GB1342484A - Method of and apparatus for producing bulked yarns - Google Patents

Abstract

1342484 Bulking yarns JOHN HEATHCOAT & CO Ltd 19 April 1971 [6 April 1970] 29 June 1970] 16192/70 and 31381/70 Heading D1F A method of producing bulked multifilament yarn includes the steps of impregnating the multifilament yarn with a gaseous fluid at one pressure, carrying the yarn continuously forward in the fluid and then causing the fluid impregnated in the yarn to expand to a lower pressure thus separating the yarn filaments to provide a degree of bulking of the yarn greater than that to be finally achieved, bringing the separated filaments towards one another and carrying the yarn forward in a second stream of the fluid. The yarn may be of a thermoplastic material, in which case the fluid is at a temperature high enough to plasticize the yarn. The yarn may after being processed by the above method, be crimp-set preferably by holding the bulked yarn to the desired degree in a non-tensioned condition to allow the yarn to set. A low-temperature fluid may be applied to the yarn to accelerate the setting. The method may be carried out in the apparatus shown in Fig. 1 wherein yarn 21 enters a high pressure passage 4 and meets hot high pressure gaseous fluid i.e. air or steam, entering passage 1 through entry 5. The fluid and yarn pass to an intermediate chamber 2 where the fluid expands to a lower pressure, and the yarn filaments are caused to separate, as shown at 22. The filaments are impacted against deflecting surface 8, causing them to be crimped. The filaments are then passed through the passage 6 to a lower pressure environment. When the fluid and yarn leave passage 6, fluid escapes via ports 13 into the jacket surrounding the stuffer tube thereby heating the tube, and the yarn is projected against the adjacent end of yarn plug 20. The yarn plug then enters the cooler 17 where crimp-setting takes place.