| 摘要 |
<p>An extruded plastic web is passed e.g. between upper and lower rows of off-set rollers or pins to corrugate it, and a flat plastic web is fused to each side of the corrugated web. Pref. the web is cooled as it is corrugated and plastic foam is injected into the channels defined between the corrugated web and the flat webs. The sheet is used as an insulator, and the method of manufacture is an improvement on the method of Parent application.</p> |
