Slip Casting
Instead of plaster, the moulds are made of polymeric materials: while porous, these have larger pores that do not generate the same capillary forces but require an externally applied pressure to drive the filtration process. However, the application of much higher pressure (<40 bar or 4.0 MPa) makes casting cycles much faster than in slip casting processes where the capillary forces correspond to a pressure of just 1–2 bar (0.1–0.2 MPa). Furthermore, the high pressure makes the cast pieces very dry and so de-moulding can be done immediately and a new casting cycle started again. Polymeric materials also last much longer than plaster and it is therefore possible to obtain shaped products with better dimensional tolerances.
To be contd….
