| 摘要 |
<p>PURPOSE: To improve mechanical characteristic while keeping heat resistance and moisture resistance and enhance the feeling in driving a ball by stranding a thick core yarn and a slender winding yarn formed by extruding polyester resin into a strand immediately after passing a cooling tank, drawing it in two stages, and further annealing it. CONSTITUTION: A polyester resin is extruded through a nozzle 4 mounted within the die 3 of an extruder 1 after heated, fused and kneaded. A number of filaments passed in a cooling vessel 7 are immediately sent into a twisting spinning machine 8 and twisted. At this time, a fine winding yarn is prevented from being superposed around a thick core wire. The resulting twisted strand 13 is drawn in two stages so that the drawing ratio is 4-7 times, and further annealed to moderate the heat to 0.7-0.95 time, whereby a core-winding structure string having a twisting number of 15-60T/W is provided. Thus, a string having mechanical characteristics such as strong elongation and elasticity similar to natural sheep gut and also excellent in heat resisting and moisture resistant characteristics can be provided.</p> |
