This is a list of things you shouldn’t laser. It is not exhaustive; there are plenty of other things we can’t know whether you should laser cut. Do not consider this list to be exclusive in any way. If you don’t know what material something is, don’t cut it!
This is not a safety thread, don’t count on this thread to make critical judgments about your laser cutter or its operation. Additionally, this list is created by forum users without any sort of official company endorsement or support.
Fire and/or melting hazards
Polystyrene foam: melts, catches fire. Reportedly #1 cause of laser cutter fires.
ABS (acrylonitrile butadiene styrene): ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching on fire and leaving behind melted gooey deposits on the vector cutting grid. With the right settings, it can be engraved - but take caution.
HDPE (high-density polyethylene - like milk bottle plastic or those white cutting boards): catches fire, melts, turns gooey.
Health and laser hazards
Any halogenated compound such chlorine (chloro-), bromine (bromo-), fluorine (fluoro-), etc: release acidic gases that can corrode your laser and endanger your health. Common compounds include PVC, also known as vinyl.
Fiberglass: it’s a mix of two materials that can’t or shouldn’t be cut. Glass (which etches, but doesn’t cut) and epoxy resin (which causes dangerous fumes).
Coated carbon fiber: emits noxious fumes. Thin carbon fiber mat can be cut, with fraying, but not the coated variety.
Back by popular request is the shiny and dangerous-to-laser Polyvinyl chloride AKA PVC AKA Vinyl. It lives a useful life outside your laser cutter, but when cut it releases poisonous and corrosive fumes that will destroy your laser cutter and possibly your lungs.
“I am scared 'cause I just accidentally lasered some PVC. Can I come out now?”
“Naugahyde”
ABS
ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching on fire and leaving behind melted gooey deposits on the vector cutting grid. It also does not engrave well (again, tends to melt).
HDPE/milk bottle plastic
Catches fire and melts. It melts. It gets gooey. Don’t use it.
PolyStyrene Foam
It catches fire, it melts, and only thin pieces cut. This is the #1 material that causes laser fires!!!
PolyPropylene Foam
Like PolyStyrene, it melts, catches fire, and the melted drops continue to burn and turn into rock-hard drips and pebbles.
Fiberglass
It’s a mix of two materials that cant’ be cut. Glass (etch, no cut) and epoxy resin (fumes)
Coated Carbon Fiber
Emits noxious fumes. Thin carbon fiber mat can be cut, with some fraying - but not when coated.
I think it would be a good idea to list some common items that people might encounter with the materials listed above, as well as the ASTM resin ID codes if applicable.
Yes a lot of things that are listed as melty and flammable can be laser cut with the right settings and air assist efficacy. I look forward to being able to engrave my 3D parts as 3D printed text is not the best.
I’m seeing many negative posts regarding styrene. From it’s bad for you and the machine, to it’s just a fire hazard. I question the inconsistency for two reasons… 1. I have access to a large quantity of black thin ‘styrene’ (per the label) that would work great for some of my various sign/frame projects, and 2. Universal Lasers doesn’t seem worried about styrene as they mention nothing negative on their site. (https://www.ulsinc.com/materials/polystyrene)
The negative posts certainly outweigh the positive, so I’m leaning towards not futzing with it. Yet the positive posts(some projects have used it), and one post in particular, is from an industry leader.
