What types of foams can a hot wire cutter handle?

In general, the hot wire CNC 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 cubic meter.

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).

XPS or EXTRUDED STYROFOAM (POLYSTYRENE)

XPS has the same chemical composition as the expanded polystyrene foam (EPS), yet it is manufactured in a different way and as a result this foam — having smaller air pockets — is denser and more homogenous. It is often pink, blue, green, etc.

XPS is perfect for logos, lettering and other forms of small decorative elements. Once hot wire cut, it has a very smooth surface that requires close to no further tooling. A simple paint job is often all it takes.

WHAT ABOUT OTHER FOAMS SUCH AS PUR, PIR, PE, PP?

These foams are not suitable for hot wire cutting as they leave a chemical residue on the hot wire and create toxic fumes during the process.

For all sorts of flexible and rigid foams, we have a separate series of fast wire cutters where a high-speed abrasive wire mechanically cuts the required shapes (instead of melting and evaporating the material as hot wire cutters do with EPS and XPS).

These fast wire foam cutters are suitable for such soft and rigid foams as:

polyurethane foam - PU
polypropylene foam - PP
polyethylene foam - PE
mineral wool, rock wool, but also EPS, XPS, EPP, foamed glass, etc.

For more details, please click here.

WHAT ABOUT THE COATINGS?

There are many choices available depending on your application:

water-based and acrylic paints (spray or brush applied),
cement-based coatings for architectural details,
two-component hard coats,
and many others.

It all depends on what kind of coat you want to achieve for a particular project. Please contact us if not sure which solution will be best for your application and we will be more than happy to provide more details as well as contact information of our partners offering various EPS coating solutions.