In a production setting, unexpected faults in electrical equipment can interrupt process controls. These faults can affect both cranes and the rectifiers controlling the anodizing process directly. This talk will look at common electrical interruptions seen in the anodizing tank, reproduced in lab settings, and discuss the effects those interruptions have on the post-anodize treatment of electrolytic color and seal. Three types of interruptions will be discussed: pre-anodizing dwelling without current; breaks in electrical flow during different stages of the anodizing process; and post-anodizing dwelling times in the anodizing tank.

Bright Dipping is a process for increasing the specularity or brightness of aluminum by leveling the microscopic roughness (“peaks and valleys”) on the surface of aluminum parts. The application for Bright Dipping is somewhat limited because it does little to macro polish or smooth scratches or pits, underscoring the need for good buffing and proper handling prior to Bright Dipping. Etching is designed to minimize or hide die lines and other surface irregularities to create a smooth reproducible finish from load to load, piece to piece. This can be achieved by caustic or acid etching. Understanding the basics of how each etching process works will allow the anodizer to make informed decisions regarding the best chemistry for their desired finish.

Design of Experiment (DOE) is a method to test the effects and statistical significance of experimental parameters. Etch matteness and appearance as measured by gloss depends on various parameters of the etch step(s) and other steps in the anodize process. In this study, the effects of acid etch temperature, time, and concentration, as well as caustic cleanup temperature on gloss were probed. All of these parameters greatly affect the gloss, and the use of DOE for process optimization and determining operational limits is discussed.