Patent attributes
A method for making a low density foamed article includes placing a desired amount of thermoplastic polyurethane foam beads in a cavity of an injection mold and closing the mold; combining in an extruder connected to the mold a molten polymer selected from the group consisting of thermoplastic polyurethane elastomers and thermoplastic ethylene-vinyl acetate copolymers with both a physical or chemical blowing agent other than a supercritical fluid present in an amount up to about 15 wt % based on molten polymer weight and a supercritical fluid that is at least one of about 0.1 to about 5 weight percent of supercritical CO2 based on molten polymer weight or about 0.1 to about 4 weight percent of supercritical N2 based on molten polymer weight, to form a mixture and injecting the mixture into the mold and foaming the mixture to form the low density foamed article.
