Powder coating system for electrical enclosures and control cabinets

With a new powder coating system, electrical enclosures, control cabinets and housings for electrical components can be coated in an energy-efficient, automated and flexible manner. It can process all common powder coatings.

As part of its current major project, the new building at the company's headquarters, Häwa GmbH, manufacturer of enclosure and housing systems, has commissioned the new powder coating system as a first step. In terms of energy efficiency, automation and flexibility, the system sets standards and makes the company future-proof for many years to come. Häwa's brand new powder coating system occupies an entire hall in the Swabian town of Wain. Company boss Arno Müller is not without pride: "The system meets the very latest standards, sets benchmarks in practically every relevant category and is an enormously important innovation for both our employees and our customers."

Häwa relies on a six-zone pre-treatment process in which a modern zirconium nanopassivation, made from high-quality V4A, is used. The technology used is phosphate-free, which minimizes waste water problems and still meets high corrosion protection standards. The highlight of the pre-treatment is a rotary blower: this blows off adhesive water particularly efficiently, which minimizes the drying requirements in the actual adhesive water dryer. Thanks to a cooperation with the neighboring Baur timber plant, Häwa also uses the partner's waste wood combustion to use renewable energy for pre-treatment. In addition to the ecological benefits, this also reduces the company's dependence on fossil fuels, which emit CO2, and creates regional added value.

The actual powder application takes place in two identical powder booths, which are specially designed for a wide range of variants. One of the booths is already equipped with a robot that takes care of pre-coating and corner coating, while the second can be retrofitted at any time. The robot is programmed using VR tracking, in which the movements are specified and saved by an experienced employee. This enables flexible adaptation to the sometimes complex workpieces.

The powder booths are designed with individually controllable infeed axes for precise coating of large product surfaces and therefore achieve an extremely high degree of automation. Häwa processes all common powder coatings available on the market and thus meets the requirements of various customer standards. "Four to five color changes a day are normal for us," explains Managing Director Arno Müller. The painting system supports this with a color change system that works independently for each booth. The automatic control system guarantees homogeneous color distribution. Special paints, such as ESD paints, are also used. The company also uses multi-layer powder coatings if, for example, the control cabinet is likely to be exposed to high levels of environmental pollution. A manual booth is also available for the manual powder coating of special jobs and reworking.

Häwa traditionally relies on natural gas for its oven technology. "At 95 degrees Celsius, the temperatures from the wood heating network are too low for the stove. Gas is therefore currently still the most economical solution," explains Müller. In order to use as little natural gas as possible, the curing oven and adhesive water dryer are divided into different temperature zones. The plant is designed in such a way that it can be converted to hydrogen in the long term. From 2030, the local energy supplier is planning a model project with hydrogen in the region, which should also have an impact on Häwa. Heat recovery also contributes to efficiency. After the curing oven, the products release their excess heat into a specially encapsulated area that runs parallel to the adhesive water dryer for around 40 meters. The energy is used to heat it up. Parts that used to come out of the curing oven at 160 degrees now leave the oven area at around 110 degrees and can therefore be processed more quickly. "All in all, we have almost halved the primary energy requirement," explains Managing Director Müller. (OM-5/25)