A new system is presented for analysis and control of the chemistry of a metal finishing line. Parameters such as metals, acids, bases and pH are measured, statistically evaluated, and replenished. Results are viewed on a CRT screen, both current and historical, and output is provided in the form of graphs, tables, printed instructions and/or relay alarms. Examples are presented of parameters measured on a metal finishing line.
THE TODD AUTOMATED CHEMICAL CONTROL SYSTEM took seven years to develop1. During that time, analysis of the critical parameters of seven processes were automated. The automation began with the electroless nickel plating process and was followed by titanium chemical milling, alkaline cleaning, chromated and non-chromated aluminum deoxidizing, chromic acid anodizing, and aluminum conversion coating. Replenishment was also implemented on two of the processes. The first half of the work was dedicated to development of analysis techniques, the last half to development of a convenient operator interface. The result was a system which analyzes and optionally controls most parameters found on a metal finishing line.
The remainder of this paper describes the analysis procedure and features of the analysis system. It also gives examples of on-line data collected.