What is the overall structure of the material?
Carbon fibre has a similar atomic structure to that of graphite. But why isn't carbon fibre as soft and flakey as graphite? But rather strong, requiring large amounts of force to fault. The answer lies in its structure and how the individual strands/ sheets are positioned. Carbon fibre is arranged in a more random "less ordered" nature (still relatively parallel to the long axis to the fibre) whereas graphite large layers of the structure lie on top of each other with weak bonds between the layers. The linear chain structure is transformed to a planar structure.
What is it comprised of?
Carbon fibre is made up of the polymer PAN. This polymer is stretched so that it lines parallel to the axis of the fibre. The polymer is the oxidised at 200-300 degree’s to remove the Hydrogen and add Oxygen to the molecule. By heating this newly treated polymer to a further 2500 degree’s in a nitrogen rich environment the polymer is then further purified and carbonisation occurs. As a result carbon is increased to 90% of the polymer.
The fibres are then weaved into sheets and embedded in epoxy resin. This process is called sizing. The finished product is the definitive black checked fibre of which is used for various processes.
The fibres are then weaved into sheets and embedded in epoxy resin. This process is called sizing. The finished product is the definitive black checked fibre of which is used for various processes.