Suitable core materials include polyurethane foam ( 38 ), optionally filled with particles ( 32 ) of granulated rubber, expanded perlite, expandable polymer beads, and/or glass microspheres.

• 适用的核心材料包括聚亚胺酯发泡体(38)，其中选择性的充满橡胶颗粒(32)，可膨胀珍珠岩，可膨胀之聚合体颗粒以及/或玻璃微球体。