Robots improve blower fan wheel production

Way back in 1962, GI Plastek patented the first-ever molded plastic blower fan wheel. Its pioneering metal-to-plastics conversion has grown to include more than 100 different designs. More than 150 million blower wheels have been produced in a wide variety of filled thermoplastics at its injection molding plants in Marysville and Bellville, OH (40 molding machines in total). Today, this diversified, resource-rich, $57+ million company is finding that robotic parts removal can add value to its blower wheel fan production lines by improving consistency and quality. Robots have helped reduce internal scrap, and even as an old hand at using plastics processing equipment, GI Plastek was surprised at the quick return on its investment in automation.

Though frequently used in a number of appliance, automotive, heavy truck, agricultural, and industrial applications, blower fan wheels are seen less frequently because they are usually internal components. They look fairly uncomplicated, but in reality, like many parts, they pose demanding molding challenges. There's a critical need for consistency in conforming to exacting standards for precision balance. When in balance, a blower fan wheel prevents power losses and reduces noise and vibrations, thereby adding value to OEM assemblies. Over the years, GI Plastek has invested heavily in improving its engineering resources and has fine-tuned its process consistency to ensure balanced, uniform fill and minimal molded-in stress -essential factors in achieving peak part performance. However, something was missing.

John Barrett, GI Plastek's injection business unit's sales and engineering manager, admits his company was upset over its internal scrap levels, which were up around 4.5 percent. Of course, no defects were shipped. Both hands-on inspection and failure-modes-and-effects analysis saw to it that shipped parts met customer specs. But still, defects were a problem. Reduced vibration and lower noise were becoming ever more important to its customers, and GI Plastek needed to maximize its process consistency. Luckily, one of its customers was Ford Motor Co.

"Our CPI [continuous process improvement] program includes our customers," Barrett explains. "A task force with representatives from Ford spent about a week walking through our processes and identifying areas where we could improve costs and improve quality. They suggested we look at using robots for parts removal. We'd never used them before. We started our investigations, singling out speed and repeatability as critical factors." GI Plastek selected U.S.-made Eagle servorobots from Mark II Automation (Germantown, WI). Six were installed last year, and two more are coming this year. "We'll keep going with them, wherever we feel they are justified."

Why? The robots stabilized cycle times for one thing, which helps improve consistency, and they're smart enough to do in-line scrap removal, if required. Internal scrap has been reduced from 4.5 percent down to about 3.9 percent, and further improvements are expected. As mentioned, the quick payback on its robots surprised the company. Payback was originally expected in 18 months. In actuality, it was seen in 13 months. "The robots met or exceeded our expectations. I can't really quantify our customers' reactions to our improved quality, though. After all, they haven't seen anything different," Barrett says.

Nevertheless, GI Plastek has maintained a Q1 rating from Ford and expects its improvements will help in other areas. It expects to achieve ISO 9002 certification in third quarter 1998, for instance. And to further improve process consistency, the company has centralized materials handling and drying systems in Bellville, in addition to machine upgrades and more robots. For more on GI Plastek, check out its website at www.giplastek.com.