SLUBBING 'ROCESS AND SLUBBING APPARATUS FOR CONTINUOUSLY PRODUCING SLUB YARN

摘要

1433083 Slub yarns MITSUBISHI RAYON CO Ltd 30 Jan 1974 04222/74 Headings D1F and D1W A process for continuously producing slub yarns comprises passing a multifilament yarn 1 through a reduced pressure region produced by sucking air from atmosphere through the region. Apparatus for carrying out the process comprises a hollow column 12 having end plates 13, 15 with yarn supply and delivery holes 14, 16 respectively open directly to the atmosphere, the periphery of the column 12 being connected to a vacuum source via a pipe 17, and the apparatus including feed and delivery means arranged to deliver the yarn from the column 12 at a slower rate than the feed rate. Air is sucked from the atmosphere through the column 12 via the holes 14 and 16, and creates a turbulence in the column which forms the slubs 7a on the yarn. An air permeable partition may be aranged in the pipe 17 or in the column 12 between the yarn path and the pipe 17 so that the yarn is sucked against the partition to increase the agitation of the yarn. In a further embodiment. Fig. 8, a yarn storage inner hollow column 42 is provided fixed to the end plate 13 and provided with holes 43 at the yarn entry end; the holes 43 may be arranged so that their axes do or do not intersect the axis of the column 42. An air vortex hollow column 52 is preferably also provided extending from an air suction device 45 adjacent the other end plate 15. The column 52 is provided with peripheral holes 56, the axes of which do not intersect the axis of the column 52. Air is sucked through holes 47 in the device 45 into the column 52 where a vortex is created as the air leaves via holes 56. The multifilament yarn is agitated and the slubs formed in the column 42 by virtue of the holes 43. In a further embodiment the air vortex column 52 may be omitted, but the air suction device 45 is provided adjacent the end plate 15. The yarn may be comprised of a single multifilament yarn or a plurality thereof, either the same or different. In the case of different multifilament yarns being used, they are preferably thermoplastic polymer yarns one of which has a lower melting point than the other, and the slub yarn is heat treated to bond the yarn due to melting of the lower melting point component. A heat treatment may be used to effect tightening of the stub yarn by shrinkage of the component filaments. The yarn may be crimped as by gear crimping or false-twist crimping before or after slub formation. The yarn may be entangled by an air jet prior to entry into the reduced pressure region; or the slub yarn may be treated with an air jet after slub formation to consolidate the yarn. The yarn may also be given a fluffy appearance by the presence of abrasive particles on the inner surface of the column 12 or the hollow column 42.