Production of Continuous Open Cell Elastomer Sheets

Continuous open cell elastomer sheets were prepared by immersing continuous open cell polymer compounds in hot water, which are obtained by the extrusion and injection of thermoplastic elastomers, pentaerythritol (PETH), polypropylene (PP) and polytetrafluoroethylene (A-PTFE) modified by methyl methacrylate. A styrene-isoprene block copolymer (PSt-E), thermoplastic elastomer, was used as a main polymer in the compounds, giving strength, shock absorptivity and water resistance to the sheets. PETH was added as an open cell forming agent in the compounds, giving continuous open cell to the sheets obtained by immersing the compounds in hot water. The addition of 10phr of PP was effective for decreasing the linear shrinkage of the sheets in the process of the extraction of PETH from the compounds. The addition of 5phr of A-PTFE was also effective for improving the melting tension of the compounds at a molding temperature and the sheeting properties such as roughness, checking, crack, end tear. Molding temperature range of 180 to 230°C was very effective for giving good sheet properties and air flow rate, at which PSt-E and PETH are blended smoothly and continuous open cells were obtained. An extrusion molding gave better continuous open cell elastomer sheets in the point of air flow rate and open cell diameter than an injection molding.