Interview for Metal Finishing News with Mr. Manfred Weil, President & CEO, Dürr Paint and Final Assembly Systems.

(?) MFN: Where do you see the largest potential for efficiency and savings in automotive painting in terms of ecology and cost effectiveness?

(!) M. W.: Dürr develops products according to the Eco+Efficiency system, in which we emphasize that economic and environmental optimizations lead directly to increased efficiency. Besides process improvements and greater flexibility, efficiency for us also specifically means energy and material savings and reduced space requirements. This brings us directly to the Eco+Paintshop, our approach to a sustainable paint shop.

(?) MFN: Then let’s specifically name the various savings potentials: Where does Dürr save energy in the painting process?

(!) M. W.: First off, we'll need to mention our system for dry separation of paint overspray, the EcoDryScrubber. This alone saves 60% of the energy in the spray booth. Our EcoRP painting robots also contribute to energy savings with higher throughput by means of a greater surface covering capacity. And with our EcoEMOS process control system, we further optimize energy consumption through intelligent plant control.
 
Currently, we are already achieving a power consumption of 430 kwh per car body. By way of comparison, only ten years ago this figure was well over 1,000 kwh, but even this figure is only a snapshot. We'll be able to prospectively save up to 30% energy for painting with the new EcoRPC robot control.

For the oven, the greatest energy consumer besides the spray booth, the future for Dürr is in the use of solar thermal energy. Low maintenance and compact Fresnel reflectors concentrate sunlight and are therefore very efficient. While conventional collectors produce process heat of only 80°C to 100°C, Dürr achieves temperatures of up to 400°C with these high-performance collectors. Temperatures of up to 220°C – required for operating an oven – can be easily achieved. This pioneering step in energy independence is topped off with the use of combined heat and power. With it, electricity is produced via a low-emission combustion process in a micro gas turbine whose waste heat is used to heat the oven.

The direct result of these energy savings is, of course, reduced CO2 emissions. We save over a thousand tons of CO2 per year by using solar energy, and even 2,000 tons by using combined heat and power. This means that we can reduce to even lower levels our already low 140 kg of CO2 per vehicle produced.

(?) MFN: And what else do you address in order to save on material?

(!) M. W.: Material efficiency is the dominant theme in application technology. A good example for this is the EcoBell3 high-speed rotating atomizer for the electrostatic painting of water-based paints without voltage block. The EcoBell3 can be used in both exterior and interior painting and is impressive due to its high transfer efficiency and highly flexible spray jet formation. Additional highlights of this atomizer family include minimal color change loss and short color change times.

The EcoBell2 ICC atomizer reduces color loss through six high-runner colors directly integrated into the atomizer. Our EcoLCC color changer already reduces paint loss to 10-15 ml during color changes. The second generation of the EcoLCC offers further optimization potential with a new skid positioning system using a servo drive, and weight reduction through new valve technology.

This brings us directly to the topic of material balances: where less goes in, less comes out. We have already achieved a VOC emission level of 2.3 g/m2 per vehicle by means of efficient exhaust air purification along the entire paint line.

An important element of material balances is the water used, as it is becoming an increasingly more valuable resource. We're able to achieve significant values with this as well: smaller bath volumes with our RoDip rotating dip coating system; no water required for the dry separation of paint overspray with the EcoDryScrubber; and water savings through intelligent control of temperature and humidity with EcoAirControl. These are just some of the components through which we can dramatically reduce water consumption. And in the future, we'll perform parts cleaning with saturated water vapor, thereby achieving more sustainable production.

(?) MFN: Let’s stay with the topic of reducing space requirements. Where do you see more potential?

(!) M. W.: Our RoDip rotating dip process makes an up-to-six-meters shorter dip tank for pretreatment and electro-dipping possible. With the dual-rail concept, our robots reduce the spray booth length by one to two meters. Dry separation of paint overspray reduces the painting booth cross-section significantly when compared to wet separation.

And Dürr has another innovation at hand here. With EcoReBooth, we have redesigned the paint booth in the truest sense of the word. The innovative paint booth concept places the process air technology components underneath the spray booth. Combined with the energy efficient EcoDryScrubber technology, the result is a compact overall concept for a modularly constructed, efficient painting line. The compact layout allows for a modular arrangement of the paint booth in a line with no interfering contours. Thanks to its integrated process air technology, the penthouse can be eliminated in ideal cases.

The EcoReBooth is therefore ideally suited for retrofitting or replacement of existing paint shops with limited space conditions.

(?) MFN: Can you make a statement about what the strongest driving force for investments in new painting technologies will be among automotive manufacturers in the future?

(!) M. W.: Automotive manufacturers are doing everything possible to reduce the CO2 emissions of their vehicles. They are reducing vehicle weights, improving fuel combustion, developing new drive concepts and reducing friction and rolling resistance. Environmental friendliness is at the center of today's automotive advertising. This thinking does not stop with the vehicle's driving characteristics, but also relates to the production of the vehicle. Hence, the OEMs have a vested interest in sustainable production. And if these new technologies also save energy and materials – and costs, of course, as a consequence – then there is not much  point spending time thinking about it.

At Dürr we set the trends in terms of sustainable production with our Eco+Paintshop, and we always deliver the best possible solution for each customer’s specific needs.

(?) MFN: More than 60% of new orders for Dürr come from the emerging markets. Have these markets already passed us by in terms of efficiency, and do you see that the German automotive industry has some catching up to do?

(!) M. W.: Quality consciousness and environmental awareness have now become as important in China as for the European markets. In addition, the emission limits for new plants now match the world's most stringent requirements.

The fact that the most sustainable automotive paint shops are currently found in China is simply due to the fact that the majority of new paint shops have been installed there, and these were equipped with our latest technology. The majority of these customers are joint ventures with German participation however, so it is German OEMs who are the driving force for the use of our Eco+Efficiency products.

Currently, several investments are on the horizon in our established markets. Therefore, trendsetting Eco+Paintshops from Dürr will soon show their qualities at European and North American locations as well.

MFN would like to thank Manfred Weil for the interview!

For Information:
Dürr Systems GmbH
Carl-Benz-Strasse 34
74321 Bietigheim-Bissingen, Germany
Tel. +49.7142.78 2614
Fax +49.7142.78 1600
E-mail: guenter.buzer@durr.com
www.durr.com