| 摘要 |
<p>A thermoformable, multi-layer, sheet comprising a foamed layer (a) comprising polypropylene, a substantially unfoamed outer heat-sealing layer (c) and a foamed layer (b) comprising a polyethylene, positioned between layers (a) and (c) wherein the thickness of the foamed polypropylene layer (a) is preferably comprised between about 45 and about 70%, of the thickness of the entire sheet, and that of the polyethylene foamed layer (b) is preferably between about 20 and about 35%. The sheet is preferably obtained by coextrusion and chemical foaming. The characteristics of thermoformability of the obtained sheet are remarkably improved over those of the known partially foamed polypropylene sheets while the characteristics of rigidity required for the specific applications are maintained.</p> |
