Patent ID: 6569366
Filing Date: 2003-05-27
Classification: D01F

Abstract:
A process for producing meta-type wholly aromatic polyamide filaments comprising the steps of preparing a polymer solution by dissolving a meta-type wholly aromatic polyamide comprising, as principal repeating units, metaphenylene diamine isophthalamide units in an amide compound solvent; subjecting the polymer solution to a wet-spinning procedure to form undrawn filaments; drawing the undrawn filaments; washing the resultant drawn filaments with water; and heat-treating the washed filaments, wherein(1) in the wet-spinning step, the polymer solution is extruded in the form of filamentary streams into a coagulation bath comprising an amide compound-containing solvent and water but substantially not comprising salts, through spinning orifices of a spinneret, to coagulate the filamentary polymer solution streams in the coagulation bath and to form coagulated porous undrawn filaments, and (2) in the drawing step, the coagulated porous undrawn filaments are drawn in a plasticizing drawing bath comprising an aqueous solution of an amide compound solvent.