Slip Casting is the process of producing complex utilitarian and decorative ceramic shapes, used in industrial productions anytime it isn’t possible to use mechanical methods.
Creating the slip
The slip is created by combining clay with water, along with some chemicals (desflocculants) that help the suspension become more homogeneous in order to facilitate the conformation.
Process
After the slip is created, it is poured into a plaster mould. Since clay doesn’t dissolve in water and the plaster mould is porous, the suspension is absorbed by the pores by capillary action. The rest of the slip, the one that wasn’t absorbed, is drained for later reuse. The slip absorbed by the mould will create the shape of the mould.
Once the liquid dries it is removed from the mould leaving us with the “green body”. Even though this body is extremely fragile, it holds its shape until it is finished and moved to a furnace – with temperatures higher than 1000ºC – for the first drying process. Due to the exposure to these high temperatures, the fragile body is transformed into a strong shape with high mechanical resistance, keeping, nevertheless, some of its porosity so that it can be later painted/ glazed. After being glazed, it is taken to its final drying which will provide him with a waterproof feature.
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