GB1198114A - Methods of Treating Textile Linear Material - Google Patents

Abstract

1,198,114. Crimping yarns. G. H. HEATH & CO. Ltd. 30 July, 1968 [31 July, 1967], No. 34979/67. Heading D1F. A method of treating or modifying, e.g. crimping or bulking, textile linear material, e.g. single or composite, polyethylene terephthalate or nylon yarn and bands of film material "of the kind which yield to fibrillation or filamentation", e.g. polypropylene ribbon, comprises forming the material into at least one loop and intertwining the leading and trailing ends in the loop a multiplicity of (possibly preformed) turns so that the intertwining zone and the loop zone form one major loop circuit to enable the leading and trailing portions of the travelling material to assist passage of each other through the intertwining zone. Differential tensions may be applied to the leading and trailing portions of the material, e.g. so that the latter portion remains relatively straight and forms a core around which the other portion spirals. The material may be coiled upon itself first in one direction and then in the other: it may be heated (to set the deformation therein) in the intertwining zone and then naturally or forcibly cooled. The treatment may be combined, and/or form part of a sequence of successive treatments, with extrusion, drawing, texturing, stuffer-box crimping, down-twisting, plying, knitting, lubricating and/or cutting. In the apparatus shown in Fig. 2, yarn at 4 passes through tension discs 5 and guides 6 and 9, over positively driven rollers 10, 11, to return through guides 6, 9, between which it coils several turns 8 around itself having formed a complete loop 7 so that both portions of the yarn in the intertwined coils travel in the same direction: from guide 9 the yarn passes between positively driven nip roller 14 and on to a windup package 16. Electric plate or block heater 12 or 13 is operated at controlled temperature by thermostatic servomechanism (not shown) to plasticise the yarn. A multiple loop arrangement, Fig. 4 (not shown) extends the healing length of the looped yarn within a heat box (28) while maintaining the trailing yarn portion at a lower temperature. Resultant twist-lively yarns of opposite torque may be plied. The required coil turns may be preformed in the yarn by use of a false-twist spindle, rotated only during such initial coil formation, Figs. 5a-d (not shown) the number of coils per inch being between that suitable for the false-twisting of the denier of the material in use and the twist suitable for a material of twice this denier.