| 摘要 |
A coherent thermoplastic substantially twistless multifilament yarn, made from a hydrophobic synthetic polymer possessing in the form of oriented fibres a water absorbency of less that 1% per weight of fibre at 70 DEG F. and 65% relative humidity, has bonds, between adjacent filaments consisting of this polymer in a crystalline or partly crystalline form, and extending substantially the whole length of the filaments, the degree of cohesion being such that the average cohered filament count-i.e. the number of separate filaments, and bundles of filaments-is 5-80% of the total number of filaments. The bonds are formed by wetting a multi-filament yarn with a liquid containing a compound which is a solvent for the polymer at an elevated temperature, passing the filaments through a heating zone at a temperature between 140 DEG C. -600 DEG C. to evaporate the liquid, and then cooling the yarn. The solvent may be applied to undrawn yarn which is then drawn and the yarn cohered during heat setting, or to a drawn yarn before the heat setting stage, or subsequent thereto with a separate heating step being provided. The yarn may be a polyester or a polymerized olefine-for example polyethylene terephthalate or polypropylene. The solvent may be tetrachloroethane, chloral g -butyrolactone, anisaldehyde, m-cresol, benzophenone, and 2-phenoxyethanol, benzyl alcohol, acetophenone salicylaldehyde, methyl cyclohexanone, acetophenone, a mixture of nitro-with chlorobenzene, and xylenes. After weaving or other processing steps the filaments may be separated by scouring, pressing, calendering or treatment with swelling agents or in strong alkaline solutions. Novel fabric effects may be obtained by a combination of cohered warp and twistless weft yarns or by using a warp with a higher degree of cohesion than in the weft to form a lawn-like fabric, by a combination of two or more yarns of different degrees of cohesion which can be treated so that the yarns with the lesser degree of cohesion are broken down into individual filaments, or by weaving or knitting fabrics from yarns having a random filament bond formed by partial break down of the bonds. For use as sewing threads the cohered yarns may be coated with a lubricant-for example polydimethyl siloxane. The yarn filament counter described in Specification 829,330 is used to provide the "cohered filament count".
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