Facts about Carbon Fiber - Properties and Uses
Carbon fiber is five times stronger than steel. It is light weight, and highly malleable. Carbon fiber is made up of thin strands of carbon, thinner than the human hair. These strands can be woven into any shape and further strengthened by using plastic resin.
Carbon fiber is used in the manufacture of many products. United States, Japan, and Western Europe produce carbon fiber on a large scale.
How is carbon fiber made?
Materials that are used to make carbon fiber are called precursors. They are organic polymers that are made up of a long string of molecules bound by carbon atoms.
The precursor used for the manufacture of carbon fiber can be polyacrylonitrile (PAN), rayon or petroleum pitch. About 90 % of carbon fiber is made from PAN, and the remaining ten percent is made from rayon or petroleum pitch.
The manufacture of carbon fiber is partly chemical and partly mechanical.
The material used to make carbon fiber is drawn out into long strands and then heated without exposing the material to oxygen. When the material is not exposed to oxygen, it does not burn but vibrates with high intensity and shakes off all the non-carbon atoms. At this stage, the fiber is made up of tightly packed chains of carbon atoms.
After carbonization, the surface is oxidized to increase the bonding properties of the surface so that it can chemically bond well with any coating material. Oxidation involves immersing the fibers in gasses or liquids.
Gasses that are used for oxidation are air, carbon dioxide or ozone. Liquids that are used for oxidation are sodium hypochlorite or nitric acid.
The next step after surface treatment is sizing. The carbon fibers are coated to strengthen and protect the fibers from damage. Epoxy resin, polyester, nylon, urethane are some of the materials that are used to coat carbon fiber. The coated fibers are rolled onto huge cylinders called bobbins. These bobbins are loaded onto spinning machines that weave the fibers into yarns of various sizes.
Evolution of Carbon Fiber
Thomas Edison used carbon fiber filaments for his experiments with light bulbs in 1879. He created the carbon fibers by heating bamboo. These carbon fibers were resistant to fires thereby making them ideal for his light bulb experiments.
In 1958, Roger Bacon made carbon fibers out of rayon material but the carbon fibers he made with rayon were not very strong.
The Royal Aircraft Establishment at Farmborough, Hampshire, UK developed carbon fibers that were very strong. Rolls Royce used this while manufacturing their aircraft engines.
Nowadays carbon fibers are made from PAN (ployacrylonitrile), rayon or petroleum pitch.
Uses of Carbon Fiber
Carbon fiber felts are used to store thousands of megawatts of energy that is generated by wind turbines and solar panels. This stored energy can be utilized in the future whenever there is a power shortage.
Carbon fiber is used in the manufacture of sporting goods like golf shafts, rackets, skis, snowboards, hockey sticks, fishing rods and bicycles. The lightweight and tensile strength properties of carbon fiber make it an ideal material to make lightweight and durable sports products.
Carbon fiber fabrics are used to strengthen concrete, steel, masonry, timber, etc. It can also be applied to walls, pipes for strengthening.
Wind turbines made from carbon fiber are lighter, stronger and very efficient. The efficiency of a wind turbine depends largely on the lightness of the turbine blade.
Carbon fiber is used in the manufacture of race cars due to their light weight and strength. BMW has used carbon fiber in the production of the electric car models i3 and i8.
In the field of medicine, carbon fibers are used in the manufacture of x-ray equipment, surgery equipment, prosthesis, and implants.
Carbon Fiber in Air Craft
Carbon fiber is used to make parts of aircraft. The fuel used by an aircraft is considerably less when the weight of the aircraft is reduced. The lightweight yet durable carbon fiber helps to reduce the overall weight of the aircraft.
The Boeing and the Airbus company have used carbon fiber to build their aircraft. Boeing 787 Dreamliner has parts made out of reinforced carbon fiber.