Composition and blowing agent for making foamed polyethylene material
AssigneeFree-Flow Packaging International, Inc.
InventorsWilliam D. McIntyre, Roderick R. Alire, Ronald N. Clazie
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Abstract
Method and composition for making an expanded polyethylene material by forming a foamable melt of polyethylene, a nucleating agent, a material which retards migration of alkanes, and a blowing agent which comprises 10 to 100 mole percent ethane. In one disclosed embodiment, the melt is passed through an annular extrusion die to form an elongated tube of extruded material which is then expanded, slit lengthwise and laid flat to form a sheet of the expanded material.
Claims17
A foamable polyethylene composition consisting of low density polyethylene, a nucleating agent in the amount of up to 200 grams of nucleating agent per 800 pounds of polyethylene, glycerol monostearate in an amount on the order of one to four percent by weight of the polyethylene, and a blowing agent consisting of on the order of 50 to 95 mole percent ethane and 5 to 50 mole percent isobutane.
A blowing agent for expanding an extrudable, expandable polyolefin foam product, said blowing agent consisting of ethane and a different alkane selected from the group consisting of C3 and C4 hydrocarbons and mixtures thereof, said ethane being present in said blowing agent in an amount of at least about 40 percent by weight based upon the total weight of said blowing agent.
A blowing agent for expanding an extrudable, expandable polyolefin foam product, consisting of ethane and fluorinated ethane, with the ethane constituting at least about 40 percent by weight of the blowing agent.
In a foamable polymer composition:
- a polymer selected from the group consisting of polyethylene, polyethylene copolymers, ionomers, and combinations thereof, and a blowing agent consisting of about 50 to 95 mole percent ethane and 5 to 50 mole percent of a second blowing agent other than carbon dioxide.
An extrudable, expandable polyolefin foam composition including a blowing agent consisting of ethane and a different alkane, the ethane being present in the blowing agent in an amount of at least about 40 percent by weight based upon the total weight of the blowing agent, with no carbon dioxide in the blowing agent.
Dependencies are inferred from the claim text.