Longevity assured
Trailer manufacturer chooses Dutch supplier
Schmitz-Cargobull has been manufacturing trailers in Gotha since 1997. With a new vehicle produced every 30 minutes, the company has manufactured over 4,500 vehicles in 2023/2024. Schmitz-Cargobull has corrosion problems under control with the new pre-treatment of MM31®.
Schmitz-Cargobull now relies on modified pre-treatment technology at its Gotha site to ensure the quality and durability of the subsequent coating. The introduction of the ‘MM31®’ system from AD Chemicals in the Netherlands was prompted by regulatory requirements and the need to optimise corrosion protection for aluminium trailers and semi-trailers. The ban on chromium (VI) led to problems with aluminium substrates. A new solution was needed.
Painting is carried out in Gotha on two state-of-the-art painting lines, using a two-coat system and a wet-on-wet process with an epoxy primer and PUR-based top coat. Drying takes place in an oven at a temperature of 90°C. The pre-treatment used to date involved cleaning with solvent-based products and coating with environmentally harmful ingredients. This made it necessary to search for alternative processes. As part of the changeover, AD Chemicals’ product, which is a water-based combination of cleaning and conversion coating, was integrated into the coating process.
The technology is based on a chemical reaction that forms a thin protective layer that bonds firmly to the surface. It uses trivalent chromium, which is incorporated into the crystal structure of the metal. Unlike hexavalent chromium, this is not restricted by the REACh regulation. The layer formed improves the adhesion of the subsequent paint coating and helps to reduce corrosion.
