About 15 different types of fibers are used to make yarn. These fibers fall into two categories, natural and synthetic. Natural fibers are those that are obtained from a plant or an animal and are mainly used in weaving textiles.
The characteristics of spun yarn depend, in part, on the amount of twist given to the fibers during spinning. A fairly high degree of twist produces strong yarn, a low twist produces softer, more lustrous yarn, and a very tight twist produces crepe yarn. Yarns are also classified by their number of parts. A single yarn is made from a group of filament or staple fibers twisted together. Ply yarns are made by twisting two or more single yarns. Cord yarns are made by twisting together two or more ply yarns.
Spinning systems and yarn manufacturing machinery will continue to become more automated and will be integrated as part of a manufacturing unit rather than as a separate process. Spinning machines have already been developed that combine carding and drawing functions. Production rates will increase by orders of magnitude as machines become available with even more spindles.