Raw materials are the foundation, and firing is the key. In the ceramic production process, firing is one of the most important processes. The firing process of ceramic products is to perform high temperature treatment on the ceramic body after forming, glazing and drying under certain temperature and atmosphere conditions, causing a series of physical and chemical changes to form a certain mineral composition and microscopic The structure, the various characteristics of ceramic products are finally obtained. A series of physical and chemical changes occur during the firing process, such as expansion, contraction, gas generation, liquid phase appearance, the disappearance of the old crystal phase, and the new crystal phase. Formation etc. Under different temperature and atmosphere conditions, the content and degree of changes are different, resulting in different mineral compositions and microstructures, which determine the different qualities and properties of ceramic products. [11]
The glaze layer on the surface of the green body also undergoes various physical and chemical changes during the firing process, and finally forms a glassy substance, which has various physical and chemical properties and decorative effects. The common firing process can be divided into one firing and two firing. The first firing is to glaze the green body, dry it, and then enter the kiln to burn the product at a high temperature. The second firing is to dry the unglazed green body, and then bake it first, then apply the glaze, and then perform the second firing (glaze firing). The one-time firing process simplifies the process and reduces the heat loss during firing. The two-time firing increases the strength of the green body, which is beneficial to the mechanization and automation of the subsequent processes, reduces damage and improves the quality of the glaze. The actual production should be selected according to the specific conditions of the product. The firing process is carried out in a special thermal equipment called a kiln. There are many types of kilns, which should be selected according to different products. At the same time, a variety of kiln furniture are often used during firing. The reasonable selection and use of kiln furniture is also of great significance to improve product quality, save energy, and reduce production costs. There are many factors that affect the firing. If the firing process is not properly controlled, it will not only waste fuel, but also directly affect the product quality, and even cause a large number of waste products, which will bring undue losses to the enterprise. Therefore, we can only improve product quality and reduce fuel when we have mastered the law of change of the green body in the high-temperature firing process, correctly select and design the kiln, formulate and implement the firing system scientifically, and strictly implement the firing operation procedures. Consumption and obtain good economic benefits.
How does the ceramics sintering?
2020 09/07