Method of foaming a milled precursor
AssigneeNIKE, Inc.
InventorsBryan N. Farris, David Turner
Life of this patent
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Abstract
A method of making a foamed article comprises (a) milling a block or sheet of thermoplastic polymer to form a precursor; (b) crosslinking the thermoplastic polymer; (c) heating the precursor to a first temperature to soften the thermoplastic polymer; (d) infusing the thermoplastic polymer with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic polymer; and (e) while the thermoplastic polymer is softened, reducing the pressure to a second pressure below the first pressure to at least partially foam the precursor into a foamed article, wherein the foamed article is substantially the same shape as the precursor.
Claims20
A method of making a foamed article, comprising:
- a) milling a block of a first thermoplastic polymer to form a precursor having a cavity;
- b) crosslinking the first thermoplastic polymer;
- c) placing an insert comprising a second thermoplastic polymer in the cavity of the precursor;
- d) heating the precursor and the insert in the cavity of the precursor to a first temperature to soften the precursor and the insert;
- e) infusing the precursor and the insert in the cavity of the precursor with a first inert gas under a first pressure;
- f) cooling the precursor and the insert to a second temperature below the first temperature;
- and
- g) reducing pressure to a second pressure lower than the first pressure to foam the precursor and the insert in the cavity of the precursor into a foamed article.
A method of making a foamed article, comprising:
- a) milling a block of a first thermoplastic polymer to form a precursor having a cavity;
- b) crosslinking the first thermoplastic polymer;
- c) heating the precursor to a first temperature to soften the precursor;
- d) infusing the precursor with a first inert gas under a first pressure;
- e) infusing an insert formed of a second thermoplastic polymer with a second inert gas, wherein the step of infusing the insert is conducted independent of the step of infusing the precursor;
- f) placing the insert in the cavity of the precursor;
- and
- g) heating the precursor and the insert in the cavity of the precursor to a temperature sufficient to soften the precursor and the insert and to at least partially foam the precursor and the insert and form a foamed article.
A method of making a foamed article selected from the group consisting of:
- a footwear midsole, a part of a footwear midsole, a footwear upper, a footwear collar, a footwear tongue, and a footwear insole, comprising:
- a) milling a block of a first thermoplastic polymer to form a precursor in a shape selected from the group consisting of:
- a footwear midsole, a part of a footwear midsole, a footwear upper, a footwear collar, a footwear tongue, and a footwear insole;
- b) crosslinking the first thermoplastic polymer;
- c) heating the precursor to a first temperature to soften the precursor;
- d) infusing the precursor with a first inert gas under a first pressure;
- e) cooling the precursor to a second temperature below the first temperature;
- f) reducing pressure to a second pressure lower than the first pressure;
- g) heating the precursor to a third temperature while at a third pressure to partially foam the precursor and form a partially foamed article;
- and
- h) decreasing pressure to a fourth pressure lower than the third pressure to further induce foaming to form the foamed article, wherein the foamed article is a member selected from the group consisting of:
- a footwear midsole, a part of a footwear midsole, a footwear upper, a footwear collar, a footwear tongue, and a footwear insole, and wherein a volume of the precursor is at least 20% and up to 80% of a volume of the foamed article.
Dependencies are inferred from the claim text.