Recently printed signs on aluminum composite 4x8 sheets looked very nice. After delivery to customer signs were sent back do to customers handling of signs, scratched off printing, We tried a roll on UV protecting coat only to have the image peel off in sheets.
Is there any specific coatings or other ways to prevent image from being scratched off these signs?
We're running an old Gerber IONx, and while not bulletproof, I can barely scratch a printed piece of ACM without using something sharp to do so.
The scratching issue is mostly on your customer, but it sounds like you also have an adhesion issue on top of that. If you are wrapping the panels in paper ( we use the rolls and rolls of laminate liner we accumulate ) and delivering them in perfect condition, they have to use some care in their handling after the fact.
We started doing a two step cleaning regimen on ACM a while back and it has really cut down on irregular print errors, streaking, mottled colors, etc. We also are peeling the plastic liner off and letting the panels outgas for a couple of hours to a full day before cleaning them. So, we give the panels a quick wipe with 99% isopropanol alcohol first, then we do a more thorough cleaning with Advantage 190 - automotive wax and grease remover. We're using this at member Artbot's recommendation along with Wypall lint free wipes and are seeing big improvements in our print quality in general and far lower error rates.
As far as a clear abrasion resistant coating, we've used FrogJuice solvent (sucks!), FrogJuice waterbase (better but not great), OneShot acrylic clear (unpredictable results), etc. etc. So far, the best stuff we've used is ClearShield "Production Clear"
