Abstract: Processes and methods for preparing glass panels for use with automobiles include mixing and melting glass particles. Molten glass is passed along into a lehr, where the molten glass is annealed. Annealed glass is cut into glass panels. A nozzle systems delivers compressed air to the glass panels to form a curvature for providing a top seal contact area. A nozzle system delivers a second blast of compressed air, which marks the glass panel to identify characteristics of the glass panel.

Abstract: Embodiments disclosed herein include systems and methods for controlling material warp that include placing the shaped mold in a heating device, forming a glass material into a shaped mold, and cooling the glass material and the shaped mold to a predetermined viscosity of the glass material. Some embodiments include, a predetermined time prior to removing the glass material and the shaped mold from the heating device, holding the glass at the mold in the heating device where the heating device temperature is substantially equal to mold and glass temperature just prior to exiting to ambient temperature. Some embodiments include removing the glass material and the shaped mold from the heating device to further cool the glass material and the shaped mold at ambient temperature, where after removing the glass material and the shaped mold from the heating device, the glass material will exhibit controlled or desired material warp.

Abstract: The invention concerns a method for cambering glass sheets that are part of the composition of a laminate, comprising raising the temperature until the sheets soften, and shaping the sheets; in said method, after said shaping, the sheets are rapidly cooled to a temperature no greater than that of the glass-transition range, said cooling being carried out in an atmosphere having a controlled temperature in a forced convection treating the two faces of the sheets exposed to said atmosphere and providing a homogeneous temperature over the entire surface area of said sheets, apart from, possibly, the edges of said sheets if said edges are in contact with the support during said cooling.

Abstract: A glass sheet forming method utilizes first and second upper molds and a lower mold to provide three stage forming. The glass is curved on the upper mold in the first stage but retains straight line elements transverse to the curvature. Transfer of the initially formed glass sheet from the first upper mold to the lower mold then provides the second stage of gravity forming and the glass sheet is then press formed between the second upper mold and the lower mold in the third stage which reduces optical distortion in the central viewing area of the formed glass sheet. In one embodiment the glass sheet is moved horizontally on the lower mold, and in another embodiment the glass sheet is moved horizontally on the first upper mold.

Abstract: To produce a meniscus lens from synthetic quartz glass for use in a microlithography apparatus, which lens has a first optical surface (7) and a second optical surface (8) with the same direction of curvature as the first optical surface (7), SiO2 particles are formed by oxidation or flame hydrolysis of a silicon-containing starting compound and deposited layer by layer on a substrate to form a cylindrical SiO2 blank which contains layers with a surface normal extending in the direction of growth. To allow such layers, which have however the least possible adverse effect on optical or mechanical properties, it is proposed according to the invention that the blank is plastically worked in a hot forming process under the effect of a deforming force to form a preform (6), which has at least the first curved surface (7) and in which the layers are curved in the direction of curvature, and that the meniscus lens is obtained from the preform.

Abstract: A glass sheet is placed on a mold and heated to a first temperature. The glass sheet is then formed into a glass article having a three-dimensional shape using the mold. An isothermal heat transfer device comprising at least one heat pipe is provided in thermal contact with the mold. With the glass article on the mold and the isothermal heat transfer device in thermal contact with the mold, the glass article, mold, and isothermal heat transfer device are transported along a thermally-graded channel to cool the glass article to a second temperature. During the transporting, the isothermal heat transfer device transfers heat from a relatively hot region of the mold to a relatively cold region of the mold.

Abstract: A glass sheet is formed on a mold into a glass article having a three-dimensional shape. The mold, with the glass article thereon, is arranged within an interior space of a radiation shield such that the mold is between a leading end barrier and a trailing end barrier of the radiation shield. The mold, glass article, and radiation shield are translated through a sequence of cooling stations while maintaining the mold between the leading and trailing end barriers, wherein the leading and trailing end barriers inhibit radiation heat transfer at leading and trailing ends of the mold.

Abstract: An apparatus and method for shaping a substantially planar glass substrate are disclosed. The glass substrate is supported on a shaping body having a substantially planar central portion and arcuate edge portions. The substrate is heated by a suitable radiant heat source wherein a thermal shield is used to shield a centrally located surface of the glass substrate so that only edge portions of the glass substrate are heated and softened. Gravity causes the glass substrate edge portions to sag and conform to the shape of the shaping body. In some embodiments, shaping members are pressed against the glass substrate edge portions to aid in the conforming. In certain other embodiments, a plurality of glass substrates are sequentially deformed by a shaping die.

Abstract: A glass molding system and a method of making glass articles using the glass molding system are disclosed. The glass molding system includes an indexing table, a plurality of enclosures arranged along the indexing table, and a plurality of stations defined on the indexing table such that each of the stations is selectively indexable with any one of the enclosures. At least one radiant heater is arranged in at least one of the enclosures. A radiation reflector surface and a radiation emitter body are arranged in the at least one of the enclosures. The radiation emitter body is between the at least one radiant heater and the radiation reflector surface and has a first surface in opposing relation to the at least one radiant heater and a second surface in opposing relation to the radiation reflector surface.

Abstract: Raised features are formed on a transparent substrate having absorption of less than about 20% within a processing wavelength range. A portion of the substrate is irradiated with a light beam to increase the absorption of the irradiated portion of the substrate. Continued irradiation causes local heating and expansion of the substrate so as to form a raised feature on the substrate surface.

Abstract: Provided is a method capable of producing a glass sheet with a bent portion in which a flattened portion has high flatness and high smoothness. A flat glass sheet 20 is radiationally heated with a first portion 21 thereof held between first and second heat-insulating members 31, 32. And then, a second portion 22a, 22b of the flat glass sheet 20 not held between the first and second heat-insulating members 31, 32 is bent.

Abstract: Methods of forming a sheet glass product comprising a plurality of growth-limited glass bump spacers. According to the methods, a glass pane of the sheet glass product is irradiated with laser radiation to locally heat the glass pane at a plurality of spacer localities and induce growth of a plurality of glass bump spacers in the glass pane. The growth of the plurality of glass bump spacers is limited by utilizing a growth-limiting plate comprising a scattering surface portion. The scattering surface portion of the growth-limiting plate mitigates damage to the growth-limiting plate and may also mitigate damage to the glass pane. Vacuum insulated glass products and systems for forming a growth-limited sheet glass product are also provided.

Abstract: A sag-bending system is disclosed. The sag-bending system comprises a sag-bending glass support mold and a perimeter thermal manager. The sag-bending glass support mold has a quadrilateral shape, a collective upper surface, and a periphery. The support mold comprises a plurality of rib members extending in a first direction, each of the plurality of rib members having a curved upper surface shaped to form the collective upper surface having a position and shape to support a quadrilateral-shaped sag-bent glass sheet into a desired contour, each of the rib members further having a lower surface, and a plurality of support members extending in a second direction between at least two of the plurality of rib members, the second direction traverse to the first direction.

Abstract: Processes for producing shaped glass articles with a defined geometry are provided. In some embodiment, the process includes arranging a glass pane on a mould, heating the glass pane by infrared radiation, deforming the heated glass pane over the mould by gravity, negative pressure, and/or positive pressure, and cooling the shaped glass pane to obtain the shaped glass article with a defined geometry.

Abstract: A furnace for heating an object in a space, including a refractory ceramic wall, a heat source, at least one metal plate coated with an adherent layer of ceramic material on one of its principal faces, the coated plate being placed between the wall and the source, the adherent layer being situated facing the source. The coated metal plate acts as a thermal barrier and improves heating efficiency of the heat source. The furnace may for example serve to bend by gravity glass sheets placed on a bending frame.

Abstract: A glass sheet is placed on a mold and heated to a first temperature. The glass sheet is then formed into a glass article having a three-dimensional shape using the mold. An isothermal heat transfer device comprising at least one heat pipe is provided in thermal contact with the mold. With the glass article on the mold and the isothermal heat transfer device in thermal contact with the mold, the glass article, mold, and isothermal heat transfer device are transported along a thermally-graded channel to cool the glass article to a second temperature. During the transporting, the isothermal heat transfer device transfers heat from a relatively hot region of the mold to a relatively cold region of the mold.

Abstract: A glass molding system and a method of making glass articles using the glass molding system are disclosed. The glass molding system includes an indexing table, a plurality of enclosures arranged along the indexing table, and a plurality of stations defined on the indexing table such that each of the stations is selectively indexable with any one of the enclosures. At least one radiant heater is arranged in at least one of the enclosures. A radiation reflector surface and a radiation emitter body are arranged in the at least one of the enclosures. The radiation emitter body is between the at least one radiant heater and the radiation reflector surface and has a first surface in opposing relation to the at least one radiant heater and a second surface in opposing relation to the radiation reflector surface.

Abstract: The present invention relates to a heating apparatus for glass-sheet-forming, which prevents formation of a heater distortion in a portion of a glass sheet facing to a temperature-distributing heat shield.

Abstract: A glass molding system and a method of making glass articles using the glass molding system are disclosed. The glass molding system includes an indexing table, a plurality of enclosures arranged along the indexing table, and a plurality of stations defined on the indexing table such that each of the stations is selectively indexable with any one of the enclosures. At least one radiant heater is arranged in at least one of the enclosures. A radiation reflector surface and a radiation emitter body are arranged in the at least one of the enclosures. The radiation emitter body is between the at least one radiant heater and the radiation reflector surface and has a first surface in opposing relation to the at least one radiant heater and a second surface in opposing relation to the radiation reflector surface.

Abstract: A deformation apparatus for reforming a glass sheet comprises a central portion, a first edge mold movably coupled to a first end of the central portion and configured to be linearly translated along a linear mold axis in a first direction toward the central portion. The deformation apparatus further includes a second edge mold movably coupled to the second end of the central portion and configured to be linearly translated along the linear mold axis in a second direction opposite the first direction and toward the central portion. Methods are also provided including the step of cooling a reformed glass sheet, wherein a greater shrinkage of the reformed glass sheet relative to a shrinkage of the deformation apparatus is accommodated by a movement of at least the first edge mold in a first direction toward the central portion of the deformation apparatus.

Abstract: A method for bending a sheet of material into a shaped article includes providing the sheet of material. A reformable area and a non-reformable area of the sheet of material are heated to a first temperature range corresponding to a first viscosity range. The reformable area of the sheet of material is subsequently heated to a second temperature range corresponding to a second viscosity range. The reformable area of the sheet of material is reformed into a selected shape by at least one of sagging the reformable area of the sheet of material and applying a force to the sheet of material outside of or near a boundary of the reformable area.

Abstract: A glass forming apparatus and a glass forming method are provided, which are capable of retaining the whole press surface at favorable temperatures for pressing glass, and forming a high-quality, efficient glass form. An upper die having a part formed such that the wall thickness of a bottom part, provided as an example of an opposite press surface, decreases gradually from the outside to the inside and the bottom part is formed as a part of the inner wall. In other words, the heat exchange chamber is in approximately a circular truncated cone shape.

Abstract: The present invention relates to a method of manufacturing a formed article comprising forming an upper surface of a forming material comprised of a thermosoftening substance into a desired shape by positioning the forming material on a forming surface of a mold and heating the forming material to a temperature permitting deformation to bring an entire surface of a lower surface of the forming material into tight contact with the forming surface.

Abstract: Disclosed is a method for producing single microlenses or an arrays of microlenses composed of a glass-type material, in which method a first substrate is provided with a surface containing impressions over which a second substrate composed of a glass-type material is placed at least partially overlapping it and is joined therewith under vacuum conditions. The substrate composite is tempered in such a manner that the second substrate softens and flows into the impressions of the first substrate, thereby structuring the side of the second substrate facing away from the first substrate in order to form at least one microlens surface.

Abstract: A method of manufacturing a microlens substrate having a plurality of microlenses includes the steps of: preparing a substrate having two major surfaces and a plurality of concave portions formed in one of the two major surfaces, each of the concave portions having a shape corresponding to that of each of the microlenses being formed in the one of the two major surfaces of the substrate; preparing a base material substrate formed of glass having a transformation point lower than that of a constituent material constituting the substrate; and pressure-joining the substrate to the base material substrate in a heating state. In the pressure-joining step, the substrate is joined to the base material substrate and the concave portions fill with the glass material of the base material substrate which is melted by the heat.

Abstract: An apparatus and method for bending and/or tempering glass substrate(s) are provided. The amount of near-IR radiation which reaches the glass to be bent and/or tempered is limited (e.g., via filtering or any other suitable technique). Thus, the IR radiation (used for heating the glass) which reaches the glass to be bent and/or tempered includes mostly mid-IR and/or far-IR radiation, and not much near-IR. In such a manner, coating(s) provided on the glass can be protected and kept at lower temperatures so as to be less likely to be damaged during the bending and/or tempering process. Heating efficiency can be improved.

Abstract: An apparatus and method for bending and/or tempering glass substrate(s) are provided. The amount of near-IR radiation which reaches the glass to be bent and/or tempered is limited (e.g., via filtering or any other suitable technique). Thus, the IR radiation (used for heating the glass) which reaches the glass to be bent and/or tempered includes mostly mid-IR and/or far-IR radiation, and not much near-IR. In such a manner, coating(s) provided on the glass can be protected and kept at lower temperatures so as to be less likely to be damaged during the bending and/or tempering process. Heating efficiency can be improved. A ceramic (e.g., aluminosilicate) filter or baffle may be used in certain embodiments in order to reduce the amount of mid-IR and/or far-IR radiation reaching the glass to be tempered and/or bent.

Abstract: An object of the present invention is to provide an improved blank such that an optical member of a high homogeneity can be obtained therefrom, and to provide a vessel and a heat treatment method for heat-treating a highly uniform synthetic quartz blank. In a first aspect of the invention a special designed blank is provided showing a concave shaped outer surface. In a second aspect of the invention a special designed vessel for heat-treating blanks is provided, whereby the degree of heat emission at the center is set higher than that of the surroundings.

Abstract: Lighting glass containing 0.3 to 1.0% by weight of Sb as Sb2O3 and 0.5 to 1.0% by weight of S as SO3 in a SiO2—Al2O3—R1O—R22O-based glass (where R1 represents Ca, Sr, Mg and Ba and R2 represents Na, K and Li) in which colloids comprising SbS2 and/or Sb2S3 are generated in the glass.

Abstract: The invention relates to a method and device for the forming of bodies (2) made from glass or glass ceramic in order to produce a three-dimensional end product. A short-wave IR radiation (3) is thus used, furthermore a mould (1) for forming a three-dimensional body (2) made from glass or glass ceramic. According to the invention, the mould (1) is made from a material with a high reflectivity and a high degree of remission thus cooling the mould (1).

Abstract: A glass composition to be softened is fed to a heating zone and is shaped continuously into a cylindrical component in a deformation zone, and the cross-sectional geometry of the component is determined. A feed device, a heating device, and a take-off device are provided, and a glass composition is supplied continuously by the feed device to the heating device, where it is softened, the component being formed from the softened glass composition by means of the take-off device under formation of a deformation zone. To produce a component with only slight deviations from the desired cross-sectional geometry and to provide a flexible apparatus suitable for this purpose, the glass composition is locally heated or cooled in at least one deformation area, which extends over only a part of the circumference of the deformation zone, as a function of a determined deviation of the cross-sectional geometry from a nominal geometry.

Abstract: On molding a glass product by pressing a glass gob by the use of a mold composed of upper and lower dies each of which has a molding surface, a molten glass is supplied as the glass gob onto the molding surface of the lower die. Cooling is carried out for an upper surface of the glass gob supplied onto the molding surface of the lower die. After the cooling, heat radiation suppression is carried out to suppress heat radiation from the glass gob so that an inner part and an upper part of the glass gob are close in temperature to each other. Thereafter; the glass gob is pressed by the molding surfaces of the upper and the lower dies when the glass gob has a viscosity within a range between 103.5 and 106.5 poises (dPa·s). Preferably, the heat radiation suppression is carried out by making a heat shielding member lower in temperature than the inner part of the glass gob approach the upper part of the glass gob in a non-contact state.

Abstract: The present invention is directed to an apparatus for thermal treatment of glass and method and thermally treated glass therefrom. The apparatus is capable of supporting the glass during thermal treatment such as tempering, annealing, bending, and/or shaping which can include any cooling or quenching to remove heat or any combination of these. The apparatus is a support member like a ring or outline mold with a horizontal surface suitable for contacting the glass. The support member has at least a surface with or without a coating for contact with the glass of one or more metals having a thermal conductivity such that the glass heated for shaping cools at a rate not much slower than the cooling rate of unsupported sections of the glass. Suitable metals include those with a thermal conductivity of greater than around 16 BTU/(hour×feet×° F.).

Abstract: An apparatus and method for bending and/or tempering glass substrate(s) are provided. The amount of near-IR radiation which reaches the glass to be bent and/or tempered is limited (e.g., via filtering or any other suitable technique). Thus, the IR radiation (used for heating the glass) which reaches the glass to be bent and/or tempered includes mostly mid-IR and/or far-IR radiation, and not much near-IR. In such a manner, coating(s) provided on the glass can be protected and kept at lower temperatures so as to be less likely to be damaged during the bending and/or tempering process. Heating efficiency can be improved. A ceramic (e.g., aluminosilicate) filter or baffle may be used in certain embodiments in order to reduce the amount of mid-IR and/or far-IR radiation reaching the glass to be tempered and/or bent.

Abstract: An apparatus and method for bending and/or tempering glass substrate(s) are provided. The amount of near-IR radiation which reaches the glass to be bent and/or tempered is limited (e.g., via filtering or any other suitable technique). Thus, the IR radiation (used for heating the glass) which reaches the glass to be bent and/or tempered includes mostly mid-IR and/or far-IR radiation, and not much near-IR. In such a manner, coating(s) provided on the glass can be protected and kept at lower temperatures so as to be less likely to be damaged during the bending and/or tempering process. Heating efficiency can be improved.

Abstract: Lighting glass containing 0.3 to 1.0% by weight of Sb as Sb2O3 and 0.5 to 1.0% by weight of S as SO3 in a SiO2—Al2O3—R1O—R22O-based glass (where R1 represents Ca, Sr, Mg and Ba and R2 represents Na, K and Li) in which colloids comprising SbS2 and/or Sb2S3 are generated in the glass.

Abstract: A method for manufacturing a discharge tube, including heating a quartz tube by irradiation and closing it shut, is presented, in which variation of the heating temperature of the quartz tube can be reduced. Laser light is irradiated on a portion of the quartz tube, and in the step of sealing the portion of the quartz tube onto which laser light has been irradiated, the laser light is scanned while oscillating back and forth. The intensity of the laser light is controlled such that the intensity of the laser light when the size of a displacement of the laser light is maximal is smaller than the intensity of the laser light when the size of the displacement of the laser light is minimal.

Abstract: To increase the strength of the glass panel of a CRT, the temperature of the glass panel is reduced during reforming from a temperature above, preferably at least 30° C. above the annealing point, to a temperature well below, preferably at least 80° C. below the strain point. This induces high surface compression in the glass panel, paired with a low rate of compaction. The glass panel is subsequently not subjected to the usual annealing step.

Abstract: A method for manufacturing a discharge tube, including heating a quartz tube by irradiation and closing it shut, is presented, in which variation of the heating temperature of the quartz tube can be reduced. Laser light is irradiated on a portion of the quartz tube, and in the step of sealing the portion of the quartz tube onto which laser light has been irradiated, the laser light is scanned while oscillating back and forth. The intensity of the laser light is controlled such that the intensity of the laser light when the size of a displacement of the laser light is maximal is smaller than the intensity of the laser light when the size of the displacement of the laser light is minimal.

Abstract: A glass sheet is separated by propagating a crack in the glass sheet by moving a laser beam across the surface of the glass sheet along a desired line of separation and then streaming coolant at the glass sheet at a predetermined distance behind the laser beam. By altering the profile of a laser beam used to score glass, and by changing the distance between the spot where the laser beam impinges on the glass and the spot struck by the stream of coolant, the penetration depth of the resultant median crack can be controlled.

Abstract: A method of and apparatus for bending and tempering a sheet of glass heated to a formable state provides an improved rigid mold and pressing member for pressing the heated sheet against the rigid mold which cools and bends the sheet. The pressing member includes a conformable pressing element which permits a manifold to be positioned between the rigid mold and the pressing member to direct a gas to cool the heated sheet of glass during bending. The conformable pressing element is pressurized into a convex shape for initially pressing on a portion of the heated sheet and for rolling the heated sheet onto the rigid mold. The rigid mold and the conformable pressing element may each include a cover to increase the heat transfer from the heated sheet to the bending and tempering apparatus. Furthermore, the covers may have increased thermal conductivity in their peripheral regions for increased cooling of the edge of the sheet of glass.

Abstract: Disclosed are a molding apparatus for glass optical elements a plurality of molds each constituted of an upper mold and a lower mold, a matrix supporting the molds, and heating means wound around the matrix for heating the molds, wherein the matrix extends in a longitudinal form and has a constant width, wherein the plurality of the molds are arranged in the matrix in a line so that the center of each mold is located on a center line of the matrix, and wherein a distance between the heating means and the matrix is constant at least at an edge of the matrix in a transverse direction, and a molding method for optical elements comprising the steps of: softening a plurality of glass material pieces by heat; and making a simultaneous press molding of the glass material pieces with a plurality of molds, constituted of upper and lower molds, arranged in a longitudinal form matrix, in a line extending in a longitudinal direction, wherein each mold is heated by thermal conductance from the matrix heated by heating mea

Abstract: A method of and apparatus for bending and tempering a sheet of glass heated to a formable state provides an improved rigid mold and pressing member for pressing the heated sheet against the rigid mold which cools and bends the sheet. The pressing member includes a conformable pressing element which permits a manifold to be positioned between the rigid mold and the pressing member to direct a gas to cool the heated sheet of glass during bending. The conformable pressing element is pressurized into a convex shape for initially pressing on a portion of the heated sheet and for rolling the heated sheet onto the rigid mold. The rigid mold and the conformable pressing element may each include a cover to increase the heat transfer from the heated sheet to the bending and tempering apparatus. Furthermore, the covers may have increased thermal conductivity in their peripheral regions for increased cooling of the edge of the sheet of glass.

Abstract: A method and an apparatus for producing an optical element capable of performing a molding temperature control required for a plurality of independent molding blocks in a short period of time, and continuously and simultaneously producing a plurality of different optical elements having a high degree of accuracy at a low cost is provided.

Abstract: A furnace is provided for the heating of glass sheets to be bent, whereby precise control of the temperature profile across a sheet may be achieved, resulting in improved control over the shape to which the sheet is bent. The furnace has at least one differential heating zone provided with a plurality of main heating elements, and at least one shield for directing heat radiated by said heating elements whereby a controlled differential heating of the glass sheet may be achieved. Transport means, e.g. wheeled boxes, are provided to advance the sheet through the furnace and bending means, e.g. gravity bending ring moulds, may bend the sheet either during, or subsequent to, the heating step.

Abstract: The invention relates to a method and apparatus for developing an edge stress in a windshield bending furnace. Adjacent to a ring mould is located a metallic, flat extra frame in a manner that the lower surface of a bent windshield remains at a small distance from extra frame. The compression stress of glass edge can be adjusted by varying the distance of extra frame from glass and/or by varying its glass-oriented dimension.

Abstract: A glass rod used as a molding material is inserted into a cylinder, pressed and heated with a temperature gradient in which the tip side of the glass rod is at a higher temperature. The glass rod is melted on the tip side thereof, and it is solidified on the rear side in the vicinity of the inlet of the cylinder, the solid portion functioning as a plunger when the rear side is pushed. When the glass rod is forwardly moved, the molten glass on the tip side is injected from an injection nozzle and is filled in the cavity of a forming mold. Since the glass rod itself is made of a molding material and functions as a plunger, when the tip side is melted and consumed, the solid portion on the rear side is forwardly moved and melted. It is thus possible to perform continuous mold forming without complicating the mechanism and steps and to improve the quality of the molded product.

Abstract: Apparatus operable in accordance with the method of the present invention is provided for selectively cooling areas of a glass sheet during heating in the lehr in order to eliminate hot spots and minimize undesirable sagging of portions of the glass sheet. The apparatus includes a gas hearth block upon which the glass sheet is supported during heating and an air nozzle or air nozzles connected to a source of compressed room temperature air located over those areas of the glass sheet that tend to develop hot spots. The air nozzle or air nozzles blow cooler air onto those selected areas of the glass sheet and even out the temperature of the heated glass sheet. This may be done prior to forming and/or tempering the glass sheet. The method and apparatus of the present invention is particularly useful with automobile glazings, such as sidelights and rear windows, bearing peripheral dark banding which show an increased tendency to sag during heating, particularly at the top edge portions.

Abstract: Material, such as, for example, sealed double bags of asbestos containing waste or ash from infectious waste or toxic material or radioactive waste, is transferred into a glass melt of a furnace. Gas bubbles released into the melt form a gas curtain which causes enhanced mixing of the material to accelerate the dissolution of the components of the added material. The presence of the gas bubbles reduces the cross-section of the molten glass through which current passes, which in turn increases the electrical resistance of the glass melt and therefore increases power generation of the melt or power density at constant current. A highly oxidizing hot region is produced under the location where the material is introduced into the furnace. Drawn off glass is shaped and quenched into at least two sizes of approximate spheres. The spheres are cooled sufficiently fast to be thermally tempered and have a surface compressive strength level above 5000 psi.

Abstract: A method of and apparatus for establishing a predetermined thermal profile in a glass sheet immediately prior to press bending outside the heating furnace. The press bending members are provided with arrays of heating elements that are individually or zone regulated to assist in establishing an optimum temperature profile in the glass sheet conducive to proper bending. The temperature profile established in the heated sheet by the arrays of heating elements is coordinated with that established in the furnace and subsequently, modified by heat dissipation as the glass sheet advances to the bending station to achieve the proper bending temperature. The heating elements can also be utilized to create a temperature profile in the glass sheet generally higher than that originally established in the furnace.