ADVANCES IN A LUMPED KINETIC MODEL FOR CARBONIZATION FOR CARBON FIBER MANUFACTURING

摘要

The global demands for the CFRP (Carbon Fiber Reinforced Plastic) among composite materials would be expected to increase in weight sensitive products due to its superior mechanical properties per its weight. The majority of the industrial carbon fiber is now produced from synthetic precursor polymer such as polyacrylonitrile (PAN). The synthetic precursor undergoes two different thermo-chemical processes, namely stabilization and carbonization, to convert into the final product – carbon fiber. The characteristics for these two thermos-chemical processes are quite unique and different from each other. Stabilization process is relatively slow and exothermic and requires controlled heat dissipation to avoid thermal runaway. The carbonization process is rapid and involving a large fiber mass transfer into the gaseous phase with endothermic reactions. While many chemical kinetics studies have been published for the stabilization process, little published research work has focused on the carbonization chemical kinetics in spite of the major mass loss during the carbonization process. As part of our ongoing work to develop a detailed model of the carbonization process we have improved our previous 2-zone fiber model with lumped kinetics releasing pseudo-pure-off-gas by applying the temperature dependent volatile concentration from published literature. Fiber conversion predictions over the fiber travel direction are obtained from the model. A parametric study was conducted on the linear density change of the fiber over the heated length with different temperature and surrounding conditions.