When chemical company BASF’s Performance Materials division wanted to develop a prototype for a new part over 10 feet in size, it knew compression molding would be the ideal production method. A compression molding press has the potential to support a fully-automated manufacturing process within a customer’s plant. But BASF pondered how to get an entirely new component ready for full-scale testing and validation without a customer risking the expense of an unproven technology.
“We first approached this as chemists. We have extensive knowledge about process and application, but making prototypes this big presented issues,” explains Staci Wegener, market segment manager of infrastructure at BASF Corporation. Wegener isn’t able to reveal too many details about the unique part under development, but did share that its size would have been a hindrance without the support of IACMI – The Composites Institute’s Scale-Up Research Facility (SURF) in Detroit, which conducts research and development on lightweighting vehicle structures and is managed by Michigan State University (MSU).
“We explored other options where we could make a prototype, but the size of the press that SURF has in their facility is really unique,” says Wegener. “I don’t think there are too many presses of that size available for this sort of application.”
The machine Wegener is referring to is a 4,000-ton hydraulic compression molding press from Schuler, which can perform closed mold infusion and thermoplastic forming in addition to compression molding. The press employs four double-acting cylinders to provide greater parallelism control for improved surface features, helping to ensure high-quality manufactured parts. Equally as important for BASF’s application, the press features a clamping surface of 142 x 94 inches and a daylight of over 8 feet for larger applications.
“SURF is helping us scale up from lab-scale-size parts to full-scale prototypes without us investing millions of dollars investment into true technology production equipment,” says Wegener. “This will speed up the path to commercialization.”
Filling a Gap
The 50,000-square-foot SURF is the only facility of its kind in the United States, and the team behind it has worked to quickly establish an operation that can match the decades of production experience behind overseas research centers. The vision for an innovation center of this type in the U.S. has been around since at least the early 2000s, when automotive industry researchers began looking for space to work on full-scale product development and testing. With support from the U.S. Department of Energy Advanced Manufacturing and Vehicle Technologies Offices, the Michigan Economic Development Corp. and a number of industry partners, SURF was born and research officially began in 2016.
“We were trying to fill a gap when we created the vision,” says Ray Boeman, director for IACMI Vehicles Scale-Up Facility and a professor at MSU. “Companies could do basic research at universities or national laboratories with non-production scale equipment. But if you’re a material provider, you’re developing material you want to sell to an OEM, and you want to take them a full-scale part.” Having a facility where companies can innovate before investing in expensive capital for development allows for greater freedom in innovation and helps OEMs make more informed commercialization decisions.
The facility offers a range of manufacturing technologies, which companies find bridge the gap between research and commercialization. The ability of the compression press to achieve high-volume production levels and ensure strong thermal stability for parts is proving particularly critical for automotive applications.
“People flip between compression and injection molding as the two workhorses,” notes Patrick Blanchard, technical leader for lightweight materials at Ford Motor Co. Ford was one of the early partners behind SURF’s launch. The company began collaborating in 2012 with material supplier DowAska, a 50/50 joint venture between The Dow Chemical Company and Aksa Akrilik Kimya Sanayii A.S. The goal was to develop viable, high-volume manufacturing techniques using DowAska’s automotive-grade carbon fiber engineered molding compound (EMC) to drive more cost-effective lightweight solutions for replacing steel in structural vehicle parts. In 2015, project managers began making plans to move to SURF, which would offer the technology capabilities to accelerate that joint research when it officially opened the following year.
The project addressed improvements at each step of the compression molding process to ensure the EMC material would be compatible with conventional high-volume sheet molding compound (SMC) manufacturing methods – notably, compression molding. Among other areas, the team examined chemistry reaction speed, resin impregnation into fiber, sheet fiber orientation and strategies for translating the sheet fiber orientation into the molded part fiber orientation. With SURF’s help, the Ford team developed a vehicle liftgate as a demonstration project and performed the full-scale validation testing required to introduce the EMC material onto a Ford vehicle.
Together, Ford, Dow, DowAska and SURF determined the EMC material offered a threefold increase in elastic modulus compared to typical glass-based SMC materials. That resulting increase in stiffness meant the materials would be able to maintain section properties within the constraints of the existing part engineering standards. The result, the team found, was an ability to balance the design freedom available with compression molding, while gaining the high-volume application of a premium reinforcement fiber.
The project ended in late 2019, with the component now vetted for future validation testing within Ford vehicles.
Achieving a Class A Finish
Volkswagen Group of America (VWGoA), another founding member of IACMI, has also worked to rethink its liftgate in composites. According to Hendrik Mainka, project manager at the Volkswagen Group Innovation Hub in Knoxville, Tenn., steel liftgates tend to incorporate a significant number of small components. Producing these using composite materials presents an opportunity to reduce complexity. Fewer parts mean less tooling, which reduces the overall cost.
In 2016, the OEM kicked off a project at SURF to lightweight the liftgate for the Volkswagen Atlas by 30% compared to its existing steel solution. “Our goal was to produce lightweight composite liftgate prototypes for the Volkswagen Atlas in a production-like setting – and we did it successfully in summer 2019 at SURF,” Mainka says.
Through the use of SMC, researchers were able to produce an outer panel with a Class A surface finish and structural inner panels for the liftgate, which were then bonded together to simplify future assembly.
That Class A surface was a significant achievement for VWGoA. Anti-corrosive electrically applied paint coatings (e-coats) are applied to steel car bodies on a standard manufacturing line. In the past, composite surfaces have required a separate, off-line painting process, which slows overall production rates.
VWGoA’s goal was to develop a composite material compatible with e-coats. The team selected SMC because, in addition to its lightweighting potential, the researchers recognized that the material’s excellent thermal stability offered the greatest potential to handle the high temperatures of e-coat paint ovens.