Full Version: Need Acrylic Help
From: Harvey only (HARVEY-ONLY) [#10]
20 Feb 2007
To: Vicky (ANDERI) [#7] 20 Feb 2007
I have seen that one or two times when using cast acrylic, extruded is far worse. (If the rastered lettering is not snow white, it is extruded.)
When the covering is lifting from vacuum or air assist, the heat going under the coating gets trapped and causes these types of marks. If you have it on the painted side also it sounds like heat affecting the acrylic. Again extruded is much worse than cast.
On acrylic I would not recommend two low power passes, the acrylic expands enough to make the second cut in a different place than the first cut.
Check to be sure that the vacuum line is totally free of bends and flats that might be reducing the suck. Be sure all metal pipe connections are tight and covered with tape to stop air from leaking in and reducing the vacuum. A faster changeover of air might solve the problem.
EDITED: 20 Feb 2007 by HARVEY-ONLY
From: (Brian) (MOSTLY_HERE) [#11]
20 Feb 2007
To: Vicky (ANDERI) [#7] 20 Feb 2007
Hi Vicky,
I cut and raster acrylic all the time. I do not usually color as you are doing. The only time I had trouble with some product was when I got some PEGT instead of acrylic. It's a product like polycarbonate. I was told you can cut it, but I had poor results. It was very brittle and turned a bit in color after vector cutting. How thick are you trying to cut? I cut both cast and extruded and have not had any troubles like the ones you are describing.
From: Rodney Gold (RODNEY_GOLD) [#12]
20 Feb 2007
To: ALL
From: Vicky (ANDERI) [#13]
20 Feb 2007
To: Rodney Gold (RODNEY_GOLD) [#12] 20 Feb 2007
The results are in. I left the backing on the acrylic, it didn't affect my cutting power at all, and there are no swirl marks. Yippee! :D
I'm cutting 0.090". My air assist is almost always on, but it might not be bang-on in positioning. At any rate, leaving the backing on works for plenty of reasons (swirl marks, scratches while bevelling, scratches during shipping, etc...), so I think my best bet is just to leave it there until the customer wants to install the thing.
Thanks a bunch, folks! :-)
EDITED: 20 Feb 2007 by ANDERI