| abstract |
The present invention provides a sheet of polymeric foam comprising chemically cross-linked, closed-cell, foam comprising at least one polyolefin;cork particles dispersed within said polymeric foam wherein said foam has a specific gravity of between 40-250kg/m3 and is essentially free of visible perforations. Also provided by the present invention is a process for producing a continuous polymeric sheet said comprising a chemically cross-linked, closed-cell, polyolefin foam comprising at least one polyolefin and cork particles, homogenously dispersed within the polyolefin foam wherein once produced, said continuous polymeric sheet has a specific gravity of between 40-250kg/m3 and is essentially free of visible perforations; the process comprising (i) continuously feeding into a mixing arrangement set at a temperature of between 60 C and 200 C a blend of at least one polyolefin resin, a blowing agent, a cross-linking agent and cork particles, to form therein a homogenous melt; (ii) transferring said melt into an extrusion line constructed to form a continuous sheet of said melt; (iii) conveying the continuous sheet into a heating module for heating said continuous sheet to a first temperature allowing cross-linking of said at least one polyolefin resin to obtain a cross-linked polyolefin sheet, said first temperature being lower than that required for activating said blowing agent; and (iv) heating the cross-linked polyolefin sheet to a second temperature allowing activation of said blowing agent, to obtain said continuous polymeric foam. |