Abstract: A method of producing a disk having a radius of r and a thickness of 2h from an oxynitride glass by pressing, said method being characterized in that the pressing load (F), the pressing temperature (T), and the pressing time (t) are defined by the expression below. 1900 ≥ T ≥ 100 × log 10 ⁡ ( 0.

Abstract: Present invention suppresses undesirable effects of the bubbles trapped in a silica glass crucible on single crystallization during the pulling process under a high-temperature load. When raw material powder is melted in a mold 1, graphite components of electrodes and impurities contained in the raw material are removed by introducing hydrogen gas and/or oxygen gas immediately after the start of arc discharge. Graphite and impurities are prevented from entering the product crucible, thereby suppressing the volume increase rate of the bubbles and reducing the inner pressure of the bubbles. Gases remaining in voids of an accumulated layer of silica powder formed inside the mold 1 can be replaced with helium gas, by supplying helium gas to the accumulated layer from the mold 1.

Abstract: The invention concerns a quartz glass body for an optical component for the transmission of UV radiation with a wavelength of 250 nm and less, especially for a wavelength of 157 nm, as well as a process for the manufacture of the quartz glass body where fine quartz glass particles are formed by flame hydrolysis of a silicon compound, deposited and vitrified. Suitability of a quartz glass as represented by high base transmission and radiation resistance depends on structural properties caused by local stoichiometric deviations, and on the chemical composition. The quartz glass body according to the inventions is distinguished by a uniform base transmission (relative change of base transmission ≦1%) in the wavelength range from 155 nm to 250 nm (radiation penetration depth of 10 mm) of at least 80%, a low OH content (less than 10 ppm by weight) and a glass structure substantially free from oxygen defect centers.

Abstract: An alkali-free glass applicable to a light transparent glass substrate in a liquid crystal display essentially consists, by weight, of basic elements of 40-70% SiO2, 6-25% Al2O3, 5-20% B2O3, 0-10% MgO, 0-15% CaO, 0-30% BaO, 0-10% SrO, and 0-10% ZnO, and a fining agent of a combination of 0.05-3% Sb2O3 and at least one of 0.05-2% SnO2 and 0.005-1% Cl2, which fining agent makes the resultant glass free from bubbles without the use of toxic As2O3 which has been known as the fining agent in the art.

Abstract: A method of providing a decorative metal pattern on an electrically non-conductive substrate, such as a glass or plastic substrate, which includes applying a mixture of heat fusible material, such as glass or plastic, with a metal having a particle size less than about 500 mesh constituting at least 50% of the mixture, to the substrate in the desired pattern, heating the so-applied mixture until the heat fusible material fuses and bonds to the substrate, cleaning the substrate with the pattern thereon, and a electroplating the pattern with the desired finish metal. In one method in which the mixture includes glass, a negative resist is adhesively secured to the substrate and the mixture is applied. The resist disintegrates upon heating. In another method, used when the substrate is plastic, a mixture of plastic and metal in past form is applied to the substrate by silk screening or pad printing to form the pattern.

Abstract: A mold for shaping the end region and the opening at a selected end of a first, hollow, generally cylindrical, glass tube to enable a second tube, of smaller diameter than the first tube, to be inserted snuggly a first distance within the selected end of the first tube resulting in the two tubes nesting and being self-centered. The mold includes two complementary elongated side pieces having inner side surfaces for, when joined, encircling the periphery of the first tube along a given portion of its selected end region, and an end cap with a cylindrical stub for insertion within the opening of the first tube at its selected end.

Abstract: When molten glass which is under an atmosphere of pressure P, is fed into a vacuum chamber capable of rendering a pressure to the molten glass to be in a range of 38 [mmHg]-(P-50) [mmHg] to perform degassing to the molten glass, a staying time of the molten glass in the vacuum chamber is in a range of 0.12-4.8 hours, whereby there is obtainable an effective degassing function to the molten glass.

Abstract: Methods for producing high purity fused silica (HPFS) glass having desired levels of dissolved hydrogen are provided. The methods involve measuring the level of hydrogen in the cavity of the furnace used to produce the glass and controlling the pressure within the furnace and/or gas flows to the furnace's burners so that the measured concentration has a desired value. In this way, the level of dissolved hydrogen in the glass can be controlled since, as shown in FIG. 3, there is a direct correlation between the hydrogen concentration in the cavity atmosphere and level of dissolved hydrogen in the glass.

Abstract: A method and apparatus are disclosed for the manufacture of an optical fiber preform having incorporated therein a comparatively high concentration of rare earth dopant material, and which thus can be drawn and processed into an optical fiber having low numerical aperture, low core attenuation, and high pumping power absorption. The high concentrations of rare earth dopant material are accomplished through either the “hybrid vapor processing” (HVP) method or a “hybrid liquid processing” (HLP) method, each capable of being practiced in combination or independently of one another. The HVP method involves the vaporization of a rare earth halogen by the exposure thereof to a sufficiently elevated temperature, independently, or contemporaneously with the transport of the resultant rare earth halogen laden vapor, into a glass forming oxidation reaction zone on a flowing stream of essentially an unreactive inert gas, such as helium.

Abstract: A method for roll forming a heated glass sheet utilizes a forming conveyor (62) including forming rolls (66) that are pivotally moved upwardly between horizontal rolls (46) of a horizontal conveyor (44) on opposite sides of a centerline (C/L) of the horizontal conveyor to rollingly engage the heated glass sheet above a plane of conveyance of the horizontal conveyor at its centerline to roll form the glass sheet in cooperation with a forming press (80) having rotatable forming members (82) that rollingly engage the heated glass sheet from above. A second set of forming rolls (68) cooperates with the first set of forming rolls (66) to provide the roll forming. First and second sets of roll cradles (76,90) are mounted by pivotal supports (128,142) on associated first and second carriages (154,156) and moved by first and second actuators (78,92). Lateral movement of the carriages (154,156) provides versatility in the glass sheet shapes that can be formed.

Abstract: In a method of manufacturing a glass substrate for an information recording medium including a step for chemically strengthening the glass substrate by contacting the glass substrate with chemical strengthening processing liquid containing chemical strengthening salt, concentration of Fe and Cr is 500 ppb or less in said chemical strengthening salt, respectively. The concentration may be detected by the use of an ICP (Inductively Coupled Plasma) emission spectrometry analyzing method or a fluorescent X-ray spectroscopy analyzing method.

Abstract: A method and apparatus are disclosed for the manufacture of an optical fiber preform having incorporated therein a comparatively high concentration of rare earth dopant material, and which thus can be drawn and processed into an optical fiber having low numerical aperture, low core attenuation, and high pumping power absorption. The high concentrations of rare earth dopant material are accomplished through either the “hybrid vapor processing” (HVP) method or a “hybrid liquid processing” (HLP) method, each capable of being practiced in combination or independently of one another. The HVP method involves the vaporization of a rare earth halogen by the exposure thereof to a sufficiently elevated temperature, independently, or contemporaneously with the transport of the resultant rare earth halogen laden vapor, into a glass forming oxidation reaction zone on a flowing stream of essentially an unreactive inert gas, such as helium.

Abstract: A process and furnace for melting glass is set forth wherein the majority of the combustion energy over the melting zone of the furnace is provided by oxy-fuel combustion while a majority of the combustion energy over the fining zone of the furnace is provided by air-fuel combustion. In many cases, it will be preferable to provide greater than 70% and up to and including 100% of the combustion energy over the melting zone by oxy-fuel combustion and greater than 70% and up to and including 100% of the combustion energy over the fining zone by air-fuel combustion. By proper tailoring of the combustion space atmosphere through oxy-fuel and air-fuel firing, the present invention can result in an improvement in glass productivity and quality. The present invention can be applied in the construction of a new furnace or can be applied to existing air-fuel furnaces.

Abstract: A clutch mechanism having an easy-to-manufacture and inexpensive constitution, by making use of frictional engaging force in thrust direction, in a coat film transfer tool of automatic winding type. At least at the feed reel side, a clutch mechanism is provided between a driven member of a tape winding portion and a drive side rotary gear for rotating and driving it, and its power transmission makes use of the frictional engaging force in thrust direction between the driven member and drive side rotary gear. This frictional engaging force can be set by properly adjusting the dimensional relation in thrust direction between the mutual constituent members, and therefore the designing and manufacturing conditions of the constituent members are less strict, manufacture is easy, assembling is easy, and hence the manufacturing cost and device cost can be lowered.

Abstract: An aluminosilicate transparent glass has corrosion resistance in the form of mass loss of 4.0 mg or below per 1cm2 of the surface of a specimen upon holding the specimen for five hours in sodium hydroxide solution having concentration of 300 mg(L under test pressure of 50 MPa at 250° C. The glass has a coefficient of thermal expansion within a range from 35×10−7/° C. to 50×10−7/° C. within a temperature range from 100° C to 300° C. The glass has also powdered glass mass loss rate of 0.1% or below in terms of water resistance, acid resistance and alkali resistance.

Abstract: Embodiments include a method for forming a glass which displays visible cracking prior to failure when subjected to predetermined stress level that is greater than a predetermined minimum stress level and less than a failure stress level. The method includes determining a critical flaw size in the glass and introducing a residual stress profile to the glass so that a plurality of visible cracks are formed prior to failure when the glass is subjected to a stress that is greater than the minimum stress level and lower than the critical stress. One method for forming the residual stress profile includes performing a first ion exchange so that a first plurality of ions of a first element in the glass are exchanged with a second plurality of ions of a second element that have a larger volume than the first ions. A second ion exchange is also performed so that a plurality of the second ions in the glass are exchanged back to ions of the first element.

Abstract: The present invention is directed to microemulsion techniques for rapidly preparing photochromic glass nanoparticles and to the photochromic glass nanoparticles so prepared. More particularly, the method of the invention comprises the combination of two microemulsions, one containing a water-soluble silver salt and a glass precursor and the other containing a halide salt and an initiator for glass formation, which process rapidly yields silver halide particles. This invention gives nanometer-sized silver halide particles embedded in glass, thus providing photochromic glass nanoparticles without further annealing, or at most mild annealing. These nanoparticles are valuable as added components to any macro-material that one might wish to have photochromic properties. The particles would impart photochromism while not affecting the physical properties of the material.

Abstract: A method and apparatus are disclosed for the manufacture of an optical fiber preform having incorporated therein a comparatively high concentration of rare earth dopant material, and which thus can be drawn and processed into an optical fiber having low numerical aperture, low core attenuation, and high pumping power absorption. The high concentrations of rare earth dopant material are accomplished through either the “hybrid vapor processing” (HVP) method or a “hybrid liquid processing” (HLP) method, each capable of being practiced in combination or independently of one another. The HVP method involves the vaporization of a rare earth halogen by the exposure thereof to a sufficiently elevated temperature, independently, or contemporaneously with the transport of the resultant rare earth halogen laden vapor, into a glass forming oxidation reaction zone on a flowing stream of essentially an unreactive inert gas, such as helium.

Abstract: Disclosed are a shaping mold for producing an optical fiber guide block which permits highly accurate positioning and fixing of optical fibers, an optical fiber guide block having such excellent properties, processes for the production of these, and an optical fiber array.

Abstract: Disclosed is a method for fabricating high-purity silica glass using a sol-gel processing that includes the steps of: (a) mixing deionized water with a monomer and a dimer to prepare an aqueous premix solution; (b) mixing the aqueous premix solution with a fused silica and a dispersion agent; (c) mixing the resulting mixture to form a dispersed sol; (d) aging the dispersed sol at the ambient temperature to stabilize silica particles, and removing air voids from the sol; and, (e) adding a polymerization initiator and a gelation agent to the aged sol.