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US 2019/0291314 A1Published application
Polymer foam processing including different types of blowing agent
AssigneeTrexel, Inc.
InventorsSamuel Edward Dix, Levi A. Kishbaugh
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Abstract
Injection molding methods used to form polymeric foam articles (e.g., microcellular foam articles) are described herein.
Claims20
A method of molding a microcellular foam article comprising:
- conveying a mixture comprising polymeric material and a chemical blowing agent in a downstream direction in a barrel of an extruder, wherein the chemical blowing agent is decomposable to form carbon dioxide and is present in an amount between 0.20 and 3.00 weight percent based on the total weight of polymeric material;
- and
- introducing a physical blowing agent comprising nitrogen into the mixture, the nitrogen being present in an amount between 0.025 and 1.50 weight percent based on the total weight of polymeric material;
- and
- injecting the mixture into a mold cavity of a mold;
- and
- recovering an injection molded microcellular foam article from the mold cavity.
4 more elements
A method of molding a microcellular foam article comprising:
- conveying a mixture comprising polymeric material and a chemical blowing agent in a downstream direction in a barrel of an extruder, wherein the chemical blowing agent is decomposable to form carbon dioxide;
- introducing a physical blowing agent comprising nitrogen into the mixture;
- and
- injecting the mixture into a mold cavity of a mold;
- and
- recovering an injection molded microcellular foam article from the mold cavity, the article having a thickness of less than 5 mm, a skin thickness of greater than 25% of the thickness of the article, and a void volume percentage of between 2% and 15%.
3 more elements
An injection molded microcellular foam article comprising a semi-crystalline polymeric material, the article having an average cell size of less than 100 microns, a thickness of less than 5 mm, a skin thickness of greater than 25% of the thickness, a void volume percentage of between 2 and 15% and a percentage elongation between 5% and 200%.
Dependencies are inferred from the claim text.