Forming methods of alumina ceramic products include dry pressing, grouting, extrusion, static pressing, injection, casting, hot pressing and other methods. In recent years, there have been developed such molding technologies as filter press molding, solidification injection molding, gel injection molding, centrifugal grouting molding and solid free molding. Products with different product shapes, sizes, complex shapes and precision require different molding methods. Extract its commonly used molding introduction:

Dry press molding:

Alumina ceramic dry pressing technology is limited to objects with a simple shape, an inner wall thickness of more than 1mm, and a length-to-diameter ratio of not more than 4:1. The molding method is uniaxial or bidirectional. There are two types of presses, hydraulic and mechanical, which can be semi-automatic. The maximum pressure of the press is 200Mpa. The output can reach 15~50 pieces per minute. Because the stroke pressure of the hydraulic press is uniform, the difference in powder filling is the height of the pressed part. However, the pressure applied by the mechanical press varies with the amount of powder filling, which may easily lead to differences in dimensional shrinkage after sintering and affect product quality. Therefore, the uniform distribution of powder particles during dry pressing is very important for mold filling. Whether the filling amount is accurate or not has a great influence on the dimensional accuracy control of the manufactured alumina ceramic parts. When the powder particles are larger than 60μm and between 60 and 200 meshes, the maximum free flow effect can be obtained, and the best pressure forming effect can be obtained.

Injection molding:

Slotting molding is the earliest molding method of alumina ceramics. Due to the use of plaster molds, it is low in cost and can be used to shape large-sized and complex parts. The key to grouting is the preparation of alumina slurry. Usually water is used as the flux medium, and then the debonding agent is added to the binder, fully ground and exhausted, and then poured into the plaster mold. Due to the adsorption of water by the capillary of the plaster mold, the slurry gradually solidifies in the mold. When hollow grouting, when the mold wall absorbs the slurry to the required thickness, the excess slurry needs to be poured out. In order to reduce the shrinkage of the green body, a high-concentration slurry should be used as much as possible.

It is also necessary to add organic additives to the alumina ceramic slurry to form an electric double layer on the surface of the slurry particles, so that the slurry can be stably suspended without precipitation. In addition, it is necessary to add binders such as vinyl alcohol, methylcellulose, alginate amine, and dispersants such as polyvinylamine and gum arabic, all of which are aimed at making the slurry suitable for grouting operation.