| 摘要 |
<p>Green ceramic mass (I) contg. more than 80% alumina is compacted in a mould and then baked to make a tubular roller. The compacting pressure, the baking temp., and the baking time, are all chosen so the roller is free from pores. Mass (I) pref. contains 99.5% alumina; or conforms with type 706 or type 710 of DIN specification 406685; and the baker rollers pref. have an external dia. below 50mm with a wall thickness of min. 4mm. In conventional furnaces for baking glazed tiles, the ceramic rollers are porous, so the tiles must be located on carrier plates to prevent glaze dripping onto the rollers and entering the pores to cause premature fracture of the rollers. The carrier plates wear rapidly, and e.g. 3000 plates are required each month at high cost. The invention provides pore-free rollers onto which glaze can drip without causing damage, so the need for carrier plates is eliminated.</p> |
