The purpose of the invention is a method for coating a substrate made of an aluminum alloy in the AA3000 or AA5000 series, comprising the following steps: a) coating by (co-)extrusion of a polypropylene modified by maleic anhydride adhesion layer on each face of said substrate, and a surface layer made of polypropylene comprising at least one slip agent, so as to form a metalloplastic strip; b) calendering said metalloplastic strip; c) heat treatment of said metalloplastic strip; d) cooling of the metalloplastic strip, to obtain an H48 metallurgical temper and a coefficient of friction of 0.06 or less. The method being particularly suitable for the fabrication of food packaging and particularly for beverage can lids.