Extruded Polystyrene Foam :
Extruded polystyrene material can be used in crafts and model building, in particular architectural models. Cause of the extrusion manufacturing process, XPS does not need facers to keep its thermal or physical feature performance. Then , it makes a more uniform substitute for corrugated cardboard. Thermal resistivity is typically about 35 m•K/W (or R-5 per inch in American customary units) but can range between 29 and 39 m•K/W subject to bearing/density. Thermal conductivity differs between 0.029 and 0.039 W/(m•K) subject to bearing strength/density and the average value is ~0.035 W/(m•K).
Water vapor publication resistance (μ) of XPS is between80–250 and so makes it more appropriate to wetter environments than EPS.