Acrylic engraving dilemma

[Simon Arthur]

I have a problem with engraving acrylic: when I turn on air assist, I get a fine white powder all over the workpiece that's nearly impossible to clean. When I turn off air assist, the part comes out looking good, but the lens gets gunk on it fairly quickly.

This seems like it should be a fairly common problem, but I can't figure out how to fix it.

Does anyone have any ideas for keeping the lens clean while not producing the fine powder?

[David Fairfield]

Hmm, I get the powder, but it cleans up easily. I use Delvies Plexi and I generally use Windex as an all purpose cleaner for lasered stuff.

Dave

[Scott Shepherd]

I don't recall whether this is exactly correct or not, but I seem to remember the white residue being a result of too much power. Try lowing the power to the lowest you can set it and still get the results you want and see if that changes it.

It's been a while since I ran into it and I can't recall, but I think that fixed it.

[Mike Null]

If it's cast acrylic I clean it up with DNA.

[Simon Arthur]

What kind of cleaner is 'DNA'?

[Dave Johnson29]

What kind of cleaner is 'DNA'?

DeNatured Alcohol. Get it from the hardware store.

[Joe Pelonio]

Using good quality cast such as Acrylite this has never been a problem for me, any bit of dust simply blows off or wipe off with a drafter's brush. I have seen it get nasty but only when using some cheap stuff I got a hold of, that was made in Malaysia, which also cut strangely as if the density varied within the sheet and the edges were not glossy.

[Stuart Orrell]

Hi Simon,

I have the same problem. Turning the power right down, per Scotts recommendation seams to work for solid graphics.

However, for bitmaps I need more power to get good definition and contrast. For these I just turn the power down as far as I can and turn the blower off. Cleaning the lens regularly as you mentioned.

Also, in Lasercut, there is also a setting that allows you to burn bi-directional or not. For some materials (not usually Acrylic though), I turn this off, meaning that the laser will pass over the job, lasering it. It will then return without lasering, increment and then do the next pass.

This is slower as it is not incrementing and burning every time the laser passes over the work piece. However, it seems to leave less gas hanging over the workpiece at any given time and gives the extractor more time to pull it away before it settles onto the job. This really helps a lot for me.

When "Bi-Dir" is on I get more residue on the work piece that is hard or impossible to get off with soap and water. I think that each time the blower passes, it cools any gas hanging over the part and allows it to settle more quickly on the part as residue.

Hope this helps. I don't know the details of the particular task you are looking at but maybe some combination of the above will help to get you better results.

[Frank Corker]

I use quality acrylic and I actually use isopropanal alcohol to clean that off and it works a treat. However with some acrylics it is known to crack (hasn't happened to me thought :D )

[Lee DeRaud]

I use quality acrylic and I actually use isopropanal alcohol to clean that off and it works a treat. However with some acrylics it is known to crack (hasn't happened to me thought :D )That's more of a problem with vector-cut edges...something having to do with stress points put in by the high heat of cutting.