SUPERCRITICAL DEBINDING OF INJECTION-MOLDED CERAMICS

Extraction of organic additives from extrusion-molded cylinders of alu mina by a supercritical fluid is investigated. Hildebrand parameters a lone are not adequate to predict conditions for optimal polymer extrac tion with supercritical CO2. The results obtained with two models deve loped for the kinetics of binder extraction suggest that polymer extra ction from green samples is controlled by diffusion without developmen t of a reaction front. The solubility and diffusivity of polymers both affect the extraction rate, with opposite pressure and temperature de pendencies.