| 摘要 |
<p>A multi-layer composite sheet made up of two basic sheets, one at least of which has distended bulges to form air pockets, is arranged so that the basic sheet containing the bulges is connected to a cover sheet over the summits of the bulges. In a preferred embodiment, the cover sheet is of two layers, the inner layer melting at a lower temp. than the outer, during application, the sheet is heated sufficiently to soften the inner layer without softening the outer layer, thus bonding the sheet to the cellular structure.</p> |
