Abstract: The present invention is directed to a silica container for pulling single crystal silicon, the silica container including a straight body portion, a curved portion, and a bottom portion, wherein the outside of the silica container is made of opaque silica glass containing gaseous bubbles, the inside of the silica container is made of transparent silica glass containing substantially no gaseous bubble, and, on the inner surface of the bottom portion, a silica glass layer containing the OH group in a concentration of more than 300 ppm by mass but 3000 ppm by mass or less, the silica glass layer having a thickness of 20 ?m or more but 1000 ?m or less, is formed. As a result, a low-cost silica container for pulling single crystal silicon, the silica container that can reduce cavity defects called voids and pinholes in pulled single crystal silicon, is provided.

Abstract: In various embodiments, provided are methods of refining silicon wherein impurities of different densities are separated and concentrated using centrifugal force, and controlled crystallization of molten silicon provides further purification through concentration of impurities at a solid/liquid interface.

Abstract: The invention proposes a process for the production of a container made from glass, in the form of a hollow body open on both ends for pharmaceutical and medical applications, in particular in the form of a syringe barrel, where a glass drop (14) is dispensed from a melting unit, is placed into a mold (12) that is driven to rotate, and is formed by the effect of the centrifugal force, the mold being driven at a rotational speed of at least 5000 rpm, preferably approximately 50000 rpm.

Abstract: The cake (7), fitted with the rough pressing (71) of the stem parison (61) is situated on the ring (8) where by the action of its own gravity, it streams off till the rough pressing (71) fits into the cavity (41) of the bottom mould (4). There the rough pressing (71) is fastened by the underpressure and the air is blasted into the flask (6) and, in the same time, the bottom mould (4) is forced downwards. When the orifice (42) of the cavity (41) comes on the level of the surface (51) of the bottom opening of the glass-blowing mould (5), the glass-blowing mould (5) is closed and the air is blasted into the flask (6) until it obtains the shape of the inner wall (52) of the glass-blowing mould (5).

Abstract: The cake (7), fitted with the rough pressing (71) of the stem parison (61) is situated on the ring (8) where by the action of its own gravity, it streams off till the rough pressing (71) fits into the cavity (41) of the bottom mould (4). There the rough pressing (71) is fastened by the underpressure and the air is blasted into the flask (6) and, in the same time, the bottom mould (4) is forced downwards. When the orifice (42) of the cavity (41) comes on the level of the surface (51) of the bottom opening of the glass-blowing mould (5), the glass-blowing mould (5) is closed and the air is blasted into the flask (6) until it obtains the shape of the inner wall (52) of the glass-blowing mould (5).

Abstract: A device for the production of a glass rod is provided. The device has a Danner blowpipe constructed to avoid problems attributed to different heat expansion coefficients of the participating materials. The Danner blowpipe has an outer metal jacket surrounding a ceramic body and defines a supply end and a discharge end of the blowpipe. A clamping plate is provided at both the supply and discharge ends. The clamping plate on the discharge end is rigidly joined with a shaft and engages the outer metal jacket at the discharge end. The clamping plate on the supply end is joined in an axially displaceable manner on the shaft, which is rigidly joined with a pressure plate against displacement in an axial direction. A pressure spring is disposed between the pressure plate and the clamping plate on the supply end to urge the plates away from one another.

Abstract: An object of the invention is to provide a quartz glass crucible for pulling up silicon single crystal and a method for producing the same, suitable for improving the productivity of the crucible and the quality of the silicon single crystal, which, by forming a crystalline layer on the inner surface of the quartz glass crucible during pulling up silicon single crystal, prevents degradation from occurring on the inner surface of the crucible and increases the ratio of single crystal while preventing the dislocation from forming on the single crystals.

Abstract: A crystal puller for growing monocrystalline silicon ingots according to the Czochralski method includes a housing and a crucible in the housing for containing molten silicon. The crucible has a side wall having a transmittance of at least about 80% generally throughout a light wavelength range of about 500 to about 2500 nanometers. A pulling mechanism is included for pulling a growing ingot upward from the molten silicon. In operation, polycrystalline silicon is charged to the crucible and the crucible is heated to melt the polycrystalline silicon for forming a molten silicon melt in the crucible. A seed crystal is then brought into contact with the molten silicon in the crucible and a monocrystalline silicon ingot is pulled up from the molten silicon.

Abstract: Methods and apparatus for manufacturing silica crucibles 9 containing few, if any, white point defects. The white point defects are reduced by decreasing the amount of silica vapor condensing on electrodes 4,5,6 used in the manufacturing process. The silica vapor condensation is decreased by providing a flow of a protective or non-reactive gas or gas mixture through protective devices 11,12,13, over portions of the electrodes where the silica vapor would otherwise condense.

Abstract: Quartz powder is fed into a rotating mold to form a crucible-like quartz powder layer body with the help of centrifugal force in the mold. The layer is melted by heating through the inner surface with an arc discharge to manufacture an outer crucible member. A hollow cylindrical inner crucible member having a beveled lower edge is welded to the outer crucible member while a temperature of the inner surface portion of the outer crucible member remains at 1400.degree. C. or higher by a remaining heat.

Abstract: In a quartz glass crucible obtained by heating and fusing a rotating layer (3) charged with a powder of silicon dioxide, impurity elements are controlled so that copper, chromium, and nickel each amount to 0.5 ppb or less, iron amounts to 120 ppb or less, and sodium amounts to 20 ppb or less. The silicon dioxide powder is supplied to a rotatable mold (1) having an open top, thereby forming a layer (3) charged with silicon dioxide along the inner peripheral wall of the mold. The layer (3) is internally heated and fused while covering the open top with a lid (5) having two or more holes (6,7), and the mold (1) is ventilated to discharge the high temperature gases through the holes (6,7).

Abstract: A method of making a quartz dome for a reactor chamber from a substantially flat quartz disk. The quartz disk is placed on a graphite ring which is rotated. The quartz disk is heated until the disk is softened slightly and it begins to slump. The softened portion of the disk is drawn by a change in pressure to contact a fixed wiper blade. The wiper blade controls the size and shape of the deformation of the quartz disk to form the dome surface.

Abstract: A method and apparatus for producing a glass ware, such as a bowl or plate, via vacuum forming. A deformable glass ribbon is passed through a pair of parallel rolls or rollers, one of the rollers having a recessed cavity thereon for forming a thicker product zone and a thinner cullet zone on the glass ribbon. The product zone may be specifically configured to compensate for process stretching of the glass ribbon during the vacuum forming process. The product zone is registered over a vacuum mold, and a vacuum is applied to the mold to thereby deform the glass to a concave shape and thus form the dish. The dish is separated from the glass ribbon by trimming at the periphery of the dish.

Abstract: Halide glass articles, e.g. rods, tubes and preforms for making fluoride glass fibres, are prepared by melting and/or casting the articles under a low pressure, e.g. 0.01 to 500 mbars and, during the low pressure regime, a gas flow rate of between 0.01 to 100 liters/min (measured at NTP) is maintained. It has been found that subjecting the melts to a low pressure reduces the attenuation of the fibre which eventually results from the melts.

Abstract: The disclosed process involves the feeding of particulate SiO.sub.2 into a rotating cylindrical furnace in which a gas plasma arc has been established, for melting the feed at a temperature of at least 2400.degree. C. The feed rate is regulated so that the rate of growth of the radius of the ingot melt will not exceed the rate at which bubbles move through the melt to the inner cylindrical surface. The preferred apparatus is a rotating horizontal furnace having a pair of opposing hollow electrodes mounted in its opposing end surfaces for establishment of an arc therebetween. A feeding device introduces the SiO.sub.2 feed through the open bore of one of the electrodes for melting by the plasma arc.

Abstract: A quartz glass crucible for use in a process for pulling a single crystal silicon and having an outer layer and an inner layer. The outer layer contains less than 0.3 ppm each of Na, K and Li and more thant 5 ppm of Al. The outer layer further contains bubbles to present an opaque appearance. The inner layer is made by melting powders of high purity non-crystalline synthetic silica and contains less then 200 ppm of OH group. There is also disclosed a method for producing the crucible.

Abstract: Improved fluoride glass optical fibers are produced by a process introducing several improvements in the production of fluoride glass preforms and the drawing of fibers therefrom. Reduced bubble formation and crystallization are obtained by vertically spinning a fluoride glass melt within a glass cladding tube at a high rotational speed, or alternatively, pouring a flouride glass core melt into a cladding tube while slowly raising the mold from an inclined position to a vertical position, or alternatively, introducing a core tube inside a cladding tube. The production of fibers is enhanced if at least one production phase, i.e., preform formation or fiber drawing, is conducted in an atmosphere containing reactive gases that scavenge molecules that could otherwise react with, hydrolyze and oxidize the fluoride glass. The disclosure also describes several devices uniquely useful in the process of the present invention.

Abstract: Apparatus for removing a fused silica glass object from a rotating pot has a gripping member which grips the upper rim of the fused silica glass object and a rotational synchronization member connected to the gripping member which is lowered vertically into frictional contact with the rotating pot. The rotation of the pot drives the rotation of the synchronization member which drives the rotation of the gripping member. The object can be withdrawn vertically from the pot without the angular velocities of the object and pot diverging.

Abstract: This invention relates to a method of making an object of silica glass, such as a crucible, according to which a pot capable of rotating about its axis is filled with a refractory pulverulent material. The pot is rotated and a cylindrical cavity is formed in the material, the axis of which coincides with that of the pot. The bottom and the wall of the cavity are then formed to a certain thickness with a silica-rich material. This silica-rich material is melted, the object thus produced is cooled and then extracted vertically by an extraction mechanism comprising a gripping member which is rotating, at least initially, at the same speed as the pot.

Abstract: A quartz glass crucible adapted for use in a process for pulling a single crystal semiconductor material having an opaque outer substrate of a quartz glass with a relatively high bubble content and an inner transparent glass layer which is substantially free from bubbles. The crucible is produced while the substrate is supported by a rotating mould by forming an atmosphere of high temperature gas and supplying a metered quantity of powders of quartz to the high temperature gas atmosphere to have the quartz powders molten at least partly and directed toward an inner surface of the substrate to be adhered thereon.

Abstract: A method of manufacturing taxidermic glass eyes and the like utilizes flat sheets of glass. This glass is printed with the markings and coloring for the eye image. The printing is accomplished by silk screening or other production methods. The eye is then shaped by heating the glass to a plastic state while being positioned over an opening. The heated glass slumps to form the eye shape. Excess material is trimmed away once the glass has cooled. A double wall, parabolic curve taxidermic eye is thereby provided.

Abstract: A centrifugal casting device adapted to mold and cast a casting material melted by a casting material melting means, by the centrifugal force of a rotary arm, in a mold disposed on the centrifugal side of the arm through a casting crucible disposed at one end of the arm, in which device the melting means is designed to move outside the path of rotation of the arm at least when the arm is rotated so as to reduce the force of rotation of the arm to thereby increase efficiency of casting. And also a centrifugal casting device having the above features in which device the righting reaction of a charged compression spring is used as the driving force of the rotary arm and further included a clutch member and sensors so that the rotary arm stops as soon as possible at the end of casting and returns automatically to its normal position after stopping so as to be ready for the next step of casting and so as to automatically keep the force of rotation of the arm invariably constant.

Abstract: A flat-bottomed quartz glass crucible for the manufacture of monocrystalline silicon is made by disposing granular quartz particles on a flat base in a cylindrical mold. A vacuum is drawn on the particles through vacuum holes in the base to retain the particles thereon while the base and mold are rotated, and while the particles are heated to fuse them into a quartz glass crucible shape.

Abstract: A method for molding calcium phosphate type glass, which comprises pouring a melt of calcium phosphate into a mold, and cooling and solidifying it, wherein the mold contains boron nitride at least at the surface thereof.

Abstract: In the manufacture of a quartz glass crucible of low bubble content, a first layer of granular quartz material is disposed on the interior of a rotating mold through the walls of which a vacuum can be drawn. A second layer of finer quartz material is then disposed on the first layer. The quartz material is then heated, melted and fused to form a crucible.

Abstract: A centrifugal casting apparatus comprises a mold mounted for rotation about the vertical axis thereof and having a bottom provided with a through axial opening. A member having a helicoidally shaped surface is axially mounted within the opening in the bottom. The member has a lower portion to be immersed into a melt and extending out of the opening and downwardly of said bottom of the mold. The mold and the member are connected with a rotation drive and a vertical motion drive.

Abstract: Conoid surfaces can be generated by rotation of a material at different angles and under differing constraints. An axis of 45.degree. can produce hyperboloids; with perpendicular axes, concentric spheres can be produced; magnetic fields can be used to shape the lenses; and multielement lenses can be produced with special chambers.

Abstract: Conoid surfaces can be generated by rotation of a material at different angles and under differing constraints. An axis of 45.degree. can produce hyperboloids; with perpendicular axes, concentric spheres can be produced; magnetic fields can be used to shape the lenses; and multielement lenses can be produced with special chambers.

Abstract: A vapor shield supporting ring is attached to the envelope of a vacuum device. The supporting ring is embedded in the inner wall of the envelope and extends into the interior of such envelope. A welding flange is mounted on the interior portion of the ring. The ring does not extend to the exterior wall of the envelope. To embed the ring in the envelope, the ring is suspended by a holding means such as a magnet, which is placed into the desired position within a centrifugal mold. The molten glass is poured into the mold and the mold is spun, thereby flowing the glass along the walls and surrounding the outer portion of the supporting ring. When the glass solidifies, the supporting ring is firmly embedded in the wall of the envelope.