Application US20200130241

COMPOSTABLE OR BIOBASED FOAMS
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US20200130241

1. A method of making a molded article, comprising: (10) (7)

forming biobased polymer foam beads;

pressurizing the biobased polymer foam beads in a sealed vessel;

depressurizing the sealed vessel;

feeding the biobased polymer foam beads into a mold; and

molding the biobased polymer foam beads to form a molded article,

wherein the biobased polymer foam beads undergo a secondary expansion during molding, and

wherein the molded article has a density of less than or about 0.03 g/cm³.

2. The method of claim 1, wherein the step of forming the biobased polymer foam beads comprises: (2) (2)

mixing a feed composition and a blowing agent in an extruder to form a biobased polymer melt,

wherein the extruder has a temperature that is above a melting point of the feed composition.

3. The method of claim 2, wherein the feed composition comprises: (0) (3)

4. The method of claim 2, wherein the step of forming the biobased polymer foam beads further comprises: (2) (3)

extruding the biobased polymer melt by forcing the melt through an extrusion die opening to form an extrudate,

wherein a temperature of an exit of the extrusion die is lower than a melting temperature of the biobased polymer melt, and

wherein the blowing agent expands within the extrudate upon exiting the extrusion die opening.

5. The method of claim 4, wherein the step of forming the biobased polymer foam beads further comprises: (1) (1)

6. The method of claim 4, wherein extruding the biobased polymer melt induces crystallization without the use of an annealing step. (0)

8. The method of claim 1, wherein the step of pressurizing the biobased polymer foam beads in a sealed vessel comprises pressurizing the biobased polymer foam beads at about 0.45 MPa for less than 30 minutes. (0)

9. The method of claim 1, wherein the step of depressurizing the sealed vessel comprises a rapid depressurization. (0)

10. The method of claim 1, wherein the step of depressurizing the sealed vessel produces biobased polymer foam beads having an internal pressure exceeding atmospheric pressure. (0)

11. The method of claim 1, wherein the step of feeding the biobased polymer foam beads into a mold is performed within 1 minute of removal from the sealed vessel. (0)

12. The method of claim 1, wherein the step of feeding the biobased polymer foam beads comprises heating the mold to an initial temperature of 25° C. (0)

13. The method of claim 1, wherein the step of feeding the biobased polymer foam beads comprises vacuum feeding. (0)

14. The method of claim 1, wherein the step of molding the biobased polymer foam beads comprises purging the mold for 1 second at 0.55 bar steam pressure. (1) (0)

19. The method of claim 1, wherein the step of molding the biobased polymer foam beads comprises subjecting the mold to a cross steam process. (0)

20. The method of claim 1, wherein the step of molding the biobased polymer foam beads comprises applying a cooling water followed by applying a cooling air. (0)

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Application US20200130241

COMPOSTABLE OR BIOBASED FOAMS

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