| 摘要 |
<p>It consists of two layers, namely from the inside outwards: - a first layer of nonwoven fabric made of high-density polyethylene or of polypropylene, such as the fabrics marketed under the names Tyvek and Typar respectively, impregnated with a solution of salts optionally containing halogens, and - a second layer of polyethylene of class M1 extruded and laminated to the first one. w</p> |
