| 摘要 |
1,260,957. Fibrillated yarns. ALLIED CHEMICAL CORP. 13 March, 1969 [13 March, 1968], No. 13410/69. Heading B5B. [Also in Divisions C3 and D1] A fibrillated shaped extrudate is produced by extruding an intimate mixture consisting of 10 to 80% by weight of each of (a) a fibre-forming polyamide, (b) fibre-forming polyester and (c) a fibre-forming polyolefin, orienting the extrudate by stretching it at a temperature between the extrusion temperature and ambient temperature and then fibrillating the oriented extrudate so as to convert it into a relatively high bulk fibrillar structure, the degree of stretching being sufficient to permit fibrillation of the extrudate without disintegrating it. The extrudate is suitably in the form of a "strand", which term is defined as including narrow strips of film tapes and mono-filaments. In the examples, the strand is a monofilament of 0À3 to 0À5 mm. diameter prior to being stretched. The polyamide, which desirably constitutes 20-70% of the mixture may be polycaprolactam or polyhexamethylene adipamide. The polyester may be polyethylene terephthalate and the polyolefin may be polypropylene. The stretching of the extrudate may be effected in more than one step. Thus a strand, after having been stretched in one or more stages, e.g. using a pin, may be fibrillated by mechanical means, e.g. slightly crushed by passing it between two rollers, the clearance between which is somewhat less than the diameter of the drawn monofilament and may then be passed through a device in which the partially fibrillated monofilament is subjected to turbulent vibratory or flagellating action by a high pressure air jet whereby further fibrillation is effected and the bulk of the material increased. The process of the invention may be used for the production of fine apparel yarns without the necessity of extruding continuous filaments and forming staple fibres as an intermediate step.
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