抄録
The plasticity are originally analyzed by speculating water content in ceramic body. Water in ceramic body are classified into two types; 1) free water occupied the space among particles (clay and other particles), and 2) water bonded to the surface of clay particle. These water can be distinguished by drying test at 40°C and 100°C, and measured as water content at each temperature. The monotonic or bent curve of free water content with increase of nonplastic mixture can be explained by the binary particle packing model. The binding water is normalized as characteristic value of plastic clay (CV) which is calculated as the ratio of binding water film on clay particles at room temperature and 40°C. The CV shows more dependence on the clay mineral species in the body than the clay content or the surface area. Clay for ceramic bodies of Japan are classified into 5 categories according to their constituent minerals. The CV is exceedingly consistent with the mineralogical classification and plasticity feeling test by hand. The CV is considered to be more adequate to estimate the plasticity of ceramic bodies than any other values proposed previously. It is also shown that the conception of the CV is useful to evaluate the plasticity of modern ceramic bodies (for example: Fe2O3, SiO2, SiC and Al2O3).
