| 摘要 |
<p>PURPOSE:To prevent deterioration with time and to improve impact resiliency by a method wherein monofilaments of spiral twist are prepared by twisting polyamide core threads and side threads directly after spinning threads and stretched, heat-treated and then irradiated by radiation beams. CONSTITUTION:Nylon is extruded by an extruder into core threads and side threads and molded into spun threads. Directly thereafter, core threads and side threads are twisted and welded to form spiral lays of monofilament externally. This monofilament is stretched, heat treated according to the ordinary method. Then, gamma rays of 10<5>-10<7> rad are irradiated from the radiation source of Cobalt 60 to the monofilament to manufacture racket gut 4. In this manner, gut having a rugged surface where twist remain can be obtained. Spin drives can be given easily by a racket made from this gut for the tennis ball, etc.</p> |
