The dies are permeable to liqs. but not to ceramic particles and pressure is exerted on the plastic ceramic mass so it undergoes a thixotropic transformation to a quasi-liq. state and, on removing the pressure it reverts to the plastic state; water is extracted while the mass is in the quasi-liq. state. The ceramic mass is pref. forced through a jet at high speed for the transformation, during which partial phase sepn., e.g. of water, occurs, suitable speeds for stoneware being 5m/sec. min.; for crockery 20m/sec. min; and for porcelain 100m/sec. min.; and the Reynold's number should be min. 3000. The pref. mould is made of silica flour, max. 15 mu mixed with a plastic binder and hardened, and with a pore size of max 10 mu. Process provides uniform redn. of the water content from 22% to 14-16% so that a plastic ceramic mass known as "leather-hard" is obtd.
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