Patent ID: 6949210
Filing Date: 2005-09-27
Classification: D01F,Y10T

Abstract:
1. In a method for producing a polytrimethylene terephthalate composite fiber by a melt-spinning method, wherein the composite fiber is a plurality of single filaments which comprise two kinds of polyester components laminated to each other in a side-by-side manner or an eccentric sheath-core manner, at least one of which is polytrimethylene terephthalate, the improvement comprising conducting the melt-spinning method under the following conditions (a) to (d): (a) the melting temperature is from 240 to 280° C. and the melting time is 20 minutes or less, (b) after the two kinds of polyester components have been joined together, an extrusion condition per one spinning orifice is such that the product of a average intrinsic viscosity [η] (dl/g) and an extrusion linear speed V (m/min) is from 3 to 15 (dl/g)·(m/min), (c) after the polyester has been extruded, cooled and solidified, a finishing agent containing 10 to 80 wt % of a fatty ester and/or a mineral oil, or a finishing agent containing 50 to 98 wt % of a polyether is imparted to the fiber at a ratio from 0.3 to 1.5 wt %, and (d) at any of the steps before the fiber has been finally wound, an interlacing and/or twist is imparted to the fiber.