Germany’s Durr has developed a new technique that applies paints over large areas or in simple patterns with high edge definition – and absolutely no overspray. The innovative EcoPaintJet applicator won this year’s innovation award ‘Deutscher Innovationspreis’ in Germany, and is now available for the general industry in an easily integrated set. Paint company Adler has developed paints tailored to the new application technology.
In woodworking, shipbuilding, electronics manufacturing, and many other industry sectors, product and component surfaces are coated to protect them or add colour. This previously involved a great deal of effort if the coating had to be applied with high edge definition since the surfaces either need to be manually masked or film-wrapped. There is also a significant amount of waste, both in terms of adhesive tape and paint loss due to overspray. According to Durr, with the new overspray-free application set, both of these challenges are a thing of the past. EcoPaintJet, the innovative applicator contained in the set, is already successfully in use in automotive series production. Since 2019, the new Dürr technology has made it possible to paint car roofs in contrasting colours with no masking.
More options for painting
The EcoPaintJet applicator delivers precise coating with no overspray. This increases coating efficiency and offers companies more options when it comes to product design and the transportation of goods. Instead of adhesive film, decorative surfaces can be protected for transport through the targeted application of a spray film. This can be simply pulled off again at the destination.
The technology also enables new options for the function and design of products. For example, the precise coating method means that window frames can have a weatherproof coating applied to the outside and get a decorative or differently colored application on the inside. Decorative effects can be easily realized on furniture fronts. “The overspray-free application set enables application with high edge definition, fast colour changes, and a custom surface design,” says Holger Beiersdorfer, vice-president – Industrial Products at Dürr, in summarizing the benefits.
No atomizer air required
The most important component in the overspray-free application set is the paint supply, combined with the cleaning and pre-painting process. The EcoPaintJet controls this using three valves. The heart of the applicator itself is a nozzle plate that produces several dozen parallel paint jets depending on the design. These can be activated or deactivated at any given moment to start or interrupt the coating process.
Unlike painting processes involving spray guns or high-speed rotary atomizers, this process does not require any atomizer air. The overspray that must be filtered from the booth air in a complex process when using conventional methods therefore does not occur.
Another big difference compared with classic atomisers is that the width of the painting path can be adjusted by means of the applicator’s angle of application. This enables a painting path from 30 to 50 mm in width. Narrower path widths can also be produced by adapting the nozzle plate. The desired coating thickness is controlled via the applicator speed and solid content of the paint.
Multiple benefits with single application
Application techniques that save paint are particularly important when dealing with large surfaces. Even with airless guns or high-speed rotary atomizers, up to a fourth of the material is lost. Recovering this paint is both time-consuming and energy-intensive, and only works with certain paint types. The so-called pouring technique, where the excess paint is collected in tanks, avoids overspray but does not permit fast colour changes. Other surface design options such as applying films or decorative strips often mean a high level of manual effort.
The new Dürr technology eliminates all the disadvantages of the individual methods and makes painting faster, more cost-efficient, and more environmentally friendly in all industry sectors. “This makes our technology attractive even in scenarios where an automated painting method was not previously conceivable,” says Holger Beiersdorfer, hinting at other application possibilities.
Together with Dürr, the Austrian paint manufacturer Adler is promoting the new application technology by developing colorless and pigmented coating solutions that, in addition to the usual paint requirements, are precisely tailored to the special features of this technology. “For this visionary application technology, we developed innovative and environmentally friendly, water-based products that deliver maximum durability and at the same time visual individuality for more than just sheet material,” says Dr. Albert Rössler, CTO at Adler.