PROCESS FOR MAINTAINING OR IMPROVING THE MECHANICAL PROPERTIES OF FIBERS OF AROMATIC COPOLYAMIDES IN ALKALINE MEDIA AND SHAPED ARTICLES CONTAINING SUCH FIBERS

摘要

A process for maintaining or increasing the tensile strength of fibers of aromatic copolyamides which are built up chiefly from para-monomers and are soluble in organic aprotic and polar solvents in the course of storage in alkaline media is described. The process comprises the measures: a) production of fibers from the said aromatic copolyamides by dry or wet spinning processes which are customary per se, b) after-treatment of the resulting fibers in a manner which is known per se, and c) storage of the fibers in an aqueous environment which has a pH of at least 10 for at least a period of time and at a temperature such that the tensile strength of the said fibers, based on the tensile strength of the fibers employed in step c), is at least retained or increased.