What EPS Density Can an EPS Cutting Machine Cut? (Wire vs CNC Limits)
EPS foam density ranges you will actually meet
Expanded polystyrene (EPS) used for cutting comes in a wide bead-density spread. Most shape and block producers work between 8 kg/m3 (very light packaging) and 40 kg/m3 (structural, insulation, architectural). Specialty grades can reach 60 kg/m3. An EPS Cutting Machine must stay controllable across this whole window, not just at one density.
Hot-wire cutting: adjust temperature and feed speed by density
A resistance hot wire melts and parts the bead strand as it moves. Lower density foam cuts almost effortlessly; higher density needs more heat and a slower pass. As a practical starting point:
| EPS density (kg/m3) | Recommended wire temp | Feed speed | Wire diameter |
|---|---|---|---|
| 8 – 15 | Low – medium | Fast | 0.2 – 0.3 mm |
| 15 – 25 | Medium | Medium | 0.3 – 0.4 mm |
| 25 – 40 | Medium – high | Slow | 0.4 – 0.5 mm |
| 40 – 60 (specialty) | High | Very slow | 0.5 – 0.6 mm |
If you force a fast feed on dense foam, the wire drags and leaves a rough, melted edge. Slow down and raise the temperature a little instead.
CNC routing: the better tool for very high density and 3D
Above roughly 30 kg/m3, or whenever you need true three-dimensional shapes, an EPS CNC cutting machine with an oscillating or spindle blade beats a hot wire. It does not rely on melting, so dense bead stock cuts cleanly without smearing. For architectural cornices, letters and moulds this is the standard choice.
One machine, the full density range
A well-built EPS Cutting Machine pairs a hot-wire contour table with optional CNC routing, so you can run 8 kg/m3 packaging and 40 kg/m3 insulation on the same line by changing the wire setting and feed program. See the full hot-wire vs CNC speeds and maintenance FAQ for day-to-day tuning.