BINDER REMOVAL FROM CERAMICS

The physico-chemical processes that occur during binder thermolysis of porous ceramic bodies are reviewed. The discussion initially focuses on intrinsic and extrinsic mechanisms of polymer degradation, with emphasis on the formation of volatile degradation products and involatile carbonaceous residue. The transport of volatile species (e.g. residual solvents, plasticizers, etc) and degradation products through both empty and binder-filled pores is then considered. The particular case of debinding highly loaded ceramic bodies is addressed in detail. Recent developments in modeling the onset of defect formation and the effects of capillary redistribution of thermoplastic binders on removal kinetics are outlined. On the basis of this fundamental knowledge, the criteria for optimizing binder removal processes is established.