Those rayon's in which the cellulose raw material is changed physically but not chemically. Viscose, cuprammonium and nitro-cellulose rayon's are of this type.
Rayon, Lyocell® and Tencel® are made from regenerated cellulose and is a wood-pulp by-product. They are man-made fibers that are wet-spun and exhibit similar properties to cotton.
A material which begins as cellulose but at some stage in the chemical processing takes the form of another chemical compound then appears again in its completed state as cellulose. Viscose and cuprammonium rayons are regenerated cellulose.