POLYESTER YARN AND METHOD FOR PRODUCTION THEREOF

摘要

A multifilament yarn consisting essentially of polytrimethylene terephthalate, characterized in that a strength in a stress-strain curve of 3 cN/dtex or more, a Young's modulus of 25 cN/dtex or less, a minimum differential Young's modulus in the range of 3 to 10 % elongation of 10 cN/dtex or less and an elastic recovery after 10% elongation of 90 % or more. A method for producing the polyester yarn, characterized as comprising subjecting a polytrimethylene terephthalate having a limiting viscosity [ eta ] of 0.7 or more to melt spinning to form a multifilament yarn, taking the multifilament yarn up at a spinning rate of 2000 m/min or more, stretching the yarn while treating it with heat without temporarily winding it up, successively subjecting the resulting yarn to relaxation treatment at a relaxation degree of 6 to 20 %, and then winding the yarn up to a package. The polyester yarn and a woven fabric made of the yarn are free from excessively tight winding even when the yarn is spun with high speed, and are reduced in the dispersion of its properties in the longitudinal direction of its fiber and in the feeling of squeeze.