Batch and continuous  foaming equipment  available  including  Single Screw Extrusion for high and medium density foams, Tandem Extruders for low density foams (PPI Patent ), and Coextrusion of A-B-A or A-B-C-B-A structures (B-foamed layer). Measurement of solubility of physical blowing agents can be performed off-line and in-line. Foams can be characterized as Closed vs. Open Cell and for Mechanical, and Thermal Properties.