| 摘要 |
PURPOSE:To increase an adhesive strength between a reinforcement layer and a coated layer by minimizing the diameter of the reinforcement layer at a coated layer forming gate section, maximizing it at a coated layer final charge section, and also forming the reinforcement layer with thermoplastic polyurethane elastomer. CONSTITUTION:A reinforcement layer 5 is thinnest at a gate section and thickest at a weld generating section 9a, and its wall thickness is varied gradually. Though a coated layer is formed with a polyurethane foam body, an integral type foam body is desirable. Also, an ester, ether, or ether carbonate thermoplastic polyurethane elastomer is used for the reinforcement layer with which the polyurethane foam body is made in contact. Because these both layers can be connected tightly, it is not necessary to introduce intentionally a different diameter cross-section in these reinforcement layers to prevent idle rotation. |
