Process for manufacturing viscose

Claim 1

A process for manufacturing viscose comprising: (a) treating cellulose with an excess of alkali metal hydroxide solution in a first alkalization treatment, under conditions such that alkalized cellulose is produced; either (b1) freeing the alkalized cellulose produced in step (a) from at least part of the excess hydroxide solution without pressing the alkalized cellulose, comprising the step of draining at least part of the excess alkali metal hydroxide solution from the reaction vessel in which step (a) is effected, and treating the drained alkalized cellulose with a second alkali metal hydroxide solution having a lower alkali metal hydroxide concentration than the alkali metal hydroxide solution used in step (a) in a second alkalization treatment while maintaining the temperature of the reaction mixture at not more than 18° C.; or (b2) treating the alkalized cellulose produced in step (a) with an alkali metal hydroxide solution obtained by diluting the alkali metal hydroxide solution used in step (a) in a second alkalization treatment while keeping the temperature of the reaction mixture at not more than 18° C.; (c) pressing the twice-alkalized cellulose from step (b1) or (b2) to remove excess hydroxide solution; (d) shredding the pressed alkali cellulose from step (c); (e) aging the disintegrated material from step (d) for a period of time to produce a product having a desired average degree of polymerization; (f) sulfiding the shredded and aged alkali cellulose; and (g) dissolving the sulfided product to produce a viscose solution.