Usually called isostatic molding refers to cold isostatic molding, is a method of using a fluid (water, oil) as a transmission medium to obtain a uniform static pressure applied to a material. That is, the incompressibility of the liquid medium is used to uniformly transfer the pressure properties, pressing from all directions to obtain the method of forming a product. According to its different molding process, it can be divided into two forms: wet bag type and dry bag type. It is mainly used in wet bag method.
1.
Static pressure such as wet bag type
Wet bag isostatic pressure technique is to put granulation ceramic powder or preformed blank body into a deformed rubber jacket, and then apply uniform pressure through the liquid, when the pressing process is over, and then the rubber jacket containing the blank body is removed from the container, which is a continuous forming method.
The technology is relatively low cost, can form moderately complex parts, and the pressure is up to 500MPa, suitable for small-scale production, but in a certain period of time the number of molding products is small, the billet size and shape is not accurately controlled, production efficiency is not high, can not be continuous large-scale production.
2.
Dry bag type and other static pressure
Dry bag isostatic pressure is to batch fill the ceramic powder into the flexible preformed mold, and then apply isostatic pressure. Because the mold is fixed to the equipment, when the pressing is completed, the molding product is out, as in the schematic diagram.
Dry bag isostatic pressure molding period is short, the mold service life is long, especially convenient for large-scale continuous industrial production. The mold materials used are polyurethane synthetic rubber or silicone rubber, compared with the wet bag isostatic pressure molding, dry bag isostatic pressure pressure is low, generally within 200MPa. The most familiar ceramic spark plug is currently formed with dry bag isostatic pressure, and the suppression time is usually only 1~2s.