Home Built Hot Wire EPS Foam Recycler (work in progress)

It turns out that there is a lot of foam left over after cutting moldings.

Here is a very in-expensive way to cut down the excess foam into small pieces.

Once in small pieces, you can use them as packing material or have an easier way

to transport them to your local recycler.

We first start with a cage design. in this example we used an instrument rack,

But you can build a wooden cage that will perform just as well

The next step is to set up a wire mesh that would cut the foam as it falls and then cuts

it again into small squares.

The closer the wires are to each other, the smaller the EPS foam cubes will be,

But the closer the wires are to each other, the higher the power you will need

to get the wires hot enough.

At the local hardware store, find metal eye-hooks and place them about 1.5" apart. Run a hot wire from the 1st eye hook to the one across it and back to the 2nd eye

hook, the end of the hot wire will be connected to the spring.

We used a spring to make sure that the hot wire will be nice and tight even when it is heated, if you don't use a spring, the wire will sag, and it may hit the 2nd row of wires causing a short circuit. We use an isolated variac on each set of wires (two variac in total)

Above is a simplified diagram showing how to wire the wires and springs.

The variac above, the green lines are power lines, any 12 guage wires will do.

the red lines are the NiCrome wires (the hot wire). In this example we used two

hot wires, but on the real machine we used 5 sets of wires plus another 5 sets for

the wires below. Take a closer look at the 1st picture on this page to see the wire


Here is a video of the system in operations.

We first cut / break the foam into smaller pieces so it would fit on top of the mesh

Then simply let gravity do its business

If you have the money, an EPS foam compactor would be the better way.

The below machine will shred and then compact the EPS foam by a ration of 40 to 1

Another video showing a foam compactor pressing the EPS foam pieces into logs