During the surface coating process, single drums transport the parts through the coating unit. First, the drum is filled with fasteners ready for decoction degreasing, a process during which oils, greases and other residual contamination are removed. ARNOLD thus ensures that the surface is clean and non-greasy. Then the items are rinsed before moving on into the pickling bath. This is where we remove oxide layers, such as rust and scale so as to produce a bright metallic surface. The items are rinsed again before they move into the electrolytic degreasing unit, our ultra-fine cleaning process which eliminates the last traces of any contaminants.
Another rinse and the ARNOLD fasteners are now perfectly prepared for the electrolytes. As a rule, we apply 8 to 16 microns of zinc to ensure cathodic protection against corrosion. Once again, this is followed by the obligatory rinsing stage. Depending on what the customer needs, a transparent, yellow or thick film is applied in the passivation process. After the final rinse, the items are dried inside the centrifugal drier.
