Pre-anodizing

Vertical pre-anodizing

Vertical pre-anodizing in a powder coating line is unique in the Netherlands.

Pre-anodizing, or PREANO+ as we call it, is the conversion of a very thin layer of the aluminum base material to an artificial aluminum oxide layer, which ensures a very high corrosion resistance and excellent adhesion of the subsequent coating layer.

The process

Pre-anodizing is an intermediate step in the entire pre-treatment process, ie degreasing, pickling, pre-anodizing, rinsing and then applying a conversion layer. Pre-anodizing is a dipping process and with Jonkman Coating this is done vertically. The aluminum alloy is dipped in a sulfuric acid solution after pickling (acid and alkaline). A voltage difference is then set up there (direct current). The aluminum is then the anode, whereby the aluminum surface is converted into an aluminum oxide that is very porous. There is then no question of a separate layer, but a transition from the aluminum oxide to the aluminum alloy. The pores in this layer, unlike normal anodizing, are not sealed . To optimize the adhesion, the pre-anodizing layer is provided with a conversion layer: the “Plus” is our system.

The process is Qualicoat certified.

For a video: https://vimeo.com/397135691

Application

The application in the case of vertical pre-anodizing is the market for aluminum profiles (including construction, transport sector, noise barriers, greenhouse construction etc.)