Freudenberg Group: Clever solution in paint plants

Paint plants in the automotive industry are energy intensive and need considerable resources, particularly water. Freudenberg Filtration Technologies develops smart processes that eliminate H₂O and help industry and the environment.

A modern car paint plant is a little like a theater stage: Robotic arms work elegantly, buzzing around the chassis and spraying a fine mist of paint as it slowly glides through the room. A fully automated ballet shepherding one vehicle after the other with vigor and determination. It happens thousands of times a day in car factories all over the world.

A fascinating spectacle that uses a formidable amount of energy and resources - particularly water. For many decades, wet scrubbing systems were the first choice for removing excess paint from a plant’s air flow. Air is directed through the water and the water then helps separate the paint particles. They remain in the water and chemicals are used later to separate the particles from the water and to be disposed of as paint sludge. This is also expensive and time-consuming: For example, painting 1,500 vehicles produces up to three tons of paint sludge. But that is not all: The air circulating in the system - 10 percent of which is usually fresh air - and the reused water are treated with antifungal and antibacterial chemicals to inhibit microbial growth.

This effort is increasingly problematic for automotive manufacturers and suppliers, as the ecological footprint for water-based processes is high - too high for the ambitious political and industrial goals of reducing energy and resource consumption in production. “To minimize the long-term footprint, we developed products, know-how and services that use a dry process to separate the paint,” says Jürgen Becker, Head of Surface Technology at Freudenberg Filtration Technologies. “Waste, energy consumption, emissions and water consumption can then be significantly reduced.”

A modern car paint plant is a little like a theater stage: Robotic arms work elegantly, buzzing around the chassis and spraying a fine mist of paint as it slowly glides through the room. A fully automated ballet shepherding one vehicle after the other with vigor and determination. It happens thousands of times a day in car factories all over the world.

Edrizzi carton boxes are placed under the floor of the paint line where they collect the paint.

A fascinating spectacle that uses a formidable amount of energy and resources - particularly water. For many decades, wet scrubbing systems were the first choice for removing excess paint from a plant’s air flow. Air is directed through the water and the water then helps separate the paint particles. They remain in the water and chemicals are used later to separate the particles from the water and to be disposed of as paint sludge. This is also expensive and time-consuming: For example, painting 1,500 vehicles produces up to three tons of paint sludge. But that is not all: The air circulating in the system - 10 percent of which is usually fresh air - and the reused water are treated with antifungal and antibacterial chemicals to inhibit microbial growth.

This effort is increasingly problematic for automotive manufacturers and suppliers, as the ecological footprint for water-based processes is high - too high for the ambitious political and industrial goals of reducing energy and resource consumption in production. “To minimize the long-term footprint, we developed products, know-how and services that use a dry process to separate the paint,” says Jürgen Becker, Head of Surface Technology at Freudenberg Filtration Technologies. “Waste, energy consumption, emissions and water consumption can then be significantly reduced.”

Recycled cardboard and nano-coatings

Freudenberg is focusing on two technical innovations in this area. One is the Edrizzi Separator System. It has been a patented concept for paint separation since 2003 and Freudenberg holds the exclusive worldwide distribution rights. The basis is a handy cube made of recycled cardboard. Dozens of these cardboard boxes are placed in the floor of the paint line. Low pressure directs the paint mist into the branched system of cardboard edges and openings, which have a very large absorption capacity due to their ingenious folded design. Once the cavities of the boxes are filled with enough paint, they are replaced and burned, generating power.

By comparison: The Edrizzi Separator System with collected paint and before use in the paint plant.

“The system is very effective and popular in the industry,” says Jürgen Becker. In China alone, seven local car manufacturers rely on the clever cardboard boxes. A German premium car manufacturer is now installing them in its new Moscow plant. “The system is designed so that the cartons are changed weekly, making three continuous shifts possible on weekdays.”

Recycled cardboard and nano-coatings

Freudenberg is focusing on two technical innovations in this area. One is the Edrizzi Separator System. It has been a patented concept for paint separation since 2003 and Freudenberg holds the exclusive worldwide distribution rights. The basis is a handy cube made of recycled cardboard. Dozens of these cardboard boxes are placed in the floor of the paint line. Low pressure directs the paint mist into the branched system of cardboard edges and openings, which have a very large absorption capacity due to their ingenious folded design. Once the cavities of the boxes are filled with enough paint, they are replaced and burned, generating power.

“The system is very effective and popular in the industry,” says Jürgen Becker. In China alone, seven local car manufacturers rely on the clever cardboard boxes. A German premium car manufacturer is now installing them in its new Moscow plant. “The system is designed so that the cartons are changed weekly, making three continuous shifts possible on weekdays.”

Viledon DryPleat nano filter plate technology

Viledon DryPleat nano filter plate technology is another dry separation technology and Freudenberg Performance Materials played a key role in developing its filter media. These are the only filter media in the world that use nanofiber technology in painting systems. The high-tech application makes sense because the plates achieve extraordinary filtration performance in limestone dry separation plants: The wet paint mist is mixed with fine-powdered limestone in the plant’s exhaust air stream. The dust adheres to the plate surface, which has a very low air flow resistance thanks to the nano-coating. A dry dust cake then forms on the exterior and compressed air from the interior of the plate regularly detaches the dust cake. The nano-coating makes it uniquely simple and energy saving. The dust cake falls downwards against the air stream, is collected and later disposed of. “Compared to conventional sintered plastic plates, nano filter plates can reduce energy consumption by up to 50 percent” says Becker.

two filter plates — Viledon DryPleat nano filter plates collect the dust that results from mixing paint mist with limestone.

Consultation and service from the start

Freudenberg uses the new technologies and processes worldwide in close cooperation with plant manufacturers - e.g. Geico Taiki-Sha - either for new installations or by retrofitting existing water systems to dry ones. "Nearly 80 percent of all new car manufacturing paint plants now use dry systems," estimates Jürgen Becker. There is also a stable positive trend for retrofitting. Freudenberg's sales, filtration technology and development teams have done a lot of informing and persuading. After all, factories are hesitant to abandon the painting processes they have used for decades.

So, Freudenberg specialists work closely with their customers from the start and support all stages of the retrofitting process. They study the technical requirements, processes and logistics on site. They measure, test, advise and find the best design for all the components in a paint line. And even afterwards, the cooperation continues, says Jürgen Becker, because there is still much that can be optimized on the factory floor. “Our service teams are always ready to provide assistance during production, even daily if required.”