The substitution of high strength carbon fiber composites for steel in automobile bodies is gaining momentum (See also earlier posts as background on carbon fiber). As reported in Bloomberg Business News, BMW has taken the lead by investing in a plant to make the fiber in this country, as the auto firm seeks to decrease the weight of its large models, thus reducing fuel consumption and therefore emission of carbon dioxide. A light weight frame is also of value for electric vehicles to compensate for the weight of the large battery. So, BMW is already using a carbon fiber body on its i3 electric model, which competes with Nissan’s Leaf and is 20% lighter.
Carbon fiber bodies have for some time been used for Formula1 racers, as well as for very expensive European sports cars, but there is now some urgency for manufacturers to reduce the body weight of cars on the commercial market, with more stringent CAFE standards ahead.
The firm was looking ahead in 2009 when it acquired a 16% stake (later increased to 43%) in SGI Carbon, a German firm making carbon fiber products, including carbon fiber itself. This led the joint venture to the construction of a recently commissioned $ 100 million carbon fiber plant in Moses Lake, Washington, where electricity costs are about one fifth of what they would be in Germany. High strength carbon fiber has been produced here by firms like Hexcel and Cytec, but these companies have largely served the commercial and military airplane and aerospace markets and they must now consider the new competition from the two German firms. Japanese firms like Toray and Teijin are also leading producers.
While carbon fiber is many times as expensive as steel, BMW is aiming to substantially increase its use of the fiber in its next 7 Series, due to come out in 2015. Other car manufacturers are also adding carbon fiber composites to different parts of car bodies, but none of them are as committed as BMW.
The next breakthrough will be in the development of carbon fiber made from a substrate other than polyacrylonitrile(PAN). Sooner or later, this will happen, leading to a dramatic increase in the use of this material for high strength structural applications without the prohibitive cost of PAN fibers.