A “perfect storm” of high fuel costs, the economic recession, government bailouts and ever-higher fuel-efficiency standards has rocked the automotive world to its foundations over the past two years. The situation has left OEMs highly motivated to lightweight their vehicles to improve fuel economy and, hopefully, sales. The U.S. energy bill passed in 2007 raised average fuel-efficiency standards to their highest level ever — 35 mpg by the year 2020 for OEM fleets, including light trucks. While composites continue to be attractive replacements for steel in efforts to lightweight automotive body panels, structural components and under-the-hood parts, as part of an overall material mix, some automotive OEMs say that composites must become even lighter to compete with aluminum in high-volume applications.
Automaker BMW (Munich, Germany) made the most car noise in 2010 by forming a joint venture with carbon fiber manufacturer SGL Group (Wiesbaden, Germany) to create SGL Automotive Carbon Fibers. The latter is building a facility in Moses Lake, Wash., that will produce 3,000 tons per year of 50K carbon fiber tow exclusively for BMW’s forthcoming all-electric Megacity Vehicle. The fiber will be used in the car’s chassis, for which BMW has developed a high-volume resin transfer molding (RTM) process. A concept version of the car is expected at the Frankfurt Auto Show in September 2011, with a production version in 2013.
McLaren Automotive’s (Woking, Surrey, U.K.) new MP4-12C sports car features a first-of-its-kind MonoCell, a carbon fiber composite chassis “tub” that uses technology transferred from F1 racing designs. Although the tub’s immediate function is to carry the main operating loads between the front and rear of the car and protect the passengers, it also meets requirements of corrosion prevention, overall structural stiffness and ease of access to the passenger compartment. The RTM resin used to make the tub is supplied by Huntsman Advanced Materials (The Woodlands, Texas). Preforms are made from high-strength carbon fibers manufactured by Toray Industries (Tokyo, Japan). The preforms are made in two formats — noncrimp fabric (NCF) and woven unidirectional (UD) tape — with a small amount of cross-stitching to hold the assembled reinforcements together. Production is starting in early 2011, with cars available for sale soon after.