I am VERY new to the CNC world, and wondered if anyone could offer any advice for the following. I am attempting to cut 1.15mm sheet aluminium which has a white polyester coating on one side, protected by a plastic film, which is used within the world of photography!

To date, I am dry cutting the sheet with the coating face down and getting very mixed results. The biggest issues appear to be that chips are getting between the spoil board and the sheet, which in turn the tool is beginning to lift the sheet causing jagged edges. The edge cut quality is paramount and on part of the cuts it meets the grade, and other parts it doesn't. I have asked a few CNC users that have cut aluminium and of course each has a different answer for RPM/Feed rate etc, but currently I use a 6mm carbide tool @4000RPM with a feedrate of 0.5.

Any advice would be gratefully received in terms of tools / rates / technique!