Process for the chemical treatment of metal surfaces and installation suitable therefor

US6171409A · kind A · utility

Assignee

• Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

• Matthias Hamacher · Frechen, DE
• Berhard Kotschy · Mettmann, DE
• Peter Kuhm · Hilden, DE

Key dates

• Filing date: Jul 16, 1999
• Grant date: Jan 9, 2001
• Expiry date: Jul 16, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23G1/08
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Metal surfaces are contacted with a solution of a process bath (1), for example a phosphating or pickling solution, which comprises several components in aqueous solution, the composition of the process bath (1) being maintained within a given range by addition of solutions or gases, in particular air. The profitability is improved considerably if the solution of the process bath (1) is circulated via a first line (2) and a circulating pump (3) and the solution to be added and/or the gas to be added is fed to the process bath where, as a consequence of the ending of the line (2), vigorous thorough mixing prevails, or if the solution to be added or the gas to be added is fed to a suction pump (4), the solution to be added or the gas to be added mixing with the circulated solution.