PRODUCTION OF ORGANIC COMPOSITE PLATED STEEL SHEET

PURPOSE:To remove a thin plating film of Zn or Zn alloy together with a chromate film after electrodepositing uniformly said plating film over the entire surface of the non-plating surface of a one-side org. composite plated steel sheet by using a horizontal type fluid supporting electrolytic cell in the stage of producing said steel sheet. CONSTITUTION:A steel sheet on one side of which a plating layer of Zn or Zn alloy is formed and a chromate film and org. film are painted thereon and which is not treated with the other side is used as a steel sheet to be used for an outside sheet for an automobile, etc. The plating liquid and chromate treating liquid spreads to the one side on the opposite side as well and an unnecessary plating layer and chromate layer are formed thereon in the stage of forming the plating of Zn or Zn alloy and chromate film on one side of the steel plate. A horizontal type fluid supporting electrolytic cell is used in this case to form uniformly a thin plating layer on the non-plating surface to 0.3-1.5g/m and the non-plating surface as an anoide is electrolyzed together with the chromate layer sticking thereto, by which the chromate layer and the Zn plating layer are simultaneously electrolyzed away.