Abstract: A graphite crucible for silicon single crystal manufacturing by the Czochralski method, having a long life cycle, contains at least one gas venting hole provided in a corner portion of the crucible. Gas generated by reaction between the graphite crucible and a quartz crucible is released to the outside through the gas venting hole, and formation of SiC on the surface of the graphite crucible and deformation of the quartz crucible caused by the pressure of the generated gas are prevented.

Abstract: Provided is an optical fiber drawing apparatus and optical fiber drawing method using the same. The apparatus may include a crucible accommodating core and clad sources and having a bottom hole through which the core and clad sources pass, and a plug disposed under the crucible, the plug passing through the bottom hole. The plug may include a bottom plug disposed under the crucible to close the bottom hole, and a first upper plug disposed on the bottom plug to pass through the bottom hole.

Abstract: Several versions of ceramic bushing/s consisting local heating element/s integrated in apparatus for manufacturing mineral/basalt fibers from natural basalt rocks have been designed based on alternatives to Pt/Pt-Rd bushings approach. The ceramic bushing/s having local heating element/s concept promotes minimization or complete replacement of platinum group metals from the process of continuous basalt fiber manufacturing. More specifically, the invention discloses ceramic bushing/s comprising in combination apparatus are designed for manufacturing continuous mineral (basalt) fibers from 7 to 20 micrometers (?m), and also the coarse fibers from 20 ?m to 100 micrometers (?m) in amorphous structural state which exhibit flexible/ductile properties.

Abstract: A novel spinner, for fiberizing hollow, irregularly-shaped insulating fibers is the subject matter of the present invention. The spinner is unique in a sense that its hole/slot pattern can be done by some standard drilling/milling techniques, which lower the cost of manufacturing. The invention uses two molten glasses (A and B) of different coefficients of thermal expansion, which are moved outwardly around the corresponding gas orifices by centrifugal force in a spinner pot. A stream of pressurized combustion gases is thrust through these central gas orifices to produce a hollow, non collapsible fiber of irregular shape. Molten glass A is introduced from the bottom of the spinner, and molten glass B is introduced above an uppermost flange and by means of centrifugal force, the two glasses A and B are forced upwardly and downwardly, respectively, into fiberizing centers.

Abstract: An object of the present invention is to effectively reduce mixing of bubbles into a spun glass fiber. A glass-melting device 10 for producing glass fibers includes: a first glass-melting tank 12 exposed to a reduced-pressure atmosphere; a second glass-melting tank 14 and a third glass-melting tank 16 arranged below the first glass-melting tank 12; an ascending conduit 18 that sends up molten glass resulting from melting in the second glass-melting tank 14 to deliver the molten glass to the first glass-melting tank 12; a descending conduit 20 that sends the molten glass down from the first glass-melting tank 12 to deliver the molten glass to the third glass-melting tank 16; a decompression housing 22; and a bushing 24. The glass-melting device 10 further includes heating means for separately heating the first glass-melting tank 12, the second glass-melting tank 14, the third glass-melting tank 16, the ascending conduit 18, the descending conduit 20 and the bushing 24.

Abstract: A method of fabricating an optical fiber preform, capable of depositing glass particles with high deposition rate without reducing deposition efficiency and fabricating an optical fiber preform having little bubbles using a burner having a simple structure, is provided. In the invention, a mixed gas of a glass raw material gas with a combustion assisting gas is ejected from an annular nozzle of a burner having a coaxially multiple tube structure, and a burnable gas is ejected from an inner nozzle located inside the annular nozzle. Alternatively, a mixed gas of a glass raw material gas with a burnable gas may be ejected from an annular nozzle, and a combustion assisting gas is ejected from an inner nozzle located inside the annular nozzle. In each case of the above, the burnable gas and the combustion assisting gas, respectively, are ejected from outer nozzles located outside the annular nozzle.

Abstract: A neutralization system for controlling the pH of the washwater used to clean and maintain polyacrylic bound glass forming equipment. The neutralization system introduces a base solution to a washwater solution when the pH of the washwater solution contained in a closed loop washwater recovery system falls below about 8.5, thereby substantially reducing the corrosion rate of the components of the equipment associated with acidic polyacrylic acid binder, maleic acid cobinder or maleic anhydride cobinder and washwater solution. A closed-loop hoodwall washwater recovery system may also be introduced in addition to the neutralization system that allows for the recovery and reuse of polyacrylic acid binder and maleic acid cobinder or maleic anhydride cobinder with a minimal amount of base solution, thereby minimizing degradation of insulation properties of polyacylic acid bound glass fiber products.

Abstract: A process includes the steps of disposing a solid core glass rod at a point removed from hot temperature that can cause crystallization in the core glass rod, disposing a solid clad glass rod at a point removed from the core glass rod; softening to the flowing condition the solid clad glass rod, transferring the softened clad glass to a lower point, the softened clad glass having a central void therethrough, heating the softened clad glass above its crystallization temperature, cooling the softened clad glass to a draw temperature, transferring the solid core glass rod into the central void in the softened glad glass, softening to the flowing condition the solid core glass rod with the heat from the softened and cooled clad glass, and drawing the core/clad, glass fiber by allowing the clad and core glasses to flow in the form of a fiber.

Abstract: The double crucible for a glass drawing method has a heatable outer crucible (1) and an inner crucible (2) surrounded by the outer crucible (1), which is heatable separately from the outer crucible (1). Both crucibles (1,2) have an outlet nozzle (1a, 2a) for the glass to be drawn. To make glass fibers from heavy metal oxide glass (HMO-glass) with higher quality and comparatively simple crucible features, the outlet nozzle (1a) of the outer crucible (1) extends a certain distance beyond the outlet nozzle (2a) of the inner crucible (2). Surfaces of the outlet nozzles coming in contact with the glass melt are polished and are provided on a material, which has a reducing action on heavy metal glass in the melt in all cases. These surfaces also have sufficient mechanical strength for and chemical inertness to heavy metal oxide glass.

Abstract: An apparatus for fabricating a soot preform for an optical fiber. The soot preform is fabricated by depositing glass particles on a starting rod capable of being rotated and pulled up. The apparatus comprises elements as follows. A reaction chamber is used for depositing the glass particles on the starting rod. An upper room is located above the reaction chamber for receiving the soot preform formed in the upper portion of the reaction chamber. At least one core burner is installed in the reaction chamber. A gas-supplying inlet is located in the top part of the sidewall of the reaction chamber closest to burner(s), and a gas-exhausting outlet is located in the top part of another sidewall opposite to the gas-supplying inlet. In addition, at least one cladding burner is installed in the reaction chamber.

Abstract: The double crucible for a glass drawing method has a heatable outer crucible (1) and an inner crucible (2) surrounded by the outer crucible (1), which is heatable separately from the outer crucible (1). Both crucibles (1,2) have an outlet nozzle (1a, 2a) for the glass to be drawn. To make glass fibers from heavy metal oxide glass (HMO-glass) with higher quality and comparatively simple crucible features, the outlet nozzle (1a) of the outer crucible (1) extends a certain distance beyond the outlet nozzle (2a) of the inner crucible (2). Surfaces of the outlet nozzles coming in contact with the glass melt are polished and are provided on a material, which has a reducing action on heavy metal glass in the melt in all cases. These surfaces also have sufficient mechanical strength for and chemical inertness to heavy metal oxide glass.

Abstract: The invention discloses a multifunctional apparatus and method to manufacture mineral (basalt) fibers to be drawn/attenuated into a continuous strand made from natural rock basalts with and without supplemental minerals. More specifically this invention discloses apparatus designed to manufacture a high quality continuous amorphous mineral (basalt) fibers with flexible/ductile properties from 7 &mgr;m to 100 &mgr;m in diameter without traces of crystalline phases which are suitable for a variety of industrial applications.

Abstract: A starting material for producing optical fibers contains metal halides. The refractive index of the optical fiber formed from the starting material is predeterminable by adjusting a partial pressure ratio of a halogen-containing gas mixture. The starting material is produced by mixing halogenated gases into a gas mixture with the desired partial pressure ratio, causing a chemical reaction at a first temperature of the gas mixture with at least metal to form a reaction product, the first temperature being higher than the melting temperature of the reaction product and cooling the reaction product to a second temperature that is below the melting temperature.

Abstract: The disclosed invention includes a method of making an optical fiber drawn from a multiple crucible. The method includes moving a first crucible of the multiple crucible relative to a second crucible of the multiple crucible. The invention also includes minimizing core and cladding diffusion. A tip of the first crucible is disposed axially above a tip of the second crucible by a preselected distance. The invention further includes the ability to alter a diameter of the core of the fiber. A differential pressure is applied to the first crucible. A positive differential pressure is applied to increase the core diameter. A negative differential pressure is applied to decrease the core diameter. Furthermore, the invention includes drawing the fiber under non-isothermal conditions; there is a thermal gradient of at least 10° C./m between the two tips.

Abstract: This invention pertains to apparatus and process for making core/clad glass fibers. The apparatus includes a central tube or receptacle connected at the top to a pressure controller and terminating in a reduced section; a side tube or receptacle positioned at about the level of the upper portion of the central tube; an outer tube or receptacle disposed around the bottom portion of the central tube terminating in a smaller section which is concentric with and spaced directly below the section of the central tube; a side arm connecting the side tube and the outer tube; and furnaces around the side, outer, and the reduced sections of the central and the outer tubes.

Abstract: The disclosed invention is a rotationally symmetrical resistance furnace heating element. The heating element has at least two ends. A respective cooling element is disposed in communication with each end. The heating element includes at least first and second high current density sections. The high current density sections are axially separated by at least one low current density section. The high current density sections have a smaller diameter than the low current density section. The invention also includes a multiple crucible method of drawing an optical fiber from the draw furnace described above. The method includes the step of heating an entire body of raw materials in a hot zone in the furnace.

Abstract: A spinner is adapted to be fixed at one end of a rotatable shaft in a fiberizer, the spinner including a radial wall extending radially out from the shaft and having an upper surface, a dam separating the upper surface into an inner portion and an outer portion, a lower surface, at least one first flow hole connecting the upper surface to the lower surface, and at least one second flow hole connecting the inner portion and the outer portion of said upper surface, and an outer peripheral wall connected to the radial wall and having a plurality of orifices therethrough.

Abstract: The invention relates to a process for the manufacture of, in particular, continuous mineral fibers from rock, glass-containing technical wastes, technical glass wastes, and to an apparatus. The object of the invention is to create a process which enables the said group of starting materials to be processed from a stable melt to give, in particular, continuous fibers and thus to improve fiber quality and processability. The starting products are melted in a melting bath, transferred to a forehearth, a feeder device and then fed to a bushing device and from there taken off as thread, the melt being fed to the feeder device from a take-off area of the melt in which the melt has the parameters according to the invention of temperature, processing range, viscosity, quotient of viscosity and surface tension and energy of activation of viscous flow of the melt, and the ratio of height of the melt in the forehearth to the height of the melt in the melting bath being in a defined range.

Abstract: This invention relates to a high throughput glass fiber production system and process to provide optimum glass delivery to the glass fiberizing bushing and enhanced glass production of textile fibers or filaments of glass. The fiberizing system includes dual melters which feed the molten glass through various screens within a high throughput feed bushing positioned below the melters to reduce seeds and condition the glass. The feed bushing directs the molten glass into a dual flow diverter for supplying the molten glass into the optimum location of the glass fiberizing bushings placed below the dual flow diverter.

Abstract: The material is in a fluid state at a predetermined temperature above the ambient temperature. According to the invention: a) at least two different compositions of this material in the fluid state are prepared; b) simultaneously and concentrically both the core of the rod with the aid of one of the compositions and a sheath enveloping this core with the aid of another composition are cast; and c) the casting is then taken to a temperature at which it solidifies to constitute the rod. Advantageously, the section of the casting is made to grow by its passing through a cylindrical mold shaped to define the final section of the rod. Application to the manufacture of a glass rod presenting a cross-sectional refractive index gradient.

Abstract: A core/clad glass optical fiber is made by melting a core glass rod and a adding glass rod in separate crucibles which are not concentric with respect to each other and the respective core and cladding glass melts passed out of contact with each other to a glass melt contacting zone proximate a fiber drawing orifice in which the cladding glass surrounds the core glass and a core/clad glass fiber is drawn. This process enables the clad glass fiber to be drawn directly from core and cladding glass rods without the need for a preform or forming a melt from glass chards or chunks, thereby reducing the cost of producing the fiber and also producing a glass clad optical fiber of high purity and excellent concentricity. Chalcogenide glass fibers having a concentricity of 100% have been made.

Abstract: An apparatus for producing an optical fiber porous glass preform using the VAD method which can stably produce a high quality optical fiber porous glass preform, wherein a target bar is only rotatably supported by a chuck and is not pulled upward, a lower tip of a soot body is detected by a laser and a photodetector, and a core burner and a cladding burner is lowered in response to the result detected. A tip position detecting drive and burners are synchronizingly lowered while the deposit of porous glass grows at the lower portion of the target bar.

Abstract: An apparatus for melting materials is provided comprising a melter body having a batch injection portion including a batch inlet port, a batch melting portion including a batch melting chamber adapted to receive materials from said batch injection portion, and a molten materials delivery portion including a molten materials outlet port. At least one jet stream injection assembly injects a jet stream into said batch melting chamber. The jet stream comprises a fuel, an oxidant, and heated products of combustion and produces a vortex flow pattern in said batch melting chamber. Fuel and oxidant within said vortex flow pattern react to form laminar flamelets within said vortex flow pattern. The heat generated in the flamelets melts the materials.

Abstract: A multi-screen mixing apparatus for installation in a fiber-forming bushing used in the manufacture of glass fibers. The multi-screen mixer attaches to the walls of the bushing, and includes a first screen having openings therein through which the glass flows and a second screen having openings through which the glass flows longitudinally spaced from the openings in the first screen such that the molten glass must flow in a non-linear path as it passes through the screens. Additional screens can be added to cause additional flow diversion to further mix the molten glass.

Abstract: A vertically disposed apparatus used to make core-clad optical fibers inces an inner elongated cylinder removably closed at the top and provided at the bottom with an inner exit port of a smaller diameter than the inner cylinder and an outer cylinder, disposed around the inner cylinder, removably closed at the top and provided at the bottom with an outer exit port of a smaller diameter than the outer cylinder. The inner exit port is of a smaller diameter than the outer exit port and is disposed directly above the outer exit port. The apparatus also includes a heater for heating the inner and outer cylinders and acces to the inner and the outer cylinders for individually pressurizing inner and outer cylinders.

Abstract: A core/clad glass optical fiber is made by melting a core glass rod and a adding glass rod in separate crucibles which are not intersecting with respect to each other and the respective core and cladding glass melts passed out of contact with each other to a glass melt contacting zone proximate a fiber drawing orifice in which the cladding glass surrounds the core glass and a core/clad glass fiber is drawn. This process enables the clad glass fiber to be drawn directly from core and cladding glass rods without the need for a preform or forming a melt from glass chards or chunks, thereby reducing the cost of producing the fiber and also producing a glass clad optical fiber of high purity and excellent concentricity. Chalcogenide glass fibers having a concentricity of 100% have been made.

Abstract: A method for delivering a coated glass stream having a first inner layer and a second outer layer wherein the method includes providing a vertical orifice, delivering molten glass from a first source through the orifice, providing a gap about the orifice intermediate its upper and lower ends, delivering glass from a second source about the gap such that the glass from the second source flows through the gap to provide an outer layer about the glass from the first source as it flows through the orifice, and controlling the size and shape of the gap parallel to the flow and the size of the gap perpendicular to the flow such that the gap provides sufficient flow resistance and the gap is of sufficient size and shape to prevent clogging.

Abstract: A spinner is adapted to be fixed at one end of a rotatable shaft in a fiberizer, the spinner including a radial wall extending radially out from the shaft and having an upper surface, a dam separating the upper surface into an inner portion and an outer portion, a lower surface, at least one first flow hole connecting the upper surface to the lower surface, and at least one second flow hole connecting the inner portion and the outer portion of said upper surface, and an outer peripheral wall connected to the radial wall and having a plurality of orifices therethrough.

Abstract: The melting tub for producing the molten mass from a mixture of raw material is associated with an additional melting unit by means of which a recycled molten mass is obtained from mineral wool waste largely corresponding to the molten mass obtained from the mixture of raw materials in quality and composition. The recycled molten mass is supplied to the molten mass in the melting tub through a suitable introduction device. The recycling exhaust gas from the additional melting unit is fed to the tub exhaust gas, and the mixture of exhaust gas is utilised for pre-heating combustion air and mixture of raw materials.

Abstract: In a method of and an apparatus for forming composite and other fibers, individual filaments from two or more sets of continuous primary filaments of two or more heat-softenable fiberizable materials are brought together lengthwise to form pairs of continuous primary filaments. The groupings of continuous primary filaments are fed into a high energy attenuation blast where the filaments are heated, attenuated and formed into composite or other staple fibers of the heat-softenable fiberizable materials. Preferably, the individual continuous primary filaments of the groupings of continuous primary filaments are fused, adhesively bonded or otherwise joined together, prior to being introduced into the high energy attenuation blast, to prevent the individual primary filaments of the groupings of continuous primary filaments from separating in the high energy attenuation blast.

Abstract: Apparatus for making dual component fibers is provided and includes a spinner having a peripheral wall. The spinner includes orifices located on the peripheral wall thereof for centrifuging the dual component fibers, with the spinner being divided into a series of generally vertically-aligned compartments by baffles positioned circumferentially around the interior of the peripheral wall. First and second molten thermoplastic materials are supplied to the spinner and directed into alternate ones of the compartments so that adjacent compartments contain different thermoplastic materials. Passages are located in each of the compartments through which the respective molten thermoplastic materials flow to the orifices on the peripheral wall of the spinner. The passages in adjacent ones of the compartments communicate with one another and with the orifices to join the first and second molten thermoplastic materials together into dual component fibers.

Abstract: A fiber manufacturing apparatus including a spinner, fixed to one end of a rotatable shaft and equipment for supplying at least one molten thermoplastic material to the spinner is provided. The spinner includes a radial wall and an outer peripheral wall. The radial wall extends radially out from the shaft and has an outer periphery. The peripheral wall is disposed around the outer periphery of the radial wall and has a plurality of orifices for centrifuging fibers from at least one molten thermoplastic material. The spinner is operatively adapted to be radially balanced during the centrifuging operation. By being so balanced, the spinner is less likely to exhibit temperature induced deformation that introduces undesirable process variables during the fiber manufacturing process.

Abstract: A method for making dual-glass fibers includes supplying first and second molten glass to a rotating spinner having an orificed peripheral wall, where the first glass has a higher viscosity than that of the second glass, centrifuging the first and second glasses through the orifices as molten dual-glass streams, maintaining the dual-glass streams at a temperature sufficient to enable the second glass to flow around the first glass, and cooling the dual-glass streams to make dual-glass fibers.

Abstract: An apparatus for making dual component fibers is provided and includes a distributor having orifices in the peripheral wall and nested within a rotary spinner. The distributor is divided into a series of generally vertically-aligned compartments by baffles positioned circumferentially around the interior of the peripheral wall, with the orifices communicating with the compartments. First and second molten thermoplastic materials are supplied to the distributor and centrifuged as alternating thin layers to the face of the spinner. The spinner is also rotated to centrifuge dual component fibers through the orifices in the peripheral wall of the spinner.

Abstract: An apparatus for making dual component fibers is provided and includes a spinner having peripheral and bottom walls. The spinner includes orifices located on the peripheral wall thereof for centrifuging the dual component fibers, with the spinner being divided into a series of generally vertically-aligned compartments by baffles positioned circumferentially around the interior of the peripheral wall. A first divider is provided in the spinner for directing the first molten thermoplastic material into alternate ones of the compartments, and a second divider is provided for directing the second molten thermoplastic material into the remaining ones of the compartments so that adjacent compartments contain different thermoplastic materials. Passages are located in each of the compartments through which the respective molten thermoplastic materials flow to the orifices on the peripheral wall of the spinner.

Abstract: An apparatus is provided for making dual component fibers. The apparatus comprises a distributor, equipment for providing first and second thermoplastic materials to the distributor, a rotatable spinner and a rotation mechanism. The distributor has an outer casing and a divider cup fixedly positioned within the outer casing. The outer casing has first and second orifices extending through its peripheral wall. The divider cup defines with the outer casing first and second chambers for receiving first and second molten thermoplastic materials. The first orifices communicate with the first chamber and the second orifices communicate with the second chamber. The rotatable spinner includes first and second passages in its peripheral wall.

Abstract: Apparatus for making dual-component thermoplastic fibers, such as glass fibers, comprises a spinner having an orificed peripheral wall for centrifuging fibers from thermoplastic material, the spinner having vertically aligned compartments with first and second thermoplastic materials in alternate compartments, and a series of elongated orifices in the peripheral wall in communication with each of two adjacent compartments to enable centrifuging of both the first and second thermoplastic materials from a single orifice.