Rayon is one of the most peculiar fabrics in commercial use today. Strictly speaking, it is not an artificial fiber, because it is derived from naturally occurring cellulose. It is not, however, a natural fabric, because cellulose requires extensive processing to become rayon. Rayon is usually classified as a manufactured fiber and considered to be “regenerated cellulose”.
Rayon is the oldest manufactured fiber, having been in production since the 1880s in France, where it was originally developed as a cheap alternative to silk. Dupont Chemicals acquired the rights to the process in the 1920s and quickly turned rayon into a household word, churning out yards of the cheap, versatile fabric. Rayon drapes well, is easy to dye, and is highly absorbent, although it tends to age poorly. Many rayon products yellow with age and pill or form small balls and areas of roughness where the fabric is most heavily worn.
Rayon is used in a variety of textile applications, including shirts and skirts, and appears in both woven and knitted forms. The fabric has gained an unfair reputation because it is frequently used in cheaply constructed garments that do not stand up to heavy wear. However, rayon is an excellent, nicely draping alternative to silk and is frequently used in evening gowns and other flowing garments.
The manufacture of rayon begins with cellulose, frequently extracted from wood pulp, although any plant material with long molecular chains is suitable. The cellulose is steeped in caustic soda, which concentrates some of the cellulose into soda cellulose, which is then rolled or pressed to remove excess soda solution. After pressing, the cellulose is shredded into a substance called white crumb.
The white crumb is allowed to oxidize, forming shorter molecular chains, and treated with carbon disulfide. The soda cellulose reacts with this substance, forming yellow crumb due to inorganic compounds that emerge during the chemical process. This yellow crumb is dissolved in a caustic solution, which relaxes the hydrogen bonds in the cellulose, producing a highly viscous substance. This substance gives its name to the manufacturing process, called the viscose process.
This viscous fluid is allowed to age, breaking down the cellulose structures further to produce an even slurry, and then filtered to remove impurities. Small air pockets are forced out to ensure a strong, even fiber, and the mixture is forced through a spinner, which forms many even strands of fine thread that enter a setting solution to form cellulose filaments: also called rayon. The rayon is stretched to form a strong, even bond, washed, and then formed into rayon fabric.
This complex process results in a great deal of environmental pollution, inspiring a drive to clean up the industry. The rayon industry has also suffered from the development of cheaper artificial fabrics with a much shorter manufacturing process, such as nylon. Rayon is frequently blended with true synthetic fabrics for various applications, and it is advisable to follow individual care labels on rayon garments, as these blends have specific handling needs.