| 摘要 |
<p>The invention describes a novel process for producing a highly expanded open cell cross-linked polyolefin foam comprising the following steps: (i) preparing one or more compositions forming highly expanded open cell cross-liked polyolefin foams, such as polyethylene, (ii) molding one or more solid pre-forms from the composition or compositions; (iii) obtaining a precursor of the final foam to be obtained, comprising a core (5) prepared from one or more solid pre-forms obtained in the previous step covered at least in part by a cross-linked polyolefin skin (6) with a specific melting temperature, viscosity and gas permeability; (iv) subject the precursor to pressure and temperature in a first mold (7), followed by the opening of the same and a first expansion; (v) subject to temperature the pre-expanded piece (9) resulting from the previous step in a second mold (10), followed by the opening of the same and a second expansion, and demolding the expanded open cell cross-linked polyolefin foam (11). The invention also describes the polyolefin foam obtainable by the process of the present invention and its use as acoustic absorber, as thermal insulator, or as oil absorber, as comfort element in seats and mattresses, as gasket or as component to dissipate mechanical vibrations and impacts.</p> |
