Manufacture of crimped viscose rayon fibres

Claim 1

A PROCESS FOR THE PRODUCTION OF CRIMPED VISCOSE RAYON FIBERS COMPRISING EXTRUDING A VISCOSE CONTAINING FROM 5 PERCENT TO 10 PERCENT OF CELLULOSE, FROM 5 PERCENT TO 10 PERCENT OF CAUSTIC SODA, MORE THAN 0.05 PERCENT OF A MODIFIER AND AN ALKALI METAL ZINCATE IN THE PROPORTION OF FROM 0.01 PERCENT TO 0.8 PERCENT OF ZINC BASED ON THE WEIGHT OF THE VISCOSE, AT A SALT FIGURE OF BETWEEN 3 AND 14, INTO A COAGULATING AND REGENERATING BATH CONTAINING FROM 5 PERCENT TO 14 PERCENT OF SULPHURIC ACID, FROM 0.5 PERCENT TO 4 PERCENT OF ZINC SULPHATE AND MORE THAN 12 PERCENT OF SODIUM SULPHATE, TO FORM INCOMPLETELY REGENERATED FILAMENTS, STRETCHING THE FILAMENTS BY AT LEAST 50 PERCENT, CUTTING THE STRETCHED FILAMENTS INTO STAPLE FIBRES AND CRIMPING THE FIBRES BY RELAXING THE FIBRES IN A SOLUTION CONTAINING BETWEEN 1 PERCENT AND 5 PERCENT OF CAUSTIC SODA, BEFORE COMPLETING THE REGENERATION OF THE CELLULOSE IN THE FIBRES.