Innovation in atomizer cleaning
Bietigheim-Bissingen, September 2015 – Dürr's new EcoBell Cleaner D2 offers a fully automated solution for cleaning atomizers. It reduces solvent use for each cleaning cycle to just 50 ml, from a previous 500 ml. In addition, the EcoBell Cleaner D2 meets stringent requirements for short cycle times.
Failure to remove overspray from the atomizer exterior will result in residual build-up. This build-up can then be blown onto the vehicle body by the atomizer’s shaping air—resulting in paint finish defects. Thorough, timely cleaning of the overspray prevents this costly result. Cleaning frequency depends on both the paint system and the painting scope; sometimes cleaning is required after 15 vehicle bodies are painted, sometimes cleaning must be as frequent as after every paint cycle. The use of fast drying paint also has an effect on atomizer cleaning; as paint dries faster, more frequent cleaning is required.
But, it is not just the atomizer exterior that must be cleaned; during color changes, the paint channels inside the atomizer must also be rinsed. The EcoBell Cleaner D2’s greatest strength is that it can simultaneously perform both external cleaning and internal rinsing. Cleaning takes just 15 seconds to complete (half the time it took the previous EcoBell Cleaner D) and occurs during the normally unproductive paint load-time—true time efficiency at work!
Solvent use is reduced, too. The EcoBell Cleaner D2 sets a new standard because it requires no more than 50 ml per cleaning cycle. The previous model used more than ten times that amount. Implementation of specially designed, precisely located, rotating cleaning nozzles is the main reason for reduced solvent use. These nozzles emit compressed air, pushing the solvent out through a thin, coaxial hose. The action of the compressed air creates a strong cleaning pulse, despite the low solvent pressure.
No residual moisture problems
Dürr performed rigorous testing to determine precisely how many nozzles are needed to achieve thorough, uniform cleaning. The result? It requires only three nozzles, because the atomizer rotates 60° during the cleaning process. Once the atomizer leaves the EcoBell Cleaner D2, its surface is then dried with a blower ring. This ensures that there is no residual moisture to cause problems during electrostatic paint application.
When using 1K paint, the paint/solvent waste is collected in a tank in the EcoBell Cleaner D2. Compressed air then pushes the waste out of the paint booth through a return hose. Similarly, the atomizer’s inner channels are cleaned with solvent, and then compressed air pushes the paint/solvent waste out through the return hose. For 2K paint, the resulting waste cannot go into a tank because 2K waste dries faster and can clog both the tank and the return hose; instead, the 2K waste is sent into a rinsed hopper at the base of the booth.
For both 1K and 2K paints, proper paint waste disposal is essential to prevent VOCs from entering the booth air. Reducing VOC emissions is a key environmental goal of the Dürr painting process—a goal supported by the innovative EcoBell Cleaner D2.
The EcoBell Cleaner D2 is available for all atomizers in the EcoBell3 family. A model for EcoBell2 atomizers is expected in 2016.