Anodising (electrolytic process

After mechanical or chemical pretreatment and cleaning, the profile is placed in a bath of electrolyte and connected to a source of direct current. Dilute sulphuric acid at room temperature is the usual electrolyte. During the process, the surface of the metal oxidises in the same way as the natural oxidation of aluminium in air. The oxide layer produced is porous and is subsequently sealed by treating it in deionised water at 95-98 °C.

This results in a pleasant-to-handle, dirt-repellent surface with even better corrosion resistance. It is very wear resistant and has good sliding properties. In addition it is electrically insulating and is an ideal surface for subsequent painting or joining.

Anodised profiles can be coloured using organic or inorganic pigments. The pores in the material accommodate the pigments superbly. The final operation is again sealing of the surface, which makes the coloured coating very resistant to wear and impact.