Process of making fibers or films of regenerated cellulose

摘要

A process for producing a fiber or film of regenerated cellulose from a composition having a base of cellulose formate is provided. The composition is characterized by the following: (1) the composition is a solution; (2) the concentration of cellulose formate in the composition is at least 8% by weight; (3) the degree of substitution of the cellulose by formate groups is greater than 20% and (4) the composition contains one or more compounds selected from among alkylsulfoxides, lactams, acrylic amides and cyclic derivatives of urea as a solvent. The process for producing the fiber or film involves (i) transforming the composition into a liquid extrudate having the form of a fiber or film at a temperature at which the solution is isotropic at rest; (ii) coagulating the liquid extrudate; (iii) regenerating the cellulose of the fiber or film obtained and (iv) washing and drying the regenerated cellulose fiber or film.