Filter elements
AssigneeMonsanto Chemicals Limited
InventorsSamuel Baxter, Pushpkumar D. Cuangani
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Abstract
A polyolefin filter for tobacco products and the like was prepared. The extruded element is an open-cell foamed polyethylene or polypropylene having a TPM filtration efficiency greater than 20%. The filter rod can be made by extruding polyethylene containing less than 0.2 moles of a volatile blowing agent per 100 grams of resin at a melt temperature between 130.degree. C. and 150.degree. C., the temperature of the die being between 120.degree. C. and 136.degree. C. Higher melt temperature and die temperature are required for polypropylenes.
Claims6
A foam product comprising polypropylene or high density polyethylene, said foam having a substantially open-cell structure wherein a majority of the cells have a diameter ranging from 40 to 1000 microns with more than half of the cell walls present containing one or more perforations, and wherein the microstructure of said foam is characterized by the presence of fiber elements which bridge across said perforations in the cell walls.
A polypropylene or high density polyethylene foam having an open-cell structure wherein a majority of the cells have a diameter ranging from 40 to 1000 microns with more than half of the cell walls present containing one or more perforations, and wherein the microstructure of said foam is characterized by the presence of a web of interconnected fiber elements which extends across said perforations in the cell walls.
Dependencies are inferred from the claim text.