Process for making high shrinkage acrylic fibers

Abstract

High-shrinkage acrylonitrile polymer fibers that shrink with unusually high shrinkage force are prepared by a process in which as-spun, dry-spun filaments are extracted to remove solvent by passing the filaments continuously through aqueous baths at 63.degree. to 75.degree. C., drawn between 1.5X and 3.5X during passage through the baths, and cooled to a temperature below 50.degree. C. while free of tension. The filaments are further drawn 1.1X to 1.5X while passing continuously through at least one aqueous bath at 70.degree. to 80.degree. C. and are then dried at a temperature no higher than 60.degree. C. The filaments may be crimped at 55.degree. to 65.degree. C. in a stuffer box prior to drying. The filaments may be cut to staple fibers for use in pile fabrics; they are particularly useful in preparing artificial furs.

Dependencies are inferred from the claim text.