The production process of sanitary ceramics includes raw materials, molding, glazing, and firing. Grouting is the most widely used method in the molding process. This article will introduce the meaning, advantages, disadvantages and applications of grouting.
The concept of grouting
Grouting is a very simple and flexible molding technology. Its basic principle is to inject a slurry with a high content and good fluidity into a porous mold (usually gypsum abrasives), because the mold is porous The inner wall of the mold absorbs water from the slurry to form a solidified blank along the mold wall, and the blank can be demolded when the blank has a certain strength.
1. The composition of the grouting process:
Mixing mud → grouting → slurry release → demoulding → splicing and punching → blank repair
(1) Mixed mud: The ceramic powder is formulated into a fluid mud.
(2) Grouting: injected into the porous mold (mainly plaster mold), and the water is absorbed by the mold.
(3) Slurry: Use the inserted pipe to discharge the excess mud at the bottom.
(4) Demoulding: apply adhesive mud on the semi-finished product, and then reverse the bottom of the manufactured sanitary ware to complete the fixation. Repeat the steps to obtain a large number of semi-finished products. Mastering the release point is a key. If the demoulding is too early, the strength of the blank is insufficient, the demoulding is difficult, and the blank is easily collapsed after demoulding; if the demoulding is too late, the blank will crack.
(5) Splicing and punching
(6) Repairing blanks: repairing excess blanks and filling holes.
2. The main process methods of slurry molding: hollow grouting, solid grouting, pressure grouting, vacuum-assisted grouting, and centrifugal grouting.
the characteristics of grouting molding:
1. Advantages:
(1) It has strong applicability and does not require complex mechanical equipment, and can be formed as long as a simple plaster mold.
(2) Any complex shape and large thin-walled injection parts can be produced.
(3) The molding technology is easy to master and the production cost is low.
(4) The green body structure is uniform.
2. Disadvantages:
(1) High labor intensity, many operating procedures, and low production efficiency.
(2) The production cycle is long, and the plaster mold occupies a large area.
(3) The injection piece has high water content, low density, large shrinkage and easy deformation during firing.
(4) The mold loss is large, and it is not suitable for continuous, automated and mechanized production.
Third, the application of grouting
Grouting is an ancient and traditional method of ceramic molding, which is widely used. Any utensils with complex shapes, irregular shapes, thin walls, large volumes and loose size requirements can be formed by grouting. Including general daily ceramic vases, soup bowls, dishes, teapots, sanitary ware toilets, washbasins, various shapes of craft porcelain, as well as a considerable number of industrial ceramics, special ceramics and so on.