Process for melt-spinning transparent acrylonitrile polymer fiber from a hydrophobic polymer

A process for preparing a substantially transparent shaped article from a hydrophobic fiber-forming acrylonitrile polymer which comprises preparing in a compacting and melting zone a fusion melt of about 70 to about 90 parts of a hydrophobic fiber-forming acrylonitrile polymer, from about 10 to about 30 parts of water, from about 3 to about 25 parts of an N-vinylamide which is water-soluble below 120.degree. C. and uniformly distributed in said melt an effective amount of a polymerization initiator, said melt being at a temperature above the boiling point of water at atmospheric pressure, and at a pressure sufficient to maintain water in liquid state, the amounts of polymer and water in said melt being such that they form a single phase melt;

• converting a major portion of the monomer content to polymer while said melt remains within said compacting and melting zone;
• extruding the polymerized melt through a spinneret directly into a steam-pressurized solidification zone maintained under conditions of saturation, and at a pressure and temperature that control the rate of release of water from the nascent extrudate and maintain said extrudate in stretchable state;
• stretching said extrudate while it remains within said solidification zone to provide polymer orientation;
• exiting said stretched extrudate into the atmosphere;
• and drying the resulting extrudate at a dry-bulb temperature in the range of about 110.degree. C. to 180.degree. C. and at a wet-bulb temperature in the range of about 60.degree. C. to 100.degree. C.