Patent ID: 8728364

Claim:
A method of forming a foam form sheet material comprising open cells comprising: heating and admixing at least one thermoplastic olefin polymer, at least one foaming agent, and at least one crosslinking agent for a period of time sufficient to form a first intermediate product; substantially continuously engaging the first intermediate product through the nip of a first pair of rollers under conditions sufficient to partially decompose the at least one foaming agent and the at least one cross linking agent to form a second intermediate product having closed void cells, wherein less than all of the at least one foaming and the at least one crosslinking agent of the first intermediate product are decomposed, and wherein the first pair of rollers have a first gap width; substantially continuously engaging the second intermediate product through the nip of a second pair of rollers under conditions sufficient to further decompose the at least one foaming agent and the at least one cross linking agent to form a third intermediate product having more closed void cells than the second intermediate product, and wherein the second pair of rollers have a second gap width greater than the first gap width; substantially continuously compressing the third intermediate product at a temperature of up to about 40° C. and under conditions sufficient to rupture the closed void cells and to thereby produce a foam form sheet material having surfaces comprising a skin and an internal volume comprising substantially open cells.