PRODUCTION OF POLYESTER BASED HIGHLY STRETCHABLE PREVIOUSLY DYED YARN

摘要

PURPOSE:To obtain the title previously dyed yarn useful for stockings, etc., at a low cost, by false-twist texturing a polyester multifilament yarn with the first heater satisfying specific conditions, relaxing the yarn, fixing crimps with the second heater, winding the yarn into a package and directly dyeing the yarn. CONSTITUTION:A polyester based multifilament yarn 1 is taken from a package 2, drawn between a bed roller 6 and the first delivery roller 9 and simultaneously false-twist textured with a false twister 8 at a temperature N1 ( deg.C) of the first heater 7 satisfying formula I [Tm is the melting point ( deg.C) of the yarn]. Crimps of the resultant yarn are then fixed at a temperature H2 ( deg.C) of the second heater 10 satisfying formula II [rho is the density (g/cm3) of the yarn; D is the size (denier) of the yarn] while applying prescribed relaxation between the first and the second delivery rollers 9 and 11 at =60% overfeeding ratio. The resultant yarn is subsequently wound into a package in the form of a cheese at an overfeeding ratio so as to provide =0.25g/cm3 winding density and dyed in the state intact to afford the aimed previously dyed yarn.