Fire when cutting acrylic sheet 1/8

Hi
I usually use mdf and acrylic sheet but today when I tried to cut a cork, there was a flame and it burnt the material pretty bad so I will probably not use cork again.

But the problem is that when I cut an acrylic sheet which I use, it flared again. I don’t know why it is happening since I never had this problem before.

Should I be worried or it is just normal to see flames like this?

I will attache the video I took.
Any advice would be appreciated.

alwa

ys

Did you clean out the tray? There could be little bits of flammable stuff in it.

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I always take off the top tape of acrylic, sometimes the bottom too. Any acrylic. Haven’t had a flame since.

I have had one or two batches of acrylic where the backing paper (or maybe the adhesive on it) seemed to be very flammable. I have gotten in the habit of pulling it off and remasking it with my usual medium tack Nekoosa masking. This seemed to fix it for me.

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Cork is a PITA to cut - I do 2 passes, and sometimes a 3rd because you cannot power your way through the stuff. To engrave it’s crazy easy though, it hardly needs any power at all to darken up.

It’s possible when you had your flame up you ended up with debris in the bed as @chris1 suggested, but also I’d take off the head and the carriage plate and clean that too - soot should be dealt with sooner rather than later.

but yeah, that flame is not terribly unusual in acrylic. If it were leaving black marks on the paper I’d be more worried, but tiny pops like that I ignore.

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Well at least we know your air assist fan is doing its job. I think as long as you keep an eye on things you’ll be ok. Like # deirdrebeth said, it isn’t scorching the paper so just watch it closely.

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The brown masking paper that comes on a lot of acrylic has wax in the adhesive. Vaporized wax ignites like a candle flame. For a safer cut, remove that masking and put your own transfer paper on, or a thin layer of Dawn dish soap.

A small, candle-like flame where the laser beam strikes the material is normal. The flame should move with the laser, and not remain lit when the laser has moved past.

Unfortunately, I can’t comment on materials that were purchased from another company

Do you have any Proofgrade acrylic you could test with? If you see this on Proofgrade materials, please let us know and we’ll determine next steps.

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It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this please either start a new thread or email support@glowforge.com.