process for the production of faeden or films with glanzeffekten from synthetischemorganischem material

摘要

Highly drawn fibres, films &c. of a synthetic organic polymer having a uniform cross-sectional area along their length and having along their length alternating clear segments of homogeneous structure and opaque lustrous segments containing small elongated voids are produced by forming in the as yet undrawn and substantially unoriented fibres or films localized draw initiation zones whose response to a drawing tension differs from that of the remainder of the fibre or film, and subsequently cold drawing the fibres or films at a temperature of not more than 80 DEG C. at its natural draw ratio. The localized draw initiation zones preferably have a birefringence greater than 0,01, and the remainder of the fibre or film a birefringence of less than 0,01. The L.D.I. zones may be formed by various methods, including mechanical methods (which are preferred), use of air jets, spaced heating and cooling means, interrupted infra-red radiation, uneven quenching techniques in spinning, intermittent application of warm liquid jets or droplets, intermittent or random application of chemical plasticizers or thermal treatment, and intermittent crystallizing of the yarn. The fibre or film material may be a polyester, a polyamide, a polyacetal resin, a polyolefine or a polyurethane. In the treatment of yarns and ribbons according to the invention, undrawn yarn may be passed from feed rollers through a yarn-driven rotary deforming device comprising a notching roller and a smooth back-up roller. The notching roller may consist of a smooth brass cylinder with spaced ribs parallel with its axis raised above its peripheral surface. The yarn may then be passed over a snubbing pin heated to 50 DEG -140 DEG C. and finally over a pair of drawing rollers. Examples are given of the treatment according to the invention of undrawn ribbons of polyethelene terephthalate, polyhexamethylene adipamide, 6-nylon, polyacetal resin, polypropylene and a 90/10 polyethylene terephthalate polymethylmethacrylate blend. Specifications 461,236, 578,079, 753,299, 851,881, 903,914 and U.S.A. Specifications 2,071,251, 2,130,523, 2,130,948, 2,352,725, 2,571,319 and 2,731,446 are referred to.