| 摘要 |
1,224,255. Nylon filaments. TORAY INDUSTRIES Inc. 2 July, 1968 [4 July, 1967; 8 July, 1967 (2)], No. 31626/68. Heading B5B. Nylon 6 filaments are produced which satisfy the following conditions:- #=35Œ5 degrees, and 0À50 # I M /I P # 0À89, where 8 is the angle formed by the meridian and the straight line drawn from the intersection of the meridian and the equator line toward the point indicating a maximum strength in the X-ray low-angle interference image; I P is the interference strength at the point indicating the maximum strength; and I M is the interference strength at the point where a straight line drawn parallel to the equator line from the point indicating the maximum strength intersects the meridian; and a relation between tenacity and breaking elongation is given by:-S x E # 207À0 and 15 #E # 35, where S is the tenacity of the filament in g./denier and E is the breaking elongation of the filament in per cent. Preferably S # 9À2. The method comprises melting nylon 6 chips having a relative viscosity over 2À9 with respect to sulphuric acid and extruding the melt through a spinneret to form filaments which are rapidly cooled to coagulate them, the filaments are then drawn successively in at least 3 stages at such a rate that in the early drawing stages no measurable birefringence is observed and in the later stages the filaments are drawn to the desired final drawing ratio. The time for cooling and coagulating to the start of the drawing process is preferably less than 10 seconds. Also during at least one intermediate drawing stage the content C 8 of the 8-form crystal structure of the filament should preferably be in the range 0À65 # C 8 # 0À90. The nylon 6 filaments can be used to make yarns for tyre cords.
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