GB1297340A - - Google Patents

Abstract

1297340 Crimping yarns and fibres MITSUBISHI RAYON Co Ltd 19 April 1971 [5 March 1970] 27211/71 Heading D1F In a method of crimping single or doubled, multifilamentary yarns or tows of continuous filaments e.g. conjugate fibres or fibrillated films or tapes, the thermoplastic filaments which may have been preheated as by passage between heated plates and/or stretched as between drawing rollers with or without snubbing and/or fed directly from a spinneretare entrained in a heated fluid e.g. dry or moist air, steam preferably superheated, or hot water, and projected thereby into a stuffing chamber one wall of which is formed by a circulating endless surface e.g. as provided by a rotary cylinder or an endless belt. The fluid flows at a higher speed than the endless surface moves so that filaments are compressively crimped and transported by the surface to the outlet of the chamber whence the crimped material is withdrawn for winding. The filaments may be additionally heated at a first stage and positively cooled at a succeeding stage of their progression through the chamber. The method imparts random, rounded, threedimensional crimp at high processing speeds. As shown in Fig. 1, a yarn 26 is fed by rollers 13a, 13b, and guide pin 14 into a hot fluid nozzle 3 and are ejected thereby into a stuffing chamber 2 formed by a screen surface 4 of a rotary cylinder 1, side walls 7 attached thereto (and encircling the cylinder) and a stationary cover 8. A device 11 injects cooling air into chamber 2 over a portion downstream of a partition 9. Crimped yarn 27 passes to package 23 by rollers 16a, 16b. guide pins 17, 18, 19, rollers 21a, 21b under tension determined by spring mechanism 24. The outlet of nozzle 3 may project divergently into chamber 2 and the fluid flow arrangements Figs. 4, 5A, 5B, 6, 7 (not shown) in the nozzle may create turbulence and also such suction in the yarn passage as to ensure self-threading of the yarn end therethrough. According to one modification Fig. 8 (not shown) the chamber 2 comprises three successive zones of entry, additional heating and cooling, the fluid heating medium and the coolant entering and leaving the chamber through apertures in the cover 8. The side and screen walls of the chamber 2 may be provided with internally projecting ribs perpendicular to the circulating direction of the endless surface to ensure even crimping of fine filaments and/or filamentary strands.