| 摘要 |
PURPOSE:To obtain a porcelain plate free from crack and warpage, etc., and useful as roofing tile, tile, etc., quickly in high efficiency, by continuously supply ing and firing a clay-containing raw material with an extruder, a conveyor, a drier, a travelling cutter and a delivery mechanism, etc. CONSTITUTION:A raw material composed mainly of clay such as porcelain stone is formed with an extrusion molding machine 1 provided with a die 2, a mandrel 3, etc., and a hollow article A is extruded at a speed of 200-2,000mm/min and introduced into a drier 13 with a conveyor a having free rollers 10. The hollow article A having an initial water-content of 22-15wt.% is dried to a water-content of 8-1wt.% within 5-30min by heating at about 150 deg.C with a microwave heater 14, a far infrared heater 15 and a hot air zone 16, etc., in the drier 13. The dried article A is cut to a prescribed length with a travelling cutter 17, delivered with a delivering mechanism 18, introduced into a primary firing furnace 19 of a roller hearth kiln and fired at 700-1,300 deg.C with LPG gas, etc. The fired product is cooled to about <=1,000 deg.C, decorated, glazed, introduced into a secondary firing furnace 26 and fired at 700-1,300 deg.C to tighten the texture of the porcelain.
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