One of the first man-made fibers, rayon was first developed as an artificial silk in 1855. The fabric wasn't used for clothing until the early 1900s, when it was patented under the name "viscose." Nylon was developed much later, in the late 1930s, when it was manufactured for toothbrush bristles. By the early 1940s, nylon hosiery was being mass produced, which increased the fabric's popularity in women's wear.
Most nylon manufactured today is nylon 6.6, a chemical composition that was developed by DuPont in 1935. A thermoplastic material, the fiber is produced by combining equal parts diamine and dicarboxylic acid, which react and create nylon salt. This compound is high in carbon, hydrogen and nitrogen. The salt is heated and dehydrated to form the polymer, which is melted and spun to create the nylon fiber.
One of the major differences between nylon and rayon is their chemical makeup. Rayon is made from organic matter. A cellulose fiber, meaning it's derived from wood, rayon is made from a high-grade wood pulp called "dissolving cellulose." The pulp is refined with a caustic soda or lye solution before it's streamed through a spinneret, a device that resembles a shower head. The fibers solidify in an alkali-based bath to produce fine silken fibers.
Nylon fibers are stronger than rayon, producing a smooth fabric that's strong, elastic and abrasion-resistant. It's difficult to permanently mar the man-made fabric, because it's resistant to oil and chemical stains, and easy to wash. Unlike nylon, rayon is a highly absorbent fabric that can be more luxurious to the touch. However, the fabric is more fragile; rayon can be more difficult to wash and must be dried flat. Furthermore, unlike nylon, rayon has a low melting point, so rayon fabric must be ironed with a medium to cool iron.
Rayon fabric is used in fashion, home textiles and woven surgical products, such as tape and sponges. In fashion, the fabric is used to make silken blouses, sweaters and dresses, and it's popular for bedspreads and linen in the home textile industry. Though nylon is still used for foundation garments and stockings, it's also used for high-performance athletic apparel. Athletic nylon is often engineered to wick or moves water away from the body. In the home industry, nylon can be used for carpets and heavy duty curtains. Other uses include fishing line, dental floss, and conveyor and safety belts.