I have someone who wants me to cut polycarbonate in various thicknesses (all pretty thin). Is this safe with a laser? I know acrylic is good to go but I thought that polycarbonate was dangerous.
It’s kind of a relative of acrylic and you can cut it. They make police shields out of it… GE began production under the name Lexan in 1960…
I have regular glasses and they are made of polycarbonate.
1 Like
Well then… I’m about to open up a huge revenue stream for myself! Fantastic news.
FWIW at the last place I worked we used to cut thin 0.4mm and it worked ok but left a yellowish stain and stunk. Using app tape on both sides helped.
We also did a test cutting of 3mm thick Polycarbonate and it was not very successful. It wouldn’t cut in one pass on a 120W laser. It seemed to get a carbon layer, which sparked bright white light.
I tried multiple passes, but always ended up with the carbonisation issue, and it would cut no more. I was told that it could be done, but never told how - I would love to know. We gave up and put it on the router.
Maybe very light multiple cuts could work?
In any case, it may be prudent to do some testing of your own first before accepting a big contract.
Regards.
That’s good feedback! I’ll be cutting with my epilog so it should be interesting. I only have 60w to work with which isn’t a ton! I’m going to order some samples this week of buna-N and poly and see how they run before I accept any jobs. I can get the dxf/solid works models to qc/qa the test parts after cutting and see how the parts turn out.
It will be interesting to hear how it goes. What I do remember is that the smell reminded me of highly concentrated elephants urine.
Well that sounds attractive… haha. I’ll report back in a week or two.
I thought you might have asked me how I was able to compare the smell so accurately? 
1 Like
Momma always taught me it is better to not ask certain questions. 
3 Likes
Yeah, you’re right. I’d rather not speak of it as well.
It will cut, but gives off toxic fumes and looks pretty ugly with black/brown residue. Not so good for your laser either. Get good ventilation and make a swmall sample cut before comitting.
1 Like
I don’t think it’s any more toxic than regular acrylic, both stink and breathing of any ‘burnt’ stuff is a bad idea… If you can smell it, your ventilation is lacking…
Can’t say I’ve ever ‘sniffed’ elephant urine, fortunately, I have nothing to compare it to.
I was able to cut some 1/16" (about 1.6mm) on my 60w with no real issues, as others mentioned it leaves a brown stain so I cut mine with the original masking on (when peeled off was pretty clean) I don’t think I would cut anything thicker than that though I didn’t get too bad of smell but I have a pretty good exhaust fan.
Maybe you are just used to being around elephants… 
Best test on anything you cut is to heat up a piece of copper wire and melt a bit of what you’re cutting on to it. Then place back in the flame, if it gives of a green flame DONT CUT IT it contains chlorine and eats away at wiring and damages the laser👍
3 Likes
That’s the Beilstein test. Not sure if it’s suitable for testing Polycarbonate or any other plastics other than PVC.
1 Like
ditto on the yellowing. I cut 1/4-inch polycarbonate with 100W. Diabolical amount of smoke. regular old exhaust fans do not evacuate enough air volume fast enough. I replaced the fan with a high flow furnace fan and increased air intake open area.
1 Like
So you did manage to cut through 1/4" of it? That’s good going. I had a build up of carbon, then that was it. No going through that layer of carbon.
And the stench?..
Oh well, What happens on Safari, stays on Safari.
I found that you need to use nitrogen or argon instead of shop air.
as for thinner stock I cut at 100mm/sec @25% (150W) with 3 passes and yes with the protective coating or tape on the cut line. Just a little cleaning to do with a file or sandpaper to the edges
I think you’ll find that just copper alone in a fire will produce a green flame so I’m not sure if copper would be the best carrier.