Abstract: An apparatus for continuous electro-thermal poling of glass or glass ceramic material, includes a lower support conveying and contacting electrode structure, an upper contacting electrode structure positioned above the lower support structure, and one or more DC bias voltage sources connected to one or both of the upper contacting structure and the lower support structure. A process for continuous electro-thermal poling of glass or glass ceramic sheets or substrates includes heating the sheet or substrate, feeding the sheet or substrate continuously or continually, while applying a DC voltage bias, and cooling the sheet or substrate to within 0-30° C. of ambient temperature.

Abstract: In a heating drawing, a base material glass plate is heated and softened in a heating furnace, and drawn to a desired thickness to form a glass strip. In the heating drawing, the base material glass plate is heated so that the base material glass plate has a U-shaped temperature distribution in a width direction. Such process can be realized through heating by a heating element which has a non-heating portion at a position opposite to a central portion of the base material glass plate in the width direction and a heating portion on both sides of the non-heating portion. Thus provided is a method of manufacturing a glass strip, the method includes heating and softening the base material glass plate, and drawing the base material glass plate to a desirable thickness to form a glass strip, and is capable of manufacturing a thin, rod-like glass strip with an excellent flatness.

Abstract: Disclosed are methods for compensating the varying weight of a glass ribbon the glass ribbon is drawn from a molten glass forming material, and an apparatus therefore. The weight compensating apparatus is configured to apply a force to the glass ribbon that is inversely proportional to the weight of the glass ribbon such that as the glass ribbon weight increases, the force applied to the glass ribbon by the weight compensating device decreases.

Abstract: A manufacturing apparatus for a thin glass sheet includes a forming member main body configured to form the thin glass sheet by fusing together, at a lower end portion of the forming member main body, streams of molten glass, which have overflown from an overflow trough to both sides of the forming member main body, under a state in which the streams of the molten glass are caused to flow down along outer surface portions having a substantially wedge shape. The manufacturing apparatus also includes a pair of covering members fitted onto both widthwise end portions of the forming member main body, respectively, the pair of covering members forming restricting wall portions for restricting widthwise spread of the streams of the molten glass flowing down along the outer surface portions of the forming member main body.

Abstract: Managing pressure within a thickness-control-zone (muffle door) housing (20) relative to pressures in a glass-making machine enclosure (60) and an upper chamber (40)—that is disposed outside the enclosure—so as to minimize or control undesired airflows that would adversely affect thickness (9) of glass ribbon (8). According to one pressure-management technique, the pressure at a location (25) in the housing (20) is managed so as to be less than the pressure at a location (65) that is within the enclosure (60) as well as both outside and adjacent to the housing. In the event of a leak, as by a crack or unintended opening in the housing, for example, this pressure difference reduces or prevents airflow toward the ribbon and, thereby, undesired thickness variation in the ribbon. According to a second pressure-management technique, the pressure at location (25) is managed so as to be greater than the pressure in the upper chamber.

Abstract: After a glass film ribbon is formed while allowing a glass to descend, the glass film ribbon is annealed while allowing the glass film ribbon to descend in an annealer to remove an internal strain. Then, when the glass film ribbon having a thickness at a center portion excluding both widthwise ends of 300 ?m or less is cut, after processing in the annealer is executed and before a cutting step is executed, main tensile rollers that play a role as principal tensile rollers hold the descending glass film ribbon and are driven to rotate, to thereby provide at least the glass film ribbon in the annealer with tension in a vertical direction.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: There are provided, a method for efficiently manufacturing a glass substrate for magnetic disk in which the degree of surface irregularity of the principal surface is suppressed, and the glass substrate for magnetic disk. When manufacturing a glass substrate for magnetic disk including a pair of principal surfaces, a glass blank is formed by pressing molten glass or softened glass with planar press forming surfaces of dies in such a way that the molten glass or the softened glass is sandwiched from the both sides. Temperature condition is equalized around the pair of principal surfaces of the glass blank during the pressing.

Abstract: The present invention provides a manufacturing method of a sheet glass material excellent in flatness. A manufacturing method of glass substrate for magnetic disk including a pair of principal surfaces, the method comprising the steps of: dropping process for dropping a lump of molten glass; pressing process for forming a sheet glass material by performing press forming to the lump while sandwiching the lump from both sides of the dropping path of the lump with facing surfaces of a pair of dies, the pair of dies being set to substantially the same temperature; and processing process for processing the sheet glass material, while the lump drops down while revolving around its dropping axis.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: In the formation of sheet glass by the overflow downdraw process, the width of usable sheet glass is maximized by downwardly flowing edge portions of the sheet over web-like members and thereafter over extensions which intersect with and are downwardly inclined relative to the web-like members to thin edge portions of the glass flow and maintain sheet width. The extension members are preferably removably attached to the web-like members, greatly facilitating replacement of the more easily damaged extension members.

Abstract: The present invention relates to improvement in a method of supplying a glass ribbon in a molten state to be supplied from a glass melting furnace to a flat glass forming apparatus, which can further improve the smoothness of a flat glass after formed. A glass ribbon 13 supplied from a glass melting furnace 14 to a flat glass forming apparatus 15 is stretched between one pair of tension rollers 24A and 24B in an S-shape and the tension rollers 24A and 24B are rotated while applying a surface pressure to the glass ribbon 13 face via a thin layer of a steam film generated by vaporization of a steam film forming agent. By means of rotation of the tension rollers 24A and 24B, the face of the glass ribbon 13 still in a molten state is polished via the steam film 18.

Abstract: A method and apparatus is described, with which individual rectangular glass panes of thickness between 0.03 mm and 2 mm can be cut from a glass band (2) drawn vertically from a hot forming device (1) in an in-line process with reduced rejects and reduced waste. The method provides that the glass band (2) drawn vertically downward through a vertical zone is cooled below a lower cooling point of the glass and subsequently is deflected through a bending zone (3b) with a bending radius between 0.1 m and 4 m into a horizontal zone (3c) in which it is horizontally oriented. The vertical alignment of the glass band (2) in the vertical zone (3a) is continuously monitored. At least one cutting process is performed on the horizontally oriented glass band (2) in the horizontal zone (3c). The device (20) for monitoring the vertical alignment of the glass band (2) includes at least three sensors (22a, 22b, 22c; 22a′, 22b′, 22c′) that detect the glass edges These sensors can be mechanical rollers.

Abstract: Glass surfaces are produced having a highly polished surface by polishing with a glass polishing liquid having a pH approximating the pH of the glass being polished. The method provides highly polished, smooth, highly accurate glass surfaces suitable for use optical filters and solid camera devices and solid image sensors. Phosphate and fluorophosphate glass filters and the like so formed have hair-like surface flaws, if any, of a width of 7 &mgr;m or less.

Abstract: In a process for improving the smoothness of the surfaces of foils made from thermoplastics materials, particularly glass, the foil is stretched in two directions or dimensions. In a particular method, the foil is laid on top of a first frame and subsequently heated to a temperature which lies in a temperature range within which the foil starts to soften. A second frame which is at the same temperature as that of the foil is then placed on top of the foil so that the latter is effectively clamped between the frames. The two frames and foil is then cooled. The material chosen for the frames is one having a coefficient of thermal expansion smaller than or equal to that of the material of the foil.