Bead foam compression molding method with in situ steam generation for low density product

摘要

Disclosed is a method for molding a foamed article, such as a midsole or outsole for footwear, in which first water, then a desired amount of thermoplastic polyurethane foam beads are placed in a compression mold in the shape of the article and the mold is brought to a peak temperature of from about 130° C. to about 180° C. over a period of from about 300 to about 1500 seconds, then cooled to from about 5° C. to about 80° C. over a period of from about 300 to about 1500 seconds within about 30 seconds after the peak temperature is reached. The foamed article made by the method has a density of from about 0.1 to about 0.45 g/cm3.

主权项

1. A method for molding a foamed article, comprising:
placing an amount of water in a compression mold in the shape of an article; then placing a desired amount of thermoplastic polyurethane foam beads in the compression mold, wherein the thermoplastic polyurethane foam beads have a density of from about 0.01 to about 0.3 g/cm3 and wherein 1 part by weight water per from about 1.5 to about 20 parts by weight of the thermoplastic polyurethane foam beads is used; closing the mold; bringing the mold to a peak temperature of from about 130° C. to about 180° C. over a period of from about 300 to about 1500 seconds; cooling the mold to a temperature of from about 5° C. to about 80° C. over a period of from about 300 to about 1500 seconds within about 30 seconds after the peak temperature is reached; and removing the article.