Brown Edges Cutting 1/8 inch Acrylic

So I am pasting a picture of what is happening when we go to cut this acrylic. I have tried applying different masking but it still turned a strange brown or yellow color. I cant get this out once the letters are cut out and we are trying to make necklaces out of these letters.

This acrylic is a marbled grey color

Any help would be appreciated.

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The biggest concern I have is that it might not be acrylic.

Does it smell like acrylic when you cut it? You probably know the smell, it’s really distinctive. If it doesn’t smell like that, I wouldn’t cut it until you find out what it is. It’s probably not pvc (which would be bad), but you don’t want to risk it until you find out for sure.

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Well I purchased it and it said acrylic. What could it be? When I tried to sand the brown off it did smell like acrylic.

Lots of people mislabel plastics for lots of reasons. Right now there is a big worldwide push to get acrylic, so some people have been reporting “acrylic” being some other clear plastic. This can be a problem if that other plastic has undesirable lasering characteristics, like melting, flammability, or … discoloration.

Is it masked? If so, is it masked with plastic? Again, I’d reach out to the seller for an MSDS, and once I was sure it wasn’t PVC I might try removing the masking and trying again, see if you get the same discoloration.

PVC is so bad that if it came down to it and I wasn’t sure there was no PVC I’d just eat the cost and move on to a different material. Not worth losing the machine.

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A lot of the dyes in colored acrylics do odd things too. Might not be a bad idea to test the plastic to make sure it is acrylic, but it might just be the dye. (Which might mean no way around the browning problem.)

It says PMMA - There was plastic on the outside of it the first time I cut so I took it all off the second time and used some other masking I purchased which I use all the time and it has not had a problem. So I am leaning towards the dyes used in making the acrylic because I have used a polisher on the edges and it does get rid of the stains but it takes too long so we can’t do this on every single letter moving forward. UGH

How do you test the plastic?

yeah PMMA is acrylic, so you should be good on that part.

I will try it and let you know. Its worth a shot. Everything else I ordered from this company is great and not causing this kind of stain when I cut so it must just be some kind of dye in the acrylic. But I can’t use it if it doesn’t clean up.

Nope still yellowish brown.

if your not sure what you got! burn it!

Did you try less power and more passes? Maybe theres too much heat in one pass?

Careful when using alcohol anywhere with acrylic, especially extruded. It can cause cracks to appear and propagate, it’s called crazing and it’s wild.

I did not try less power. I honestly think it has got to be some kind of dye that was used because none of the other acrylic we got from this company did this when cutting. Some of it was also a grey marbled.
Don’t ever put thieves dish soap on acrylic either!! I used it thinking I could clean up an engraved item and it immediately cracked all around the engraving. crazing like crazy…

True, I avoid using it on acrylic surfaces because it fogs it. I haven’t had cracking, but I don’t normally have issues with acrylic, so I hardly use it. I guess it’s the only cleaning supply I have on hand because it’s next to the 3D printer. :rofl:. I’ll remove the suggestion so no one tries it.

So BIG update the maker got back to me and that acrylic did have PVC in the material. So I am getting a full refund on that product. I also placed a nasty review on his page for selling a product listed Acrylic PMMA when it is not and stressed that misrepresenting the product could cause a fire. I am sure he took my warning (eye roll) seriously.

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Who’s the maker so we can avoid?

Off Etsy - called iMaterials - Like I said though we actually purchased 4 different styles and the other 3 were amazing. No problems great quality. We did get a full refund. I don’t know that I would avoid the company, I would just make sure to ask whomever you buy from - which is the important lesson for me. I need to ask when working with someone new.
Thank you everyone for your help - I would not have gone back and asked without guidance.