Porous mould with drain for ceramics - has inlet-outlet hole for material and second hole fitted with non-return valve to supply compressed air without allowing entry of material

摘要

A casting mould with drain-off has the main mould tools with an inlet/outlet for pouring the material into or draining the material out of it and another inlet to admit compressed air so that the material can be expressed from the mould; both the inlet/outlet and the second inlet are holes on the internal faces of the mould tools. The compressed air inlet has a non-return valve to prevent material from being pressed into it. This valve has a body which is pref. made of neoprene or silicone rubber. The mould consists of two porous plastic components (1) forming the mould cavity (2) together. This has the inlet (3) for admitting or draining material; the other hole (4) admits the compressed air. The material inlet/outlet (3) has a tube (6) for the purpose fitted with a valve (5). The air supply similarly has a feed tube (8) with its valve (7). ADVANTAGE - The mould eliminates waste of material and mould marks on the inner sides of the mouldings produced (both these features are common faults with existing mould designs).