| 摘要 |
PROBLEM TO BE SOLVED: To obtain a plastic core material for foundation, having performances closer to rigidity and spring elasticity (shape restoring force) of a core material made of a metal, thin thickness, excellent shape retention and high safety. SOLUTION: In this core material 1 to be incorporated into a cup part of a foundation and used, the core material 1 is an approximately fishhook shape obtained by bending a ribbon-like belt consisting essentially of a thermoplastic resin having >=100 kgf/mm2 modulus of elongation in the width direction and making the edge parts in the longer direction of the ribbon-like belt form the outer periphery 3 and the inner periphery 2. |
