Abstract: In general, the present invention is directed to a continuous method of making a polymer foam by using a polymer having a first monomeric component and a second monomeric component. The method employs a tandem type extruder having a first extruder and a second extruder. The method disclosed herein can provide a foam having a desired cell size, cell density, porosity, foam density, and/or thermal conductivity, etc. In turn, the polymer foams produced according to the present method can have numerous applications, such as thermal insulation applications for appliances including ovens, freezers, refrigerators, etc.