Carbon Fibre

Based on manufacturing procedure, there are three types of carbon fibre available named as Ex-PAN, Ex-Cellulose and Ex-Pitch. Typical Density - 1700-1600 -2200 Kg/m³ , E - 230, 340 - 390, 690 Gpa. The Manufacturing steps are as follows:

• Fiberization - to make a precursor fibre - wet,dry or melt spinning
• Stabilization (to prevent from melting)
• Carbonisation - to remove impurity
• Graphitisation to enhance strength etc.

In case of Ex-PAN fibres, the fiberization involves development of Poly- acrylo-nitrile which is a ladder polymer - Polyethylene with a nitrile CN group in every alternate carbon atom. The PAN is stabilised around 250^oC, followed by carbonisation at around 1000-1500^oC and finally Graphitisation By heating up to 3000^oC.

The Ex-Cellulose route involves the development of Carbon fibre from Cotton, Rayon etc. It is expensive and not commonly used. The Ex-pitch rout has sources of Carbon fibre from PVC, Coal-Tar etc. This is the cheapest route of producing carbon fibre. In this procedure anisotropic, liquid crystalline mesophase of the raw material could be directly spun in the form of fibres. Typical applications include: shuttle booster, turbine & compressor blades, prosthetics etc.