Hi Makers,
Can the lasers be used to cut polypropylene or Teflon?
Thank you,
Eric Brunner
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Polypropylene, yes. Teflon, no, it creates highly toxic chemicals when heated over 500 degrees.
Like Kevin said, do not cut Teflon on the laser cutters. One of the combustion byproducts is hydrofluoric acid. Most of the time you can tell if a material is safe to laser cut or not based on the combustion byproducts on the MSDS under the firefighting measures section. For example here’s one on Teflon.
There are also some good resources out there from laser cutter vendors that cover what can be cut and what to avoid. This is a good one.
If you ever have any doubt do what you’ve done here and ask the laser committee.
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Great! I’ll be sure to check out those links. Thank you all for the info!
I was searching to see if Teflon is safe for the laser cutter and came across this post. In the synrad pdf document that @lukeiamyourfather posted, Teflon is listed as having “good” general cut quality with no safety considerations (see page 8 and 13). I also found this on the Universal Laser Systems website:
https://www.ulsinc.com/materials/teflon
“Teflon is an excellent absorber of CO2 laser energy (wavelength=10.6 µm). When Teflon absorbs laser energy, it rapidly converts optical energy into molecular vibrations (heat). With sufficient heat, Teflon undergoes “scission”, where the bonds between repeating units are broken cleanly, without significant degradation of the base unit. Material directly in the laser path is cleanly ablated away into vapor and a fine Teflon powder.”
Other hacker spaces including Austin, permit laser cutting Teflon:
http://atxhackerspace.org/wiki/Laser_Cutter_Materials
So yes if you burn a chunk of Teflon over 500 degrees it produces toxic fumes, but from what I’m reading Teflon produces virtually no hazardous fumes using CO2 lasers because the small amount of material in the laser path is ablated into fine powder.
If any issues it will be with the Florine. But whether or not it it produces a form that attacks the glass laser lens, I don’t know. This is probably what the concern is over.
I called Universal Laser and Epilog. Both said that Teflon is safe to laser cut on their machines. If we’re concerned about fluorine gas damaging the mirrors then just turn on the air assist. Since we have fume extractors that are vented to the outside we shouldn’t have to worry about any fumes, and fluorine gas is heavier than air anyways.
I think MSDS overrules what laser companies say…
"
Hazardous decomposition products including carbon dioxide,
carbon monoxide, hydrogen fluoride, toxic gases or particles
may be formed during combustion. These products may cause
severe eye, nose, and throat irritation or toxic effects.
"
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Even acrylic produces hazardous flammable gasses when burned. That’s why we have a fume extractor right?
Hydrogen fluoride = Hydrofluoric Acid, which is used to etch glass. It’s the damage it does to the lens that is the problem, not the purging of it to the outside. The lens is right next to where it is being generated is what the concern is.
It might be worth a second look at the subject, but with these expensive machines, better safe than sorry.
1 missed member project <> cost to replace lens.
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and that’s why I brought it back up, to get some clarity.
So the questions are: how much HF gas is generated in the path of the laser, is that gas around long enough to dissolve in the moisture in the air to produce hydrofluoric acid, and is there enough acid to damage the lens? From my talks with the manufacturers and looking at forums it sounds like it’s safe, especially with the air assist turned on which blows air downwards away from the laser mirrors.
I probably wouldn’t try cutting Teflon on the laser cutters but nobody is physically going to stop you from trying. If things go sideways we’ll know who to talk to.
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Sounds like an expensive experiment at the cost of other members ability to use the laser.
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