PRODUCTION OF POLYESTER SLUB YARN HAVING PEPPER-AND-SALT TONE

摘要

PURPOSE: To extremely stably obtain excellent polyester slub yarn containing highly dispersed thick parts and having pepper-and-salt tone by drawing undrawn polyester yarn having a specific birefringence in two stages under specific condition, thereby suppressing the decomposition of spinning oil on the surface of a roller. ;CONSTITUTION: A polyethylene terephthalate is spun by melt-spinning and wound at a winding speed of 2,500m/min to obtain an undrawn semidull polyester fiber having round cross section, a birefringence of 0.025-0.040, a crystallization temperature of 127°C (determined by a scanning calorimeter), a glass-transition temperature of 72°C (determined by dilatometry) and a maximum draw ratio of 3.100. The undrawn polyester yarn is drawn in two stages under the condition satisfying formula I (TDR is total draw ratio; MDR is maximum draw ratio of the undrawn yarn), formula II (DR₁ is 1st-stage draw ratio; DR₃ is 2nd-stage draw ratio), formula III, formula IV, formula V [HRT is temperature of the take-up roller of the 1st-stage drawing (°C); Tg is glass transition temperature of the undrawn yarn (°C)] and formula VI [HPT is temperature of heat-setting hot plate placed in the 2nd-stage drawing zone (°C); Tc is crystallization temperature of the undrawn yarn].;COPYRIGHT: (C)1993,JPO&Japio