Laser cutting two layers of acrylic glued together with Tensol - Safe?

[Dan Kozakewycz]

Is is safe to cut two pieces of acrylic glued together with tensol? I notice in the contents it states 'Dichloromethane', the Chloro bit is concerning due to the well known issues with chlorine gas cutting PVC, and the methane bit is concerning due to flammability issues.

Has anyone got any experience doing this sort of thing?

To be clear it's two sheets that would be glued together and then cut as one double thickness sheet.

[Lee DeRaud]

I have no data or opinion regarding the chemical aspects of that adhesive.

But I will note that the one time I tried cutting a double layer of acrylic (just taped together), the laser did an excellent job of welding the layers together along the cut line.

[Gary Hair]

I have to ask - why not just buy the thickness you need to start with?

Having said that, I would think that the solvent/glue would evaporate if you left it sit for a while so you may not have anything left to worry about.

[Dan Kozakewycz]

That's how we used to do it. Seems the new laser with 3x the power actually makes a worse job of it, I managed to pull apart over 50% of the batch I made today.

Perhaps with more power available it does it too fast and doesn't get enough heat in to properly weld?

[Dan Kozakewycz]

Each layer has different cutouts in it, wouldn't be possible to make the part with a single piece and a laser!

[Lee DeRaud]

That's how we used to do it. Seems the new laser with 3x the power actually makes a worse job of it, I managed to pull apart over 50% of the batch I made today.

Perhaps with more power available it does it too fast and doesn't get enough heat in to properly weld?Yeah, mine is rather low-powered and therefore very slow on acrylic. In this case that seems to be a feature rather than a bug.

[Lee DeRaud]

Each layer has different cutouts in it, wouldn't be possible to make the part with a single piece and a laser!So you're doing the cutouts on each layer, gluing the layers together, and then doing the perimeter cut on the glue-up?

[David Somers]

Dan, Have you pulled an MSDS on that adhesive to see what it puts out when heated? That would be the key.

[Joseph Shawa]

The carbon compounds produced under high heat are great in variety and vary from material to material and can be different under different conditions. Though you may get the green light on the safety of some materials I would suggest always venting well and always using gloves to touch it post processing.

I wash my pieces before handling. Why might you ask? Well after a day of handling small polyester cuts my fingers started going numb....an odd numb. Repeated another time or two before it struck me what was going on. I don't even trust the char on wood. Now it's rubber gloves or tweezers until washed. No more numbness.

[John Blazy]

I laser laminated acrylic all the time. I looked up Tensol, and its the same as what I use. Its basically PMMA monomer with methylene chloride as solvent to thin it, and weld to the solid acrylic. This is not related to the chlorides in PVC, and is so very little in a glue line, that its toxicity is nil compared to the general toxicity of the thick acrylic itself. Basically you are cutting through solid acrylic when cutting laminated acrylic. IIRC, the dichloromethane is a "safer" version of methylene chloride solvent, which is the staple in all acrylic cements.

[Dan Hollis]

it is safe. DCM is an acrylic solvent which dissolves the acrylic and causes it to weld together. the DCM itself totally evaporates so there will be none left.

[Mike Lysov]

I do not know what Tensol is but you need to take into consideration that you are not burning the whole area covered by it. You only burn a kerf thick line covered by Tensol.

So basically the question should be if I burn a hair thick and hair wide line that is as long as my cut curve length will it harm me? I would guess the answer should be "no" because I doubt it would not be available as a product if such a tiny amount of this stuff can make any harm to people health.

[Joseph Shawa]

...and by what method do they test the combustion fumes and at what temperature?
My point is, do you want to find out in 20 years that you should have been wearing gloves?

[Joseph Shawa]

Evaporates into what compounds? ....No vapor deposition?

[Joseph Shawa]

I am going to dig a little. Not to be a pest but maybe to save a pen pal or two.

Using Laser Photoacoustic Spectroscopy (LPAS), smoke samplesproduced in vitro by CO2 laser vaporization of fresh animal tissues were investigated.Traces of acetonitrile, acrolein, ammonia, benzene, ethylene, and toluene were detectedin surgical smoke in the ppb to ppm range.

This is just from animal tissue.