Method of making foams using partial molds

Patent metadata

Field	Value
Publication number	US-10730231-B2
Application number	US-201816120395-A
Country	US
Kind code	B2
Filing date	Sep 3, 2018
Priority date	Nov 5, 2014
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

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.

First claim

What is claimed is:

1. A method of making a closed-cell foamed article comprising
a) forming an unfoamed article at a first location using a three-dimensional printing process, the unfoamed article comprising unfoamed, thermoplastic polymer deposited as interconnected, unfoamed, thermoplastic polymeric members spaced to define openings therebetween;
b) heating the unfoamed article to a first temperature to soften the unfoamed article and infusing the softened unfoamed article 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 unfoamed article;
c) cooling the unfoamed article to a second temperature and reducing the pressure to a second pressure;
d) transferring the cooled unfoamed article to a partial mold at a second location; and
e) heating the unfoamed article in the partial mold to a third temperature to soften the unfoamed article and at least partially foam the unfoamed article, wherein pressure is adjusted to a third pressure sufficient to allow the infused inert gas to partition out of the softened unfoamed article to at least partially foam the unfoamed article into a foamed article, and wherein a surface of a partial mold limits foam expansion in at least one direction but less than all directions.

2. A method according to claim 1 , wherein the third temperature is the same as the first temperature.

3. A method according to claim 1 , wherein the third temperature is different from the first temperature.

4. A method according to claim 1 , wherein the pressure is greater than atmospheric during heating of the unfoamed article to the third temperature and is reduced to the third pressure less than the second pressure after heating to the third temperature to at least partially foam the unfoamed article.

5. A method according to claim 1 , wherein the surface of the partial mold that limits foam expansion is flat and optionally includes one or more spaces through which the unfoamed article can expand beyond the surface during foaming.

6. A method according to claim 1 , wherein outer surfaces of the unfoamed article before the foaming step define a top, a bottom opposite the top, and an outer circumference between the top and the bottom; and further wherein the partial mold limits foam expansion of at least a part of the outer circumference.

7. A method according to claim 6 , wherein the partial mold limits foam expansion to expansion in directions of the top and the bottom.

8. A method according to claim 1 , wherein the partial mold has a bottom surface and side surfaces that limit foam expansion and is open in a direction opposite the bottom surface.

9. A method according to claim 8 , wherein the partial mold has a first mold part comprising the bottom surface and a second mold part comprising the side surfaces, wherein the first mold part and the second mold part are adjacent but not conjoined.

10. A method according to claim 9 , further comprising after step e) moving the second mold part away from the first mold part before unmolding the foamed article from the second mold part.

11. A method according to claim 1 , wherein the partial mold has a surface that imparts a pattern or decoration on at least a portion of the foamed article.

12. A method according to claim 1 , wherein the partial mold comprises a bottom portion and a side portion.

13. A method according to claim 12 , wherein the side portion incompletely surrounds the unfoamed article.

14. A method according to claim 12 , wherein the partial mold is in a shape of a midsole for footwear.

15. A method according to claim 1 , wherein the partial mold comprises adjacent sections that separate during foaming and while forming the foamed article.

16. A method according to claim 1 , wherein a portion of the partial mold becomes attached to the foamed article.

17. A method according to claim 16 , wherein the foamed article is a midsole for footwear having a first major surface and a second major surface opposite the first major surface, wherein the portion of the partial mold becomes attached to the first major surface or to the second major surface.

18. A method according to claim 1 , wherein at least a portion of the interconnected, unfoamed, thermoplastic polymeric members are arranged in a repeating pattern comprising repeating units.

19. A method according to claim 18 , wherein the repeating pattern repeats in two directions perpendicular to one another.

20. A method according to claim 18 , wherein the repeating units are uniform.

Assignees

• Nike Inc

Inventors

• Farris Bryan N
• Turner David

Classifications

• B29C64/00

  Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering · CPC title

• B29C64/106 Primary

  using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/118

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title