Secondary firing technology is a typical representative of soft porcelain in the history of bone China, with high temperature plain firing and low temperature glaze firing as its most obvious technological characteristics. The secondary firing process of bone China is different from the traditional low temperature plain firing and high temperature glaze firing and can better solve the problems of high temperature deformation and glaze luster. In Japan, low temperature (900℃ or so) without glaze body called plain burning, high temperature (1300℃ or so) without glaze body called joint firing, glaze is called primary firing.
1.40%-50% non-plastic De bone powder is used for the molding of Jiangyi bone China. The total clay content of the body formula is low, and the plasticity is poor compared with ordinary ceramics, and the molding is difficult.
2. Sagger is the most representative process of bone China firing. Because of the narrow firing range and large shrinkage of bone China, the soft couch is easy to deform during firing, so buckle firing, support firing or buried firing must be used to solve the deformation problem.
3. Kiln furniture materials The kiln furniture materials used for bone China have higher requirements than ordinary ceramics. Most kiln furniture should be consistent with the product. Generally, each product has a supporting kiln, which is also the reason why the production of bone China is more complicated than ordinary ceramics. Bone China production team has a great demand for kiln furniture materials and a high requirement for the working surface of kiln furniture products.