Abstract: The fibrillation tendency of solvent-spun fiber can be increased by subjecting the fiber to a treatment which reduces its degree of polymerisation by about 200 units or more. Suitable methods of treatment include severe bleaching, for example application of an aqueous liquor containing 0.1 to 10 percent by weight sodium hypochlorite (as available chlorine) to the fiber followed by steaming. Fiber may be treated in never-dried or previously-dried form. Fiber treated by the process of the invention is useful for example in the manufacture of paper and hydroentangled fabrics. Fiber of increased tendency to fibrillation can be beaten to a Canadian Standard Freeness 400 in the Disintegration Test by 30,000-150,000 disintegrator revolutions and to a Canadian Standard Freeness 200 in the same Test by 50,000-200,000 disintegrator revolutions.

Abstract: A process of manufacturing lyocell fiber with an increased tendency to fibrillation which includes dissolving cellulose in a tertiary amine N-oxide solvent to form a solution. The degree of polymerization of the cellulose is not more than about 450 and the concentration of cellulose in the solution is at least 16 percent by weight. The solution is extruded through a die to form a plurality of filaments which are washed to remove the solvent, thereby forming the lyocell fiber which is then dried.