Patent ID: 6149847
Filing Date: 2000-11-21
Classification: D01D,D01F

Abstract:
A method of making a polyester yarn, comprising the steps of:(a) melt-spinning a multiplicity of molten polyester filaments;(b) cooling said molten polyester filaments at least sufficiently to solidify them into solid polyester filaments;(c) heating and prestretching said solid polyester filaments by passing said solid polyester filaments separated from one another through a counterflow heating zone in counterflow to a gaseous medium while heating said solid polyester filaments to a temperature of 100.degree. C. to 199.degree. C. and above the glass transition temperature thereof to generate a crystallinity of >24% in prestretched polyester filaments;(d) thereafter gathering the prestretched polyester filaments and stretching the gathered polyester filaments as a yarn to a final titer following the stretching of 1.0 dtex to 7.5 dtex at a temperature of 80.degree. C. to 250.degree. C. and at a stretching ratio of 1:1.5 to 1:1.15; and(e) thereafter winding up said yarn at a rate of 5000 m/min to 8000 m/min.