| 摘要 |
1,210,927. Thermoplastic polymer filaments. TORAY INDUSTRIES Inc. 30 Nov., 1967 [9 Dec., 1966; 30 June, 1967 (4)], No. 54665/67. Heading B5B. [Also in Division D1] A thermoplastic synthetic high polymer e.g. poly-#-caproamide, crimped or latent crimped filament is of non-conjugate structure with a two-phase transverse cross-section in which the two phases have a mutually different dyeability or refractive index and the outer surface portion of one of the phases is roughened with more than 20 indentations per mm. of filament length, each indentation being 0À5-10 microns. The phase with the roughened surface may subtend an angle of 45-240 degrees to the centre of the filament and the ratio of the crosssectional area thereof to the cross-sectional area of the filament may be 1: 8-3: 4. In a manufacturing process, a filament of the polymer is melt-extruded, cooled, perhaps lubricated or oiled, directly (i.e. without wind-up) stretched whilst drawn over and in pressure contact with a curved surface of a heated body e.g. a cylindrical pin, maintained at a temperature 250-700‹ C. above the melting temperature of the polymer: the length of contact may be more than 15 mm. and a relatively high coefficient of friction between filament and body is specified, the contact portion of the filament being thereby subjected to an abrasive action and concentrated heat treatment. Crimp in the filaments is developed after initial cooling by subjection thereof in relaxed condition to a heat treatment at a temperature at least 80‹ C. below the melting temperature of the polymer but higher than the second order transition temperature thereof. |
