PAN carbon fiber is produced by pyrolysis of a precursor fiber in an inert atmosphere at temperatures above 982°C.
The most common precursor material used to manufacture carbon is polyacrylonitrile (or PAN), that is 90% of all carbon fiber production. The process consists of the five following steps:

• Spinning (and Polymerization): PAN is mixed with other ingredients and spun into fibers, which are washed and stretched. The quality of finished fiber depends a lot on the quality of the precursor.


• Stabilizing (or Oxidation): Chemical alteration to stabilize bonding at about 200°C-400°C.


• Carbonizing: Stabilized fibers are heated to very high temperature (~1000°C) to remove hydrogen, oxygen, nitrogen and other non carbon elements, forming tightly bonded carbon crystals. In order to manufacture stiffer (high modulus) fibers, the pyrolizing process continues for longer, and at higher temperature, (up to 3000°C,) creating a smaller diameter round fiber. Higher modulus fibers are more expensive and more brittle. For this reason, they should be further processed (when weaving, winding, etc) with greater care.


• Surface treatment: Surface of oxidized fibers is treated to improve bonding properties.


• Sizing: Fibers are coated and wound onto bobbins.