Does anyone have good settings for 4mm corrugated plastic (polypropylene). Looked but could not find anything on here talking about it.
I have the Glowforge basic. I’m just looking for somewhere to start. I could make a test piece and try different speeds and power but I know this stuff can catch fire pretty easily and figured some of you may already have already dialed it in.
Thanks for any help.
-James
Be really, really careful and do not take your eyes off of it for even fifteen seconds. You have got a couple of things working against you…it’s melty plastic, and it’s corrugated which is going to add air to the flame from the chambers in the material. It could get out of hand very quickly.
Thanks for the advice!
I have watched a couple of videos of people cutting this stuff and Yes it does go up quickly. I plan on having a mist bottle with water next to me and a wet cloth. The cuts I need to make are super simple and will only take 10-20 secs so I do not plan on taking my eyes off of them while cutting. 
I hope you really really need this material. I would never cut it, it’s a fire begging to happen.
I’d look at frosted acrylic way before I’d use that stuff.
What they said…
Here are the settings that I used successfully to engrave on PP. Worked for me but use at your own risk.
I used 160 spd, 70 pwr, 1 pass and got a cut that ~just~ required you to run an xacto over the back for separation at the ribs (we were making it transport friendly)
No issues with flame or fire at all
Thank you,
Power seems a little high and speed seems a little slow for as thin as the stuff is but it gives me somewhere to start. Just to clarify is the material below about the same thing you were using? Each of those sheets are only about 4mm.
Yup, that’s it exactly - mine had ink on them as they were old political signs, but yes.
Perfect, Thank you again.
You just saved me lots of trial and error.
I happen to have the same material, do you have any updates on what you did if you varied from 160 spd, 70 pwr, 1 pass?
The project I had to do was really small so I did not mess with any other variances. The 160,70,1 pass worked just as deirderbeth said. I had to run a X-acto knife to cut some of the center ridges but I never had any fire. I did keep a wet cloth and water next to me the whole time and never took my eye off it. I am sure if you did mess with the speed, power, or number of passes you could get a perfect result I just didn’t really want to spend the time to do so as of right now. But I bet if you just did a second pass it would make it all the way through.
what did you use for the focus height?
I’ve got calipers - so whatever they said the thickness was…
