The ceramic foam filter has the characteristics of a simple production process, easy operation, low cost, and easy industrialization. Ceramic foam filter not only has good mechanical properties and thermal shock resistance, but also has a good consistency and chemical stability.
The ceramic foam filter is made of organic Porous Ceramic Foam Material as a carrier, a filter body is made through a secondary dipping process, and after drying, it is sintered at a high temperature.
Ceramic Foam Filter Production Process
Most of the Foundry Foam Ceramic Filter production process uses the roller sizing process. The sponge undergoes a certain amount of dimensional extension after being compressed by a pair of rollers and the slurry is attached. The elongation of the two sides of the inverted web and the forward web is different, and the elongation is 1 to 3%. The resilience of the sponge after sizing determines the final size of the dried body.
For sponges with good elasticity and high strength, the green body has a small extension size, the slurry is uniformly distributed without blind holes, and the two sides and thickness dimensions are easy to control. For sponges that have poor elasticity, low strength, or can not meet the sizing of large specific gravity slurry (such as zirconia slurry), the green body will have large size extension after sizing, the thickness can not rebound or the rebound is uneven, and the slurry will hang.
The dried green body has a certain strength due to the action of the binder, and the green body is sintered in the kiln after surface spraying and secondary drying. The polyurethane sponge does not volatilize during the drying process, but melts ooze out of the surface and oxidizes and volatilizes at 200 ~ 600°C during the sintering process.
The polyurethane sponge itself is wrapped by the ceramic slurry, and the heat is transferred in through the ceramic slurry to form an oxygen-free combustion process, which causes the sponge to melt, ooze, and finally oxidize and volatilize. A sponge with high strength and good elasticity can make the body shrink slowly. Of course, the sintering temperature and sintering system for foam ceramics of different materials are different.