| 摘要 |
<p>Elastic sealing material comprises a supporting layer carrying a bitumen-polymer based sheet. This sheet consists of two layers, a main layer and a surface layer, the proportion of polymer being greatest in the latter. Used to provide economical roofing; the high proportion of polymer in the surface layer imparts resistance of the material to atmospheric conditions, and the polymer content of the main layer is calculated to impart the desired elasticity.</p> |
