Abstract: One aspect relates to a method for producing an optical blank from synthetic quartz glass by vitrifying and shaping a porous, cylindrical SiO2 soot body having a longitudinal axis, in a heating zone including a melt mold with bottom plate. The SiO2 soot body vitrified in the heating zone at a vitrification temperature so as to form a full cylindrical, completely vitrified, transparent quartz glass body. Subsequently, the vitrified quartz glass body is shaped by softening in the melt mold at a softening temperature so as to form a viscous quartz glass mass which partly fills the volume of the melt mold, and cooling the quartz glass mass and removal from the melt mold so as to form the optical blank. During shaping in the melt mold, the full cylindrical quartz glass body is brought into contact by way of controlled supply with a centering means of the bottom plate.

Abstract: A method for manufacturing glass, including the steps of heat-melting a raw material for producing glass by using a melting furnace having a plurality of gas flow paths while the raw material is levitated from the melting furnace by a gas ejected from the gas flow paths, and performing cooling so as to produce glass, wherein the melting furnace includes a recess portion, at least one first gas flow path configured to eject the gas in the vertical direction into the recess portion, a plurality of second gas flow paths configured to eject the gas in the direction toward the center axis of the melting furnace into the recess portion, the raw material is heat-melted while the raw material is levitated by the gas ejected from the first gas flow path and the gas ejected from the second gas flow paths, and the molten raw material is cooled.

Abstract: In illustrative implementations of this invention, a crucible kiln heats glass such that the glass becomes or remains molten. A nozzle extrudes the molten glass while one or more actuators actuate movements of the nozzle, a build platform or both. A computer controls these movements such that the extruded molten glass is selectively deposited to form a 3D glass object. The selective deposition of molten glass occurs inside an annealing kiln. The annealing kiln anneals the glass after it is extruded. In some cases, the actuators actuate the crucible kiln and nozzle to move in horizontal x, y directions and actuate the build platform to move in a z-direction. In some cases, fluid flows through a cavity or tubes adjacent to the nozzle tip, in order to cool the nozzle tip and thereby reduce the amount of glass that sticks to the nozzle tip.

Abstract: A manufacturing method of a sheet glass material for magnetic disk, the method includes, dropping process for dropping a lump of molten glass; pressing process for sandwiching simultaneously the lump from both sides of the dropping path of the lump with surfaces of a pair of dies facing together, and performing press forming to the lump to obtain a sheet glass material, wherein at least one of the pair of dies has a concave shape with respect to the dropping path of the lump.

Abstract: A method for manufacturing a disklike glass material comprising the successive molding of multiple pieces of disklike glass material from glass melt. Being suppressed variation over time in the concentration of infrared radiation-absorbing ions contained in the glass melt being molded into the pieces of disklike glass material so that the variation in the sheet thickness of the multiple pieces of disklike glass material falls within a range of ±15 percent of a reference value. The reference value being the median between the maximum value and the minimum value of the sheet thickness of 1,000 pieces of the glass material. In the course of molding multiple pieces of disklike glass material comprised of glass containing 0.1 to 100 ppm of infrared radiation-absorbing ions, vaiiation over time in the concentration of the infrared radiation-absorbing contained in the glass melt is suppressed to suppress variation in the sheet thickness of the multiple pieces of sheet like glass material.

Abstract: A rough mold of a machine for forming glass items is provided with a multifunctional group, which has a common support head; a handling device for moving the common head along a first handling axis; and a further handling device for rotating the common head about a second handling axis; the common head being fitted with a mold closing member for sealing the top opening of the rough mold, and at least one further operating member selectable from a funnel-shaped member for guiding at least one glass gob into the rough mold, a blowing member for blowing pressurized air into the rough mold, and one or more members for treating the inner surface of the rough mold.

Abstract: The present invention provide a fluorophosphate glass comprising 3 to 25 cation % of P5+, more than 30 cation % and 40 cation % or less of Al3+, 0.5 to 20 cation % of Li+ and 65 anion % or more of F? as glass ingredients, and having a liquid phase temperature of 700° C. or less. The fluorophosphate glass of the present invention has ultra low dispersibility and stability, and is preferably used for glass materials for press molding, optical element blanks and optical elements.

Abstract: Glass-forming molds comprising titanium aluminum nitride glass release coatings are reconditioned with aqueous mineral acid solutions comprising fluoride and phosphate ions to provide molds with restored glass release characteristics without recoating, permitting the molding of glass articles from aggressive ion-exchange-strengthenable high-alkali aluminosilicate glasses at high temperatures over extended mold service intervals.

Abstract: A rough mold of a machine for forming glass items is provided with a multifunctional group, which has a common support head; a handling device for moving the common head along a first handling axis; and a further handling device for rotating the common head about a second handling axis. The common head being fitted with a mold closing member for sealing the top opening of the rough mold, and at least one further operating member selectable from a funnel-shaped member for guiding at least one glass gob into the rough mold, a blowing member for blowing pressurized air into the rough mold, and one or more members for treating the inner surface of the rough mold.

Abstract: A fluorophosphate glass having a fluorine content of 25% or more by anionic %, which is produced from a glass raw material containing 0.1 to 0.5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine, and a phosphate glass having a fluorine content of less than 25% by anionic %, which is produced from a glass raw material containing 0.1 to 5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine.

Abstract: The present invention relates to a quartz glass blank for an optical component for transmitting radiation of a wavelength of 15 nm and shorter, the blank consisting of highly pure quartz glass, doped with titanium and/or fluorine, which is distinguished by an extremely high homogeneity. The homogeneity relates to the following features: a) micro-inhomogeneities caused by a local variance of the TiO2 distribution (<0.05% TiO2, averaged over a volume element of (5 ?m)3 in relation to the mean value of the TiO2 content), b) an absolute maximum inhomogeneity in the thermal expansion coefficient ?? in the main functional direction (<5 ppb/K), c) a radial variance of the thermal expansion coefficient over the usable surface of the quartz glass blank of not more than 0.4 ppb/(K.cm); d) a maximum stress birefringence (SDB) at 633 nm in the main functional direction of 2 nm/cm with a specific progression; and e) a specific progression of the ??, averaged according to (b) on the optical surface.

Abstract: Disclosed is a lower molding die that can well prevent the occurrence of an air bubble without narrowing the range of choice for materials for the lower molding die and, at the same time, is highly durable. Also disclosed is a method for manufacturing a molding die for molding molten glass droplets. The method comprises a step of machining a molding surface of the molding die, a polishing step of polishing the molding surface to an arithmetic average roughness (Ra) of not more than 10 nm after the machining step, a step of forming at least one cover layer on the surface of the molding surface after the polishing step, and a step of roughening the surface of the cover layer formed on the molding surface.

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: A transfer arm holds a plurality of preforms arranged in a single line and simultaneously drops and supplies the preforms downward. A positioning arm has a pair of arm split members split in its widthwise direction. The arm split members have positioning surfaces formed on their contact surfaces to be brought into contact with outer peripheries of the preforms. After the preforms are dropped and supplied from the transfer arm, the arm split members of the positioning arm are opened and closed so that the positioning surfaces are brought into contact with the outer peripheries of the preforms. Thus, the performs are properly positioned.

Abstract: The invention relates to a manufacturing apparatus for simultaneously making different hollow glass products having different gob sizes comprising at least one feed apparatus (12), that has at least one glass reservoir (14), at least one plunger (18a, b), and at least one appurtenant cutting device (24a, b) in the discharge from the reservoir, at least one conveying means (28) to successively transport at least one of the gobs discharged from the feed apparatus (12) into a plurality of shape-imparting units (32a–c) disposed next to each other for variously sized gobs, at least one controller (22) to control the plunger (18a, b) and the cutting device (24a, b) of the feed apparatus (12), the conveying means (28), and the shape-imparting units (32a–c), and said controller (22) controls the activity of the shape-imparting units (32a–c), the feed apparatus (12), and the conveying means (28) in coordination with the gob-size-specific processing time of the products in the shape-imparting units (32a–c) or their cyc

Abstract: Disclosed are processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 109 poises, preheating molds at a temperature at which the glass material has a viscosity of from 109 to 1012 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20° C.

Abstract: Processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 109 poises, preheating molds at a temperature at which the glass material has a viscosity of from 109 to 1012 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20° C.

Abstract: A method for producing glass balls, wherein a glass flow is fed between two rollers which are driven synchronously but counter-rotatingly in a flow direction, from a feed tank containing a mass of molten glass. The rollers have hemispherical depressions distributed over the circumference and form spherical beads on a thin glass strip successively in the region of an imaginary contact tangent. A thickness of the glass strip is fixed by the spacing between the rollers externally of the depressions in the region of the contact tangent. Crude balls are separated from the glass strip by a separating device, once the glass strip, containing the spherical beads, is cooled. The crude balls are subjected to a cold surface finishing treatment.

Abstract: Disclosed is a method of and device 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 said 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 said nozzle is constantly positioned outside the space vertically above said gas outlet. Methods of manufacturing press molded articles of glass and optical glass elements are described. In these method, a molded glass object manufactured by the above method is heated, softened, and press molded or precision press molded.

Abstract: The invention relates to lead-free optical glasses having a refractive index nd of from 1.52 to 1.58, an Abbe number vd of from 50 to 57 and a negative partial dispersion &Dgr;Pg,F of <−0.0090, having a composition (in % by weight, based on oxide) of SiO2>15-25; B2O3 45-55; Al2O3 8-13; CaO 2-8; ZnO 0-5; with CaO+ZnO 2-10; Li2O 0-4; Na2O 0-4; K2O 0-4; with Li2O+Na2O+K2O 3-8; La2O3 0-14; Nb2O5 0-4.8; Ta2O5>10-17; with Ta2O5+Nb2O5>10-17; SnO2 0-2; ZrO2 0-7; with Ta2O5+ZrO2>10-<18.

Abstract: A method for supplying a glass molding material by dropping it from a higher level onto a molding surface of a lower mold of a mold constituted of an upper mold and the lower mold, in which a guide means is used for dropping the glass molding material and is disposed at a position such that the glass molding material drops onto the molding surface of the lower mold, and the guide means used for this method are disclosed. Moreover, a method for supplying a glass molding material to a molding surface of a lower mold of a mold constituted of an upper mold and the lower mold, in which after the glass molding material is supplied to the molding surface of the lower mold the position of the glass molding material is corrected so that the vertical center of the glass molding material substantially coincides with the center point of the molding surface of the lower mold, and a position correcting means used for this method are disclosed.

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: Gradient refractive index elements are fabricated from the melt, using two or more molten glass compositions, to prevent bubble formation in the elements. The individual glass compositions are melted in separate containers, and then added as appropriate to a single crucible. The more dense glasses settle to the bottom of the crucible, while the less dense glasses float on top of the melt layer. As a consequence of using molten glass, no bubbles appear. Batching of the process can be done by the level of the free melt surface, which means that one can control the batched volume of the melted glass by controlling the level of the free melt surface in the crucible.

Abstract: Processes are disclosed for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 10.sup.9 poises, preheating molds at a temperature at which the glass material has a viscosity of from 10.sup.9 to 10.sup.12 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20.degree. C.

Abstract: A method of manufacturing an optical device having a profile of refractive indices along its optical axis. A desired volume of each of a plurality of types of optical material are dispensed into a mold of known plan area in the form of a frit or a melt and the mold is heated to cause the materials to melt and fuse together to define a contiguous body of optical material having a desired profile. As the optical materials melt, the different types of material separate out so that they are arranged with the most dense material closest to the bottom of the mold and the least dense material closest to the top of the mold. To enhance this effect, the optical materials are layered in the mold in decreasing order of density of the materials from the bottom to the top so that the layers of optical material with the greater densities are closer to the bottom of the mold than the layers of materials with lesser densities.

Abstract: A process of making hermetically sealed glass semiconductor packages by injecting molding an electronic device within a body of molten thermoplastic glass which is solidified by cooling. The glass has a sealing temperature not over 350.degree. C. and a CTE not over 110.times.10.sup.-7 /.degree.C. and may be made of tin-phosphorus oxyfluoride or lead sealing glasses.

Abstract: A gob of molten glass from a gob delivery system is introduced into a blank mold of a glass container forming machine of the individual section type by way loading funnel immediately upstream of an opening into the blank mold. The loading funnel has an upper annular gathering portion in the shape of an inverted frustum of a cone and a cylindrical lower shaping and orienting section. The internal diameter of the shaping and orienting section is somewhat less than the outer diameter of a gob passing therethrough, to thereby contact the gob in a substantially circumferential pattern, and the shaping and orienting section has a length that is sufficient to precisely align the longitudinal central axis of the gob with a longitudinal central axis of the blank mold, to thereby eliminate or substantially eliminate the need to swab the interior of the blank mold with a mold dopant composition.

Abstract: Method and apparatus for producing vitreous optical elements by injection molding, which essentially includes the stages of: melting down a glass material into a molten state in a viscosity at or lower than a working point of the glass material; injecting molten glass under pressure into a mold cavity defined between transfer surfaces of relatively movable mold members of a mold assembly unit in communication with a sprue connecting the mold cavity with an injection port on the outer side of the mold assembly unit; and applying a predetermined pressure on the glass material in the mold cavity while cooling the mold assembly unit down to a temperature in the vicinity of yielding point of the glass material.

Abstract: A gob distributor has an outlet from which issues a gob that is fed via a channel arrangement to a mold having an upwardly open inlet mouth. The channel arrangement has a central trough having an inlet adjacent and aligned with the distributor outlet and an outlet. This central trough extends downward from its inlet to its outlet. A deflecting trough has a generally straight upstream portion with an upper inlet aligned with the central-trough outlet and a downwardly directed lower outlet centered on a generally vertical axis and an upright downstream portion having a funnel-shaped and downwardly tapering passage also centered on the generally vertical axis and having an upper upstream end aligned with the upstream-portion outlet and a lower downstream end aligned with the mold mouth. An adjuster is connected to a hanger for displacing the downstream portion relative to the upstream portion to align the downstream-portion downstream end exactly with the mold mouth.

Abstract: Processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 10.sup.9 poises, preheating molds at a temperature at which the glass material has a viscosity of from 10.sup.9 to 10.sup.12 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20.degree. C.

Abstract: A sealing system for the engagement of a container (24) beneath a melting pot containing a molten material, comprising a shell (30) surrounding a nozzle (40), the nozzle being located in the axis of the neck of the container and permitting the pouring of the material from the melting pot into the container. The shell (30) has tight connection means with the nozzle (40), a base (32) having a bearing surface for the reception of a corresponding bearing surface on the container neck and at least one bellows (33, 34) surrounding the nozzle and connecting the tight connection means to said base, the bellows being able to render the shell retractable along the nozzle axis, means for introducing a gas flow between said bearing surfaces being provided in order to permit the circulation of part of said flow towards the nozzle.

Abstract: In a method of manufacturing glass optical elements at high operational efficiency, a mass of molten glass which is dropped down is cut at a first step by a wind blast into a sequence of glass gobs each of which is received by a gas stream spouted from a lower portion. Each glass gob is kept afloat with a gas stream spouted to be adjusted to a temperature corresponding to a glass viscosity between 10.sup.5.5 and 10.sup.9 poises. Thereafter, the glass gob is pressed in a third step by the use of a pair of forming dies kept at a temperature which corresponds to a glass viscosity between 10.sup.8 and 10.sup.12 poises and which is lower than the temperature of the glass gob. During the third step, the forming dies are cooled to a temperature lower than the temperature corresponding to a glass viscosity of 10.sup.13.4 poises with the glass gob kept within the forming dies and are thereafter opened to release a shaped article from the forming dies.

Abstract: A method and apparatus are provided for controlling the delivery of multiple gobs to the blank molds of a glass forming machine having multiple cavities or sections, wherein multiple gobs are delivered from a glass feeder to plural scoops that are oscillated to deliver the gobs in multiples to aligned troughs and funnels in a timed sequence. An infrared gob sensor at each exit detects passage of a gob, and a computer controls application of air under pressure to control the velocity of delivery of each gob to the scoops in order to influence gob exit timing at the deflectors that are positioned adjacent the mold cavities.

Abstract: In manufacturing a glass material used for a re-heat press method of manufacturing high-precision optical glass components including a lens, prism or the like, a glass material can be manufactured which has no defect inside of or on the surface of the glass, and without requiring a process of grinding and polishing the glass. The glass material is manufactured by dropping melted glass from the glass outlet of a glass melting furnace to a mold and cooling the dropped glass on the mold. The distance between the mold and the glass outlet is in a range which maintains the temperature of the stretched area of dropping glass--the area where the melted glass dropped on the mold is spontaneously separated by its own weight and surface tension at its softening temperature or above. The temperature of the glass around the stretched area is at least its softening temperature, and the glass around that area is instantaneously incorporated into the glass on the mold after separation.

Abstract: A method of distributing molten glass gobs in an IS machine whereby gob scoops are positioned beneath associated gob discharges for motion independently of each other. Each scoop is driven by a three-phase electric servo motor to swing through an arc independently of the other scoops while maintaining a position beneath the associated gob discharge.

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: A thick glass coating protects fluorescent or phosphorescent pigment particles from greying or fading due to service conditions, such as photochemical reactions. The pigment particles are mixed with a finely ground heavy metal-free glass in a ratio of approximately 5 parts glass to 1 part pigment. The pigment and glass mixture is then heated to a point where said glass is softened to such an extent that the pigment particles are surrounded by the glass. The glass is thereafter comminuted into a granulate consisting of a plurality of small glass bodies. The granulate is reheated so that pigment particles exposed by the comminuting are resurrounded by the resoftened glass. The glass pigment mixture can alternatively be suspended in a liquid and poured into a mold before heating in order to form glass bodies having a particular shape.

Abstract: The present invention relates to a glass blank for producing optical element used for the press molding thereof, having a core glass and a surface layer covering at least the optically functional surface of the core glass. The surface layer consists of an evaporation glass. This invention also relates to the technique to mold a glass lens using the glass blank.

Abstract: The present invention pertains to a process for manufacturing a road warning device for a divided driveway, expecially a process for manufacturing a warning device in different colors, in order to match the traffic signs, in such a way that one first presses a melting pulp of potash-glass to form a main body, then high pressure spray a tinfoil metal powder on the spherical surface of the warning device, trim the circumferences of the uncooled reflecting spheroid, remove the excess metal alloy powder, and finally spray a metal-oxide or metal-halide (e.g. silver oxide, plumbous oxide or gold sodium chloride etc.) either on the entire spherical or semispherical surface of the reflecting spheroid, in order to show different colors on the reflecting spheroid.

Abstract: The invention provides a method of manufacturing extremely precise glass optical element by thermally deforming optical glass on the optical surface of a thermal processing jig coated with chemically stable thin film, followed by the molding of optical glass preform having free surface on one side and transcribedsurface from the optical surface of the thermal processing jig by means of a press mold which thermally presses the optical glass preform.

Abstract: A method and device for enabling a molten radioactive glass to be cast from a crucible (2) situated in a top cell (1) and a container (4) situated beneath said crucible in a bottom cell (3), the radioactive glass flowing vertically downwards along a casting axis through an opening provided in a concrete slab (5) which separates said cells, said device being characterized in that it comprises the following components in succession going downwardly: a deformable guide tube (11) constituted by two housings (14, 15) slidably mounted in each other, with the inner walls (20, 21) thereof being frusto-conical in shape, and the apex of said frusto-conical shape being situated beneath said guide tube, the top housing (14) being fixed beneath said concrete slab, the bottom housing (15) having an end wall (22) in the form of a portion of a sphere, and said two housings being interconnected by a metal bellows (23); and a moving tube (12) constituted by an enclosure (32) whose inside wall extends downwardly so as to be cap

Abstract: A method of making a fiber reinforced glass matrix composite wherein a continuous length of fiber is impregnated with glass and at least partially consolidated to form a fiber-glass matrix system encompassing the continuous length of fibers, cutting the fiber-glass system into a plurality of short fiber reinforced composites, heating the short fiber reinforced composites to form a composite batch wherein the glass matrix is in a molten condition, and molding the composite batch to form a reinforced glass composite article with uniform random distribution of short fibers, is disclosed.

Abstract: Cast-iron mold for the production of glass containers by using a "pressed-blown" or "blown-blown" technique wherein the parts exposed to the parison are coated with a uniform alumina layer of which the thickness is less than 5 micrometers. The invention applies to industrial techniques for producing glass containers such as bottles, flasks, jars or the like.

Abstract: A method of manufacturing a polygonal glass fiber is disclosed. According to an embodiment of the present invention, a glass in a melted state is poured into a dividable polygonal slit having a cross section 5 to 20 times larger than a finally required cross section of a glass fiber to be made, and the glass poured into the slit is drawn so as to make a polygonal glass fiber. According to another embodiment of the present invention, a glass in a melted state is passed through a twin roller having a required cross section so as to make a polygonal glass fiber.

Abstract: A mold for press-molding glass elements comprising a base member made of a super hard alloy or a cermet; at least one intermediate layer made of a nitride, a carbide, an oxide or a metal, provided on the base member; and a noble metal layer provided on the intermediate layer for forming a mold surface. An active metal contained in the base member is prevented from diffusing to the mold surface by the presence of the intermediate layer.

Abstract: A lead phosphate glass to which has been added indium oxide or scandium oe to improve chemical durability and provide a lead phosphate glass with good optical properties.

Abstract: Disclosed is a molding method for producing an optical glass element which comprises the steps of preparing a mold coated with a thin film of a noble metal alloy, and molding optical glass into the form of an optical glass element by using the mold while applying heat and pressure to the optical glass. Further disclosed is such a mold that is coated with a thin film of a noble metal alloy, for producing an optical glass element.

Abstract: Method and apparatus is set forth for forming a laminated gob or charge of molten glass having a core glass which is not only completely surrounded by a skin glass but also has a reentrant portion of skin glass which projects inwardly within the core glass from the periphery of the molten charge intermediate its upper and lower extent. The reentrant portion of skin glass is formed within the charge during the gobbing cycle by momentarily retarding or retracting the outward flow of the core glass while simultaneously positively pulsing the flow of the skin glass. Thus, a laminated gob or charge of molten glass is formed which not only has a skin glass completely surrounding and encompassing a core glass but also has a reentrant portion of the skin glass which is continuous with the remainder of the skin glass surrounding the core glass.

Abstract: A method for producing decorative glass objects in which the decoration is created by blisters formed by air bubbles within solid glass and/or by a pattern on the outer surface of the glass. When producing glass objects provided with air bubbles by means of known methods the bubbles remain on the surface of the objects which then easily break. In addition, the bubbles are formed at random, which may make them appear as dim impurities. When, in accordance with the invention, molten glass is poured from above in the shape of a band into a hot mould, the molten glass is spread into the mould in layers between which microscopic air bubbles remain. As the glass surface cools, the air enclosed within the bubbles expands in the molten glass which, while cooling, leaves the bubbles as clear pearls inside the glass. As the molten glass is spread in layers towards the wall of the mould, a pattern is formed as the glass surface cools.

Abstract: Molding of hollow glass articles wherein a gob flows from a feeder into a mold and forms a hollow tube as it enters the mold, and a pressure differential is applied across the tube so that the tube is shaped in the mold to form the hollow article. During application of the pressure differential, deformation of the glass between the feeder and mold, is prevented by proximately positioning of the feeder and mold. This pressure differential is obtained by applying vacuum between the mold and molten tube.