Robotic powder coating improves efficiency at Electrolux

Every second of every day in any year around the world, Electrolux sells two of its products. This requires state-of-the-art manufacturing facilities, such as the fully automated and flexible powder-coating facility for oven and grill cavities recently installed at Electrolux’s manufacturing plant in Dudley Park, South Australia.

Utilising four ABB six-axis robots to control powder-coating gun movement, the automated process ensures a consistent and superior high-gloss ceramic coating for over 2000 oven and grill cavities a day, and a coating material efficiency improvement of 10%.

The total investment in the powder-coating facility will be returned through savings within two years, and Electrolux has been able to achieve substantial energy savings of up to 15% when compared to the old production line process.

By using six-axis articulated robots rather than linear reciprocators, the system is also highly flexible and allows different types of cavities to be processed at any time, which is critical as the site manufactures over 120 different oven models. The new process was installed under the stewardship of Colin Thomas, manufacturing engineering coordinator of Electrolux Home Products and replaces an enamel flow-coating process that was very labour intensive.

“The benefits from deploying the robots were almost immediate. The automated powder-coating system replaces a wet enamel flow-coating process, where ovens and grill boxes were manually loaded onto a station that flooded the inside with wet enamel. Operators had to manually clear away the enamel from the interior before the oven cavity was sent through a drying oven. Following this, there was another manual spray station,” said Thomas.

“The ceramic powder-coating facility is unique and designed specifically to be fully flexible to suit our oven cavity fabrication methods. It provides all the automation benefits of other cavity-coating systems around the world, but does not sacrifice production flexibility.”

The new process consists of a four-stage ceramic powder-coating line in which different sized and orientated oven and grill cavities are suspended from a moving, overhead transfer conveyor. Four ABB IRB 2400 robots are fixed to an inverted support structure, equipped with a ceramic powder-coating nozzle system supplied by Nordson Australia. They operate in conjunction with the conveyor, which travels along at speeds of up to 3.2 metres per minute. This enables up to 240 items per hour to be coated and equates to a production rate of one item every 15 seconds.

At the identification station in the four-stage process, the robot’s IRC5 controller monitors the conveyor’s progress and distinguishes the orientation and differences in the oven cavities and grill boxes. This information is transferred to the Nordson supervisory controller via a Profibus network, which enables the appropriate powder gun setting to be selected for that particular item. The robotic arm moves itself to the precise position to apply the perfect powder pattern for a high-gloss enamel finish to the oven cavity or grill cavity.

This process ensures consistent quality for the coating operation, reduces waste and eliminates repetitive tasks for personnel. The entire system, including the tracking of the conveyor, item identification, robot arm motion and powder nozzle positioning is all facilitated by ABB’s Multimove software installed on the IRC5 controller.

The production level at the site now sees more than 1000 ovens and cookers roll into the packing room every day, fully tested and ready for delivery to the retail stores, and ultimately into the kitchens of Australian and New Zealand homes.

With ABB’s help, Electrolux has been able to achieve substantial energy savings of up to 15% when compared to the old production line process. The automated powder-coating solution not only saves energy by eliminating the need for the drying process. It also reduced water usage and is helping to increase productivity, achieve savings and improve health and safety in the workplace.

According to Colin, “Installing ABB’s robotics equipment on the new coating process has been instrumental in our sustainability success and made a huge contribution to the site’s achievement in reaching its emission reduction goals for the year.”