Abstract: A process for producing a continuous foam sheet of a synthetic resin having a polyolefin base which comprises admixing an organic peroxide, a blowing agent, and a pore regulator with the synthetic resin, finely distributing said peroxide, blowing agent and pore regulator within said resin at a temperature below the decomposition temperature of the peroxide and the blowing agent in the thermoplastic range, shaping the resulting admixture into a sheet or panel and thereafter effecting thermal crosslinking and foaming of the resin. The pore regulator comprises an oligomeric and/or polymeric saturated dicarboxylic acid ester or a mixture of such esters having average molecular weights of from between 500 and 40,000, and flow points and/or melting ranges that are below the decomposition temperature of the peroxide and of the blowing agent.

Abstract: Extruded structural members are produced from polyolefins reclaimed from lead-acid battery cases which heretofore, because they are not biodegradable, have created an ecological problem. Such structural members have an impact strength which nominally is 17% greater than the impact strength structural members formed of corresponding virgin polyolefins.

Abstract: A process for the manufacture of a multicellular stretched sheet which comprises melt compounding a thermoplastic matrix polymer and an additive comprising a polymeric or non-polymeric organic compound or a metal salt of an organic acid, forming the blend into a shaped article and stretching the article at a temperature within the normal orientation temperature of the matrix polymer and below the glass-transition temperature of the polymeric additive or below the melting or softening point of the non-polymeric additive.

Abstract: a filled, biaxially oriented, void-containing thermoplastic film suitable for making heat-shrinkable bands is provided having shrinkage on heating to 100.degree. C. of greater than 5%, which shrinkage in turn is at least 5% greater than the shrinkage in a direction perpendicular thereto.A process for preparing this film with its preferential shrinkage is provided including the steps of:(a) melt-blending a C.sub.2 -C.sub.10 .alpha.