Taking the global lead on composites
Teijin Automotive Technologies was awarded the Society of Plastics Engineers (SPE) Automotive Composites Conference & Exhibition (ACCE) People’s Choice Award in 2022 for their latest multi-material battery enclosure. The enclosure, a one-piece cover and one-piece tray, is used in electric vehicles. It includes multiple innovations, some with patents pending, in assembly and fastening methods as well as advancements in structure and safety.
This new product, however, is only one step on Teijin Automotive Technologies’ path to reimagining automotive design using composites. “There is almost nothing in the car that can’t be made out of composites. It is only a matter of time,” prophesies Hugh Foran, Executive Director of the Advanced Development Center.
Teijin Automotive Technologies was formed in 2021. It all began in 2017 when Teijin acquired Continental Structural Plastics and its joint venture CSP Victall. Over time, the company added Inapal and Benet Automotive, and integrated Teijin Automotive Center Europe. The company’s headquarters remains where Continental Structural Plastics was founded, within a hub of automotive supplier headquarters in Auburn Hill, Michigan, US, leading a global presence across North America, Europe, and Asia.
For Foran, the work he had been doing at Continental Structural Plastics continued, but on a much larger scale. “Teijin’s acquisition really helped us to grow and expand into other areas.” Foran believes that thinking globally is an absolute necessity for the automotive industry. He explains, “It doesn’t matter which car manufacturer you look at; they all have a global footprint. Having a supply chain that can deliver globally is essential to work with them.” Given that Teijin Automotive Technologies’ customers comprise leading car manufacturers like Nissan, Toyota, Mercedes-Benz, Stellantis, General Motors, Ford, BMW, and many more, it is almost certain that the company’s materials are in the car sitting in your driveway or garage right now.
Teijin brought decades of research in materials to the group, building on the molding technology Continental Structural Plastics had developed. “We had specialized in sheet molding compounds and thermal plastics until that point, but Teijin opened the door to carbon fibers, aramid fibers—a large portfolio of materials to experiment with,” says Foran. “This enabled us to move from sheet molding compounds into other materials, which in turn led us to develop other automotive parts and then multi-material products.”
This is a continuation of Continental Structural Plastics’ work with electric vehicles, which began over a decade ago with the Chevrolet Spark EV, an all-electric version of the Spark model, as the interest in hybrid, then electric, cars soared in the early 2010s. “Right now, we have over forty battery covers in production for various manufacturers,” explains Foran. “With our experience, materials end up being somewhere between 15 and 30 percent lighter on average, coupled with less need for tooling by the manufacturer, as we mold most parts as a single piece.”
Electric-vehicle design has come of age in a surprisingly short time thanks to composites. “We are now at the point where some of our composites are exceeding aluminum for temperature resistance, and not just by a little, but by as much as 30 percent,” enthuses Foran.
For electric-vehicle batteries, heat resistance is a primary concern, followed by the prevention of leaks into the battery. Foran continues, “When you mold single-piece composites, you essentially remove leak paths into a battery case. In the past, sealant was used to prevent this issue in tooled battery enclosures, but if you are driving an electric vehicle through a flood, you don’t want to take any chances.”
Foran is known for his hands-on approach and is seen (usually wearing jeans) more often in the Advanced Development Center than in the boardroom. “My team and I get our hands dirty every day!” laughs Foran. “I like to be proactive and give manufacturers sample battery enclosure designs that they can test themselves. And if a customer needs certain specifications, we put it together for them, and they can come in and see it in action for themselves.”
Working with customers so closely gives Foran the insight to design products that meet the needs of the market. The award-winning multi-material battery case exemplifies Teijin Automotive Technologies’ approach, which is to respond directly to customers’ practical concerns, not just to benchmarks. “It allows for increased range of the vehicle, it takes up less space in the vehicle, and it is simply safer,” explains Foran. But those comparative improvements are not really what is new here. “It is the design geometry that is key. With this approach, we can consider, for example, making the battery enclosure the floor of the car, and so on. We have the materials to mold structural elements like the seats and the central console of the car as an integral part of the battery box. That changes everything,” clarifies Foran. This battery-centric approach is a new chapter in automotive design.
For Foran, sustainability has always been important in the design process, but he recognizes that the challenges have evolved greatly over time. “Originally, the percentage of recycled parts was the metric that manufacturers would ask us about, and this is something we have improved over time. However, the big issue in North America was not about the recycling process itself, but about getting back the component to be broken down and recycled,” explains Foran. “We have also pursued development in materials with recycling in mind, especially thermalplastics,” continues Foran. “Many of our thermoset products can withstand temperatures so high that they cannot be melted down and are difficult to recycle. It is a delicate balance, made all the more difficult by different manufacturers having different standards, especially for temperature.”
This focus on durability and longevity, however, has benefits as well. “First, the battery will see around 400,000 miles in its lifetime. But also, compared to steel or aluminum boxes, the composite battery box prevents corrosion and other damage to the battery, meaning that instead of being recycled, the battery can be repurposed elsewhere in the second-life battery market,” says Foran. These uses include back-up power for streetlights and cell towers, as well as many other applications. Making sure that the battery is used for its full product life is just as important as ensuring that it is eventually recycled.
But recyclability alone is not a sufficient metric for assessing the environmental impact of a product or material. The use of energy is also a key measure. Foran says, “Cycle time, the time spent to produce a product, is an important issue for me. We use 4,000-ton presses to mold parts, so cutting the cycle time even a little is a big energy savings. Again, materials are key here. Using thinner materials to reduce energy consumption is only possible with advanced materials, such as those incorporating our new Hexacore™ technology.”
Bringing together ideas and values from across the whole of Teijin Automotive Technologies also contributes substantially to the company’s tangible progress. Foran explains, “Since we became one cohesive company as Teijin Automotive Technologies, we are more engaged internally as a company, both on a day-to-day basis and through larger gatherings. The ideas for the award-winning battery enclosure were actually first recognized at one of these internal opportunities for exchange.”
Finally, where is Teijin Automotive Technologies headed next? “When working with composites, only your imagination is going to limit you,” concludes Foran.
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