GB924086A - Improvements in composite textile yarns and in processes for their production - Google Patents

Abstract

924,086. Spinning and finishing yarns; woven fabrics. E. I. DU PONT DE NEMOURS & CO. March 31, 1959 [April 14, 1958; March 13, 1959], No. 10924/59. Drawings to Specification. Classes 74 (2) and 120 (3). Composite e.g. cored, yarn of varying denier is produced by feeding at least two groups of filaments e.g. multifilamentary yarns, simultaneously through a turbulent fluid e.g. air which may be heated or steam, zone at such different rates of feed that the extensibility factor i.e. the sum of the increase in length required to straighten the filament without stretching it and the elongation at break of the filament, of one group is higher than that of another group and stretching the resultant composite assembly of filaments, by withdrawal from the zone at a speed predetermined in relation to the feed speeds of the separate groups thereto or at a subsequent stage, so that the filaments of the first group break to form at random intervals along the length of the yarn distinct bundles of discontinuous filaments interentangled with the filaments of the other group (which may constitute a core). The groups may comprise filaments of nylon and rayon, nylon with acrylic, polyethylene terephthalate with rayon, acetate or acrylic, acrylic with rayon or acetate, or nylon with silk or glass. The turbulent zone may be provided in a jet such as described in Specifications 732,929, 842,742, 905,895 or U.S.A. Specification 2,852,906. The intertanglement of the bundles may be consolidated by twisting, as effected by a spinning frame or downtwister or by passage through a " wrapping " jet, such as described in Specifications 871,112 and 924,089, producing a fluid vortex or zone of " fluid torque " which may cause opposed and/or superimposed twist effects in the yarn, or by chemical treatment such as sizing or plasticizing with heat or solvent. Fluid pressure, filament or yarn tension, feed and/or withdrawal speeds may be varied or rendered intermittent in application to achieve different and/or varying loop, slub, denier or bulk effects. The yarn may be produced continuously with other processes e.g. twisting, drawing, back-winding. Composite slub yarn may be woven into a plain-weave fabric e.g. with a warp of multifilament polyester yarn.