CRIMPED MULTIFIBER YARN, POLYESTER CRIMPED STAPLE FIBER AND METHODS FOR THEIR PRODUCTION Russian patent published in 1995 - IPC

FIELD: textile industry. SUBSTANCE: crimped multifiber yarn produced from thermoplastic polymer has higher double refraction factor in outer layer than that in inner layer of cross-section of composite monofilament. Distribution of double refraction factor is such that position featuring minimum double refraction factor is located with deviation from longitudinal axis of fiber and irregular crimp has 10 crimps for 25.4 mm. In case of polyamide, the grade of crystal growth determined by wide-angle X-ray diffraction amounts to 0.2 and higher; and in case of polyester, 0.4 and higher. Preferable method for production of said crimped multifiber yarn consists in that aqueous solution is fed from one side to given yarn, extruded through spinneret until the moment its temperature drops down to definite level, and then, yarn is drawn 1.0-1.5 times with subsequent treatment with jet of flowing medium (for nylon) at 150 C and higher or relaxation heat treatment. EFFECT: higher efficiency. 24 cl, 12 dwg, 10 tbl