METHOD FOR PRODUCING AN ALUMINIUM FOIL WITH INTEGRATED SECURITY FEATURES

摘要

Method for producing an aluminum foil with integrated security features. An aluminum foil is rolled down to a thickness of less than 150 μm in a plurality of cold rolling passes, texturing that runs in the direction of rolling being induced simultaneously on both surface sides of the foil. In a final cold rolling pass, the foil is fed to a working roller pair, in which, on at least one roller surface, the relief-like surface structuring generated in the rolling direction by grinding was reduced on the basis of contrast and motif in a region of 10 to 50% relative to the average surface roughness to form a motif for a security feature that is transferred to the surface side of the foil facing the roller surface. The generated aluminum foil has a glossy appearance on both sides such that the security feature rises clearly due to its dull appearance.

主权项

1. Process for the manufacture of an aluminum foil (1) with integrated security features (6) whereby an aluminum foil (4) is rolled down in several cold rolling passes to a thickness of less than 150 μm, and whereby at the same time on both outer faces (4a, 4b) of the aluminum foil a texturing (5a, 5b) extending in rolling direction is created, whereby the aluminum foil (4) is fed into a working roller pair (9) in a last cold rolling pass, in which on at least one roller surface (11) the relief type surface structure produced by grinding is reduced, depending on contrast and motif, in a range (7) of 10-50% relative to the average depth of surface roughness, for the formation of a motif for a security feature (6) which is transferred to the outer face (2a) of the aluminum foil facing the roller surface.