Audi Uses Energy-Saving Technology for Paint Facility in Mexico
Dürr is building a paint facility for automotive manufacturer Audi in Mexico that employs the latest technology for energy savings. As the general contractor at the site in San José Chiapa, Dürr will build one of the most efficient paint shops in terms of water, energy and materials usage. The company is responsible for the complete Eco+Paintshop.
The paint shop design ensures that all interfaces and processes are efficient, from the e-coat pre-treatment, to application technology in the paint booths, through to the curing ovens. Attention will be paid to sustainability, starting in the PT/ED phase. The Ecopaint RoDip rotational dip painting system is used during pre-treatment and e-coat. RoDip eliminates entry and exit inclines, as the car body gets completely rotated in baths. Less water, chemicals and power are used for bath conditioning because of the smaller volumes of these shortened dip baths. RoDip lowers unit costs and offers the best possible corrosion protection via an optimized process of immersion, flooding and draining.
Underbody and seam sealing are accomplished with 10 EcoRS16 robots. Armed with EcoBell3 high-speed rotary atomizers, 36 EcoRP L133 robots are responsible for the fully automated interior and exterior painting in the primer and topcoat line. Color changing in the base coat is possible within 10 seconds in the push-out process with atomizers combined with the color changer EcoLCC2. During the push-out process, the paint valve is closed before painting and the paint material in the color hose is pushed towards the atomizer with solvent. Paint loss during the changing of coat colors is between 10 and 15 ml. For the paint supply, Audi uses proven circulation technology for standard colors, while special colors can be applied with the flexible piggable special paint system EcoSupply P. The color is pushed through the pigging piping without resistance by using pigging (pipeline inspection gauge = fitting body). This procedure is particularly material efficient and saves money. The facility will use 24 handling robots to hold the doors and hoods open during interior painting.
The overspray is separated via the energy efficient paint booth system EcoDryScrubber. This dry separation of the overspray does not use water and chemicals, and the paint booth can be powered by up to 90% recirculated air. The EcoDryScrubber saves up to 60% energy in the paint booth, as less air conditioning is needed.
The straight-through ovens are designed for complex car body structures with considerable aluminum add-ons. They are also designed to have low exhaust gas temperatures. The exhaust air streams of all ovens are purified by the integrated oxidation Ecopure TAR with heat recovery and used again for thermal heating. The highly efficient Ecopure exhaust air purification system cleans the remaining minimal exhaust air from the spray booths, which has already been reduced by the EcoDryScrubber and its recirculation. The dry separation is responsible for a highly concentrated and very efficiently filtered exhaust air. This enables the use of a very compact exhaust air purification system, which lowers investment costs for the exhaust system by 60%. In this combination, the power consumption for the exhaust air purification is reduced up to 80% and the solvent emissions are reduced by 90%.
Audi entered into an agreement with Dürr for the Eco+Paintshop in December 2013. Audi Q5 models will roll off the production line in San José Chiapa starting the middle of 2016.