| 摘要 |
PURPOSE:To obtain the durability of the joint part of a ball without breaking the weight balance and elasticity balance of the ball. CONSTITUTION:The joint part of the tennis ball formed of a rubber compsn. without having melton clothes is polished to a recessed shape and rubber glue is applied therein. Unvulcanized rubber is inserted into this joint part like h and is compression bonded and vulcanized to increase the adhesive area of the joint part, by which the durability of the joint part is obtd. |
