Patent ID: 6878326
Filing Date: 2005-04-12
Classification: D01F,Y10T

Abstract:
1. A process for preparing an industrial polyester multifilament yarn, comprising: A) melt-extruding a polyester polymer having ethylene terephthalate units of 90 mol % or more forming an extruded yarn and passing the extruded yarn through a delay quenching zone and then a quenching zone to solidify the extruded yarn as an undrawn yarn having an intrinsic viscosity of 0.88 or more; B) oiling and taking up the undrawn yarn at a speed to provide an undrawn yarn having a density of 1.338 to 1.365 g/cm C) drawing the undrawn yarn at the glass transition temperature or lower in three stages with the proviso that the draw ratio is greater in the 1 to obtain an industrial polyester multifilament yarn having a terminal modulus of 35 g/d or less and a tenacity of 7.2 g/d or more.