Carbon Fibers
Properties
Carbon fibers are one of the strongest man-made fibers and have an outstanding strength-to-weight ratio and excellent rigidity.
Polyacrylonitrile (PAN) and Rayon are used as the precursor for 90% of the carbon fiber production. These materials are first spun into filament yarns and then pyrolyzed (heated under oxygen exclusion) to drive off all non-carbon atoms. The fibers are often bidirectional woven to sheets and then converted to carbon-fiber-reinforced-plastics (CFRP). This is achieved by layering sheets of carbon fiber cloth into a mold in the shape of the final product and by infiltrating the layers with epoxy resin. The parts are then heated to cure the resin. The resulting CFRPs are very corrosion resistant, and have excellent mechanical properties (stiffness & strength at low weight).
COMMERCIAL Carbon Fibers
Major manufacturers of carbon fibers are DowAksa, Hexion, and Teijin.
Applications
Carbon-fiber-reinfoced-plastics find many uses in the sport goods, automotive and aerospace industry. They are used for light-weight structures where a high strength-to-weight ratio and rigidity is required. Approximately 20 to 25 % of Boeing's and Airbus's wide-body airframes are carbon fibers. Carbon fiber reinforced plastics are also used extensively in high-end sports and racing cars. However, applications are limited by the high price of the carbon fibers and expensive manufacturing process of (large) CFRP parts. However, prices of CFRPs have come down over the years, and recently, several mainstream car manufacturers have started to use CFRPs in everyday high-end road cars.