Abstract
A Petroleum pitch produced by the Eureka process contains small mesophase spherules which are dispersed in an optically isotropic pitch. A precursor of generalpurpose carbon fiber is available from the isotropic pitch which was filtered off the mesophase spherules.
The filtration of viscous molten pitch under constant pressure was experimentally studied by using an experimental apparatus equipped with a cylindrical filter medium.
After the experimental study, it was confirmed that the process of constantpressure filtration of the molten pitch consists of two stages : an initial filtration process that follows Ruth's cake filtration law, and a final filtration process that follows Hermans-Bredee-Grace's standard blocking law. Concerning the reason for the occurrence of blocking in the final filtration process, it is conceivable that the phenomenon may originate in the blockage of trace infusible materials contained in the molten isotropic pitch.
