Extruded foam product with reduced surface defects

A method for making an extruded foam product having improved surface characteristics comprising:

• a) heating to a first temperature of about 135° C. to about 175° C. a resin mixture comprising an alkenyl aromatic polymer, thereby melting the resin mixture to produce a plastified resin mixture, wherein said alkenyl aromatic polymer comprises at least 50 weight percent of the extruded foam product,
• b) thoroughly mixing one or more halo-carbon free blowing agents under a first pressure and under conditions to prevent foaming thereby producing a foamable gel, and
• c) cooling the foamable gel to a second temperature of about 105° C. to about 130° C. and extruding the foamable gel into a second pressure less than the first pressure thereby causing the foaming of the foamable gel and formation of the extruded foam product, wherein polyethylene wax is added in the process.

A method for reducing surface defects in an extruded foam product comprising:

• a) heating to a first temperature of about 135° C. to about 175° C. a resin mixture comprising an alkenyl aromatic polymer, thereby melting the resin mixture to produce a plastified resin mixture, wherein said alkenyl aromatic polymer comprises at least 50 weight percent of the extruded foam product,
• b) throughly mixing one or more halo-carbon free blowing agents under a first pressure and under conditions to prevent foaming thereby producing a foamable gel, and
• c) cooling the foamable gel to a second temperature of about 105° C. to about 130° C. and extruding the foamable gel into a second pressure less than the first pressure thereby causing the foaming of the foamable gel and formation of the extruded foam product, wherein polyethylene wax is added in the process.