Fabrication of multilayer glassy ceramic filters by fine particle migration during slip casting

Cylindrical, glassy ceramic filters with multilayer compaction, consisting of filtration layers of varied pore sizes on granular assemblies with specific interlayers, were shaped by a fine particle migration phenomenon during slip casting. The interlayer provided structural integrity of the filter material and thus the occurrence of the fine particle migration is vital for the success of the casting process. The production of non-crack, dry compaction was investigated from the experiments, which were designed to systematically combine varied sizes of mixture powder particles (quartz–zeolite–frit glass) and its granules. This technique can be applied to the production of ceramic filters with the median pore size of about 0.35 μm. The problem in dealing with finer pore sizes is in the fabrication process: a low casting rate is obtained with finer particles, which results in a low viscous drag on the particles, preventing particle migration.