Treatiment of acrylonitrile polymer fibers

Claim 1

A PROCESS FOR PRODUCING CRIMPED, STABILIZED FIBERS COMPRISING AN ACRYLONITRILE POLYMER CONTAINING, BY WEIGHT IN THE POLYMER MOLECULE, AT LEAST 75 PERCENT OF ACRYLONITRILE, WHICH COMPRISES CONTINUOUSLY PASSING CONTINUOUS INTERNALLY STRAINED FIBERS COMPRISING THE POLYMER THROUGH A ZONE, HEATING THE FIBERS IN THE ZONE AND STRETCHING THE FIBERS IN THE ZONE AT LEAST 100 PERCENT WHILE THEY ARE UNDER THE INFLUENCE OF THE HEAT CONTINUOUSLY PASSING THE STRETCHED, ORIENTED FIBERS FROM THE ZONE INTO AND THROUGH A CRIMPING ZONE, CONTINUOUSLY FOLDING THE BUNDLE BACK AND FORTH UPON ITSELF IN A PACKED CONDITION IN THE CRIMPING ZONE TO THEREBY CRIMP THE FIBERS, CONTINUOUSLY TREATING THE PACKED BUNDLE OF FIBERS PASSING THROUGH THE CRIMPING ZONE WITH STEAM TO THEREBY HEAT THE FIBERS TO AT LEAST 100* C. AND RELAX THE INTERNAL STRAINS, REDUCE THE RESIDUAL SHRINKAGE CAPACITY OF THE FIBERS TO NOT MORE THAN 3 PERCENT AT 100* C., AND STABILIZIE THE RELAXED FIBERS IN THE CRIMPED CONDITION, AND CONTINUOUSLY REMOVING THE STABILIZED, CRIMPED FIBERS FROM THE CRIMPING ZONE.