Foam Technical Information

The most common types of foam which are suitable for cutting on a hotwire foamcutter are expanded polystyrene and extruded polystyrene. Expanded Polystyrene Foam: Expanded polystyrene foam is used for coffee cups, coolers, insulation, packaging products for shipping, etc. It is made up of about 2% polystyrene and 98% air. It is manufactured by heating styrene pellets with steam so they expand rapidly within a mold and form a large block of low density foam. The expanded beads remain as air filled closed cells that resist the conduction of heat, and therefore are efficient insulators. This foam is light, usually 1 to 2 pounds per cubic foot, and very inexpensive. No CFC's are used in creating the foam. It doesn't degrade under normal circumstances because EPS is inert and has a very stable molecule. Foam is increasingly being recycled, to the benefit of the environment. Extruded Polystyrene Foam: Extruded polystyrene foam is the same chemical product as the expanded foam, but it is manufactured using a different process which extrudes the foam, resulting in a denser, more homogenous product with much smaller air pockets. It is commonly found in sheets of 2 pound per cubic foot density or higher, and is usually colored blue, green, gray or another color. Styrofoam