Carbon fiber is a material that is made of twisted strands of carbon fiber that are composed of carbon atoms. Carbon fiber is strong, lightweight, highly flexible, high resistance, high temperature tolerance and has low thermal expansion. Carbon fiber is used in aerospace, civil engineering military and motorsports. It is used mostly as a reinforcement material and is used as a polymer with other materials.
How is carbon fiber made?
Carbon fibers are produced from specific polymers such as rayon, polyacrylonitrile (PAN) or petroleum pitch. Rayon and PAN are then spun into filaments. Chemicals are added to align the carbon atoms to form strong fibers. Different mechanical processes are used to spin the polymer into fibers depending on the manufacturer. The fibers that result are then heated to drive away any non-carbon atoms. This process is called carbonization. In some cases the carbon fibers are further treated to create greater strength. They may also be added to other polymers such as a plastic resin to create carbon fiber reinforced plastic. The final carbon fibers are wound onto bobbins. These bobbins are placed into machines which use the wound carbon fiver to create yarn or thread. The carbon fiber thread or yarn is then used to create textile by weaving or braiding them together.
Spun PAN carbon fibers are usually dried in air up to 300 °C to oxidize the material. It then placed into a furnace where it is heated to 2000 °C. This creates carbon fibers which are 93–95% carbon. PAN produces higher quality carbon fiber than either rayon or petroleum pitch.