artificial cellulose fibers Cuprammonium fibers are formed by the wet method in water or alkaline solution. The spinning solution is prepared by the action of aqueous copper-amine hydrate solution [Cu(NH3)«]-(OH)2 on cellulose. Cuprammonium staple fibers are used primarily in the manufacture of carpets and cloth; fine textile filaments (thickness, 5-10 tacks) are used in the production of knitted goods and lightweight fabrics. Because of their low strength, Cuprammonium fibers are not used for industrial purposes. There have been cutbacks in the manufacture of these fibers, because they are more expensive than viscose fibers. In 1971 Cuprammonium fibers accounted for less than 1 percent of the world chemical fiber output.