The production of sanitary ceramics includes the stages of batching, pulping, molding, drying, glazing and firing.
(1) Raw material process
The raw materials of sanitary ceramics include green body raw materials and glazes. The ceramic body and the external glaze are made of a variety of raw materials, which are pulverized, shaped and fired. The quality of raw material process control directly determines the level and appearance of sanitary ceramic products. It is the production link of sanitary ceramics. important parts of.
(2) Forming process
Forming is to make blanks with various methods and have a certain shape and size of blanks, which is an important process in the production of ceramics. The molding methods of ceramic products are divided into three categories: plastic molding, grouting molding, and pressing molding. Because of their large size and many shapes, sanitary ceramic products are still mainly grouting molding.
Grouting is to take advantage of the fact that the porous model can quickly absorb water. The prepared mud is injected into the porous model. After the water in the mud close to the mold wall is absorbed by the mold, a uniform mud layer with a certain thickness is formed. After the residual slurry is poured out, the mud blank is separated from the model due to syneresis to form a blank.
(3) Billet repair
Sanitary ceramic products need to be trimmed after demoulding, including demoulding and trimming, and trimming and wiping water after the body has a certain strength. The demoulding and trimming of the green body includes trimming and drilling of the rough surface of the green body. Repairing and wiping water is the final process of grouting. After the green body reaches a certain strength, the green body is cut or leveled, and then the sponge is dipped in clean water to wipe the entire green body to make the surface of the green body smooth. This process produces a lot of dust, so centralized wet repair should be adopted to do a good job of dust removal.
(4) Drying process
All kinds of green bodies after molding contain a certain amount of water, and the water content of grouting molding is 19-23% when it is just demolded. The moisture content of the green body must be reduced, the strength of the green body must be increased, and the subsequent green body inspection, repairing, handling, glazing and firing must be facilitated, and firing cracking should be reduced. Sanitary ceramics manufacturers currently mainly use the hot air drying method to dry the green body. There are two process modes: drying in the molding workshop and centralized drying in the drying room.
(5) Glazing process
Glaze is a layer of glass applied to the surface of the ceramic body. Glazing improves the surface properties of the green body and plays a role in decoration and beautification. The quality of glaze and glazing process directly determines the level and grade of sanitary ceramic products. The preparation of the glaze slurry is basically the same as the production process of the blank slurry, but the purity of the glaze is required to be higher, and attention should be paid to preventing raw material pollution. Ensure that the thickness of the glaze layer on the outer surface of the body is uniform. The spray glaze method is used for manual glaze spraying and manipulator spraying.
(6) Firing process
After glazing, the ceramic white blank must be fired, and firing is one of the most important processes in ceramic production. The firing of sanitary ceramics is a single firing, and the kilns used are tunnel kilns and shuttle kilns.