Low density foamed article made by bead foam compression molding method

Patent metadata

Field	Value
Publication number	US-9682522-B2
Application number	US-201514599009-A
Country	US
Kind code	B2
Filing date	Jan 16, 2015
Priority date	Jul 10, 2012
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

Disclosed is a molded foamed article, such as a midsole or outsole for footwear, made by a method in which 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/cm 3 .

First claim

What is claimed is:

1. An article prepared by a method comprising:
placing a desired amount of thermoplastic polyurethane foam beads in a compression mold in the shape of an article, wherein the thermoplastic polyurethane foam beads have a density of from about 0.01 to about 0.3 g/cm 3 ;
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.

2. An article according to claim 1 , wherein the article is a midsole, a cushioning pad, a sockliner, or an outsole for footwear.

3. An article according to claim 2 , wherein the article has a molded-in character line or design.

4. An article according to claim 1 , wherein the peak mold temperature is from about 140° C. to about 170° C.

5. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads have a density of from about 0.01 to about 0.1 g/cm 3 .

6. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads comprise a thermoplastic polyurethane with a melt flow index of at least about 160 grams/10 min. (at 190° C., 21.6 kg) as measured according to ASTM D1238.

7. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads comprise an elastomeric thermoplastic polyurethane selected from the group consisting of thermoplastic polyester-polyurethanes, polyether-polyurethanes, and polycarbonate-polyurethanes.

8. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads comprise an elastomeric thermoplastic polyester-polyurethane or an elastomeric thermoplastic polyether-polyurethane and wherein the article is a midsole, a cushioning pad, a sockliner, or an outsole for footwear.

9. An article according to claim 8 , wherein the elastomeric thermoplastic polyether-polyurethane is a reaction product of diphenylmethane diisocyanate.

10. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads have a diameter of from about 0.5 mm to about 1.5 cm.

11. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads have a compact outer skin.

12. An article according to claim 1 , wherein the thermoplastic polyurethane foam beads and the mold are each at a temperature below about 80° C.

13. An article according to claim 1 , wherein the amount of the thermoplastic polyurethane foam beads placed in the mold is selected to provide a foamed article having a density of from about 0.1 to about 0.45 g/cm 3 .

14. An article according to claim 1 , wherein the mold is brought to the peak temperature over a period of from about 300 to about 1200 seconds.

15. An article according to claim 1 , wherein the peak temperature is selected to produce a skin thickness of from about 9 to about 200 micrometers.

16. An article according to claim 1 , wherein the mold is cooled over a period of from about 300 to about 1200 seconds.

17. An article according to claim 1 , wherein the mold cooling step is begun immediately after the peak temperature is reached.

18. An article according to claim 1 , wherein the mold is cooled at a rate of from about 0.09 to about 0.55° C./second.

Assignees

• Nike Inc

Inventors

• Baghdadi Hossein A
• Schiller Denis
• Yu Sui-Chieh J

Classifications

• B29C44/445

  in the form of expandable granules, particles or beads · CPC title

• B29D35/122 Primary

  Soles · CPC title

• B29C44/02

  for articles of definite length, i.e. discrete articles · CPC title

• B29C43/18 Primary

  incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles {(B29C43/206 takes precedence)} · CPC title

• B29C44/3415

  Heating or cooling · CPC title