Melt spinning pitch-based carbon fibers

Abstract Although pitch-based carbon fibers can be melt spun, the flow characteristics of mesophase pitch make it extremely difficult to process. Mesophase pitch, like many fluids, can be non-Newtonian, but its viscosity is considerably more temperature sensitive than most melt-spun materials. In the present study, energy and force balances are applied to demonstrate the influence of process variables and material properties on the spinability of mesophase. The results indicate that the extreme temperature dependence of the viscosity of mesophase can create filament stresses during melt spinning that are near the ultimate tensile strength of the filament. Therefore, the control of both temperature and heattransfer rate is extremely critical during the formation of pitch-based carbon fibers.