Abstract: A method of making a glass product comprising: providing a feedstock formed from at least one sedimentary rock comprising at least two minerals suitable for making the glass product; melting the feedstock to form a melt; and forming a glass product from the melt.

Abstract: An optical element manufacturing method has a preparation step of preparing a lower mold and an upper mold. The lower mold has an outer shape restricting surface for the optical element. A reference surface formation step of forms a positioning reference surface on a rim of the optical element by heating the outer shape restricting surface of the lower mold and dropping molten glass onto the lower mold surface so as to collide with the lower mold surface and spread to be in contact with the outer shape restricting surface. A pressing step forms the two opposed optical function surfaces of the optical element by pressing the glass. A temperature of the outer shape restricting surface in the reference surface formation step and the pressing step is higher than a temperature which is 100° C. less than a glass transition temperature (° C.) of the glass.

Abstract: The invention relates to a furnace for continuously melting a silica-containing compound comprising at least two series-arranged baths each of which is provided with at least one burner submerged into molten material. Said invention also relates to a method for producing silica-containing compounds, the silica and the melt thereof being loaded into the first bath. The invention is intentionally adapted for the high performance production of frits for re-enameling ceramic products (sandstone, faience and burnt clay) at low temperatures and a fast transition time.

Abstract: An optical class comprising, by mass %, 12 to 30% of total of B2O3 and SiO2, 55 to 80% of total of La2O3, Gd2O3, Y2O3, ZrO2, Nb2O5 and WO3, 2 to 10% of ZrO2, 0 to 15% of Nb2O5, 0 to 15% of ZnO and 0% or more but less than 13% of Ta2O5, wherein the ratio of the content of Ta2O5 to the total content of La2O3, Gd2O3, Y2O3, Yb2O3, ZrO2, Nb2O5 and WO3 is 0.23 or less, the ratio of the total content of La2O3, Gd2O3, Y2O3 and Yb2O3 to the total content of B2O3 and SiO2 is from 2 to 4, the optical glass having a refractive index nd of 1.86 or more and an Abbe's number ?d of 38 or more, and a rod shaped glass shaped material and an optical element formed of the above optical glass each.

Abstract: For providing glass-ceramics having properties suitable for use as a substrate of an information storage medium of next generation such as one for the perpendicular magnetic recording system without employing arsenic and antimony components which adversely affect human beings and the environment, there are provided glass-ceramics comprising SiO2, Li2O and Al2O3 on oxide basis, comprising lithium disilicate as a crystal phase, and comprising one or more elements selected from the group consisting of Sn, Ce, Mn, W, Ta, Bi, Nb, S, Cl and F.

Abstract: The invention starts from a known component of quartz glass for use in semiconductor manufacture, which component at least in a near-surface region shows a co-doping of a first dopant and of a second oxidic dopant, said second dopant containing one or more rare-earth metals in a concentration of 0.1-3% by wt. each (based on the total mass of SiO2 and dopant). Starting from this, to provide a quartz glass component for use in semiconductor manufacture in an environment with etching action, which component is distinguished by both high purity and high resistance to dry etching and avoids known drawbacks caused by co-doping with aluminum oxide, it is suggested according to the invention that the first dopant should be nitrogen and that the mean content of metastable hydroxyl groups of the quartz glass is less than 30 wtppm.

Abstract: The present invention relates to a dental glass containing 50 to 70 wt. % of SiO2, 5 to 18 wt. % of Al2O3, 6.1 to 30 wt. % of MgO, 1 to 15 wt. % of La2O3, 1 to 15 wt. % of WO3, 0.1 to 8 wt. % of ZrO2, and optionally further oxides except for the oxides of Sr, Ba or alkali metals, wherein the stated quantities in total add up to 100 wt. %.

Abstract: A preform production apparatus for precision press molding, which is downsized but can produce preforms at a lower cost, and a production method thereof using the apparatus are provided. The production method of a preform for precision press molding includes forming a molten glass body C by way of receiving and cutting molten glass A, being flowed continuously from a discharge nozzle 2, by a support member 1 or by way of allowing molten glass to fall in drops from a discharge nozzle 2 and receiving thereof by a support member 1, and transferring the molten glass body C from the support member 1 to a mold 5 by way of displacing the support member to near the mold 5, disposed not to be beneath the discharge nozzle 2, while increasing the viscosity of the molten glass body C on the support member 1.

Abstract: The present invention is that, in a glass passage where it is usual that the flow rate near the center tends to become high, stirring effect for the glass flow is enhanced whereby temperature distribution is made uniform and generation of stria and devitrification is reduced. As a result, there is provided a passage by which glass blocks of highly refractive glass or low-Tg glass in recent years where selection of molding conditions is very difficult are able to be obtained easily and in high quality. Another object is to provide a passage by which simple control in a short distance is made possible whereby miniaturization of the device is possible even in the conventional glass. A passage which is connected to a melted glass vessel and flows out the melted glass which is characterized in that, in the inner wall, the above-mentioned passage has a control board for controlling the flow of the melted glass.

Abstract: Al2O3—Y2O3—ZrO2/HfO2 ceramics (including glasses, crystalline ceramics, and glass-ceramics) and methods of making the same. Ceramics according to the present invention can be made, formed as, or converted into glass beads, articles (e.g., plates), fibers, particles, and thin coatings. The particles and fibers are useful, for example, as thermal insulation, filler, or reinforcing material in composites (e.g., ceramic, metal, or polymeric matrix composites). The thin coatings can be useful, for example, as protective coatings in applications involving wear, as well as for thermal management. Certain ceramic particles according to the present invention can be are particularly useful as abrasive particles.

Abstract: A method of manufacturing a glass substrate for a display including the steps of: preparing a glass raw material blended so as to adjust as, on the basis of mass percentage, SiO2 40-70%, Al2O3 2-25%, B2O3 0-20%, MgO 0-3.5%, CaO 0-15%, SrO 0-10%, BaO 0-2%, ZnO 0-10%, R2O 0-25% (where R denotes at least one of Li, Na and K), As2O3 0-0.4%, Sb2O3 0-0.9%, and 0.1%<SnO2<0.5%; and melting the material and forming the substrate with contact with a platinum group element or a platinum group element alloy in at least a part of the melting and forming; wherein the substrate has a surface area of 0.1 m2 or more, a thickness of 2.5 mm or less, and surface projections of 2 pieces/m2 or less, the surface not being ground, and wherein the substrate has 40 pieces/kg or less of stones of a platinum group element or a platinum group element alloy.

Abstract: An internally nucleated, toughened cordierite glass-ceramic is disclosed. The cordierite glass-ceramic has good oxidation resistance and fracture toughness and coefficient of thermal expansion rivaling that of silicon nitride. The glass-ceramic may be cast as a liquid. Annealing produces a material of high crystallinity combining high hardness, high Young's modulus, good thermal stability, high strength, low density and good dielectric properties. The glass-ceramic comprises interlocking crystalline phases dominated by cordierite and a second phase having an elongated or acicular structure. A third phase may comprise a crystalline ceramic that promotes acicularity of the second phase. The third phase is preferably capable of twinning.

Abstract: Abrasive particles and methods of making the same. Embodiments of the invention can be used to make abrasive particles. The abrasive particles can be incorporated into a variety of abrasive articles, including bonded abrasives, coated abrasives, nonwoven abrasives, and abrasive brushes.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: [Object] To provide a high-refractivity high-dispersion optical glass having excellent stability [Solution Means] An optical glass which is formed of an oxide glass containing 30 to 70 cationic % of Bi3+ and has a liquidus temperature of 800° C. or lower.

Abstract: The invention relates to dental glass-ceramics and a process for producing them and their use, with these comprising at least one crystal phase containing xenotime or monazite or mixtures thereof.

Abstract: The balance spring is made from a photostructurable glass plate by UV irradiation, thermal treatment and etching, said glass having a Young's modulus thermal coefficient CTE0. The value CTE0 of selected zones of the balance spring are altered to a value CTEi by UV irradiation through one or several masks, possibly completed by a thermal treatment.

Abstract: Disclosed is an ultraviolet absorbing glass for fluorescent lamps which is composed of a borosilicate glass containing, in mass %, 60 to 80% of SiO2, 1 to 7% of Al2O3, 10 to 25% of B2O3, 3 to 15% of Li2O+Na2O+K2O, 0 to 5% of CaO+MgO+BaO+SrO+ZnO, 0.001 to 0.05% of Fe2O3, 0.1 to 5% of CeO2, 0.01 to 5% of SnO+SnO2 and 0.01 to 5% of ZrO2+ZnO+Nb2O5, and having an average linear expansion coefficient in a range of 36 to 57×10?7/° C. at 0 to 300° C. defined in JIS R 3102.

Abstract: A method for changing the width of particle thickness size distribution of flakes of material with the flakes being formed by a process that includes the steps of feeding a stream of molten material in a downwards direction into a rotating cup or disc and allowing the material to pass over the edge of the cup or disc in such a manner as to be forced into a gap between a pair of plates surrounding the cup or disc. The movement of material in the process used for forming the flakes is maintained in an angular direction and effected by a flow of air passing through the plates and either side of the material, so as to pull the stream of material in a manner for keeping it flat and, further, to pull the stream of material so that, as solidification of the material is effected, the sheet of material so formed is broken into flakes.

Abstract: A precision press-molding preform for producing an optical element for use in an imaging device using a CCD type or MOS type solid image-sensing device, which is formed of a glass composition containing, by mol %, 25 to 45% of P2O5, 0.5 to 10% of CuO, 0 to 10% of B2O3, 0 to 10% of Al2O3, 2 to 30% of Li2O, 0 to 25% of Na2O, 0 to 15% of K2O, the total content of Li2O, Na2O and K2O being 3 to 40%, 3 to 45% of BaO, 0 to 30% of ZnO, 0 to 20% of MgO, 0 to 20% of CaO, 0 to 20% of SrO, 0 to 10% of Bi2O3, 0 to 5% of La2O3, 0 to 5% of Gd2O3 and 0 to 5% of Y2O3, the total content of these components being at least 98%, and a precision press-molding preform, which is formed of a phosphate glass containing CuO, an alkali metal oxide, BaO and ZnO and having a BaO content/ZnO content molar ratio (BaO/ZnO) of greater than 1.

Abstract: The invention relates to a device capable of rotating about an axis (6), for the refining and homogenization of glass, comprising a receptacle (1) intended to receive the molten glass to be treated, a vacuum compartment (2) and at least one glass outlet orifice (5, 19), furthermore including a conveying means (7, 8, 17, 18) for conveying the molten glass from the feed receptacle (1) to the vacuum compartment (2). It also relates to a process for manufacturing substrates employing the device according to the invention, and to the substrates thus manufactured.

Abstract: Molten glass is press-molded by a metallic die in which a cylindrical body is provided in a vertically standing manner at a central part of a bottom surface of a bottomed hole and a molding surface corresponding to a chamfering shape of an outer peripheral edge surface of a glass substrate is consecutively formed in an inner peripheral wall, and a glass substrate precursor provided with the chamfering shape axially consecutive on an outer peripheral surface thereof and a through hole formed at a central part thereof is thereby formed. The glass substrate precursor is cut perpendicular to an axial direction to be separated into respective glass substrates. Next, the respective glass substrates are subjected to a lapping process and a polishing process, if necessary, to produce a glass substrate as a final product. According to the manufacturing method, a glass substrate for information recording medium whose inner and outer peripheral edge surfaces are chamfered can be manufactured with an improved efficiency.

Abstract: An apparatus for lubricating a mold in an individual section glassware forming machine by combustion of at least one combustible gas. The apparatus includes a shaft positioned adjacent to the mold, a burner head on the shaft and including a spark electrode for igniting a combustible gas exiting the burner head, a manifold on the shaft spaced from the burner head for connection to a combustible gas supply, and a gas passage within the shaft extending from the manifold to the burner head.

Abstract: A preform manufacture apparatus is provided which can produce a preform at low cost. A preform manufacture apparatus 1 has a first mold 20 which receives molten glass, and a second mold 50 which receives a molten glass block moved from the first mold 20. The first mold 20 has a receiving surface 20A which receives molten glass, and is dividable into two or more of split dies 30 and 40 at the receiving surface 20A.

Abstract: A high-quality glass gob is easily obtained that is adapted to glass of recent years having higher refractive indices or lower Tg of which the molding temperature is close to or below the temperature of liquid phase. A nozzle, which is connected to a bath of molten glass to flow out the molten glass, has a site disposed where the center of gravity of a cross-section, which is perpendicular to the flow-out direction of the molten glass in the flow path within the nozzle, is shifted from the center of gravity of the cross-section of upstream side. A method for producing a glass shaped body includes steps of melting a raw material of glass within a bath of molten glass, flowing out the molten glass into a molding tool through a nozzle connected to the bath of molten glass, and molding the glass shaped body.

Abstract: A process for stably and efficiently producing quality glass articles such as preforms at high yields, and a process for producing an optical device from the preform obtained by the above process. In the process for producing a glass article, molten glass gobs having a predetermined weight each are poured, or molten glass drops having a predetermined weight each are dropped through a nozzle, into a boiling liquid having a boiling point lower than the class transition temperature of the glass constituting said glass article or a liquid which is temperature-adjusted beforehand so as to be caused to boil by the amount of heat of the glass, to form glass articles.

Abstract: The present invention relates to optical glass having a high refractive index, high dispersion, and a low glass transition temperature; a preform comprised of the optical glass for precision press-molding and a method of manufacturing the same; and an optical element comprised of the optical glass and a method of manufacturing the same.

Abstract: A glass forming apparatus and a glass forming method of high economical merit and high production efficiency are provided. More specifically, the glass forming apparatus has dies, in which at least one die is divided into a heat exchange unit and a press unit, and in the glass forming apparatus and glass forming method, the plane precision is improved in the contact dividing surfaces of the heat exchange unit and the press unit. A glass forming apparatus includes a die having a press surface for pressing a glass material, in which the die has a plurality of dies, and at least one die is divided into a heat exchange unit and a press unit. Preferably, the surface precision of at least one part of each dividing surface in contact with the heat exchange unit and the press unit has a flatness (PV) of 500 ?m or less, and the plane precision of at least one part of the dividing surface has a surface roughness (Ra) of 100 ?m or less.

Abstract: A high-refractivity optical glass which has both a low-temperature softening property suitable for precision press-molding and glass stability suitable for hot-shaping of a preform, which contains, by mass %, 13 to 30% of B2O3, 0.1 to 4% of Li2O, 17 to 35% of ZnO, 15 to 45% of La2O3, 4 to 15% of Ta2O5 exclusive of 15%, 0 to 10% of ZrO2, 0 to 10% of Nb2O5 provided that Ta2O5/(Ta2O5+ZrO2+Nb2O5)>0.3, 0 to 20% of WO3 and 0 to 1% of Sb2O3 and which has a refractive index (nd) of 1.80 to 1.84 and an Abbe's number (vd) of 40.0 to 45.0.

Abstract: To provide a glass molding die which is more excellent in durability than the conventional ones. A glass molding die 10 includes a base body 12, an Au layer 14 which is laminated on a surface of the base body 12, and an Rh layer 16 which is laminated on a surface of the Au layer 14. On a surface of the Rh layer 16, an Ir-containing layer may be further laminated. The Au layer 14 functions as a bonding layer, the Rh layer 16 functions as an anti diffusion layer, and the Ir-containing layer functions as a mold releasing layer. The Au layer 14, the Rh layer 16, and the Ir-containing layer are preferably formed by plating.

Abstract: The apparatus for producing glass beads of the present invention comprises a melting pot 2 for heating and melting glass, a nozzle 2A for dripping molten glass 4 in the melting pot 2, which is disposed at the bottom of the melting pot 2, and a liquid glass droplet receiver 11 filled with cooling solution 150 for cooling the liquid glass droplet 10 dripped from the nozzle 2A, which is disposed under the nozzle 2A, wherein the cooling solution 150 is made from a material that forms a bubble layer around the liquid glass droplet 10 as the cooling solution 150 is vaporized due to the heat of the liquid glass droplet 10 during a period when the liquid glass droplet 10 is cooled down to a temperature lower than the glass transfer temperature in the cooling solution 150.

Abstract: In accordance with the present invention, a system and method for the automated casting of infrared glass optical components is provided. The system includes a mold for casting infrared glass into lenses, a mold chamber operable to heat the mold to a temperature above the melting temperature of the infrared glass, and a casting chamber operable to fill the mold with molten infrared glass. The method includes heating a mold in a mold chamber to a temperature above the melting temperature of infrared glass, casting molten infrared glass into the mold in a casting chamber; and cooling the mold to a temperature below the glass transition temperature of the infrared glass.

Abstract: A system and method for forming infrared glass optical components are provided. The system includes first and second mold halves having first and second respective faces. The first and second mold halves are configured to be removably coupled such that the first face and the second face form an interface that defines a lens-shaped cavity. A tapered surface of the first face cooperates with a tapered surface of the second face to enhance centering of the first face with respect to the second face.

Abstract: Disclosed is a method for manufacturing a molded glass object. In the method, glass melt is made to flow from the front end portion of a nozzle; a prescribed weight of the glass melt flowing out is received by a glass melt receiving portion provided on a forming mold moved beneath the nozzle, wherein multiple forming molds are sequentially moved beneath the nozzle; the glass melt gob received is moved from the glass melt receiving portion to a hollow provided on the forming mold; and in the hollow, a molded glass object is formed while blowing gas upward through a gas outlet provided in the bottom of the hollow. The method is characterized in that the front end of the nozzle is constantly positioned outside the space vertically above the gas outlet. Methods of manufacturing press molded articles of glass and optical glass elements are described.

Abstract: The invention relates to a method for producing mineral wool, whereby a cracking catalyst having an aluminum oxide content of at least 35% by weight is used as a base material or aggregate. Said catalyst materials produce waste products which are difficult to eliminate in the chemical industry and which can be reused in the production of mineral fibers and can be used in an economical and resource sparing manner.

Abstract: A transparent substrate for a cover for a solar battery and a method for producing the same are presented. Hemispherical concave portions are formed in a surface of light entering side of a cover glass almost over the entire surface wherein the ratio d/D of the depth d of the central portion of each concave portion to the radius D of the opening of the concave portion is from 0.10 to 0.50 and the proportion of area occupied by a flat portion where no concave portion is formed in the surface of light entering side is not more than 40%.

Abstract: Methods and a device of manufacturing glass gobs with good productivity without defects in appearance from a glass melt. Glass gobs are manufactured from glass melt gobs by molding and cooling glass melt gobs in glass gob molding parts that are intermittently rotated. In one method, single intermittent rotation period of said glass gob molding part is in a range of 0.1 to 0.25 second, and the single intermittent rotation distance of said glass gob molding part is 0.8-7 cm. The device for molding glass gobs from a continuously flowing glass melt has a turntable intermittently rotated around a rotation axis and glass gob molding molds positioned on said turntable. The glass gob molding mold has multiple glass gob molding parts that receive glass melt on the upper surface thereof and mold the glass melt into glass gobs. The glass gob molding mold is positioned on a turntable so that said glass gob molding parts are disposed at equal intervals around a circumference centered on the rotation axis of the turntable.

Abstract: Disclosed are a process for producing a glass shaped material having high quality and high mass accuracy and a process for producing an optical element, which includes the preparation of a glass shaped material having high quality and high mass accuracy, the heating of said glass shaped material and the precision-press-molding thereof.

Abstract: The present invention relates to low-dispersion optical glass having a low glass-transition temperature suited to precision press molding, a press molding preform comprised of this glass, a method of manufacturing the same, an optical element, and a method of manufacturing the same. The optical glass comprises, given as molar percentages, 28 to 50 percent of P2O5; more than 20 percent but not more than 50 percent of BaO; 1 to 20 percent MgO; a sum of Li2O, Na2O, and K2O exceeding 3 percent (with 0 to 25 percent of Li2O, greater than or equal to 0 percent and less than 10 percent of Na2O, and 0 to 12 percent of K2O); more than 0 percent but not more than 15 percent of ZnO; 0 to 25 percent of B2O3; 0 to 5 percent of Al2O3; 0 to 8 percent of Gd2O3; 0 to 20 percent of CaO; 0 to 15 percent of SrO; and 0 to 1 percent of Sb2O3; with a sum of oxide contents of P, Ba, Mg, Li, Na, K, Zn, B, Al, Gd, Ca, Sr, and Sb being greater than or equal to 98 percent. The press molding preform is comprised of the optical glass.

Abstract: An optical element manufacturing method has a preparation step of preparing a lower mold having a lower mold surface for forming an optical function surface of an optical element to be manufactured and an upper mold having an upper mold surface for forming another optical function surface of the optical element, said lower mold having an outer shape restricting surface for the optical element or being combined with a member having the outer shape restricting surface, said upper mold being opposed to the lower mold; a reference surface formation step of forming a positioning reference surface on a rim of the optical element by heating the outer shape restricting surface of the lower mold or combined with the lower mold and the lower mold surface and dropping molten glass onto the lower mold surface so as to collide with the lower mold surface and spread to be in contact with the outer shape restricting surface; a pressing step of forming the two opposed optical function surfaces of the optical element by, afte

Abstract: The invention relates to a glass-plastic composite film, especially for use in electronic components and devices, such as displays. The inventive film consists of a glass film which is between 10 &mgr;m and 500 &mgr;m thick, and is characterised in that a polymer layer with a thickness of between 1 &mgr;m and 200 &mgr;m f is applied directly to at least one of the side faces of said film and in that at least one side on the surface of the film has a waviness of less than 100 nm and a roughness RT<30 nm.

Abstract: In accordance with the present invention, a system and method for the automated casting of infrared glass optical components is provided. The system includes a mold for casting infrared glass into lenses, a mold chamber operable to heat the mold to a temperature above the melting temperature of the infrared glass, and a casting chamber operable to fill the mold with molten infrared glass. The method includes heating a mold in a mold chamber to a temperature above the melting temperature of infrared glass, casting molten infrared glass into the mold in a casting chamber; and cooling the mold to a temperature below the glass transition temperature of the infrared glass.

Abstract: Optical glasses and optical articles comprised of the optical glass are disclosed. One of which comprises, by means of weight percentages, more than 32 percent and not more than 45 percent P2O5, more than 0.5 percent and not more than 6 percent Li2O, more than 5 percent and not more than 22 percent Na2O, 6-30 percent Nb2O5, 0.5-10 percent B2O3, 0-35 percent WO3, 0-14 percent K2O, and 10-24 percent Na2O+K2O, and the total of all the above components is not less than 80 percent.

Abstract: Method for making ceramic particles. Embodiments of ceramic particles made according to the present invention can be are particularly useful as abrasive particles.

Abstract: A method of making a fragrance delivery system comprising forming fused microspheres and incorparting a fragrance therein. The method relates to the mixing together of two separate factions comprising a silicate part and a modifier part, drying the mixture, heating the mixture to form an agglomeration, removing any free-flowing spheres from the agglomeration, soaking the agglomeration in fragrances or essential oils, and then drying the agglomeration.

Abstract: Provided are optical glass exhibiting a refractive index (nd) in a range of 1.75 to 1.87, an Abbé number (&ngr;d) in a range of 80 to 45, and excellent low-temperature softening properties even when not incorporating Th2O5 as well as permitting a low production cost; a precision press molding preform and an optical element comprised of such glass; a method of manufacturing the preform; and a method of manufacturing the optical element. The optical glass comprises, in a molar percent, 30 to 45 percent of B2O3, 2 to 15 percent of SiO2, 10 to 20 percent of La2O3, 1 to 10 percent of TiO2, 10 to 30 percent of ZnO, 2 to 15 percent of Li2O, higher than 0 percent and 10 percent or less of WO3, 0 to 15 percent of Nb2O5, and 0 to 10 percent of ZrO2, wherein the total amount of the above-mentioned components is higher than 95 percent, the glass exhibits a refractive index (nd) in a range of 1.75 to 1.87, and an Abbé number (&ngr;d) in a range of 80 to 45.

Abstract: A laminated glass container has an inner layer of amber glass surrounded by an outer layer of flint glass. The container is manufactured by forming a cased glass stream, having an amber glass core and a flint glass casing layer, cutting the stream into individual gobs and molding the gobs into containers, all sufficiently rapidly that the amber glass does not have an opportunity chemically to react with the flint glass.

Abstract: A method of floating glass gobs by means of a gas flow. A method of manufacturing glass gobs by floating a molten glass gob and simultaneously cooling it. A method of manufacturing glass spheres by floating a softened glass gob and simultaneously rendering it spherical. These methods employ a device having a depression for floating and holding a glass gob or the like, with a gas flow being supplied along all or part of the inner surface of the depression from the opening side of the depression toward the bottom. A manufacturing method comprising the steps of adjusting a glass gob to a temperature suited to press molding while floating said glass gob by means of a gas flow injected along part or all of the depression-shaped forming surface of a lower mold from the opening side of the lower mold toward the bottom of the lower mold; and a step of press forming the glass gob.

Abstract: The process according to the invention reduces the effort required to shape a glass piece. In this process a liquid glass piece is provided on a structured supporting surface of an electrically conducting base. A voltage is applied across the liquid glass piece by connecting a voltage source between a contact position on the liquid glass piece and the electrically conducting base. The apparatus for performing the process has an electrically conducting base on which the liquid glass piece is supported and a device for applying a voltage between a contact position on the liquid glass piece and the electrically conducting base.

Abstract: A mold has a moling surface of a material containing silicon carbide and/or silicon nitride as a main component and a carbon thin film formed on the molding surface to prevent fusion sticking. A glass substance which has a sag point not higher than 565° C. and a predetermined composition free from arsenic oxide is introduced into the mold. The glass substance is press-formed in a heated and softened condition into a glass optical element of high precision.