When dry press molding is needed, the powder is sprayed and granulated, and polyvinyl alcohol is introduced as a binder. A research institute in Shanghai developed a water-soluble paraffin as a binder for Al203 spray granulation, which has good fluidity when heated. The powder after spray granulation must have good fluidity and loose density, and the flow angle friction temperature should be less than 30℃. The particle gradation ratio is ideal and other conditions to obtain a larger green density.
Alumina ceramic products are formed by various methods such as dry pressing, grouting, extrusion, cold isostatic pressing, injection, casting, hot pressing and hot isostatic pressing. In recent years, domestic and foreign countries have developed molding technology methods such as filter press molding, direct solidification injection molding, gel injection molding, centrifugal grouting molding and solid free molding. Different product shapes, sizes, complex shapes and precision products require different molding methods.
