| 摘要 |
Process according to which the internal walls of a mould are coated with a layer of barbotine without any foaming agent, this layer preferably having a thickness of 5 to 12 mm. The layer is hardened, then the rest of the mould is filled with a mixture of the same composition but containing a foaming agent, then the contents of the mould are hardened, demoulded, dried and then fired and possibly its surface vitrified or enamelled. Advantageously a mould, at least one part of which is porous, is used and filled with a barbotine, in which case the part of the latter situated in the vicinity of the porous wall of the mould is hardened up by absorption of the water of the barbotine by this wall and then the fraction of the barbotine, which is away from the porous wall and has not hardened up, is removed. |
