Super Eco

Rayon is neither entirely synthetic nor entirely natural; it is a semi-synthetic textile manufactured from cellulosic fiber. The major sources for cellulosic fiber are cotton linters (a cotton manufacturing byproduct), as well as pine, spruce and hemlock trees. The most common type, viscose rayon, is made through a reaction of carbon disulfide and cellulose (usually wood). However, the term "rayon" can describe any textile which is made through a process which combines cellulose in a chemical reaction.

Rayon's best qualities are its ability to imitate a variety of fibers, including silk, wool, cotton and linen; in addition, rayon's attractive characteristics include softness, smoothness, absorbency, and coolness. Rayon does not insulate well so is appropriate for tropical climates and in hot and humid weather. Rayon has several drawbacks; it is not elastic or durable, it wrinkles readily, and does not retain its appearance well, especially when exposed to water.

Other types of rayon

• High Wet Modulus rayon, known by the trade name Modal, is a type of viscose rayon that can hold up to water (and can be machine-washed) and retains its appearance and durability better than normal viscose rayon.
• Cuprammomium rayon, known by the trade name Bemberg, is produced using a reaction of copper and ammonia with cellulose. This process has environmental impacts that the U.S. Environmental Protection Agency has banned its production in the U.S., although Italy allows it.
• Microfibers are manufactured from rayon fibers but are not a type of rayon.

Production and environmental effects

Production of rayon is similar to the production of plastic. After the cellulose is processed, is goes through many steps, including immersion in caustic soda, aging through exposure to oxygen, "xanthated" by mixing with carbon disulfide, ripening, degassing, extruding and immersion in a bath of sulfuric acid. In addition to requiring a great deal of power and water, this process has a number of toxic byproducts that pollute both the air and the waste water; zinc and hydrogen sulfide are the most dangerous. The production of cuprammomium rayon is the most toxic of all.

Many studies of the impact of exposure to carbon disulfide on rayon plant workers have revealed the risk of death from cardiovascular causes is greatly increased (as much as 2-3 times fatality risk) if the levels of this toxin are high.

Reportedly, rayon manufacturers are seeking to reduce the environmental impact of their manufacturing processes, but little public education about those new processes has occurred. Rayon producers are also blamed for clearing old-growth forests to generate cellulose for use as their raw material.

(Photo credit: Meknits)