Abstract: In a method for ceramising glass plates, in which the plates to be ceramised are hung vertically, a plurality of plates are hung transversely of the transport direction so that they form a plate package. This plate package is passed through a plurality of chambers of an oven in which it is subjected to a direct succession of different temperatures.

Abstract: A method of improving device performance of optical devices formed in optical substrates is disclosed. The method requires that the optical substrate material, for example, lithium niobate, be pre-annealed to form a surface layer with a known congruent composition before diffusing the waveguide material into the substrate. It has been determined that the composition of optical substrates can vary from boule-to-boule, or even along the length of a given boule. These variations affect the diffusion rate of the waveguide material and result in varying mode sizes (both width and depth of the mode). By pre-annealing all material, the diffusion rate will remain relatively constant, regardless of the particular boule. The pre-annealing can be accomplished either by pre-equilibrating the lithium niobate in a vapor-phase equilibrating crucible containing pre-reacted lithium niobate cullet with the desired composition, or pre-equilibrating the lithium niobate to the Li.sub.2 O-rich phase boundary in a two-phase (LiNbO.

Abstract: A method for fabricating a glass CRT panel that exhibits high compressive surface stress and low compaction comprising thermally processing the panel during the initial annealing stage for a prescribed period of time at about those temperatures that produce minimum compaction, which processing temperatures are substantially lower than the processing temperatures that produce minimum surface stresses in the panel, and then cooling the panel to room temperature.

Abstract: A method is provided for the manufacture of glass containers (10) of the type having a sidewall (12) and having a bottom (16) that is thicker than the sidewall (12). The method comprises a step in which a centered portion (44) of the bottom (16) is cooled subsequent to the molding step. Cooling the centered portion (44) is effective to develop a reverse strain in the transition portion (42a) of the sidewall (12) that is proximal to the bottom (16). This reverse strain corrects the strain that is induced by unequal cooling of a relatively thin sidewall (12) and a relatively thick bottom (16) and results in a reduction of annealing time.

Abstract: A new phototropic glass in which the phototropic properties arise from precipitations of silver halide and which in the unirradiated condition is slightly tinted or completely colorless while showing a brown color in the light-exposed condition, comprises, in known phototropic glass compositions, an additional content of at least 0.001 wt % of TeO.sub.2 and/or Yb.sub.2 O.sub.3.

Abstract: The present invention is directed to a four-step process for molding glass articles of high precision and excellent surface figure. A glass preform having an overall geometry closely approximating that of the desired final product is placed into a mold, the mold and preform are brought to a temperature at which the glass exhibits a viscosity between 10.sup.8 -10.sup.12 poises, a load is applied to shape the glass into conformity with the mold, and thereafter the glass shape is removed from the mold at a temperature above the transformation range of the glass and annealed.

Abstract: Metal-coated optical fibers are often employed in high temperature optical communications applications. However, such optical fibers have been found to evidence a substantial decrease in optical transmission as a function of increased temperature. Optical fibers having a temperature-insensitive optical transmission are obtained by annealing a metal-coated optical fiber at a temperature at which optical transmission is substantially the same as that observed at room temperature. Aluminum-coated optical fibers annealed at 560.degree. C. evidence an optical transmission independent of temperature between about -200.degree. C. and at least about 560.degree. C.

Abstract: A method for sealing a rim-like opening in a glass container is described. The surface of the opening is treated with tin and/or titanium oxide precursors and with or without one or more of the groups consisting of fluorides, sulfur oxides and sulfur oxide precursors and then overcoated with a chromium III organic metallic complex. A membrane comprising a thermoplastic film is pressed onto the coated opening surface and heated to cause glass-plastic adhesion, forming a closure. The coating steps may be applied to glass containers immediately after forming and annealing as appropriate, or may be applied to glass containers taken from storage.

Abstract: An improved method for the heat treatment of quartz-glass tubes at temperatures above 1200.degree. C. is disclosed wherein a pressure is maintained within the glass tube which is 3 to 110 mm Hg higher than the pressure on the external surface of the quartz tube over the heated area of the tube for at least the length of time that a temperature of 1200.degree. C. is exceeded. The process is particularly useful for the treatment of quartz-glass tubes within which silicon wafers are disposed for the purpose of diffusing doping agent into silicon wafers or of depositing doped epitaxial layers on silicon wafers.

Abstract: A method for preparing a glass container, and for sealing a glass mouth of a container and the seal are described. The sealing surface, or finish, of the container is subjected to a hot end treatment after forming and before annealing to enhance adhesion between the container finish and a thermoplastic membrane seal. The container is next annealed and after annealing is subjected to a cold end treatment in which the exterior container surface is coated with a material which enhances the lubricity and increases the abrasion and scratch resistance of the container. The container finish only is then subjected to a brief heat treatment sufficient to remove any lubricity enhancing material from the finish. A membrane comprising a thermoplastic film is pressed onto the container finish and heated causing glass-plastic adhesion and forming a closure.

Abstract: An improved acousto-optic device and method featuring an acousto-optic element having an alkali metal oxide-tellurite glass composition comprising at least 92 wt % tellurium dioxide and one or more alkali metal oxides selected from the group consisting of sodium oxide and potassium oxide. A process for decreasing the acoustic attenuation of the aforementioned glass composition by annealing is also disclosed.

Abstract: A process for strengthening a glass object by chemical reaction at the glass surface of the object between the glass and a chemical strengthening agent reactive with the glass to alter its composition and thereby either directly generate compressive stress therein or reduce the thermal expansion coefficient thereof. The object is kinetically contacted with the chemical strengthening agent in a bed comprising gas-fluidized particulate solid material under conditions of temperature and active fluidization such that the reaction proceeds but the formation of either stress-concentrating surface defects or an adherent coating of solid material on the surface of the object is substantially avoided. The object is maintained in the bed for a time sufficient for the reaction to alter the composition of a marginal stratum of the object adjacent the surface. The object is thereafter cooled, producing an object of increased strength and toughness having the marginal stratum under compressive stress.

Abstract: This invention relates to a process for strengthening glass articles immediately after their formation and prior to annealing to remove stresses, and more specifically to increasing the strength of glass containers in terms of internal pressure retention as well as in thermal shock and impact resistance. The process involves allowing the newly-formed glass containers to cool down to a limited extent immediately subsequent to their formation, subjecting the defect-bearing exterior surfaces of the glass containers, which contain surface checks or cracks, to an elevated temperature for a brief period of time to physically alter the crack geometry of the defects and partially heal the same, and then annealing the glass containers to remove stresses therefrom.

Abstract: A process for suppressing the out-diffusion of Li.sub.2 O from LiNbO.sub.3 and LiTaO.sub.3 waveguide structures by exposing the structures to a Li.sub.2 O-rich environment at sufficient vapor pressure that Li.sub.2 O diffuses into the structure as a compensation process and a solid-solid surface interaction occurs. In one embodiment of the invention, the out-diffusion of Li.sub.2 O from LiNbO.sub.3 and LiTaO.sub.3 crystals into which Ti has been diffused is eliminated by annealing the structure in a high purity powder of LiNbO.sub.3 or LiTaO.sub.3. In a second embodiment, the Li.sub.2 O out-diffusion is partially suppressed by annealing the structure in molten LiNO.sub.3. In a third embodiment of the invention, a waveguide structure comprising a Li.sub.2 O-rich guiding layer is formed by annealing LiNbO.sub.3 or LiTaO.sub.3 crystals in a high purity powder of LiNbO.sub.3 or LiTaO.sub.3, which not only suppresses Li.sub.2 O out-diffusion but also promotes Li.sub.2 O in-diffusion into the crystals.

Abstract: Glass containers received on a machine conveyor which passes a plurality of forming machine sections and receives the ware from the sections is coordinated in its relationship to the machine sweepouts, such that a gap is provided periodically in the row of ware carried by the machine conveyor. A bottle-transfer device which transfers the ware from the machine conveyor to a cross-conveyor is operated so that it also will maintain the gap that is provided in the line of ware. The ware on the cross-conveyor moves in line across the open-receiving end of the lehr and is pushed from the cross-conveyor onto the moving lehr mat. By providing a gap in the line of ware, the lehr loader pusher bar may be operated more slowly than in the past and to thereby provide a more stable transfer of ware from the cross-conveyor to the lehr.

Abstract: A process for producing transparent high-annealing-point 96% silica glass comprising the steps of depositing a carbon film on the pore walls of the glass, heating the glass and film under non-oxidizing conditions, and removing the carbon film by oxidation, is described.

Abstract: Glass articles are thermally treated in a gas-fluidized bed of particulate material which is maintained in a quiescent uniformly expanded state of particulate fluidization. Heat exchange within the bed with the material of the bed regulates the bed temperature, and the heat exchange is enhanced by engendering agitation within the bed.

Abstract: A colored glass article composed of a phase-separated borosilicate glass comprising a separated, glassy boron-rich phase having, in association therewith, a coloring metallic silver phase imparting a broad range of absorption colors thereto is provided by heat-treating a specified phase-separated borosilicate glass containing silver and a weak thermal reducing agent such as antimony at a temperature above the annealing point.

Abstract: Thermally crystallizable glasses of the Na.sub.2 O--Ta.sub.2 O.sub.5 --SiO.sub.2 and the Na.sub.2 O--Li.sub.2 O--Ta.sub.2 O.sub.5 --SiO.sub.2 systems, and glass-ceramics made therefrom which are highly transparent, have high indices of refraction, and excellent strength properties. By varying the heat treatment schedule for crystallization of a glass to a glass-ceramic, a specific high index of refraction coming within a prescribed range may be imparted to the finished, transparent glass-ceramic. A transparent glass-ceramic having two or more different indices of refraction may also be produced.

Abstract: A silver-halide photochromic glass of alkali-boroaluminosilicate base composition, having a brown coloration in the faded and darkened state, is provided by treating a potentially photochromic glass of specified composition according to a defined two-phase heat treatment to develop photochromic properties therein.

Abstract: Photochromic glass compositions are photochromically activated by immersion in a hot liquid bath at activation and/or annealing temperatures to provide improved thermal efficiency and control of the degree of activation, making possible the rapid production of uniform photochromic glass products. The hot liquid bath is a molten salt bath having a density very close to that of the glass composition. A silver salt may be employed in the salt bath to prevent silver diffusion from the glass, the required amount of silver being already present in the glass prior to its immersion in the salt bath. The glass is not simultaneously ion exchanged during the annealing process in order to tint and/or strengthen the glass. Coloring may be effected.

Abstract: Glassware treating apparatus in which bottles which have been coated with a non-abrading coating are treated to remove surface irregularities in the coating on the bottom of the bottles. The bottles are gripped and suspended from conveyor means and pass consecutively over a heating zone, a cooling zone and a drying zone for removing the surface irregularities.

Abstract: A method for forming a glass article of a devitrifiable glass having an optimum working temperature in the vicinity of its liquidus temperature, wherein the temperature of the molten glass is, during the molding operation, maintained at considerably higher temperature than both the optimum working temperature and the liquidus temperature, the molded article is passed through water or a layer of wet granular materials floating in water before the temperature of the molded article drops down to the liquidus temperature and before the molded article is deformed to rapidly cool the article to a temperature below the devitrifying temperature.

Abstract: A method for sealing a rim-like opening in a glass container is described. The surface of the opening is treated with tin and/or titanium oxide precursors and with or without one or more of the groups consisting of fluorides, sulfur oxides and sulfur oxide precursors and then overcoated with a chromium III organic metallic complex. A membrane comprising a thermoplastic film is pressed onto the coated opening surface and heated to cause glass-plastic adhesion, forming a closure. The coating steps may be applied to glass containers immediately after forming and annealing as appropriate, or may be applied to glass containers taken from storage.