Abstract: A method of treating a component adapted for use in a gas turbine engine is described herein. The component may comprise ceramic matrix composite materials. The treatment to the ceramic matrix composite component may reduce or eliminate the wear or damage of crack propagation in the ceramic matrix composite component.

Abstract: A method of forming complex structures in a ceramic-, glass- or glass-ceramic-body microfluidic module is disclosed including the steps of providing at green-state refractory-material structure comprising least a portion of a body of a microfluidic module, providing a removeable insert formed of a carbon or of a carbonaceous material having an external surface comprising a negative surface of a desired surface to be formed in the microfluidic module, machining an opening in the green-state structure, positioning the insert in the opening, firing the green-state structure and the insert together, and after firing is complete, removing the insert. The insert is desirably a screw or screw shape, such that interior threads are formed thereby. The insert desirably comprises graphite, and the structure desirably comprises ceramic, desirably silicon carbide.

Abstract: In various embodiments, a microreactor features a corrosion-resistant microchannel network encased within a thermally conductive matrix material that may define therewithin one or more hollow heat-exchange conduits.

Abstract: A process of producing a ceramic matrix composite turbine bucket, an insert for a ceramic matrix composite turbine bucket, and a ceramic matrix composite turbine bucket are disclosed. The process includes providing a bucket preform having a dovetail cavity, the dovetail cavity being enclosed within a dovetail shank of the bucket preform, positioning an insert within the dovetail cavity, then forming the ceramic matrix composite turbine bucket in a furnace. The insert includes a geometry configured to be fit within a dovetail cavity of the ceramic matrix composite turbine bucket, a bucket preform, or both. The insert is foam material or a plurality of ceramic matrix composite plies. The ceramic matrix composite turbine bucket includes a dovetail shank and a dovetail cavity enclosed within the dovetail shank. The dovetail cavity is arranged and disposed for receiving an insert.

Abstract: Teaching disclosed herein is an apparatus comprising a support layer. The support layer may be adapted for supporting a heat generator, wherein the support layer includes a flow passage. The flow passage may seal working fluid therein. The flow passage may extend along a thickness direction of the support layer.

Abstract: A process of producing a ceramic matrix composite turbine bucket, an insert for a ceramic matrix composite turbine bucket, and a ceramic matrix composite turbine bucket are disclosed. The process includes providing a bucket preform having a dovetail cavity, the dovetail cavity being enclosed within a dovetail shank of the bucket preform, positioning an insert within the dovetail cavity, then forming the ceramic matrix composite turbine bucket in a furnace. The insert includes a geometry configured to be fit within a dovetail cavity of the ceramic matrix composite turbine bucket, a bucket preform, or both. The insert is foam material or a plurality of ceramic matrix composite plies. The ceramic matrix composite turbine bucket includes a dovetail shank and a dovetail cavity enclosed within the dovetail shank. The dovetail cavity is arranged and disposed for receiving an insert.

Abstract: A method of forming complex structures in a ceramic-, glass- or glass-ceramic-body microfluidic module is disclosed including the steps of providing at green-state refractory- material structure (140) comprising least a portion of a body of a microfluidic module, providing a removeable insert (120) formed of a carbon or of a carbonaceous material having an external surface comprising a negative surface (122) of a desired surface to be formed in the microfluidic module, machining an opening (132) in the green-state structure (140), positioning the insert (120) in the opening (132), firing the green-state structure (140) and the insert (120) together, and after firing is complete, removing the insert (120). The insert (120) is desirably a screw or screw shape, such that interior threads are formed thereby. The insert (120) desirably comprises graphite, and the structure desirably comprises ceramic, desirably silicon carbide.

Abstract: A method for making a thin walled ePTFE tube having improved axial and radial strength includes the steps of: providing an unsintered or partially sintered ePTFE membrane; wrapping the ePTFE membrane around a mandrel or form tool to form an ePTFE tube; matting the ePTFE tube; immediately thereafter, sintering the matted ePTFE tube; removing the sintered ePTFE tube from the mandrel or form tool; stretching the sintered ePTFE tube in the axial direction; stretching the ePTFE tube in the radial direction over a second mandrel that is greater in diameter than the reduced axially stretched diameter, but less than the first mandrel diameter; overwrapping the second mandrel with a second ePTFE membrane; matting the ePTFE tube; immediately thereafter, sintering the matted ePTFE tube; and removing the sintered ePTFE tube from the second mandrel or form tool.

Abstract: A process for manufacturing a composite block of closed geometry, in the form of a continuous ring, based on fibers and on a crosslinkable resin, by continuous winding and superposition of several layers of a tape of reinforcement fibers embedded in a matrix based on a composition comprising a crosslinkable resin. The process comprises from upstream to downstream, the following steps: producing a rectilinear arrangement (12) of reinforcement fibers (11) and conveying this arrangement in a feed direction (F); degassing the arrangement (12) of fibers by the action of a vacuum (13); after degassing, impregnating said arrangement (12) of fibers under vacuum with said resin composition in the liquid state (17); passing the pre-preg thus obtained through a die (20) to make said pre-preg into the form of a tape (21) composed of reinforcement fibers (11) in their liquid resin (17) matrix, the thickness of said tape being less than 0.

Abstract: Rollers faced with silicone and having no build lines are produced by wrapping pigment/filler-containing addition-curable silicone rubber strips around a roller substrate followed by curing to an integral silicone layer, wherein build lines are prevented by selecting the strips such that physical properties at the edge regions of the strip due to orientation of pigment/filler particles is minimized.

Abstract: A biodegradable polymer stent with radiopacity and a method of making and using a stent with enhanced mechanical strength and/or controlled degradation for use in a bodily lumen is described.

Abstract: A method for the production of components made of ceramic-matrix composite material, in the fields of aerospace engines and turbines and turbine systems and plants; according to the method, a preform of ceramic fibers is shaped and set in a draining mold, for example made of plaster; the fibers of the preform are impregnated with a suspension of ceramic powders, the liquid of which is drained by capillarity from the draining mold; simultaneously to draining, a suspension of ceramic powders is infiltrated between the fibers of the preform so as to fill the empty space left by the drained liquid; at the end of the steps of draining/infiltration a body is obtained with a solidified or compacted porous matrix, which is removed from the draining mold and is sintered.

Abstract: A method for making a thin walled ePTFE tube having improved axial and radial strength includes the steps of: providing an unsintered or partially sintered ePTFE membrane; wrapping the ePTFE membrane around a mandrel or form tool to form an ePTFE tube; matting the ePTFE tube; immediately thereafter, sintering the matted ePTFE tube; removing the sintered ePTFE tube from the mandrel or form tool; stretching the sintered ePTFE tube in the axial direction; stretching the ePTFE tube in the radial direction over a second mandrel that is greater in diameter than the reduced axially stretched diameter, but less than the first mandrel diameter; overwrapping the second mandrel with a second ePTFE membrane; matting the ePTFE tube; immediately thereafter, sintering the matted ePTFE tube; and removing the sintered ePTFE tube from the second mandrel or form tool.

Abstract: An extrusion device is described herein, including an inventive die and mandrel that enable the production, using a conventional ram extruder, of strong coherent extremely thin-walled tubes having a wall thickness in the range of about 0.020 mm and about 0.080 mm.

Abstract: A co-axial catheter assembly (100), including a first lumen (110) having a first distal end (114) and a first proximal end (112), and a second lumen (120) having a second distal end (124) and a second proximal end (122). The second lumen (120) extends co-axially with the first lumen (110), wherein the second lumen is at least partially disposed within the first lumen and the second distal end extends distally of the first distal end. A method of manufacturing the catheter is also disclosed.

Abstract: A powder metallurgy process for the manufacture of powders of a refractory ceramic material, comprising the consecutive steps of: (i) obtaining a dry mixture of a hafnium dioxide HfO2 powder and an yttrium oxide Y2O3 powder; (ii) step of granulation by pelletization of the dry mixture under stirring in order to obtain a granulated mixture, this granulation step comprising the spraying, into the dry mixture, of an aqueous solution comprising polyvinyl alcohol (PVA) and polyethylene glycol (PEG); (iii) drying of the granulated mixture; (iv) filling of a mold with said granulated mixture; (v) isostatical or semi-isostatical pressing of the granulated mixture in order to obtain a compact mixture; (vi) sintering of the compact mixture in order to obtain a refractory ceramic material at a solidus temperature in the range between 2500° C. and 2800° C.

Abstract: An extrusion device is described herein, including an inventive die and mandrel that enable the production, using a conventional ram extruder, of strong coherent extremely thin-walled tubes having a wall thickness in the range of about 0.020 mm and about 0.080 mm.

Abstract: A method for manufacturing a hydrodynamic bearing (30) comprises steps of: step (201): providing a substrate (10) with a plurality of protrusions (14) formed on a periphery thereof; step (202): placing the substrate in a middle of a hollow mold, then injecting a feedstock of powder and molten binder into the mold to surround the substrate under pressure, thus forming a desired bearing preform (20); step (203): separating the substrate from the bearing preform by means of catalytic debinding; step (204): separating the binder from the bearing preform; step (205): sintering the bearing preform; step (206): precision machining the bearing preform to form the desired hydrodynamic bearing.

Abstract: A method for manufacturing a hydrodynamic bearing with hydrodynamic pressure generating grooves comprises steps of: step 201: providing a substrate with a first annular protrusion and a plurality of projections formed on a periphery thereof, the projections being in a side of the first annular protrusion; step 202: placing the substrate in a middle of a hollow mold, then injecting a feedstock of powder and molten binder under pressure into the mold to surround the substrate, thus forming a desired bearing preform; step 203: separating the substrate from the bearing preform by means of catalytic debinding; step 204: separating the molten binder from the bearing preform; step 205: sintering the bearing preform to thereby form the hydrodynamic bearing.

Abstract: A method and device for making integrally formed one-piece molded parts is provided, where the molded parts are to contain a void within their volume. An exemplary such molded part is an arc tube for a discharge lamp. A wax core is first molded onto a core pin wire in the shape of the desired void, the discharge chamber in the case of an arc tube. Then the part is molded over the wax core to provide an integrally formed one-piece part having the appropriately dimensioned void volume therein defined by the wax core. After the part has been hardened around the wax core, the core is removed by conventional means. The holes through the finished molded part left after the core pin wire is removed can be filled in, or in the case of an arc tube they are useful as passageways to accommodate electrodes therethrough.

Abstract: The present disclosure relates to a process for making a seamless tube from a liquid. A mandrel may be provided having a longitudinal axis, an outer surface and a length. A liquid material may be applied to the outer surface of the mandrel by one or more doctor blades, spaced apart from the mandrel outer surface and inclined at an angle ? with respect to the mandrel longitudinal axis, which may be moved along the longitudinal axis of the mandrel while rotating the mandrel around its longitudinal axis. One or a plurality of fingers may overly the mandrel and be positioned upstream of the one or more of blades, relative to the direction of movement of the blades along the longitudinal axis of the mandrel. The liquid material may then be converted to form a seamless tube.

Abstract: A method and apparatus for forming a member, such as a column. The invention comprises inner and outer molds that are spaced apart forming a cavity for receiving a viscous material for making the member. A core is inserted within the inner area of inner mold when the viscous material is initially disposed within the mold. Once the material attains a gelled state, an extraction member is inserted within the inner area. A vacuum is applied to the inner area that causes the flexible inner mold to separate from the material and conform to the extraction member allowing for removal.

Abstract: An arrangement for producing a blank made of metal powder, preferably titanium powder, intended for a dental crown or other product for the human body (spacer, dentine, implant, etc.) comprises at least one first apparatus for powder compression and at least one second apparatus with one or more elastic molds having at least one cavity for a punch (block) and the powder used in the initial stage. The first apparatus comprises a machine operating by impact compaction, and said mold or molds is/are arranged, when the cavity is filled with starting powder, to receive impacts effected by the impaction members in the machine and, as a function of the impact or impacts, to generate an isostatic action during the compression/compaction. The invention also relates to a device, method and use and permits a rapid production procedure while maintaining the current requirements in respect of precision and quality.

Abstract: A ceramic green body is formed by gelcasting. The ceramic green body is heated in the mold so that a solvent contained in the ceramic green body is moved to form a solvent film between the outer surface of the ceramic green body and the inner surface of the mold. The solvent film facilitates release of the ceramic green body from the mold, thereby preventing the occurrence of damage to the ceramic green body as the ceramic green body is released from the mold.

Abstract: A pushable balloon catheter assembly for use in a body vessel. The catheter includes an outer shaft having an outer wall defining an outer lumen and an inner shaft having an inner wall disposed within the outer lumen. An inflatable balloon having a balloon wall defining a balloon interior is attached at a distal tip of the assembly. The balloon wall defines a proximal aperture cooperable with a distal portion of the outer shaft at a common axial location of the catheter assembly. At least part of the outer wall is attached to at least part of the inner wall at the common axial location to define an inflation orifice in fluid communication between the outer lumen and a balloon interior for inflation of the balloon for treatment of the body vessel.

Abstract: A method of constructing a hollow fiber reinforced structure is disclosed. A spindle structure is provided for defining a preform shape. A resin binder or matrix is applied to a fiber material and the fiber material is placed around the spindle structure to create a hollow preform having a shape defined by the spindle structure. The preform structure is reshaped into a desired shape defined by the interior surface of a hollow mold and the exterior surface of an expandable insert structure. The reshaped preform structure is further conditioned to create a finished part. A hollow filament wound ceramic matrix composite airfoil suitable for use in a gas turbine engine may be constructed using the disclosed method.

Abstract: A sleeve for a fluid-dynamic bearing is manufactured by molding to obtain a molded part, degreasing the molded part to obtain a degreased part, and sintering the degreased part. The molding includes placing a resin core having protrusions on an outer circumference thereof for transferring and forming dynamic-pressure generating grooves on the sleeve into a mold having a cavity corresponding to a shape of the sleeve, and injecting a molding material prepared by mixing a binder and metal or ceramic powders. The degreasing includes preparatory degreasing the molded part to remove a portion of the binder, and further degreasing the molded part, from which the portion of the binder is removed, by heating the molded part in a sintering furnace to thermally decompose the residual portion of the binder and the core. The sintering includes further heating the degreased part to sinter the metal powders or the ceramic powders.

Abstract: A free venting pipe and method of forming same, comprising a permeable tubular core member with at least one permeable hoop reinforcement layer around the core member; a substantially non-permeable membrane layer positioned outside of the hoop reinforcement layer and at least one permeable tensile reinforcement layer positioned outside of the membrane layer whereby a free volume annulus does not exist between any of the layers of the free venting pipe. The hoop and tensile reinforcement layers are comprised of a laminate construction.

Abstract: A composite golf club shaft having a reinforcing ribbon of composite material spiraling along an intermediate portion of the shaft and bonded thereto to reinforce the hoop strength of the shaft. The ribbon is shaped into a rib of different cross-sectional shapes, the preferred embodiment being a thin rectangular shape approximately 0.125 wide of an inch and spiraling at a rate of four turns per inch, producing a groove of equal width. The methods of the invention produces the shaft by providing a mandrel having the outside shape desired for the shaft's inside surface; wrapping a ribbon of reinforcing material around the shaft in a spiral groove therein; forming the shaft body around the mandrel; and separating the mandrel from the shaft after curing, by unscrewing the mandrel.

Abstract: A heat exchanger device includes an extruded body that includes one or more layers of channels for coolant flow therethrough, the channels generally having inner diameters of between about 50 microns to about 2000 microns. The device is formed of a material having a high thermal conductivity to facilitate transfer of heat from the heating components present in the subject cooling application to the coolant passing through the heat exchanger and to be compatible with materials of the heating components. The device material is selected from the group consisting of ceramic oxides, ceramic carbides, ceramic nitrides, ceramic borides, ceramic silicides, metals, and intermetallics, and combinations thereof. The heat exchanger device is formed from an extruded filament that is arranged to give the desired channel configuration. The filament includes a central, removable material and an outer material that forms the channel walls upon removal of the central material.

Abstract: A method of manufacturing a hybrid structure (100) having a layer of CMC material (28) defining an interior passageway (24) and a layer of ceramic insulating material (18) lining the passageway. The method includes the step of casting the insulating material to a first thickness required for effective casting but in excess of a desired second thickness for use of the hybrid structure. An inner mold (14) defining a net shape desired for the passageway remains in place after the casting step to mechanically support the insulating material during a machining process used to reduce the thickness of the insulating material from the as-cast first thickness to the desired second thickness. The inner mold also provides support as the CMC material is deposited onto the insulating material. The inner mold may include a fugitive material portion (20) to facilitate its removal after the CMC material is formed.

Abstract: A method of making an inert anode (12?) for use in an electrochemical cell first provides a hollow shaped mold (12) where a metal mandrel (17?) having raised male threads (50) at its top diameter (52) is inserted into the mold (12) and a compressible powder (19, 21) added, then the powder is compressed to form recessed female grooves (70) matching the mandrel threads (50) where the mandrel (17?) is engaged and withdrawn along with the compressed powder inert anode after which the mandrel is rotated to unscrew it from the compressed powder and the compressed powder shape is then placed on a tray (27) and heated to sintering temperature.

Abstract: A process for producing hollow bodies comprising fiber-reinforced ceramic materials, in which a green body comprising compressible cores and a mouldable composition comprising binders and fiber material which is pressed with compression of the core is produced, the green body is cured and carbonized and pyrolysed by heating in a nonoxidizing atmosphere and, if desired, the body is silicized, hollow bodies produced in this way and their use, in particular as brake and clutch disks

Abstract: A bioabsorbable drug delivery device and various methods of making the same. The devices are preferably formed from bioabsorbable materials using low temperature fabrication processes, whereby drugs or other bio-active agents are incorporated into or onto the device and degradation of the drugs or other agents during processing is minimized. The method includes preparing a solution of at least one bioabsorbable polymer and a solvent. The solution is then deposited onto a mandrel and converted into a tube. The solvent is evaporated from the tube in a nitrogen rich environment. The tube is removed from the mandrel and further dried before being stored in an inert environment.

Abstract: A high density microwall ePTFE structure and a method for making, involving the manipulation of a standard extruded ePTFE graft. The final product has the desired characteristics of high density, reduced wall-thickness, above-average radial strength and enhanced suture retention.

Abstract: To form an arc tube body including a main tube portion to be a discharge space and thin tube portions for accommodating electrodes, a core (6) is disposed in a hollow space formed by a pair of arc tube body formation molds (7) and (8) and thereafter, a slurry (12) is injected into a space between the molds (7), (8) and the core (6). In the core (6), portions for forming the internal shape of the thin tube portions of the arc tube body are provided with a shaft (3).

Abstract: Forming a hollow structure having an internal coating includes the steps of placing a core shaped to form the internal surface of the structure in a mould, filling the mould with a material powder, hot isostatically pressing the powder about the mould to consolidate the powder, and removing the core from the hollow structure formed, wherein a coating is applied to the core prior to placement in the mould, which coating bonds to the hollow structure formed, during the hot isostatic pressing, to form the internal coating.

Abstract: A method of fabricating a ceramic tube with electrodes thereon suitable for use as a tubular reaction chamber for a fuel cell. In one embodiment, the method includes wrapping a first electrode material around a mandrel, then wrapping a green ceramic material over the first electrode material, and then wrapping a second electrode material over the green ceramic material. The wrapped layers are laminated together, and then removed from the mandrel and sintered, in either sequence, to produce the laminated ceramic tube having an inner first electrode and an outer second electrode. Alternatively, a first electrode tube is provided in place of the mandrel and around which the green ceramic material is wrapped. The outer second electrode may be produced by wrapping a second electrode material around the green ceramic material, before or after laminating, or by printing the electrode material onto the sintered ceramic tube.

Abstract: Channeled articles having very small diameter channels spaced very closely can be made by packing elongated cores in a fixture, clamping them, and then introducing matrix material around the cores. The matrix material is formed into a unitary body and solidified. The cores are pulled out, leaving open channels where they had been. Some core and matrix combinations will permit the cores to be pulled out. Others require a core release coating to be applied to the cores. The cores can be metal or ceramic or polymer, and the matrix can be metal or ceramic or polymer. The cores can be solid, or hollow. Rather than pulling the cores out, if they are polymer, they can be burned out. The matrix can be formed by liquid state, solid state, or hybrid liquid/solid state techniques. A related technique uses hollow cores, which are not pulled out, but which remain in the body after unification. For such tube-walled articles, the matrix can be formed similarly. Rather than insuring core release, core retention is required.

Abstract: A process for producing ceramic, or ceramic composite, components having microfeatures by creating a chemical reaction in a castable slurry to bond nano-sized or submicron-sized ceramic powders. The bonding process that gives coherency and strength to the material creates a reaction product or gel-phase resulting from a chemical reaction between the ceramic powder and a reagent, such as an acid, alkali, or inorganic salt solution, that binds the ceramic powder. This gel-phase can be de-hydrated, cured, or crystallized by a higher-temperature firing step, but at a temperature lower than the temperature range at which sintering starts to occur in the ceramic (typically lower than 1,000°C.

Abstract: An actively-cooled, fiber-reinforced ceramic matrix composite thrust chamber for liquid rocket propulsion systems is designed and produced with internal cooling channels. The monocoque tubular structure consists of an inner wall, which is fully integrated to an outer wall via radial coupling webs. Segmented annular void spaces between the inner wall, outer wall and adjoining radial webs form the internal trapezoidal-shaped cooling channel passages of the tubular heat exchanger. The manufacturing method enables producing any general tubular shell geometry ranging from simple cylindrical heat exchanger tubes to complex converging-diverging, Delaval-type nozzle structures with an annular array of internal cooling channels. The manufacturing method allows for transitioning the tubular shell structure from a two-dimensional circular geometry to a three-dimensional rectangular geometry.

Abstract: A method of making an inert anode (12′) for use in an electrochemical cell first provides a hollow shaped mold (12) where a metal mandrel (17) having raised male threads (50) at its top diameter (52) is inserted into the mold (12) and a compressible powder (19, 21) added, then the powder is compressed to form recessed female grooves (70) matching the mandrel threads (50) where the mandrel (17′) is engaged and withdrawn along with the compressed powder inert anode after which the mandrel is rotated to unscrew it from the compressed powder and the compressed powder shape is then placed on a tray (27) and heated to sintering temperature.

Abstract: A medical shaft or tubing includes an elongate tubular member having a proximal end and a distal end. The shaft also includes a tubular wall extending between the proximal and distal ends to define a first lumen. The elongated tubular member further comprises a second lumen extending through at least a portion of the tubular member. The tubular wall additionally includes a reinforcing element that surrounds at least a portion of the first lumen and that surrounds and overlaps at least a portion of the second lumen.

Abstract: Very thin cast ceramic tape, preferably approximately 12 &mgr;m in thickness, is wrapped, preferably in a reversing spiral or helix, around a mandrel, preferably a mandrel made of steel and coated with a wax releasing agent, for so many times, preferably five or greater, as achieves a desired thickness of a tube wall, preferably about 100 &mgr;m. The green ceramic tube is then laminated in a pressure laminator, preferably a hydrostatic laminator at 3000 to 5000 psi, linking polymer chains between each ceramic layer, cross-linking polymer chains within each ceramic layer, and densifying the produced ceramic laminate tube by reducing porosity.

Abstract: A catheter having an elongated shaft having at least a section which is multilayered with a first layer and a second layer secured to the first layer, and a mandrel having at least a section between the first and second layers. In one presently preferred embodiment, the mandrel is in contact with an outer surface of the first layer and with an inner surface of the second layer.

Abstract: A thin wall PTFE tube is formed from an extruded green tube. The PTFE tube includes an inner tubular surface and an opposed outer tubular surface defining a tubular wall of a first thickness. The tubular wall is compressed to uniformly reduce the wall-thickness and circumferentially orient the tube. The PTFE tube is positioned over a first elongate roller with the inner tubular surface being in contact therewith. A second roller is positioned against the outer tubular surface of the PTFE tube. The pair of rollers are counter rotated so as to circumferentially compress the tubular wall between the rollers. This results in the uniform reduction in the tubular wall from the first thickness to a lesser second thickness and a circumferential orientation otherwise not occurring in an extruded PTFE paste extrusion.

Abstract: Channeled articles having very small diameter channels spaced very closely can be made by packing elongated cores in a fixture, clamping them, and then introducing matrix material around the cores. The matrix material is formed into a unitary body and solidified. The cores are pulled out, leaving open channels where they had been. Some core and matrix combinations will permit the cores to be pulled out. Others require a core release coating to be applied to the cores. The cores can be metal or ceramic or polymer, and the matrix can be metal or ceramic or polymer. The cores can be solid, or hollow. Rather than pulling the cores out, if they are polymer, they can be burned out. The matrix can be formed by liquid state, solid state, or hybrid liquid/solid state techniques. A related technique uses hollow cores, which are not pulled out, but which remain in the body after unification. For such tube-walled articles, the matrix can be formed similarly. Rather than insuring core release, core retention is required.

Abstract: To form an arc tube body including a main tube portion to be a discharge space and thin tube portions for accommodating electrodes, a core (6) is disposed in a hollow space formed by a pair of arc tube body formation molds (7) and (8) and thereafter, a slurry (12) is injected into a space between the molds (7), (8) and the core (6). In the core (6), portions for forming the internal shape of the thin tube portions of the arc tube body are provided with a shaft (3).

Abstract: A process for forming an end cap in an extruded ceramic tube. An end cap forming cavity of an end cap forming die is positioned so that, when the body of the end cap forming die is situated against an extrusion die, ceramic material is able to be forced into the end cap forming cavity, through a passageway communicating between the end cap forming cavity and a backfill reservoir, and into the backfill reservoir. A plunger projects into the backfill reservoir to force the ceramic material from the backfill reservoir back through the passageway and into the end cap forming cavity to compact the ceramic material so that the ceramic material within the end cap will be provided with a substantially uniform density.

Abstract: A silica product, method and apparatus for manufacturing a tube-shaped silica glass product using a molded green body having a hollow rod structure. A molded green body having a hollow rod structure has a uniform outer diameter and has a bore having an inner diameter increasing gradually from one end to the other. When sintered in a vertically movable sintering furnace, a tube-shaped silica glass product having a longitudinal cross section distribution less than a tolerance limit may be obtained. Optical fiber manufactured using the silica glass tube according to the present invention may have a uniform longitudinal geometrical structure, thereby exhibiting superior transmission characteristics.