Ceramic making is a very complex and detailed process. If any process from raw materials to firing is ignored, it may lead to traps and even retribution. Some of these defects are found before scratching, some are found before firing, and some are directly caused by improper firing. The track of missing wheels is complex, and the production conditions of wheels are different.
1. Small hole
It refers to small dents or holes on the sleeve surface of the product. The first defect is the organic matter in the blank. The contents of carbon and iron oxide are significantly higher. When the lake water rises rapidly, the combustion products cannot be completely burned out and volatilized. Only when the high-temperature stage is set in the later stage can they escape and form pinholes like micro volcanoes.
Cracking refers to strong lines of different sizes on products. The reason is that the moisture in the kiln is too high and the preheating and cooling are too fast, resulting in uneven shrinkage inside and outside the products. Some of them are still in the body. They have been touched before being installed in South Korea and are charged with internal injuries. There are also uneven listening, excessive weight or poor adhesion of accessories., May cause product cracking.
There are two kinds of bubble burning: back bubble and glaze bubble. There are two kinds of bubbles: "annual bubble" and "return to Beijing bubble". Oxidation bubble means that the flower layer covers the outside of the bubble, and the folding surface is gray black, mostly formed at the lower part of the bubble. In shaft reduction materials, broken acid salt, high content of acid salt and organic matter are the main reasons for product foaming.