GB881865A - Improvements in and relating to "stretch"-type yarns - Google Patents

Abstract

881,865. Finishing yarns. ENGLISH ROSE Ltd. Feb. 19, 1958 [March 7, 1957], No. 7644/57. Class 120(3) Crimped stretch yarn is made by continuously feeding a thermoplastic, e.g. nylon or polyester, yarn into the entry end of an open-ended tunnel and continuously extracting it from the exit end thereof at a linear speed less than the input speed so that, in continuous flow, the yarn arranges itself in the tunnel in regular sinuous form without being compacted, and heat-setting the yarn in such form during its travel in the tunnel or subsequent thereto. The emerging yarn may be gripped between travelling surfaces, heated and cooled. The tunnel may have major and minor transverse dimensions such that the sinuosities are formed generally in the plane of larger dimension, e.g. the dimensions may determine the amplitude of the sinuosities and constrain the yarn in a single plane. If the tunnel is of circular cross-section, the sinuosities occur in different planes haphazardly or the yarn may form a helix, and the yarn may be set in such condition or it may be forced into one plane and set. In the operation of apparatus shown comprising a crimping and setting unit 17, yarns 10 drawn from packages 16 pass successively through eyelets 19 and 20, a converging grooved guide 28 tapered at 28b, the nip of feed rollers 11a, 11b, and a tunnel within a crimping tube 13 having chamfered ends to fit closely between opposed surfaces of feed and extraction members, Fig. 3 (not shown) and longitudinally divided into two separable parts. On emerging from tube 13, the yarn is trapped between, forwarded and heat-set by endless metal bands 14a, 14b provided with heaters, as at 30, 31, and coolers 32, 33, and travelling over rollers 15a, 15b, 15c, 15d and 27a, 27b, 27c, 27d. The crimped yarns leaving the bands pass through a diverging grooved guide 29 tapered at 29b, guides 21 and 22, to take-up spindles 18. A motor 24 operates all driven parts of the apparatus through chains and sprockets, belts and pulleys, and/or gears. The unit 17 is divided into two parts hinged at 50 to facilitate threading- up.- The tunnel may be vibrated laterally by electric, supersonic and/or hydraulic means, Figs. 13 and 14 (not shown).