It is a kind of low-temperature firing process of porcelain made of charcoal and feldspar. The two basic characteristics of Bone China are the fundamental basis for distinguishing Bone China from other porcelain. Features: the content of bone char is more than 36% (national standard); Features: secondary firing (plain firing, glaze firing).
1. Raw materials
High quality bone porcelain is formed by adding a large amount of bovine bone powder with less impurities to the raw materials with feldspar and siliceous clay as the main raw materials: because the raw materials contain a large amount of bone powder, the viscosity of the soil becomes smaller, so the molding process needs to be extra careful.
① After forming and processing, it can be fired at a high temperature of 1250 ℃. Due to the large shrinkage rate of Bone China in the firing process, the finished product will shrink by 20% after kiln firing, so the shape is easy to deform, such as plates and bowls. It must be placed on a special Quantico bowl for long-term burning and training.
②Next, check the curvature and size of the shape, polish the surface, spray the glaze with sprayer, and put it into the kiln for firing at 1150 degrees.
The general coloring method is to paste transfer paper on the white finished product and burn it at 820 ℃.
All trips are strictly controlled. Qualified products are sent to the next trip and finished products leave the factory.