This is what one of my manuals reads !! sorry about the length of post
D. Rayon
In a search for a product that could match silk, a Frenchman by the name of Count Hilaire de Chandonnet developed the first "man made" fiber. In 1891, he dissolved the pulp of mulberry trees (since silkworms fed on the leaves) in chemicals and forced the solution through a metal plate with tiny holes in it. It was then exposed to heated air, or chemicals, to harden the solution into a filament fiber. This process of taking a cellulose material, decomposing it and regenerating it with a new and more useful form, produces what is know today as a "regenerated cellulose" fiber.

This was how we came to have what is more commonly known as rayon. It is one of the more interesting fabrics, since it is man made and yet the material is actually natural cellulose with characteristics and properties of cellulose fibers. It is the natural side of rayon that we as cleaners are concerned with so we list it as natural.
The manufacture of rayon is different today than it was when Count Hilaire de Chardonnet invented and produced it in the 19th century. New and better processes have improved the quality and strength of rayon fibers.

Rayon is a filament fiber that can be cut into staple fibers, as desired. A cross section view of it shows it to be very irregular shape. It can be made into any shape desired by shaping the holes on the spinnerette. Usually, it is the jagged irregular shape that is preferred. Rayon has a very high luster and is often treated with titanium dioxide to reduce the brightness or "de-luster" the fibers.
It is possible to add color to the fiber while it is in a viscose (liquid) state prior to passing it through the spinnerette. This is termed "solution dyeing". It provides a stable color that is actually part of the fiber itself. However, this is not generally preferred by manufacturers. Rayon fibers are usually manufactured months before they are made into fabrics and, since color trends change so rapidly in the textile industry, it is better to dye the fibers, yarns, or fabric at the mill.
Rayon is inherently weak. It does not have the regular chains of molecules that other natural fibers develop in growth, since it has been decomposed and regenerated. Therefore, the molecules are randomly stuck together and have little natural strength. It is manufactured today with wood pulp and a small percentage of cotton linters (the short cotton fibers not use in the manufacture of cotton). This has improved its strength since its original form, but not much.
When wet, its strength decreases markedly. Remember how wood softens in water, and it is easy to see how weak rayon becomes, especially when you realize how thin it is as a fiber.
It is also more absorbent than even cotton or linen. The fibers actually swell with water. This causes the wall of the fiber to become thinner and, therefore, weaker.
Rayon is very unstable in its length. It is easily shrunk and does not return to normal length easily. This is apparent in rayon upholstery fabrics. When it is wet, it will shrink easily. Sometimes, if it is stretched tightly over a frame and water is applied, it will shrink and tear, due to its weakness. Unlike cotton and linen, rayon does not shrink out the manufacturer's stretch the first time it is preshrunk. Every time it gets wet it will shrink a little more. Most rayon fabrics are preshrunk and then treated with resins to reduce the problem.
Sunlight will damage rayon faster than the other cellulose fibers. Therefore, it is not good for draperies. Rayon cannot take high temperatures when dry.
There is very little pure rayon upholstery fabrics on the market today. it is used as a blend with acetate, cotton or other fibers. It can be wet cleaned as easily as other fabrics with basically the same precautions. Don't over-wet or use strong chemicals on rayon. And, as always, check for color stability prior to cleaning.
Rayon will support mildew. The only insect that attacks rayon is the silverfish.
