Panel for facings and process for its production

Claim 1

Process for the production of a nonferrous metal panel having on one side a flat surface and on its other side an embossed surface provided with irregular areal depressions predominantly having a width of at least 10 mm and a depth of 10 to 30 percent of the greatest panel thickness, the total area of the depressions corresponding to 20 to 50 percent of the embossed surface, said method comprising cold rolling one layer of nonferrous metal sheet having a thickness of 5 to 8 mm between a smooth roll and a roll provided with the corresponding counterprofile, normal roll sizes and roll stands being used for rolling said nonferrous metal sheet, said sheet also being passed between smooth straightening rolls disposed behind the roll providing the counter-profile, the whole surface of the roll showing the counter-profile being manually worked in a hard and respectively hardened condition and having impressions and elevations distributed and dimensioned such that, based on an imaginary subdivision of the rolled sheet in longitudinal zones extending in rolling direction and each having a width corresponding to approximately one-tenth of the roll width, the mean reductions of cross section of the rolled sheet in all these longitudinal zones deviate from each other for maximally 15 percent and, based on an imaginary subdivision of the rolled sheet in transverse zones extending in direction of the generatrices of the roll and each having a width corresponding to approximately one-twentieth of the roll circumference, the mean reductions of cross section of the rolled sheet in all these transverse zones deviate from each other for maximally 20 percent the mean absolute reduction of cross section as calculated over the whole axial extension of the roll being from 5 to 30 percent.