fibers made by chemical treatment of natural cellulose. Depending upon the intended use, viscose fibers are made into textile or cord threads, as well as staple fiber. The manufacturing process is composed of the following basic technological operations: making the spinning solution (viscose), forming the threads by the wet method, and trimming and drying them.
Fabrics of viscose fibers are easily dyed and have excellent hygienic properties (hygroscopicity), which is especially important in goods made for popular use. The accessibility of raw materials and the low cost of the chemical reagents, as well as the satisfactory textile properties and broad possibilities for modification, ensure that viscose fibers are economical to produce and widely used.
The shortcomings of viscose fibers are great loss of durability when wet, tendency to wrinkle, insufficient resistance to friction, and a low degree of elasticity, especially when wet. These shortcomings can be rectified by modification. Modified viscose fibers (for example, polynose fibers) have greater durability when dry and wet (durability loss when wet is 20-25 percent, as against 40-50 percent in ordinary viscose fibers), great resistance to wear, and increased elasticity. Twisted-spatula viscose fibers have more stable winding, which simplifies their combination with natural fibers in manufacturing threads. The tendency of viscose fibers to wrinkle can be diminished by further treatment with various compounds.
In the manufacture of popular goods viscose fibers are widely used for treating silk and staple fabrics, knitted goods, and fabrics for various uses made from combinations of viscose fibers with cotton or wool, as well as with other synthetic fibers. Highly durable viscose cord fiber is used for a wide variety of technical goods. For example, replacing cotton cord in tires with highly durable viscose cord increases the life of the tire and decreases the amount of rubber needed for its manufacture. In 1968 world production of viscose fibers was 3,103,400 tons (42.6 percent of the general output of chemical fibers). Industrial production of viscose fibers began in England in 1905.