Closed-cell foam structure and fused foam strands or profiles and method for the manufacture of such a foam structure

摘要

Improved closed-cell foam, which is particularly well suited for use in packaging and comprising a plurality of fused parallel strands or profiles 2 of thermoplastic resin. When the resin is a non-aromatic olefin, the heat sealing strength of a film of this is at least 30 Newton/2.5 cm. The resin is preferably a mixture of an olefin polymer resin and a copolymer of ethylene with one or more copolymeriseable co-monomers having a lower melting point than the olefin polymer resin. The cross- section of the strands or profiles and/or their spatial arrangement are advantageously such that they are united at the extremities to form a network, which defines cavities. The resin may contain up to 50% by weight of a nucleating agent, especially carbon black. The strands and profiles are appropriately extruded through a die with multiple openings, in which some of the openings are temporarily blocked for manufacturing the desired structural shape. IMAGE