Thickened slip besides being difficult to pour and flow in the intricate parts of the mould can trap air bubbles giving pinholes in the cast. The casting time or slip holding time for earthenware body varies from 20 minutes to 40 minutes. The slip is poured into the mould left for casting to happen to the desired thickness and then the excess slip is drained and returned to the storage ark meant for run of slip. The run of slip is reprocessed once again by sieving and magneting and mixed with virgin slip for further casting.
Different factories use various mechanized casting machines. Normally it takes the form of a conveyor on which the mould is filled at one end and travels for the required time. As soon as sufficient thickness builds up the mould is inverted automatically and the excess slip runs into a drain and goes back to the storage ark after processing.
To be continued……….
