Polymer foam plank with densified skin, method and apparatus for producing a densified skin on a foam plank

A method and apparatus for making a densified skin polymer foam plank comprising providing a polymer foam having a plurality of cells and heating an outer surface of the foam at a heating station. The heating step collapses and melts the cells adjacent the outer surface to form the densified skin having a density greater than a density of the foam before the heating step. Additionally, the method and apparatus may further include extruding the polymer foam from an extruder.