In general, the CNC hot wire cutting machines are suitable for cutting two types of styrofoam (poly):
EPS or EXPANDED STYROFOAM (POLYSTYRENE)
This is the white foam found in drink cups, coolers, insulation, product packaging, etc. It is made
up of over 95 percent of air and less than 5 percent of polystyrene. The styrene pellets are heated
with steam so that they expand rapidly and form a block of low density foam (various sizes of blocks
are available). This kind of foam is inexpensive and light—it usually weights between 15-30 kg per
More and more often it comes with some graphite additives for improved thermal properties (and as a
result features small grey spots or is grey altogether).