| 摘要 |
<p>It comprises three layers: a first layer of plastic material that provides the whole with mechanical strength, a second intermediate layer of foam forming a union between the first and second layer, and a third layer of impermeable plastic material and is characterised in that the first layer (2) is mase on an elastomeric polyolefin of high strength and elasticity, in that the second layer (3) is of closed-cell, physically or chemically cross-linked polyethylene foam, and in that the third layer (4) is of polyolefin with high tear resistance. A light waterproofing sheet is obtained which withstands extreme meteorological conditions, is resistant to chemical agents, while it also has optimum mechanical properties at a lower thickness thanks to the material of which the first layer is comprised and unlike other sheets existing it has no ageing limit, which measn that once the sheets have been fitted they do not have to be replaced.</p> |
