Aluminum is continuing to gain ground in selected high-volume injection mold tooling, with General Motors Co. now launching its first parts using the lightweight material.
Detroit-based GM uses aluminum for a map pocket for the Chevrolet Volt, said David Okonski, manager of the research and development engineering lab, during the Society of Plastics Engineers' Automotive Thermoplastic Polyolefins conference, held Oct. 5 in Troy.
Aluminum is already planned for more parts, he said — which is just part of the auto industry's increased focus on tapping into tooling expertise to improve production.
“I think what we're finding is, aluminum aside, [automakers] have all made comments that there's a big advantage of being partners with a tool shop,” said Darcy King, president of Unique Tool & Gauge Inc. “Tool shops can bring a lot to the table in terms of being cheaper, bigger and faster in production.”
Unique, based in Windsor, Ontario, helped launch the current emphasis on aluminum tooling for high-volume auto production when it worked with Honda Motor Co. Ltd. to make molds for injection molded interior parts for the Accord sedan in 2008.
Unique also built the aluminum mold used on the Volt map pocket.
Ford Motor Co. has also spoken about its use of aluminum, and notes that technology migration is continuing. Other automakers are developing or producing a number of parts.
A variety of molders are also developing aluminum for production parts.
“Some are further advanced, some are just getting into it, but there's real movement,” King said.
Detroit-based GM first began extensive research into aluminum three years ago, after hearing of the success taking place elsewhere in the industry. Like other automakers, it focused on molds made with recently commercialized aluminum alloys that can compete with industry standard P-20 steel, Okonski said.
It focused on parts made with unfilled polyolefins, especially TPO, he said. From the start, GM wanted to see for itself if aluminum could offer real benefits, including faster production time for toolmakers and improved cycle time for molders — thanks to aluminum's ability to heat and cool molds more quickly than steel but without losing part quality.
Successful testing represents a lot of potential business. Okonski noted there are 450 plastic parts on the average vehicle, and 135 of them potentially could be made using aluminum molds.
But GM, like other automakers, is cautious about moving too quickly. The standard GM tooling requirements call for a mold that can stand up to 1 million shots, Okonski said. Aluminum traditionally is qualified far below that, though King noted one aluminum mold Unique produced had made 1.7 million parts as of June.
It is not surprising that automakers and molders are cautious, King said. No one wants to be the person responsible for a part that fails or a tool that needs frequent repairs and potentially shuts down production for an entire supply chain. That is why Unique and other mold makers are prepared to invest in long development times.
Before it began production, GM set up development labs and protocols in its research and development engineering group, Okonski said. He developed test parts and had molds made in both steel and aluminum and ran parts in its lab so GM could do side-by-side tests on cycle times, shrinkage, rigidity, tensile strength, impact strength and other key data points.
Once the automaker had all the results — including proof that there was no statistical performance change in most tests and a 15 percent improvement on cycle time for its test parts — GM moved forward with the Volt part. It now has aluminum tooling in development on additional parts.
“Aluminum's still new, so we have to go through all these steps,” King said. “Once they feel comfortable with that and they see all the benefits, that's when things grow.”
Aluminum tooling is just part of a new movement in the auto industry that is drawing on technology from tool shops to benefit the entire production process. That is a big change from the not-too-distant past when cost drove more and more mold making to low-cost countries. Price still plays a role, but so does technology.
Honda reached out to mold makers more than five years ago, with long-term pacts with a handful of firms to encourage breakthrough technology. Unique Tool was one of the first firms selected, and that relationship helped lead to Honda adopting aluminum for its parts.
Now other automakers are developing closer bonds with toolmakers, even as business builds steadily for traditional work.
“With things being as busy as they are, it's easier to stay with the status quo, but I haven't seen that happening now,” King said.
Unique has worked closely with electric carmaker Tesla Motors Inc. of Palo Alto, Calif., for aluminum tooling for parts on its new sedan, but even old-school firms are doing more. Ford in Dearborn, Mich., touted the success of tooling innovations for a Focus liftgate grab handle — a finalist in the Society of Plastics Engineers' Automotive Innovation Award.
Ford tooling specialists developed four-piece sliders; the company has a patent pending for the tooling innovation. Ford worked with mold makers in Spain, Canada and China to build the tools.
The mold lets the molder create the 360-degree, grab-handle assembly as part of the liftgate trim, cutting part costs, weight and the number of tools required.
Ford optimized tooling for its use of Woburn, Mass.-based Trexel Inc.'s MuCell process in the instrument panel for the Escape and Kuga sport-utility vehicles, creating specific tooling guidelines for Ford parts using MuCell.
Recognizing toolmakers' expertise can help mold makers increase their business, especially in a recovering auto industry.
Unique Tool, for instance, has boosted employment to 90 workers from 65 in the past year and King said the firm has been “overwhelmed” with work, both for steel and aluminum molds. The company recently expanded its product reach when it acquired Gauge Rite Inc., another Windsor-based firm, which makes gauges and fixtures.
“All the [automakers] and molders are more involved in what we're doing,” he said. “And once they get more involved, they're starting to see a lot of synergies.”