Mechanism of plasticity development for ceramic dough (Part 2) - Investigation on plasticity by particle packing structure

Plasticity and packing structure of clay and alumina dough, and of alumina mixed with water-soluble and non-water-soluble plasticizers were investigated. It was found that both plastic clay dough and alumina dough with plasticizers showed a two-peak pore population. When the larger-sized pores increased in volume, the fluidity of the dough was improved. On the otherhand, when the smaller-sized pores decreased in volume, a high rigidity was showed. An aggregate structure was observed in the clay and the dough mixed with water-soluble plasticizer like methyl cellulose. Plasticity was generated when the aggregates were deformed by using the larger-sized pores among each aggregate. The non-water-soluble curdlan did not dissolve in the dough and remained in gel. The larger-sized pores were formed by the gel, whose deformation produced plasticity. It was understood that plasticity is generated when either the aggregates or the gel act as a buffer in the dough and enhance deformation of the dough.