Patent ID: 7300612

Claim:
A method for producing a hollow multistrand or hollow coalesced strand foam article comprising: a. providing a foamable composition comprising a blowing agent composition and at least one film-forming composition, the foamable composition being in a gel state; b. extruding the foamable composition through a die having a plurality of first orifices, each of which yields a hollow extrudate; c. converting the hollow extrudate into foamed hollow extrudate strands at a temperature that promotes foam bubble stability; and d. allowing the foamed hollow extrudate strands to contact each other while such strands retain at least some surface tackiness in order to effect adhesion between adjacent individual strands and yield a hollow multistrand foam extrudate; wherein the blowing agent composition comprises at least one blowing agent selected from carbon dioxide, nitrogen, a nitrous oxide, a noble gas, air, a hydrocarbon, an ether, a lower (1 to 6 carbon atoms) alcohol, a partially halogenated hydrocarbon, ammonia, water and mixtures of two or more of such blowing agents; and wherein the die also comprises a plurality of second orifices that yield a solid extrudate whereby step b yields a combination of solid foam extrudates and hollow foam extrudates and step d yields a multistrand foam extrudate that comprises both solid foam extrudate strands and hollow foam extrudate strands.