Dry Pressing And Injection Molding Of Alumina Ceramics

In terms of dry pressing molding technology, alumina ceramics are limited to products with relatively simple shapes and a thickness of only 1mm on the inner wall, or products with a diameter and length not exceeding 1:4. In terms of molding methods, it can also be divided into two types: bidirectional and uniaxial, and the press can be mainly divided into mechanical and hydraulic types.
When dry pressing alumina ceramics, not only can they be semi-automatic, but they can also be fully automatic. However, the press only has a maximum pressure of 200mpa, and the output can only guarantee 15-50 pieces per minute, because the hydraulic pressure is relatively uniform during the stroke, so the difference in powder will not be too large.

The injection molding method for alumina ceramics should have appeared relatively early because it requires the use of gypsum molds and has a relatively low manufacturing cost. It is more suitable for molding parts with large size requirements and complex shapes. The main method of injection molding should be the preparation of the slurry.
Under normal circumstances, the main medium for alumina ceramics is water as the solvent, followed by the addition of an appropriate amount of binder and binder. After effective grinding and exhaust, it can be directly injected into the gypsum mold. However, due to the strong adsorption of moisture by the gypsum mold, the material film will gradually solidify in the film.
If hollow grouting is used for alumina ceramics, there will be certain thickness requirements for the mold wall when adsorbing the slurry, and the excess slurry needs to be poured out. In order to reduce the shrinkage of the entire body, we should choose a slurry with a higher concentration when selecting the slurry.