摘要 |
Composite foam articles are prepared by the coextrusion of at least two interdigitated layers in abutting relationship to each other, with at least one layer of the composite article being an expanded thermoplastic resinous material. At least one blowing agent is incorporated into at least one of the layers under a pressure sufficient to keep the blowing agent quiescent and the individual melt streams are combined and interdigitated into a composite layered stream. The composite layered stream is expressed while the operating pressures and temperatures of individual melt streams are controlled to provide a coextrusion product having a stable foam structure. <IMAGE> |