PAN-Based Carbon Fibre Manufacturing
topic
PAN-based process (95% of production): (1) PAN precursor fibre (MW 100,000-300,000) produced via wet or dry spinning, (2) stabilization in air at 200-300°C for 1-2 hours (oxidative crosslinking converting linear PAN to ladder polymer, exothermic), (3) carbonization in inert atmosphere at 1000-1600°C (removing H, N, O, retaining 55-60% mass as carbon), (4) optional surface treatment (electrolytic oxidation creating functional groups), (5) sizing application, (6) optional graphitization at 2500-3000°C for ultra-high modulus grades.
Role
Multi-stage thermal processing creates turbostratic graphitic structure with controlled crystallite size (2-4 nm), preferred orientation angle (10-25°), and defect density determining mechanical properties (strength inversely related to crystallite size).