Ultra-reduction of drying and firing shrinkage on pottery slip casting by adding mullite fiber

Abstract

Slip casting is a popular method for producing ceramics. However, during the drying and firing processes, the molded bodies shrink and deform considerably, developing cracks and fractures. This reduces the product yield, limits the range of possible shapes and sizes, and reduces dimensional accuracy. This study proposes a slurry consisting of firing-nonshrinkage clay, mullite fiber, dispersant, and water. The results of slip casting a molded body using the proposed slurry indicated that the total shrinkage is significantly reduced owing to the addition of mullite fiber, particularly ≥ 10 mass%. Therefore, it is inferred that the fiber forms a rigid, bulky three-dimensional network structure in the molded body, which is retained even after dehydration and firing. This technique is expected to be useful in the creation of new ceramic industrial products and works of art involving high-precision dimensions and complex, linear, and thick-walled shapes.