LaserUser.com Forum (formerly RDWorksLab)

All sources I find for polystyrene seems to be for foam or other variants, but this looks like ordinary acrylic. Safe, or will it destroy the universe?

It catches fire quickly, burns rapidly, it melts, and only thin pieces cut.
This is the #1 material that causes laser fires.
You can cut this stuff and the universe will be safe if you cut thin pieces and watch closely.

I just tried it, and it didn't cut well. As you say, it's prone to flare-ups, which causes soot. It also gets soft from relatively little heat, which means that things quickly started to bend and warp. You also need a decent separation between cuts, 2 mm was not enough, it caused flareups and damaged nearby parts.

4mm thickness, by the way.

Not worth the trouble, won't cut it again. I'm still alive, though.

We actually use a lot of styrene, makes cheap and flexible signage, and we laser it for paint stencils. I stock .060 and .125". We also make one time use shipping shims for calipers that are shipped to Mexico for some reason. I have made thousands of them but passed the job off to another customer, it does really stink and the blown out residue from the cuts is nasty. I always get a melted bead on the lower surface which can be removed easily with a card scraper if necessary [it wasn't for the shims].

I think that if you cut large pieces, the problems will be less, but I still got a "melt welt" on the bottom side, and it occasionally melted together again after the laser had passed.