Chesterfield, Mich. — BMI Injection Molding and Assembly has partnered with Wittmann Group by investing in its injection molding machines, robots, auxiliary equipment, software and controllers, which are all integrated, during the last two years.
BMI went from three injection molding machines to seven to outfit for a $5-million job from an automotive customer, Sam Holdsworth, director of operations and engineering at BMI, told Plastics News.
"Time was of the essence, so we had to find [a machine supplier] that had equipment [in stock]," Holdsworth said.
The company's purchasing initiative started during the COVID-19 pandemic, when some equipment makers had trouble meeting orders for injection presses — especially specific sizes or all-electric machines — or secondary equipment, such as robotics, he said.
Switching between different equipment brands on the floor can cause confusion among employees and takes time for a workforce to adjust to, Holdsworth said.
"I'm a big proponent of not mixing machines out in the plant so that our team members don't have to know numerous things," he said. Using mixed machines and secondary equipment "was clunky, especially when things didn't interface correctly, or you needed parts it just again. When it's all from one place … it just works."
With most of its sales in automotive, BMI is "always about process control," Holdsworth said. "the automotive buzzword is PPM, or parts per million. And you have to keep that as near zero as you can. You're always after the type of equipment that can speak to that."
BMI has automated much of its part removal, with Wittmann robots that "gently" extract parts from molds, which is essential when producing Class A surface automotive parts.
"Scratches or any part handling marring cannot be tolerated on these parts," Holdsworth said "They aren't brackets or under-the-hood components. When you sit in your car, you see these components. For a human to only touch them at the very end of the production process is beneficial to achieving the final quality."
Using the Wittmann system, BMI produces ISO FIX bezels featuring pad-printed images that identify child seat anchor points. It also makes seat adjustment handles, seat rail trim panels, body trim grommets and assorted interior, body and engine compartment fasteners.
"Some years ago, an ISO FIX standard was put in place requiring every tether point in a vehicle that accepts a child seat anchor be identified," Holdsworth explains. "When you were in your car and you could reach down between the seats and find this metal hoop, now that has to be identified and clearly visible. These bezels snap in certain areas, and that metal hoop is in the middle. We were initially decorating the parts with the words ISO FIX on them and eventually started molding them."
BMI's five-axis robots will present the two parts, the housing and cover, of the ISO FIX bezel to an assembly cell, where they are snapped together, pad printed and off loaded to a conveyor that goes to an operator who inspects and packages them.
BMI molds ISO FIX bezels in black, and a multitude of current automotive interior colors, BMI Operations Manager Scott Lehman, said in a news release.
"We have Wittmann Gravimax blenders that let us add colorant to the resin at prescribed ratios, because we have to adhere to a master color sample. That equipment is incorporated and works seamlessly within our 4.0 cell. If we didn't have the Wittmann blenders, then we'd be adding colorant in different ways that is much less accurate."
"That's what the [Wittmann] integrated 4.0 cell does," he added. "You know the quality of the resin pellets going in. You know all that's controlled and monitored, and you can see it all from one central point."
"You get SPC data, okay, across the machine interface that can be saved to their network," Colin Drewek, founder of Equipment Solutions of Michigan and Wittmann representative, told Plastics News. "That data is stored via the HMI and PLC and is driven through all of the auxiliary equipment and the robot to the injection molding machine to one point."
"It really does work, and the proof is when you walk out on the floor and you see all the green LEDs working in concert," Lehman said. "When one piece of equipment requires attention, it turns a different color indicating intervention is required. Once a process is developed for an application, the technology provides us the ability through the machine interface to call up the program that automatically populates all Wittmann equipment in the work cell with the correct process."
"If a certain piece of equipment is not correct for any reason the machine will not allow us to run without intervention from a lead technician or engineer."
Wittmann's 240XL cell "has really exceeded our expectations," Holdsworth said in the release. Wittmann's Industry 4.0 sets "streamline set up, and process monitoring ensures delivery of quality finished goods" and adds "an element of respect and organization to the manufacturing floor."
Wittmann's phone app for operators helps with accessibility to Wittmann team members, he added.
BMI's Wittman products on its manufacturing floor include the SmartPower 240XL (a 270 U.S. ton wide-platen) servo-hydraulic IMMs, the MacroPower 450XL (500 U.S. ton wide-platen) large-tonnage IMM and the five-axis robots with a new R9 controller.