Abstract: A method for manufacturing an optical fiber preform that can produce an optical fiber having desired characteristics over the longer length thereof. A crude preform provided with a core region and a cladding region is prepared (Step S1), and at a plurality of positions in the longitudinal direction of the crude preform, a refractive index profile in the cross-section of the crude preform is measured (Step S2). Then, the shape of the cladding region is demarcated based on the shape of the profile (Step S3). Subsequently, the crude preform is ground based on the results of the demarcation (Step S4). Thus, an optical fiber preform that enables the manufacture of an optical fiber having target characteristics is manufactured.

Abstract: The production of low-loss, tunable composite ceramic materials with improved breakdown strengths is disclosed. The composite materials comprise ferroelectric perovskites such as barium strontium titanate or other ferroelectric perovskites combined with other phases such as low-loss silicate materials and/or other low-loss oxides. The composite materials are produced in sheet or tape form by methods such as tape casting. The composite tapes exhibit favorable tunability, low loss and tailorable dielectric properties, and can be used in various microwave devices.

Abstract: An invert mechanism for moving parisons between a pre-forming station and a finishing forming station of a glass forming machine is disclosed. The mechanism is disposed above a cover plate of a frame of the glass forming machine. An electric motor is disposed with its horizontal longitudinal axis above the cover plate. A driven shaft of the electric motor is connected to a horizontal invert shaft by means of a transmission. Between the driven shaft of the electric motor and the transmission a planetary gear is connected.

Abstract: A method suited for producing thin fused glass articles includes, in preferred aspects, preparing a dry gel having edges configured to reduce or eliminate warping of the gel during densification of the gel. Preferred aspects include partially densifying the gel, machining the gel into a suitable shape, and fully sintering the gel. The gel preferably is a hybrid incorporating silicon alkoxide and fumed silica particles, and it preferably is machined to have chamfered edges. The method is easier and more cost-effective than those previously known, and it allows for production of high-quality articles for use in, for example, photomask systems as pellicles.

Abstract: Disclosed herein are a highly porous ceramic having a high porosity of not less than 60% and a pore density of not less than 108 pores/cm3 fabricated from expandable microspheres and a preceramic polymer, and a method for fabricating highly porous ceramic. The method for fabricating highly porous ceramic from expandable microspheres and a preceramic polymer comprises the steps of: homogeneously mixing a preceramic polymer powder and expandable hollow microspheres, if necessary, a ceramic powder, and molding the mixture to form a molded body; heating the molded body to expand it; curing the expanded molded body; and pyrolyzing the cured molded body. Since the highly porous ceramic has a higher porosity and pore density than conventional porous ceramics, it can be suitably used for various high temperature structure materials, kiln furniture, bulletproof materials, shock-absorbing materials, insulating materials, refractory materials, lightweight structure materials, etc.

Abstract: Methods of manufacturing glass sheets with manufacturing systems that including platinum-containing components are provided. The method includes providing a barrier coating to reduce the hydrogen permeability of the platinum-containing components which reduces the propensity for blistering of glass sheets made using the components.

Abstract: A method and a machine for the production of hollow glassware articles, by the blow-and-blow, press-and-blow, press-and-blow paste mold and direct-press processes in a glassware forming machine including single or multiple machine sections each having single or multiple-cavity, comprising: forming a parison in an inverted orientation, into a blank mold and a first transferable and open-able neck ring mold held by an inverting apparatus having a first and a second diametrically opposed arms, each arm holding a transferable and open-able neck ring mold; inverting the parison held by the first transferable and open-able neck ring mold, by rotating the first arm 180° to an upright orientation at an intermediate station, while the second arm with a second transferable and open-able neck ring mold is simultaneously placed at the parison forming station; transferring the first transferable and open-able neck ring mold holding the parison in an upright orientation, from the intermediate station, to a blow mold statio

Abstract: The invention relates to a method for changing glass compositions in continuously operated melting installations which has a significantly shortened melt changeover time and therefore lower costs and in which the glass quality is not adversely affected.

Abstract: Sol-gel process for the production of optical fiber preforms or overcladdings by preparing a sol, gelling the sol, drying the wet gel to a dry porous gel and densifying the dry gel to fully dense glass, wherein during the calcination treatment from 350° C. to 900° C. to remove organic impurities in the dry gel, it is carried out at least one reduced-pressure phase at a pressure comprised between about 0.01 and 0.5 bar.

Abstract: A glassware forming machine system includes a glassware forming machine having first operating mechanisms for converting gobs of molten glass into articles of glassware, a gob delivery system having second operating mechanisms for delivering gobs of molten glass to the glassware forming machine, a ware handling system having third operating mechanisms for receiving and conveying articles of glassware from the glassware forming machine, and an electronic control system for controlling and coordinating operation of the first, second and third operating mechanisms. The electronic control system includes a machine controller coupled to the first operating mechanisms of the glassware forming machine for controlling and coordinating operation of the first operating mechanisms to produce articles of glassware.

Abstract: Each mold half is held by means of a mold half holding mechanism which can be driven so as to pivot in a reciprocating manner about a common vertical hinge column by means of a vertical shaft (6; 7), which is mounted in a rotatable manner in a frame (2) of the glass forming machine (1), and by means of first intermediate members. Each shaft (6; 7) is connected via a lever mechanism (8; 9) to a common drive shaft which can be pivoted in a reciprocating manner by means of a drive element (19), which can be moved linearly in a reciprocating manner, of a drive (20) and by means of second intermediate members (18). The drive element (19) can be mounted on a nut (26) and secured against rotating about a longitudinal axis (39) of the drive element (19) by means of a guide device (32). The nut (26) is in engagement with a spindle (33). The spindle (33) is mounted in an axially fixed, rotatable manner and can be driven rotationally in a reciprocating manner by means of the drive (20).

Abstract: Disclosed is an optical glass comprising, expressed as weight percentages, greater than or equal to 18 percent and less than 30 percent of SiO2, greater than or equal to 12 percent and less than 23 percent of BaO, 22 to 37 percent TiO2, greater than or equal to 7 percent and less than 16 percent Nb2O5, 5 to 20 percent of Na2O, 0 to 6 percent of K2O, 0 to 5 percent of CaO, 0 to 5 percent of SrO, 0 to 4 percent of ZrO2, 0 to 3 percent of Ta2O5, 0 to 1 percent of Sb2O5, and greater than or equal to 0 percent and less than 0.5 percent of P2O5, and by essentially not comprising PbO, As2O3, and F. The optical glass exhibits a refractive index (nd) greater than or equal to 1.80 and an Abbé number (vd) less than or equal to 30. A method of manufacturing a glass material for press molding is disclosed.

Abstract: The present invention provides a process for preparing an aluminum-titanate-based sintered body comprising the step of firing, at 1250 to 1700° C., a formed product prepared from a raw material mixture containing 100 parts by weight of a mixture of TiO2 and Al2O3 in a weight ratio of TiO2:Al2O3=40:60 to 60:40, and 1 to 15 parts by weight of an alkali feldspar represented by the formula:(NaxK1-x)AlSi3O8 wherein 0?x?1. According to the process of the present invention, it is possible to obtain an aluminum-titanate-based sintered body in which inherent properties of an aluminum titanate, i.e., a low coefficient of thermal expansion and high corrosion resistance are maintained, the mechanical strength thereof is improved, and which can be stably used even under high temperature conditions.

Abstract: In a first polishing step, or in a first half of a super precision polishing, a surface of a glass substrate is polished with a first suspension. The first suspension contains particles and a dispersion agent in which the particles are dispersed. The main ingredient of the particles is silicon dioxide (SiO2), and the average size (D50) of the particles is equal to or less than 100 nm. The dispersion medium comprises an acid solution the pH of which is equal to or less than 4. In a second polishing step, or in a latter half of the super precision polishing, the surface of the glass substrate is continuously polished with a second suspension. The second suspension contains particles and a dispersion agent in which the particles are dispersed. The main ingredient of the particles is silicon dioxide (SiO2), and the average size (D50) of the particles is equal to or less than 100 nm. The dispersion medium comprises an alkaline solution the pH of which is equal to or more than 8.5.

Abstract: The double-walled noble metal duct (1) for conducting a glass melt has an outer noble metal pipe (1b) and an inner noble metal pipe (1a) extending within the outer pipe, so that an inner space (21) is formed within the inner pipe and an intermediate space (23) is formed between the inner pipe (1a) and the outer pipe (1b). The intermediate space is completely filled with glass melt when the double-walled noble metal duct conducts the glass melt, when the outer pipe (1b) has an exhaust vent (4). The outer pipe (1b) also has a bottom outlet (7) communicating with the intermediate space for removal of oxygen bubbles formed on the outer wall. The noble metal duct can be used in glass conditioning and in the manufacture of glass articles that are devoid of polyvalent ions.

Abstract: A device for supporting a ribbon of glass, having at least one roller arranged in an area of an underside of the ribbon of glass. In order to keep a ribbon of glass as free as possible of mechanical damage during production, at least one support device is assigned to the roller. With an actuating device the roller or the support device can selectively be contacted with the underside of the ribbon of glass, wherein the support device is in contact, at least in some areas, with the underside of the ribbon of glass by way of a gas cushion. The rollers are then employed at the start of production or after a ribbon of glass has snapped off in order to transmit an advancement force to the ribbon of glass.

Abstract: A method of manufacturing an optical glass element for which flatness and smoothness of the surfaces of the optical glass element can be improved while securing the similarity of the cross-sectional shape of the optical glass element to that of the mother glass, and for which continuous production involving few steps can be carried out, and an optical glass element manufactured using the method. A mother glass is prepared, which has a cross-sectional shape substantially similar to a desired cross-sectional shape of the optical glass element, and the mother glass is drawn while heating to a predetermined temperature such that the mother glass has a viscosity of 105 to 109 poise.

Abstract: A roller table for supporting and transporting a hot glass strand. A plurality of rollers arranged parallel to each other and perpendicular to the transport direction of the glass strand are capable of being selectively rotated in the direction of transport of the glass strand. At least some of the rollers are sleeves, the casings of which are which are gas-permeable on at least a portion of their surfaces and the casings are provided with a supply of pressurized gas which is emitted through the openings of the gas-permeable surfaces.

Abstract: The forming apparatus of the present invention preferably includes an orifice on top of the trough. The uniquely shaped orifice substitutes for the weirs as the controlling entity for glass thickness. The orifice is designed such that as it deforms, it maintains a linear flow characteristic with respect to its length. As the orifice is made larger by the applied stress, the percentage width increase is the same over its length and consequently the percentage flow increase is the same over the length of the orifice. In another embodiment, the present invention provides an adjustment to change the flow characteristics of the trough to compensate for the degradation of the forming trough during an extended production run. A flow control plug can be inserted into the trough, such that flow dynamics can be altered during hot operation by insertion, removal or position adjustment of the flow control plug.

Abstract: The present invention provides a method of forming a glass article having a transparent hydrophobic surface during a glass-forming operation. In accordance with the method, a plurality of solid particles of inorganic material having an average diameter of less than about 400 nm are applied to a surface of the glass article when the glass article is at a temperature within the range of from about 700° C. to about 1200° C. The inorganic particles fuse to the surface of the glass article to form the transparent hydrophobic surface. Optionally, a fluorosilane agent can be applied to the transparent hydrophobic surface to further increase its hydrophobicity. The transparent hydrophobic surface has a nano-structured texture, which makes the surface of the glass article very hydrophobic and easy to clean.