Method for forming chemical film on aluminum can and device therefor

PURPOSE: To improve the corrosion resistance of a can bottom and to enhance the stability of a coating film on the peripheral wall by forming a thicker chemical film on the bottom surface than on the peripheral wall. CONSTITUTION: A chemical conversion coating soln. is applied on the surface of an aluminum can consisting of a cylindrical peripheral wall and a bottom to close one end of the wall to form a chemical film on the can surface. When the film is formed, an electric field is generated around the can W to make the electrical potential on the can surface nobler on the bottom side than on the opening side. COPYRIGHT: (C)1993,JPO&Japio