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US 11,292,163 B2Granted
Method of forming polymeric foam and related foam articles
AssigneeMuCell Extrusion, LLC
InventorsSamuel Edward Dix, Jere R. Anderson, Mark E. Lindenfelzer
Life of this patent
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Abstract
Methods of forming polymeric foams are provided. The methods may involve co-extruding a foam layer along with one or more skin layers. In some embodiments, the skin layer(s) may be removed (e.g., in a peeling operation); while, in other embodiments, the skin layer(s) may form part of the final article. The methods are particularly well suited for producing polymeric foams from polymeric materials that are considered to be difficult to foam by those of skill in the art.
Claims15
A method comprising:
- extruding a first stream and a second stream to form an annular extrudate, wherein the first stream comprises a single-phase solution of a first polymeric material comprising non-crosslinked polyether-block-amide and a blowing agent and the second stream comprises a second polymeric material, wherein the extrudate includes a foam layer comprising the first polymeric material comprising non-crosslinked polyether-block-amide and a skin layer comprising the second polymeric material, and wherein the first stream nucleates into said foam layer upon exiting an extrusion die inner passageway having an outward taper converging in a downstream direction approaching the die outlet;
- blowing to expand the annular extrudate;
- separating the foam layer from the skin layer of the expanded extrudate;
- and
- collecting the separated foam layer, wherein the foam layer, after being collected, has a smooth surface and a plurality of cells having an average aspect ratio of less than 3:1 and an average maximum dimension of less than 200 microns, and wherein the collected foam layer comprises non-crosslinked polyether-block-amide and has a substantially closed cell structure.
2 more elements
Dependencies are inferred from the claim text.