Abstract: A method of manufacturing a glass blank for a substrate for an information recording medium, the method including steps of: cutting out a gob of a glass material from a molten glass material by cutting the molten glass material discharged from a glass material outlet at a predetermined timing; causing the gob of the glass material to fall downwardly; pinching and pressing the gob of the glass material by a press unit having a pair of molds, the molds' surfaces facing to each other being press surfaces which are planes without an unevenness, so as to contact the falling gob of the glass material only to the press surfaces; and forming a circular flat plate-shaped glass blank having a target flatness as a glass substrate for a magnetic disk such that a ratio between a diameter and a thickness of the glass blank is within a range of from 50:1 to 150:1, from the gob of the glass material.

Abstract: The present invention provides a shaft high temperature continuous graphitizing furnace comprising a furnace body comprising a feeding inlet and a discharging outlet, an electrode pair, a cooling system and a discharging device; the furnace body is designed to be a shaft cylindrical structure; the electrode pair is provided within the furnace body and comprise an upper electrode and a lower electrode, the upper electrode is located below the feeding inlet, and an umbrella or cone table shape electric field having a lower cross section area greater than its upper cross section area arises between the upper electrode and eh lower electrode; and the cooling system is located between the lower electrode and the discharging outlet.

Abstract: A process for providing a thermally homogeneous flow of molten glass comprises introducing a stratified liquid layer of non-volatile evaporation resistant materials having density smaller than that of the molten glass, onto the surface of the molten glass contained within a feeding section of a forehearth.

Abstract: Method and apparatus is set forth for forming a laminated gob or charge of molten glass having a core glass which is not only completely surrounded by a skin glass but also has a reentrant portion of skin glass which projects inwardly within the core glass from the periphery of the molten charge intermediate its upper and lower extent. The reentrant portion of skin glass is formed within the charge during the gobbing cycle by momentarily retarding or retracting the outward flow of the core glass while simultaneously positively pulsing the flow of the skin glass. Thus, a laminated gob or charge of molten glass is formed which not only has a skin glass completely surrounding and encompassing a core glass but also has a reentrant portion of the skin glass which is continuous with the remainder of the skin glass surrounding the core glass.

Abstract: A glass article such as a sham bottom tumbler with decorative air bubble encapsulated in its base is produced on existing automatic glass-forming machines by injecting a bubble of air into a charge of molten glass in the gob-forming section of a glass furnace as the charge is being formed into a gob. This is accomplished by providing an air supply tube in the gob-forming plunger. Preferably, the lower tip of the tube extends below the lower tip of the plunger. Puffs of compressed air are supplied in synchronism with the plunger cycle so an air bubble is formed in the lower end of the gob, and the gob is then formed by normal procedures into a finished article.

Abstract: In the production of glass fibers by the use of a multi-tipped bushing arranged beneath an opening in the floor of a fore-hearth along which the molten glass flows, an apertured cover plate is disposed across the opening at or near its bottom and carries an upwardly extending duct connecting the aperture in the cover plate with a position in the fore-hearth above the floor and below the normal surface level of the glass, so that molten glass is supplied to the bushing from this position, where the glass is uninfluenced by cooling effects, and on its way thence to the bushing the glass can only contact the surface of the duct which is kept hot by the molten glass in the floor opening outside the duct. The risk of divitrified glass reaching the bushing and causing breakages is thereby much reduced.