PROCESS AND APPARATUS FOR PRODUCING EASILY DYEABLE POLYESTER FALSE-TWISTED YARNS

摘要

A false-twisted polyester yarn is produced by a process wherein a yarn consisting of an as-spun polyester fiber having a mean birefringence index ( DELTA n) of at least 15 x 10<-><3> but less than 150 x 10<-><3> is continuously subjected to (1) heat treatment, (2) cooling and (3) false twisting or draw-false twisting. The apparatus used comprises a feed yarn creel (8), a false twisting heater (13) and an optional stabilizing heater, a false twisting element (14) and a winder (16), wherein a heat-treating heater (9) of the non-contact type is arranged upstream of the false twisting heater (13) and between the false twisting heater (13) and the feed yarn creel (8), at a height substantially equal to the height of the feed yarn creel (8) so that the heat-treating heater (9) confronts the false twisting heater (13). A false-twisted polyester yarn having good dyeing properties and mechanical and thermal properties can be produced at a high efficiency and with a good operation adaptability.