strengths. It is one of the lightest and strongest textile fiber.

Elasticity: Although not exceptional like spandex fiber, nylon has sufficient elasticity. It recovers its original shape after being stretched, though not when stretched too much.

Resilience: It retains its smooth appearance and also wrinkles can be removed easily from nylon fabric.

Drapability: Nylon filament yarns drape very well.

Water resistance: Nylon does not absorb much moisture. Most of the water runs off the smooth fabric thereby keeping it dry.

Mildew and insects resistance: Mildew, although formed on nylon, cannot weaken the fabric. Moths and other insects are not attracted towards nylon.

Dyeing capability: Nylon 6 can be dyed easily as compared to nylon 6-6. However, once dyed, both the types can retain their colors and do not fade easily.