Method of making coextruded crosslinked polyolefin foam with polyamide cap layers
AssigneeToray Plastics (America), Inc.
InventorsPawel Sieradzki, Jesse Jude Baldwin, Dan Ben-Daat, Kaitlyn Michelle Bock
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Abstract
Described herein are physically crosslinked, closed cell continuous multilayer foam structures that includes a foam layer comprising polypropylene, polyethylene, or a combination of polypropylene and polyethylene and a polyamide cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam composition layer and at least one cap composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.
Claims18
A method of forming a multilayer foam structure comprising:
- coextruding:
- a first layer comprising:
- a first polypropylene, a first polyethylene, or a first combination of polypropylene and polyethylene;
- a chemical foaming agent;
- and
- a crosslinking promoter in an amount of 0.5-5 wt. %;
- and
- a second layer on a side of the first layer, the second layer comprising:
- 60-85 wt. % polyamide;
- and
- 10-40 wt. % of a second polypropylene, a second polyethylene, or a second combination of polypropylene and polyethylene;
- irradiating the coextruded layers with ionizing radiation;
- and
- foaming the first layer of the irradiated, coextruded layers.
Dependencies are inferred from the claim text.