What is Carbon Fiber?
Carbon fiber is composed of carbon atoms bonded together to form a long chain. The fibers are extremely stiff, strong, and light, and are used in many processes to create excellent building materials. Carbon fiber material comes in a variety of “raw” building-blocks, including yarns, uni-directional, weaves, braids, and several others, which are in turn used to create composite parts.
Within each of these categories are many sub-categories of further refinement. For example, different types of carbon fiber weaves result in different properties for the composite part, both in fabrication, as well as final product. In order to create a composite part, the carbon fibers, which are stiff in tension and compression, need a stable matrix to reside in and maintain their shape. Epoxy resin is an excellent plastic with good compressive and shear properties, and is often used to form this matrix, whereby the carbon fibers provide the reinforcement. Since the epoxy is low density, one is able to create a part that is light weight, but very strong. When fabricating a composite part, a multitude of different processes can be utilized, including wet-layup, vacuum bagging, resin transfer, matched tooling, insert molding, pultrusion, and many other methods. In addition, the selection of the resin allows tailoring for specific properties.
The properties of carbon fibers, such as high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion, make them very popular in aerospace, civil engineering, military, and motorsports, along with other competition sports. However, they are relatively expensive when compared with similar fibers, such as glass fibers or plastic fibers.
Carbon fibers are usually combined with other materials to form a composite. When combined with a plastic resin and wound or molded it forms carbon-fiber-reinforced polymer (often referred to as carbon fiber) which has a very high strength-to-weight ratio, and is extremely rigid although somewhat brittle. However, carbon fibers are also composited with other materials, such as with graphite to form carbon-carbon composites, which have a very high heat tolerance.