NIKE, Inc.
Method of making foams using partial molds

Abstract:

A method of making a foamed article, for example a foamed component for an article or footwear, comprises depositing an unfoamed, thermoplastic polymer onto a support surface in a three-dimensional printing process to form an unfoamed article; heating the article to soften the article and infusing the softened article with at least one inert gas at a first pressure greater than atmospheric pressure that is sufficient to cause the at least one inert gas to permeate into the softened article; and reducing the pressure to second pressure below the first pressure while the article is softened to at least partially foam the article, wherein a surface of a partial mold limits foam expansion in at least one direction but less than all directions. The article or a part of the article may be made by printing a thermoplastic polymeric material with a three-dimensional printer in a structure of interconnected, unfoamed, thermoplastic polymeric members spaced to define openings between the thermoplastic polymeric members.