| 摘要 |
<p>A capsule is formed from a pre-expanded foam core in a compressed condition with a thermoplastic outer covering completely enveloping the foam core to maintain it in the compressed condition. The outer covering is made of a material capable of softening sufficiently when heated to permit the foam core to expand toward its original expanded uncompressed condition. Preferably, the outer covering adheres to the foam and then is carried by the expanding foam into intimate contact with the inner surface of a hollow structural member so as to form a seal for the hollow structural member.</p> |
