The material is mill finished and uniform on both sides.
CLA surface roughness ( Ra): 0.25 – 0.50 microns
Peak to valley heigh (Rt): approx 4 microns
The material is pretreated as described below pretreatment: phosphoric-acid 59 BE, ALIM 85% complies with EC and European regulation and also with United States Food and Drug Administration requirments.
Pretreatment: The aluminium is treated by the electrochemical phosphating ( bath of phosphoric acid ).This treatment allows the creation of a layer (several microns of thickness ) of aluminium phosphates on the surface. The phosphates layer helps the grip of the laquer on the surface.The chromium is no longer used as it is toxic and difficult to dispose of.
Relubrication: no relubrication is applied to the surface, as our phospho chroming system allows to skip this process and helps itself the mobility in feeding of the sheets during the lacquering and printing stage
Dimension and shape tollerances:
Gauge: tollerance on gauge is + 0.01 mm for gauge from 0.20 to 0.23 mm
Values of sheets: flatness tollerance of 0.6% ( length of wave ). Maximum 2 mm. Up end corner: 2 mm
Squareness of sheets: deviation not greater than 0.8 mm on dimension up to 1000 mm deviation not greater than 0.4 mm on dimension up to 500 mm
Lateral curvature: 0.2 mm on dimension up to 1000 mm
Tollerances on Length and Width: on width: -0/+0.3mm / on length: -0/+1mm