Split crosslinked polyolefin foam composition and method

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. The split crosslinked polyolefin foam sheets may comprise a skin side comprising a closed cell surface, and a split side comprising an open cell surface having peak heights of about 150 μm to about 550 μm.

1 . A process for producing split crosslinked polyolefin foam sheets, comprising:
 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.   
     
     
         2 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have an average gauge of about 40% to about 60% of an original gauge of the crosslinked polyolefin foam sheet. 
     
     
         3 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have an average gauge of about 45% to about 65% of an original gauge of the crosslinked polyolefin foam sheet. 
     
     
         4 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a mass of about 40% to about 60% of an original mass of the crosslinked polyolefin foam sheet. 
     
     
         5 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a mass of about 45% to about 55% of an original mass of the crosslinked polyolefin foam sheet. 
     
     
         6 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a density of about 85% to about 115% of an original density of the crosslinked polyolefin foam sheet. 
     
     
         7 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a density of about 90% to about 110% of an original density of the crosslinked polyolefin foam sheet. 
     
     
         8 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a maximum average gauge variance of about 5% from an ideal 50%. 
     
     
         9 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a maximum average mass variance of about 2% from an ideal 50%. 
     
     
         10 . The process of  claim 1 , wherein each of the two split polyolefin foam sheets produced have a maximum average density variance of about 6% from an ideal 100%.