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 filter pressed body cake is mixed with required quantity of water approximately 35%. Small addition of deflocculants like sodium silicate and sodium carbonate is added to from a fluid slip which can be easily poured into the moulds. The casting process involving removal of the slip should be maintained very high without compromising on […]

Where the shapes are intricate and difficult to make by jiggering and jolleying, slip casting process is the best solution available. Depending on the size and shape the casting moulds are made into different parts to form the final shape. The mould making for these processes are a special technique and consist of various stages. […]

Now a days fully automatic machines are available where in plastic body is spread by a heated electric die over the mould and then finished off by rotating under a profile while being sprayed with water. In the roller machine the roller spreads the clay on the mould to the required shape using an electrically […]

The following methods are followed in shaping of tableware in earthenware industry.
1. Jolleying and jiggering
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In the next stage the cakes are transferred to a de-airing pug mill attached with vacuum chamber. The cakes are fed into the pug mill through a hopper, get pugged, simultaneously the entrapped air from the cakes is also removed by vacuum process. This improves the plasticity and workability of the final plastic body. It […]

The prepared body slurry is passed through a 200-mesh sieve and a series of permanent rare earth magnets and taken into a final mixing tank where in stirring arrangements are provided with very low rotation speed. This keeps the liquid slurry in motion and in suspension to avoid the settling of heavier particles in the […]

In the next stage of the process the liquid ball clay slurry and the liquid china clay slurry are taken into a high speed blunger as per the batch formulation requirement. The silica is ground in a separate ball mill which is lined with silex stone and is then passed through a 200-mesh sieve and […]

In the wet process the ball clays and china clays are blunged separately and sieved through a 250-mesh high frequency vibro meter. To facilitate a better sieving process in some companies they follow a special sieving system of passing through sieves of stage sieving. This comprises of a set of sieves 40-mesh, 80-mesh, 100-mesh, 140-mesh […]

In some parts of the world few factories follow dry mixing method. In this method the ingredients are mixed in a dry state in a suitable mixer and then correct amount of water is added to give required plasticity and mixed for few minutes.
The advantages of dry method over wet method is the economy of […]