| 摘要 |
PURPOSE:To obtain a molded glass product having high-surface quality by cutting glass flow flowing out from a softening and discharging device for glass with shears or a wire heated at the temp. not lower than softening point of glass. CONSTITUTION:For example lead oxide-base optical glass is charged in a softening and discharging device 1 for glass and heated at 800-900 deg.C. After glass is softened, a plunger 6 is raised to discharge glass flow and this is cut with shears 2 heated at 700-750 deg.C being the temp. not lower than the softening temp. of the above-mentioned glass. Successively the block of glass flow obtained by cutting is received with a lower die for molding and thereafter a glass product is produced by pressing the upper and lower molding dies. Further cartridge heaters 3 are used for heating the shears 2 and temp. control is performed with thermocouples 4. Furthermore as the knife edges 5 of the shears 2, material coated with a rigid film such as TiN, AlN, SiC, Si3N4 or TiC on sintered hard alloy consisting essentially of WC is used.
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