The Auto Industry’s Carbon Fiber Dilemma
The 2018 Geneva motor show featured several concept cars from manufacturers using heavy doses of composite materials to create lighter electrics and hybrids. BMW was among them. Yet just two years ago, BMW announced it was limiting its use of carbon fiber in order to sustain profit margins. This dichotomy illustrates the carbon fiber dilemma faced by automakers the world over.
Engineers would certainly like to be able to design lightweight vehicles that are amenable to electric engines and batteries. But they are also trained to think about driver safety. They have the unenviable task of finding the right balance between lightweight building material and something strong enough to offer an adequate level of safety during a crash.
It turns out that carbon fiber fits the bill in both cases. But here’s the problem: carbon fiber is expensive. While designers are seeking to build a strong but lightweight car, company accountants are responsible for maintaining affordability. If they cannot keep a new design within a certain price point, the company risks losing money should they attempt to build it
What Makes Carbon Fiber So Expensive?
Rock West Composites, a Utah company that specializes in carbon fiber, fiberglass, and other composite materials, explains that the high cost of carbon fiber is one of only a few things keeping carmakers from using the material more often. Carbon fiber might be stronger and more lightweight than steel and aluminum, but it also has a higher price tag.
So what is it about carbon fiber that makes it more expensive? It boils down to two basic things. First, the process involved in making strands of carbon molecules usable as a material for manufacturing requires a tremendous amount of energy. And because energy is expensive, the high demands of carbon fiber manufacturing translate into a higher cost for tow, fabric, and panels.
Second, fabricating car parts from carbon fiber is not as easy as doing so with aluminum or steel. Aluminum parts can be forged from molten aluminum or stamped with dye machines as needed. Steel parts can be forged directly from molten steel. Mass production makes using steel and aluminum for car parts rather affordable.
On the other hand, mass production of carbon fiber car parts is virtually unheard of right now. Creating a carbon fiber hood, for example, involves a manual layout process that is time-consuming. A completed layup then has to be exposed to high heat in order to cure the resin, consuming yet more energy in the process.
3D Printing and Other Technologies
An affordable way to incorporate more carbon fiber into auto manufacturing has been elusive thus far. But there are technology solutions on the horizon. One of those solutions is 3D printing. It is a solution already being embraced by the aerospace industry, and one that looks pretty inviting to auto manufacturing.
A 3D printing process can pretty much be ignored once it is established. As long as the printer is kept loaded with the necessary materials, engineers can start the process and walk away. Computer software controls the entire print job from start to finish. As such, 3D printing eliminates the time-consuming and labor-intensive layout process.
Carmakers would really love to make use of more composites in their designs. They are working toward a means of doing so. But until the cost of carbon fiber is made comparable with steel or aluminum, designers and car company accountants will continue to butt heads over how much composites can be relied on. It is a real dilemma that needs a real solution.