Bead foam compression molding method with in situ steam generation for low density product
AssigneeNIKE, Inc.
InventorsHossein A. Baghdadi, Denis Schiller, Sui-Chieh J. Yu
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Abstract
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.
Claims19
A molded foam article, prepared by a method comprising:
- filling a mold with a plurality of thermoplastic polyurethane foam beads and an amount of liquid water,
- wherein the plurality of thermoplastic polyurethane foam beads have a density of from about 0.01 to about 0.3 grams per cubic centimeter;
- and
- wherein the amount of liquid water is about 1 part by weight per about 3 to about 12 parts by weight of the thermoplastic polyurethane foam beads placed in the mold;
- closing the mold;
- bringing the mold to a peak temperature for a duration of time sufficient to mold the plurality of thermoplastic polyurethane beads into a molded foam article having a density of less than about 0.45 grams per cubic centimeter and a skin thickness of from about 9 to about 200 micrometers;
- and
- after reaching the peak temperature, cooling the filled mold, opening the filled mold, and removing the molded foam article from the mold.
Dependencies are inferred from the claim text.