Advanced aluminium processingBang & Olufsen uses aluminium because it is an attractive material that can be processed to achieve a durable surface. In order to achieve an attractive and durable surface, our aluminium materials are anodized. Anodizing is an electrochemical treatment which forms a very durable oxide on the surface of a material. Bang & Olufsen originally began anodizing materials back in the 1950’s. The present facility was set up in 1992, and still stands as one of the most advanced facilities in the world.
The anodizing facility consists of 30 baths, each having a volume of 3800 liters. Each bath has a certain function, e.g. degreasing, preserving, rinsing, coloring, staining, oxidation and sealing. The most significant environmental issue at the anodizing facility is water consumption. Accordingly, Bang & Olufsen has a natural focus on reducing water consumption for each m2 of anodized aluminium. We are constantly striving to improve our technology and processes with the aim of further reductions in water consumption.
Air extraction from the surface of the baths varies according to the kind of production process in motion at the anodizing facility. The extracted air consists of atmospheric air with a varying content of hydrogen and aqueous aerosols. Aerosols in the air are removed by way of a wet scrubber, where the air is washed with neutralized water. Following a two-wash cycle, remaining drops are removed in a drip catcher. The clean air is then released to the external atmosphere. Thanks to this system, the anodizing process does not cause air pollution.
Waste water in the anodizing facility contains remnants of colorants and aluminium. Waste water is cleaned in Bang & Olufsen’s internal cleaning unit before being conveyed to public utility cleaning facilities. The waste water is neutralized during cleaning. On being neutralized, the aluminium particles form a sediment and combine with coloring particles in the sump. Ongoing checks of the cleaned waste water is carried out by an independent research institute. There has never been an instance where the statutory limits have been transgressed. Sludge from the internal cleaning unit contains remnants of colorants and aluminium salts. The sludge is drained and compacted into filter cakes prior to removal. Since 1999, Bang & Olufsen has been recycling this sludge residue. The aluminium based sludge is reused in production processes for concrete, which is an environmentally sound solution for both parties. Other than the waste water mentioned above, no waste is generated in the process.