GB544928A - Improvements in or relating to the stretching of continuous filament textile materials - Google Patents

Abstract

544,928. Stretching yarns. JACKSON, T., and HILL, F. B. Oct. 30, 1940, No. 15864. [Class 120 (iii)] [Also in Groups IV and VIII] Continuous filament materials particularly those having a basis of cellulose esters or ethers are stretched by assembling a number of threads of continuous filaments side by side to form a sliverlike bundle, passing the bundle into a stretching chamber through an opening in the form of a slit of a length and width such as to embrace closely the assembly of threads, and stretching the sliverlike bundle in the stretching chamber. The stretched bundle leaves the stretching chamber by an orifice having a cross-sectional area reduced in accordance with the amount of stretch applied, the shape of the orifice preferably approaching the circular. The stretching chamber may contain wet steam, hot water, or other fluid under pressure. The threads may enter a feed chamber preceding the stretching chamber by a slit so that they remain in warp or ribbon form as they pass the nip rollers or other feed device in the feed chamber. A large number of sliver-like bundles may be passed through separate slit-like openings and treated simultaneously in a single stretching chamber. Since the slits employed closely embrace the warp or ribbon, loss of fluid from the stretching chamber and from the feed chamber, if used, is reduced to a minimum. The slits may be formed by juxtaposition of two appropriately shaped adjustable plates. The stretched material may be used for making staple fibre, cords, tyre-cords, ropes, sewing-threads, or sail cloths. The threads may be supplied from balls, cheeses, or cans. The stretched filaments may be twisted. Cellulose ester materials may be subjected to saponification. The stretched material may be subjected to a shrinking treatment to increase the extensibility. As shown in Fig. 1, ends or threads of continuous filaments are taken from sliver cans 1 and drawn through a tension device and reed. They are assembled to form sliver bundles 5 which are drawn into chamber 6 by rollers 7. The flat bundles enter chamber 6 through slits 3, and then pass into stretching chamber 13 which is supplied with moist steam under pressure from pipe 11. Chamber 6 contains, air under a pressure slightly lower than that in chamber 13. The flat sliver-like bundles pass into chamber 13 through slots 14 formed between the edges of plates 15, 16, the edge of plate 15 forming wide shallow grooves, and the flat edge of plate 16 closing the upper sides of the grooves to form the slots 14. Plate 16 is mounted to slide vertically and is operated by a screw with knob 21. The stretched bundles pass out of chamber 13 through orifices closely conforming to the size and shape of the cross-section of each bundle, these orifices being formed by pear-shaped apertures in two overlapping plates 23, 24. Plate 23 is fixed but plate 24 slides vertically and is actuated by a screw with knob 31. The stretched bundles pass round the stretching rollers 49, over and under three drying drums 50 between take-up swifts 51 with overlapping bars 32, and then into sliver-cans 33. Instead of collecting the stretched bundles in sliver-cans they may be cross-wound to form cheeses or other packages. Specifications 389,823, 438,584, 438,585, 438,586, 438,587, 438,656, 443,707, 443,773, 532,884, 537,962, [all in Group IV], and 538,194, are referred to.