| 摘要 |
<p>Plastic covering elements consist of longitudinal tubes which at one end are imbedded in a foam layer, (pref. polyurethane foam) fixed in a sealing layer at an acute angle to the carrying layer and projecting from the latter so that adjacent parts of the tubular elements partly cover each other. Specifically, the tubes are foamed in place in the carrier plate so that they lie in a row close together, the rows arranged being at a distance from each other.</p> |
