PURPOSE: To provide a string for play tool which is light-weight, strong, and prominent in resistance against creeping, weather, friction and cutting, and further retains proper softness.
CONSTITUTION: A string for play tool is made of a molecularly orientated molding of an ultra-high molecular weight ethylene polymer having an ultimate viscosity [η] of, at least, 5dl/g. By using the molecularly orientated molding of the specified polymer, the string is light-weight, strong, and prominent in resistance against creeping, weather, friction and cutting, and further retains proper softness. Since the string has high strength and friction resistance, though very light-weight, it can be preferably used as a string for a play tool, such as a rope skipping rope and Nunchakus, which has a grip part and utilizes rotating nature of a string connected to the grip part and centrifugal force produced by rotation.
YOSHIMURA FUKUHIRO
SHIRAI HIROFUMI
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