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PRODUCTS FINISHING — pfonline.com 25 TECHNOLOGY-DRIVEN POWDER SYSTEM robots, each fitted with dual Encore HD guns. Color changes are performed in an Encore HD Excel feed center. Due to the large size of the parts being coated, line speed is 4 fpm. The film build thickness requirement is anywhere from 2 to 6 mils, depending on the part being coated. Encore HD guns and pumps are ideal for robot systems as they apply higher volumes of powder at a lower velocity than a conventional venturi pump. Additionally, because of the low velocity, the gun-to-part distance can be greatly reduced. These features are critical to reducing the overall cycle time required to coat the part. With Encore HD and the reduced gun-to-part distance, the robot program requires less articula- tion of the gun and therefore a lower cycle time. "Simply by changing the angle of the Encore HD gun and reprogramming the robot, we were able to cut the overall cycle time in half as compared to the original program developed at start-up," says Dave Goodman, Miller Welding employee and resident robot programmer. Goodman's extensive experience programming robots, including Yaskawa, Motoman and FANUC, provides Miller Welding with the expertise to achieve the highest capabilities of its process machines. Quick Coatings "The Nordson powder coating systems coat so quickly that parts are coated faster than they can be unloaded," he says. The second of the two Nordson ColorMax systems contains 12 Encore automatic guns on two oscillators with in/out positioners, and two Encore LT manual guns. All of the guns are fed from an Encore powder feed center. Due to the large size of the parts, the ColorMax systems at Miller Welding were custom built to accom- modate larger than usual part openings. Color change time takes a bit longer than normal, roughly 13-15 minutes, which is still very fast consid- ering the size of the systems. Miller Welding runs two shifts per day, five days per week. "We have about thirty colors in total and do about 5-10 color changes per shift," says Mike Repine, paint line manager. Herr Industrial in Lititz, Pennsylvania, provided the process equipment for the systems at Miller Welding. A power and free conveyor carries parts to be coated through an eight-wheel auto blaster followed by a five-stage washer. The parts then enter the dry-off oven before entering the Nordson ColorMax systems for powder coating. After powder coating, the parts cure in one of two gas convection ovens. Large, Heavy, Metal Fabrications "Part identification is done through a bar code reader," says Kenny Lindermuth, a Miller Welding employee. "It allows us to know where the part is located in the process line at any given time," Miller Welding is not making tiny widgets that can be easily processed. The company produces large, heavy, metal fabrications that are complex in shape and extremely diffi- cult to process. "The employees make it appear easy and almost effortless," says Nordson's Binder. "Processes run like clockwork and every step is meticulously monitored. If anyone thinks that 'Made in America' is a dying notion or thing of the past, then they've not visited Miller Welding. "Each and every Miller Welding employee I spoke with had excellent knowledge of the production processes and equip- ment within the facility. Quality at its highest possible level is a core value that every employee appeared to share." For information on Miller Welding and Machine Co., visit millerwelding.com. For information on Nordson, call 800-433-9319. Information for this story provided by Nordson Corp. Robots fitted with dual Encore HD automatic guns coat a part in the first ColorMax system.