Automated water-based paint application: high efficiency in interior painting
Bietigheim-Bissingen, November 2015 – The compact EcoBell3 Ci atomizer is used in automated interior painting with water-based paints without the need for complex voltage block systems. It impresses with its low VOC emissions and high productivity when used in conjunction with the color changer, dosing pump and cleaning unit. Depending on the production volume and equipment of an interior painting zone, this system can yield savings of up to one million euros per year by reducing paint loss and cleaning agent consumption.
Water-based paints contain few organic solvents and are therefore very environmentally friendly. In addition, they are known to be durable and produce an impeccable finish. They are used in vehicle painting around the world.
High-speed rotating atomizers with electrostatic paint charging ensure that the water-based paint is applied efficiently and evenly. This process, which keeps overspray losses to a minimum, has now also been adapted for optimal use in interior painting. For this purpose, Dürr has expanded its product family by adding the compact EcoBell3 Ci high-speed rotating atomizer.
The cleaning unit, color changer and dosing pump have also been optimized, together with the atomizer, to create a complete system for use in interior painting. Compared to other common application systems, Dürr's automated interior painting process significantly reduces not only paint loss but also the consumption of cleaning agent.
EcoBell3 Ci optimized for interior painting
To reduce material usage in paint application, Dürr started by optimizing the bell disk with the shaping air ring system for the EcoBell3 high-speed rotating atomizer. The position of the electrode ring was changed at the same time. Thereby the spray jet can be aligned in the vehicle interior, thus visibly reducing overspray and self-contamination. Furthermore this adjustment creates a noticeably compact shape, which makes the interior surfaces of the vehicle body easy to reach.
Without the need for complex voltage block systems, the atomizer can apply the water-based paint with much greater efficiency, achieving top-quality results. The EcoBell Cleaner D2 cleans the atomizer within the usual cycle time. Changing color and cleaning the paint channels in the atomizer’s interior take place simultaneously, allowing the system to begin painting the next vehicle body after as little as 15 seconds.
Reduced VOC emissions
At no more than 50 milliliters per cleaning process, the cleaning agent consumption of the EcoBell Cleaner D2 is 500 ml lower than that of its predecessor. The clear coat line uses solvents as cleaning agents, reducing VOC emissions by up to 500 ml per cleaning process. In base coat applications, the EcoBell Cleaner D2 also achieves VOC reductions, which correspond to the percentage of solvent in the cleaning agent (approx. 10 percent). The color changer and dosing pump, which are completely integrated into the second robot arm, also ensure high productivity in the fully automated interior painting process.
A look at the EcoLCC2 color changer in the opened robot arm.
The EcoLCC2 color changer enables quick color changes (<10 seconds) while keeping paint loss to a minimum (approx. 10 ml). It activates individual colors by docking onto the relevant paint valve. As each of the 36 available colors has a separate connection to the paint carriage, there is no cross-contamination of colors. The paint hose connecting the EcoPump9 dosing pump to the atomizer is equally short for all colors, which substantially reduces paint loss during color changes. Despite this design, the robot arm remains flat and can reach all areas inside the vehicle body. The simplicity of the system, which only needs a total of five pneumatic valves to control all the colors of the color changer, lowers servicing and maintenance costs in the long term.
The Dürr system’s simple design of electrostatic exterior charging does not require any additional installations in the booth wall. In addition, there is no need for complex pigging technologies, docking systems, canister technologies or dosing cylinders for voltage block systems mounted on the atomizer arm. This simplicity also enables plant operators with little experience in automated painting to use electrostatic water-based paint application in interior painting.