ES478046A1 - Procedure of enamelled electrostatic with dry powder, on normal carbide plate, with two layers of enamel in a unique baked. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Electrostatic enameling process with dry powder, on normal carbureted sheet, with two layers of enamel in a single baking, in which, as in the processes of enameling decarburized sheet, it is subjected to a series of preliminary operations, such as degreasing, washing, pickling and nickel-plating, for the subsequent electrostatic application of the flux enamel and the covering enamel, normally applied in liquid phase, finishing the process with baking, essentially characterized in that in the nickel sulphate bath, buffer products are used self-regulating ph, constituted by a weak acid system and a dissociable salt of its conjugate base, then, once the metallic nickel film is achieved on the steel sheet, optionally subjected to a wash with demineralized water, with a ph between 2 and 4, followed by a treatment with organic-alkaline products, preferably containing g rupos diamine or tertiary amine, at a ph comprised between 11 and 13, being able to perform this treatment in both cold and hot, then practicing a neutralization based also on organic amino-alkaline compounds, with subsequent washing with demineralized water of greater resistivity than 100,000 0hm.cm, to guarantee a totally inert surface, being applied electrostatically then, after drying of the moisture due to the last washing with demineralized water, the dry powder glaze layer, in the amount of 30 to 80 g/m2, enamel that contains in its composition up to 5% oxide active adherents of nickel and/or cobalt and/or copper or any other suitable metal, also applying electrostatically, without drying or intermediate treatment, the coating enamel layer also powder dry. (Machine-translation by Google Translate, not legally binding)