Abstract: A process for producing split crosslinked polyolefin sheets comprises producing a crosslinked polyolefin foam sheet having an opposing first surface region and second surface region, and an intermediate region disposed therebetween, wherein the intermediate region is configured to have a gel content lower than an average gel content of the first surface region and the second surface region, and an average cell size larger than an average cell size of the first surface region and the second surface region; and applying a splitting force to the crosslinked foam sheet such that a controlled tear propagation travels through the intermediate region until a first side of the crosslinked polyolefin foam sheet and a second side of the crosslinked polyolefin foam sheet are separated to produce two split polyolefin foam sheets.

Abstract: A polyolefin foam having improved light-transmittance comprises an average cell size of about 70 microns to about 500 microns; a total cell wall thickness to gauge ratio of between about 0.15 to about 0.55; a basis weight of about 0.00005 lb/in2 to about 0.00050 lb/in2; an L color solid value of about 95 to about 45; and a light transmittance of about 10% to about 50% according to JIS K 7361-1. A process for producing a polyolefin foam having improved light-transmittance comprises extruding a foamable sheet at a pressure from about 1 psi to about 55 psi, and foaming the foamable sheet with a foaming agent having an average diameter of about 10 to about 25 microns to produce a foam having a light transmittance of about 10% to about 50% according to JIS K 7361-1.

Abstract: A closed cell crosslinked polyolefin foam sheet comprises an opposing first surface region and second surface region, and an intermediate region disposed therebetween, wherein the intermediate region is configured to have a gel content lower than an average gel content of the first surface region and the second surface region to enable a controlled tear propagation within the intermediate region when a splitting force is applied to the closed cell crosslinked polyolefin foam sheet. For example, a ratio of a gel content of the intermediate region versus an average gel content of the first surface region and the second surface region may be about 75% or less, and a ratio of the average cell size of the intermediate region versus an average cell size of the first surface region and the second surface region may be about 125% or higher.

Abstract: A process comprises placing a first foamable material inside of a first region of a mold space, and a second foamable material inside of a second region of the mold space, the first foamable material and the second foamable material comprising a physical, chemical or quantitative difference or any combination thereof. Both the first and the second foamable materials are concurrently foamed inside of the mold space to produce a heterogeneous foam comprising a first portion that differs from the second portion.