GB976478A - Improvements in or relating to the production of spun yarn - Google Patents

Abstract

976,478. Texturing yarn: continuous spinning. E. J. DU PONT DE NEMOURS & CO. Oct. 19, 1962 [Oct. 23, 1961], No. 39686/62. Headings D1D, D1F and D1W. A spun yarn consists of a core bundle substantially free of true twist, consisting at least in part of discontinuous textile fibres, and bound together as a compact bundle by discontinuous textile fibres twisted tightly about the core bundle in irregular helices having helix angles between 10 degrees and 80 degrees. As described ends of tow 10, 11, 12 are drafted, and in the case of continuous filaments are stretch broken, between rollers 17, 18, and 20, 21 to produce a ribbon shape bundle. The fibres may be drafted over a hot plate at 105- 110‹C. An apron 19 or other guide means are used to support the fibres. An aspirating jet 24 which fits tightly about the nip of the rollers 20, 21 forward the fibre bundle to a twisting jet 25 where initially the core and to a lesser extent the surface fibres are twisted in one direction and then the compacted yarn is back twisted so that the core is substantially free of twist while the surface fibres are helically twisted about the core. As some of the fibres may be doubled back on the yarn as the yarn passes through the twisting jet, a few helical wrappings may occur in the opposite direction. The aspirating jet 24 (Fig. 3) has a plurality of holes 39 which direct gas or vapour, from an annular chamber 37 tangentially and angularly into the central bore 34. The jet may exert some twisting effect on the yarn bundle. If two ends are separately drafted then two aspirating jets are used with a manifold from one jet directing fibres into the centre of a second manifold (Fig. 1 not shown) linking the other jet with the twisting jet. The twisting jet (Fig. 4) has a yarn passageway 49 in a member 46 which may be rotated by a handle 47 between a threading slot 50 and the operative position in which a passageway 45 directs gas or vapour, which has a speed of at least 1/2 sonic velocity and which may be air at room temperature or at 110‹C. or steam at 166‹C., tangentially into the bore 49. Instead of a tow the starling material may be a sliver, roving or low twist staple yarn, with the stretch-breaking step being omitted. The following textile fibres may be used:- cotton, wool, silk, ramie, jute, hemp polyamides, cellulose esters, polyesters, polyalkylenes, polyvinyls, polyacrylics, glass or metallic fibres. By using a cellulose acetate yarn, which during drafting alternately snap breaks and drafts, with polyethylene terephthalate a slub yarn is obtained. By introducing at the front rollers 20, 21 a yarn of material different from that of the tow a composite yarn is obtained with one material predominating in the core. In this way glass filaments or a metallic conductor may be covered or a compacted elastic yarn obtained.