Patent ID: 7759404

Claim:
An inherently open-celled polymeric foam consisting essentially of a polymer blend having cells with an average cell size of at least four millimeters defined therein wherein the foam has an inherently open-cell content of at least 40 percent (according to American Society for Testing and Materials (ASTM) D2856-94) and wherein the polymer blend consists essentially of: (a) a high melt strength polypropylene; (b) a second polypropylene selected from linear polypropylenes and polypropylenes having up to three long chain branches per 1,000 carbons, said second polypropylene having a melting point within ten degrees Celsius of (a), a melt flow rate (ASTM D-1238, condition L) that is equal to or less than one half that of (a) or equal to or greater than twice that of (a), and that are miscible with (a); and, (c) an ethylene polymer that is immiscible with (a) and that comprises greater than 50 weight-percent polymerized ethylene units by weight of the polymer and that is selected from a group consisting of low density polyethylene, linear low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymers, ethylene-ethylacrylate copolymers, and ethylene-acrylic acid copolymers; wherein the polymer blend contains 60 weight percent (wt %) or less of (c) based on polymer blend weight; and wherein (a) makes up at least 60 wt % and 90 wt % or less of the total weight of (a) and (b).