Atomizer Family Promotes Sustainable Production

Photo Credit: Dürr

Higher paint application efficiency reduces material, resources and energy consumption for a more sustainable production process. The EcoBell4 atomizer family from Dürr promotes sustainable production. The application technology achieves up to 98% efficiency for clearcoat application, the company says, reducing paint loss and rinsing agent consumption by 50% during color changes. When used in combination with the EcoProBooth modular paint booth concept, paint loss and rinsing agent consumption is said to be reduced up to 91%. The 4-main needle technology and process parameter changes make improvements for paint application possible. For clearcoat application, the Dürr atomizer is said to achieve application efficiencies of 95-98%, according to DIN EN 13966-1.

The system includes up to four main needles, which meets painting needs ranging from the 4x1C solution for base coats to the 3x2C solution for clearcoats. Dürr offers 10 versions of the EcoBell4, suitable for exterior and interior painting applications with direct or external charging. For the first time, the product family includes a basic version for standard applications and a pro version for special processes, such as 4x1C or 3x2C.

Dürr attributes the atomizer’s paint application efficiency to a variety of attributes. The speed and spray distance are reduced to improve the impact of the high voltage while maintaining a high paint flow rate. In addition, the shaping air is reduced to a minimum and the high-voltage control is adjusted.

Reducing the shaping air volume to a range of 90 and 200 standard liters per minute provides a gentler spray jet. Together with a reduced bell disk speed, energy consumption is reduced. Simultaneously, more paint reaches the body when the spray distance is decreased to approximately 100 mm. Two factors contribute to this effect. The first is a less dispersed spray pattern, and the second is an improved electrical field between the bell disk and body surface, which optimizes the utilization of electrostatic force via a constant voltage.

Consequently, the atomized paint more effectively reaches the body instead of being lost in the booth air. A paint outflow rate of up to 400 mL/min. can be obtained to meet the required layer thicknesses within the given cycle time. As a result, the EcoBell4 Pro Hu, which features direct charging, reaches up to 98% efficiency for clearcoat applications, according to Dürr.

The painting process is being tested for implementation in a concrete automotive paint shop in collaboration with interested OEMs. Existing systems have the potential for retrofitting, too.

Utilizing the EcoBell4 Pro E atomizers with external charging for exterior painting yields an efficiency boost for base coat application, elevating it from 75% to 78% compared with the predecessor model EcoBell3. The EcoBell4 Pro Ci atomizer for interior painting continues to obtain high efficiencies of up to 70%.

In addition to advancements in the painting process, technical developments in the design improve the quality. The EcoBell4 carries out color changes more quickly than any other high-speed rotary atomizer on the market, Dürr says. This is because the 4-main needle technology not only saves time but reduces paint and rinsing agent consumption, as well as VOC emissions.

Three of the four main needles are reserved exclusively for the most frequently used colors. All other colors go through the fourth main needle. Information from the automotive sector shows that more than 50% of auto bodies are painted in the three most frequently used colors. The technology uses this data, providing the three colors permanently via the main needles, which are located directly behind the bell disk.

When a color change is due, the system can switch to another main needle in a few seconds with no need to rinse and clean the channel. This reduces both paint loss and rinsing agent consumption associated with color changes. If a less frequently used color is requested, it can be primed via the fourth channel while one of the three other needles applies a main color. This means that each color is available for the next body within a short time frame.

Compared with the predecessor model EcoBell3 (1C), paint and rinsing agent consumption is reduced by 51% in the conventional line setup. This is good for the environment and minimizes process costs. As interior and exterior painting can be performed within a single booth, the color change times are shorter, but handling times are also lower when compared with the line concept.

The universal atomizer EcoBell4 Pro Ux is a well-suited match for the EcoProBooth and is suitable for interior, exterior and metallic painting applications. It utilizes a unified bell disk/shaping air ring system and an external charging system for all three painting tasks.

“This is a huge step. Our model calculations are based on a paint shop that uses 24 colors and coats 30 bodies an hour, 230 days a year on a three-shift basis. The amount of paint saved would be enough to paint an additional 15,600 bodies,” says Frank Herre, head of application technology development at Dürr.