What causes uneven colour of aluminium oxide film

What causes uneven colour of aluminium oxide film

What exactly is the reason for the uneven colour of the aluminium oxide film? Specifically, the following three aspects are the main problems.

(1) aluminum plate workpiece area is too large, the operation in the tank swing too large, the edge and the central part of the contact with the solution, update, exchange too large differences, thus leading to the oxidation film colour inconsistency. Prevention methods: aluminum plate oxidation workpiece swing amplitude to be small, static treatment can also be, but when the solution temperature is too low when easy to appear map-like spots, appear unnatural.

(2) package aluminum plate processing part of the package aluminum layer was destroyed, was cut off, the outer layer of the package aluminum is high-quality aluminum, was packaged in the inner layer is miscellaneous aluminum, two kinds of aluminum quality difference is large, so after oxidation appeared "vitiligo" like spots. This phenomenon customers often do not understand too much, manufacturers should do more to explain the work, explain the reason, so as not to cause misunderstanding.

(3) Aluminum plate oxidation process operation problems

① workpiece alkali etching treatment is not complete, local at the original oxide film, dirt can not be removed.

②alkaline etching is not immediately after the light treatment, the surface of the workpiece is still alkaline.

(3) The workpiece has been in contact with foreign objects during the transfer process.

When there is uneven colour of the film layer, we should look for the reasons from many aspects and take targeted measures to solve.

If you want to purchase evenly coated aluminum products with high quality, you can contact us Haomei aluminum for purchase. We have plenty of storage on these anodized aluminum sheets and colour coated aluminum sheets.