Anyone have experience cutting Ethafoam on a CO2 laser?

[Mark Langston]

Anyone have experience cutting Ethafoam on a CO2 laser?

I have to cut 1", 2" and 3" pieces of foam for a lot industrial cases. I'm going to use my 4" lens on it, but I was wondering if anyone out there has any tips or tricks/settings that I may need to know about so that I don't burn or melt the front or backside of the foam.

I'm using a CO2 Trotec Speedy 400.

Thanks

[Michael Hunter]

Air assist ON, low pulse rate and speed as high as you can and still get all the way through.

Stray heat to the sides of the cut will deform the foam so it gets a rounded edge which looks bad. Good air assist prevents this happening as it keeps the foam cool.

I only have a 2" lens, so with 1.5 or 2" thick foam, I bring the focus down (table up) so that the focus was about 1/3 into the thickness of the foam. (With your 4" lens you might not need to do this).

Iv'e done lots of instrument case foam this way and always had good results.
Recently I have been engraving the foam as well (logos) - again air assist is vital to keep nice sharp edges.

[Mark Langston]

Thank you!

[Jack Clague]

Thanks Michael, nice tips, I've been asked recently to quote for cutting out foam for pelican cases, this will help allot. need to be sure though I'm cutting foam safe for the laser and my health.

[Michael Hunter]

Need to be sure though I'm cutting foam safe for the laser and my health.

The grey foam commonly supplied with these cases is often referred to as "ethafoam", implying foamed polyethylene.

Polyethylene when lasered gives a gentle waxy/oily smell, but these foams really stink horribly, which makes me think that it is really polyurethane.

Whatever it is you need good exhaust!

Both types of foam may well incorporate a flame-retardant chemical : probably not good if it is in the air.

Polyethylene is a high flare-up risk. Condensing polythene vapour can give nanoparticles which you don't want to breathe.

Polyurethane breaks down into all sorts of nasties including deadly poisons and irritants.
Because it is foam, the amount of material involved is very small and I personally don't regard it as any worse a risk than the fumes that come off real tree wood.