WELCO in English WELCO auf Deutsch


Eloxal is the abbreviation for Electrolytic Oxidation of Aluminium or aluminium anodizing - artificial generation of an oxide coating on the aluminium surface.

In the DC sulphuric acid process the aluminium workpiece in a sulphuric acid electrolyte is connected to the anode of a DC source. When current flows, oxygen-containing anions migrate to the anode where they liberate the oxygen. The
oxygen reacts with the aluminium to form aluminium oxide thus forming a thin, non-porous barrier layer. As a result of the bath voltage, the resistance of the barrier layer is broken down so the electrolyte migrates into the breakdown pores and forms a new barrier layer on the metal base. The process continuously repeats which forms a porous, transparent oxide layer. It grows 2/3 into the metal and is strongly bonded with the base metal. 

Properties and advantages of our Eloxal (aluminium anodizing) coating:
  • High colour fastness and corrosion resistance
  • Extreme hardness and abrasion resistance
  • Protection of the decoratively processed surface
  • Heat resistance


Chemical process
- E0: Pickling in E0-pickle
- E6: Matt pickling in E6-pickle (decorative matt)
- Chemical shining

Bath dimensions: 1200 x 300 x 800 mm

Coating thickness: 5 - 20 µm