New resource-saving coating line for rail vehicle wheels

A new painting line for single-wheel painting of rail vehicles was installed at a manufacturer of railroad wheels to meet increasing demand. Great importance was attached to sustainable and resource-saving production.

At the site of Bochumer Verein Verkehrstechnik (BVV), founded in 1842, wheels for rail vehicles are forged and in some cases combined to form complete wheelset systems. In order to adapt to the increasing demand in rail transport, the production plant was gradually modernized in 2022. This included a modern, highly efficient coating line. More specifically, a solution for single-wheel coating for primer and top coat application that can be easily integrated into the complex production process. BVV attached great importance to sustainable and resource-saving production.

Walther Spritz- und Lackiersysteme GmbH, together with J. Wagner GmbH - both companies of the Wagner Group - enabled the installation of such a custom-fit solution. To meet the different requirements, the new painting line is divided into two segments. In the first segment, the rail wheels are masked manually and primed with the Wagner AirCoat GM 4700AC manual gun. In the second step, a robot applies the top coat fully automatically with the Wagner AirCoat gun GA 4000AC. Both guns enable excellent atomization, efficient paint application with very low overspray and uniform coating thicknesses. Ideal, therefore, for BVV's requirements: the company can expand its production capacities while saving considerable application material. In addition, the guns are very compact and easy to operate.

The modernization of the plant was carried out during ongoing production. The supply and exhaust air supply had to be adapted to the conditions of the factory hall: The exhaust air pipes were laid over a long distance under the hall ceiling and led out above the roof. This was particularly necessary to meet emission control requirements. The new coating plant has regenerative cross-flow heat exchangers, recovering up to 50 percent of the energy from the exhaust air.

Individual components such as pressure vessels, agitators, automatic lid-lifting devices, collecting trays and pneumatic control components have been combined into high-performance systems by Walther Spritz- und Lackiersysteme GmbH. The material to be processed is conveyed from different delivery containers. Overfill safety, best possible residual emptying, ease of operation, requirements of the Water Resources Act (WHG) and operational constraints were essential parameters in the project planning. Thanks to its economical use of resources, the new plant enables BVV to reduce material consumption and cut costs, especially for paint disposal (OM-05/23).