Utilising four ABB six-axis robots to control powder coating gun movement, the new 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 percent. The total investment in the powder coating facility will be returned through savings within two years.
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 co-ordinator of Electrolux Home Products and replaces an enamel flow-coating process that was very labour intensive.
According to Colin Thomas: “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.
“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,” said Colin.
Automated oven cavity enamelling process
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 six-axis 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 per 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, complete with powder gun mounted, 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. It is a well composed symphony that relies on ABB’s IRC5 programmable controller to command and synchronise the performance, in much the same way as a conductor instructs the string, brass and woodwind sections of an orchestra. Working in harmony, 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 oven and cookers production level at the site now sees more than 1000 units 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.
However, production volume is not the only measure of success at Electrolux. They have also integrated sustainability into all aspects of their operations, from performance improvements in their new Eco Range of products to factory emissions reduction targets of 15 percent by year end 2012.
With ABB’s help, Electrolux has been able to achieve substantial energy savings of up to 15 percent 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 the 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.”
Colin added: ”We have been very pleased with the performance of the robots, and perhaps even more importantly, happy with the support and the service that ABB provides. The confidence gained from dealing with them has led us to place another order for an assembly cell solution with Andrew Donald Design Engineers, an authorised ABB Robotics Partner.
“Staying competitive in Australia’s manufacturing sector means continually seeking improvements in quality, productivity, flexibility and efficiency. The Adelaide site operates at world class standards and is turning out quality ovens and cookers that have an enhanced high gloss enamel finish - which are smoother and easier-to-clean," Colin said. "ABB’s robots and automation solutions helped achieve this."