Abstract: A filter cartridge having a flexurally rigid frame with a filter element inserted therein is formed of a frame composed of a blank in a single piece, and is folded inward forming a double-walled box profile.

Abstract: A pleat filter arrangement and method of making the same wherein longitudinally extending sheets of filter media are pleated to include pliable strips adhesively extending between at least one face of the opposed pleat faces to separate the opposed pleat faces so as to allow fluid flow therethrough, the pleated filter media being cut to size as pleated filter medium units and framed.

Abstract: A filter assembly for removing soot from gas from an engine includes a housing and a filter disposed in the housing. The housing includes a housing body and a cover disposed on the housing body. The housing body has an inlet connection to a gas line of an engine and an outlet. The cover is removable from the housing body without breaking fluid lines to the inlet or the outlet. In one embodiment, a soot filter for removing soot particles from bleed gas from a engine includes a sintered fiber metal medium having a voids volume of about 50% to about 95% and including metal fibers having a diameter about 20 microns to about 100 microns and a nominal length of at least about 100 microns, the sintered fiber metal medium having an upstream surface communicating with bleed gas containing soot particles, a downstream surface communicating with filtered bleed gas, and a bore extending through the sintered fiber metal medium between the upstream surface and the downstream surface.

Abstract: A hydrogen gas-extraction module includes an intermediate layer bonded between a porous metal substrate and a membrane layer that is selectively permeable to hydrogen. The metal substrate includes a substantial concentration of a first metal at a surface of the metal substrate, and the intermediate layer includes an oxide of this first metal. In one embodiment, where the module is designed to selectively extract hydrogen at high temperatures, the porous metal substrate comprises stainless steel, and the membrane layer includes palladium or a palladium/silver alloy. A method for fabricating a hydrogen gas-extraction membrane includes reacting the porous metal substrate with an oxidizing agent to form a ceramic intermediate layer on a surface of the porous metal substrate and covering the ceramic coating with the membrane layer that is selectively permeable to hydrogen.

Abstract: A filtering medium for air filters wherein its surface conditions have been improved, whereby the porous PTFE membrane is not damaged even after pleating, thus appropriately meeting needs for clean space in clean rooms. The filtering medium comprises a porous polytetrafluoroethylene membrane (2) and an air-permeable supporting member (1) which are laminated such that at least one of exposed surfaces comprises a surface of the air-permeable supporting member (1) having a maximum frictional resistance of 25 gf or less. This filtering medium can be obtained by, for example, press bonding the air-permeable supporting member (1) to the porous membrane (2) under heating and then pressing the surface of the air-permeable supporting member (1) to a silicone roll (4) for smoothing.

Abstract: An air filter, a method for manufacturing the same, and also a high efficiency air cleaning apparatus employing the same are disclosed. The air filter includes a supporter and an inorganic material layer that is formed by fixing the powder of the fraipontite mineral to the surface of the supporter, using the powder of an inorganic substance as a binder. The method for manufacturing the filter includes the steps of immersing a supporter in a suspension in which the powder of the fraipontite mineral and the powder of an inorganic substance as a binder are dispersed as the suspensoid, and drying the supporter impregnated with the suspensoid, thereby forming an inorganic material layer fixed to the surface of the supporter. The fraipontite mineral adsorbs and removes gaseous acid or basic impurities in the air while the inorganic substance as a component of the inorganic material layer works as an adsorbent against gaseous organic impurities contained in the space of the air cleaning apparatus.

Abstract: A high efficiency filtration medium comprised of a nonwoven filter web of electret charged fibers of a nonconductive thermoplastic resin having a resistivity greater than 10.sup.14 ohm-cm, preferably polypropylene. The nonwoven filter web has a basis weight (BW) of less than 60 grams/m.sup.2, an effective fiber diameter (EFD) of less than 5 microns and a penetration (PEN) of less than 0.03%, wherein the ratio);BW/(EFD.PEN)is greater than 200. The invention filter medium can be easily used in applications requiring HEPA performance at relatively low pressure drops.

Abstract: An air cleaning apparatus such as a clean room or the like having an air circulation mechanism which circulates the humidity controlled air through a predetermined air circulation path, wherein the air circulation path is provided with a filter which has a hydrophobic zeolite layer formed on its base filter media surface and another filter which is disposed downstream from the filter having a hydrophobic zeolite layer and is used for removing particulate impurities contained in the circulating air. According to this air cleaning apparatus, gaseous organic impurities and particulate impurities contained in the air circulating in the air cleaning apparatus can be removed without lowering the humidity of the circulating air. Furthermore, since this air cleaning apparatus includes no activated charcoal which is inflammable, the apparatus is excellent from the standpoint of disaster prevention.

Abstract: A filter element is adapted to be located in a gas stream. The filter element comprises a substrate having a structure selected from the group consisting of scrimed needled felt, scrimless needled felt, woven fabric and mesh. The substrate comprises at least two different materials. A first one of the materials has a first melting temperature. A second one of the materials has a second melting temperature lower than the first melting temperature. An expanded polytetrafluoroethylene filtering membrane is adapted to be located upstream relative to the substrate in the gas stream and supported by the substrate. The substrate is attached to the filtering membrane by the second material of the substrate melted to engage the membrane and fix the membrane to the substrate.

Abstract: An improved gas filtration media with a lower initial pressure drop and increased dirt holding capacity includes a fibrous mat of randomly oriented meltblown polymeric fibers made from a polymer with between 0.2% and 10.0% by weight of: a) a nucleating agent to increase the rate of crystallization of the polymer forming the fibers and improve the heat sealability of media made from the fibers and/or b) an electrostatic charging enhancer to reduce surface tension of the polymer and inter-fiber attraction, as the fibers are cooled during formation and collection the fibers, to thereby facilitate the formation of the fibrous mat with discrete fibers. Preferably, the polymer is polypropylene, the nucleating agent is bis-benzylidene sorbitol, and electrostatic charging enhancer is a fatty acid.

Abstract: A receiver/dryer includes a canister with a cylindrical sidewall, an integral lower end, and an open upper end. A pick-up tube is disposed centrally within the canister. The lower end of the pick-up tube has a wedged-shape and is supported by the lower end of the canister. The upper end of the pick-up tube has an annular groove that carries an O-ring seal. A lower baffle and lower filter pad are received over the pick-up tube with the lower baffle having a tight slip-fit therewith. Loose desiccant is supported by the lower baffle and filter pad. An upper filter pad and upper baffle are received over the pick-up tube, with the upper baffle having a slip-fit therewith. An upper end cap is secured to the open end of the canister, with the pick-up tube being received within an outlet passage in the upper end cap, and the O-ring seal providing a fluid-tight seal between the pick-up tube and the end cap.

Abstract: A filter element which includes an annular filter media is surrounded by an external wrap in the form of preformed metal coil instead of a standard metal sleeve. The preformed metal coil has end portions in the form of circular hoops which are retained by adhesive, which adhesive is used to both seal the ends of the filter media and to retain end caps in place on the filter media. The preformed metal coil is of specific use with filter elements that are cleaned by back pulsing in industrial facilities, but is used in any situation where standard metal external sleeves are now used for filter elements.

Abstract: An exhaust gas filter having a ceramic filter body is configured such that a specific heat h (cal/g.degree. C.) of ceramic powder constituting the body, and a bulk specific gravity d (g/cm.sup.3) of the filter, satisfy the relation 0.12 (cal/cm.sup.3 .degree. C.).ltoreq.h.times.d.ltoreq.0.19 (cal/cm.sup.3 .degree. C.). The ceramic filter body includes a plurality of cells which extend axially to open at opposite ends of the body. One of the opposite axial ends of each of the cells is closed by a filler in such a manner that the closed ends of the cells and the open ends of the cells are arranged in an alternating configuration. The filter traps particulates in the exhaust gas, and the trapped particulates are removed by regeneration combustion of the filter. The filter exhibits excellent durability, thus preventing the formation of cracks in the surface and interior of the filter. When the filter is mounted on a diesel engine, the diesel engine advantageously does not discharge black smoke.

Abstract: A deodorizing air filter media which comprises a web of non-woven fibers having myriad discrete particles of a deodorizing component, such as sodium bicarbonate, uniformly dispersed throughout the thickness of the web. The media is fabricated by a two step process, wherein a non-woven web is passed through a first aqueous solution including a binder, and then dried to cured the binder and anchor the crossing points of the fibers in the web. Next, the dried web is passed through a second aqueous solution having a binder in a reduced concentration, together with a particulate deodorizing component suspended therein. The web is then again dried to cure the newly added binder and anchor the particulate deodorizing component to the fibers.

Abstract: An air/oil separator has a filter media pack arranged radially symmetrically about an axis. A bottom end cap is secured to one end of the filter media pack. A top end cap and flange assembly includes a flange and trough member having a flange portion extending radially outwardly from the axis providing a flange for mounting the separator such that the separator is suspended from the flange portion. The flange and trough member also has a trough portion providing an inverted trough within which is a hardenable material secured to the other end of the filter media pack. The flange and trough member is a single unitary member forming both flange and the trough, which eliminates separate flange and trough members which must be welded or brazed together.

Abstract: A filter is provided which includes an organic vapor adsorbing layer, a first particulate removal layer, and a second particulate removal layer. The organic vapor adsorbing layer includes porous adsorbent beads which allow air or gas to flow therethrough with little resistance and provide increased surface area by virtue of the pores. The particulate removal layer can be made from an electrostatic and/or polytetraflouroethylene. The filter can have a figure of merit greater than about 10 and a capacity for permanently adsorbing organic vapors, wherein the figure of merit is calculated based upon a fractional efficiency determined for particles having a size of 0.3 .mu.m in an air flow having a velocity of 10.5 ft./min and for Frazier permeability at 0.5 inches H.sub.2 O.

Abstract: An air filter for use in residential and commercial heating and air conditioning systems including a laminated unit (100) having a filter media (102) where either side of the filter media (102) has a porous layer (104, 106) of passive electrostatic netting. The air filter has a corrugation configuration (142, 144) to increase the available surface area when compared to conventional flat filters.

Abstract: The present invention relates to an improved method and apparatus for separating one or more condensable compounds from a mixture of two or more gases of differing volatilities by capillary fractionation in a membrane-type apparatus, and a method of forming porous structures therefor. More particularly, the invention includes methods of forming and using an apparatus consisting, at least in part, of a porous structure having capillary-type passages extending between a plurality of small openings on the first side and larger openings on a second side of the structure, the passages being adapted to permit a condensed liquid to flow therethrough substantially by capillary forces, whereby vapors from the mixture are condensed, at least in part, and substantially in and adjacent to the openings on the first side, and are caused to flow in a condensed liquid state, substantially in the absence of vapor, from the openings on the first side to the openings on the second side.

Abstract: An improved filter media that is stable in both the lengthwise and widthwise directions and that does not stretch or similarly distort during pressure stops and starts. The filter media is formed from a circular knitted felt fabric having a napped face and a knitted back.

Abstract: An air filter has a generally rectangular frame having surfaces defining generally a plane, and a pair of parallel side rails and a pair of parallel end rails along outer edges of the plane-defining surfaces, the rails flaring outboardly at an obtuse angle from the plane when the frame is unconfined, one of the rails at each corner of the rectangular frame being provided with tabs, and the other, contiguous of the rails at the corner having an open end into which the tab extends. The tabs have an angled outer surface and are of a length compared with the height of the open end to be held against movement clear of the open end in every position of the rails when the frame is assembled, to limit the outward flare of the rails and to ensure that the corners of the rails are substantially closed in every position of the rails.

Abstract: An air filter comprising a laminate of a non-woven fabric made up of polyolefin fibers or polyester fibers or a composite of the non-woven fabrics and a PTFE porous film, wherein the amount of the total gases generated from the air filter is 20 .mu.g/g by the analysis of gas chromatography. The amount of the gases generated from the air filter is greatly reduced by heat-treating the non-woven fabric at a temperature of from 80 to 130.degree. C. for from 5 minutes to 20 minutes before or after laminating with the PTFE porous film.

Abstract: An air filter unit in which the generation of organic substances is restrained by controlling at least the amount of organic substances detected from a square test piece of 5.times.5 cm (25 cm.sup.2) of a filter medium so as to be 100 ng or less in the total amount of organic substances detected from the whole air filter unit at a temperature of 40.degree. C. before using. The air filter unit is assembled by housing a filter medium that has been bent in a waveform in a frame composed of 4 outer frame members and sealing the gap between the frame and the filter medium using a sealing compound. Organic substances adhering to the air filter unit are removed by blowing a cleaned air heated at 80.degree. C. against the air filter unit at a velocity of 50 ml/min for 60 minutes. Then, an air suction port and an air exhaust port of the air filter unit are sealed with a film (for example, a PET film) which keeps the unit from contacting with organic substances and from which organic substances are not generated.

Abstract: A gas filter media with a parallel layer structure, which comprise individual layers of adhesive and adsorbent particles, wherein the thermoplastic adhesive is solvent-free and is preferably based on polypropylene or polyethylene. Using the manufacturing process according to the present invention, it is possible to intentionally prepare gas filter media with adjustable packing density and pressure drop. The gas filter media according to the present invention can be used in respirator filters, room air filters, in ventilation filters for vehicles, or in apparatus filters.

Abstract: A spaced pocket filter assembly has a pocket secured to a holding frame and a spacing member within the pocket made of a single sheet of material. The spacing member has an alternately folded Z or zig zag configuration and is secured to the interior of the pocket along each of the fold lines. The pocket assembly can be manufactured by interposing a roll of a sheet media for the spacing member between rolls of filter media for the pocket. The spacing member media is folded into the Z or zig zag configuration, layered between the pocket media, and secured to the pocket media continuously along the fold lines.

Abstract: A carbonaceous adsorbent membrane is prepared by contacting a hydrophobic carbonaceous adsorbent membrane with an aqueous solution of one or more oxidizing acids and one or more metals selected from the group consisting of copper (+2), chromium (+3), and nickel (+2). The treated membrane is rinsed and dried to yield a hydrophilic carbonaceous adsorbent membrane which is useful for removing water from water-containing gas mixtures.

Abstract: A filter is provided which includes an organic vapor adsorbing layer, a first particulate removal layer, and a second particulate removal layer. The organic vapor adsorbing layer includes porous adsorbent beads which allow air or gas to flow therethrough with little resistance and provide increased surface area by virtue of the pores. The particulate removal layer can be made from an electrostatic and/or polytetraflouroethylene. The filter can have a figure of merit greater than about 10 and a capacity for permanently adsorbing organic vapors, wherein the figure of merit is calculated based upon a fractional efficiency determined for particles having a size of 0.3 .mu.m in an air flow having a velocity of 10.5 ft./min and for Frazier permeability at 0.5 inches H.sub.2 O.

Abstract: This invention relates to a filter and a method of making a filter. The filter is made of randomly orientated fibers made from an interpenetrating network formed from at least two polymers which are substantially water soluble in their salt form and which ionically interact in an aqueous solution to form the interpenetrating network. The filter is made without organic solvents, particularly, volatile organic compounds, and the filter is sufficiently water soluble to biodegrade upon disposal. A desired use of the filter is a cigarette filter.

Abstract: A composite filter media (100 includes a meltblown/spunbond composite fiber material and a mixed fiber triboelectric material are preferably attached to each other by needling the mixed fiber material with the meltblown/spunbond composite fiber material. A netting (104) is then attached by preferably needling the mixed fiber triboelectric material and meltblown through the netting (104).

Abstract: Electret filter media comprising a fibrous web of a blend of a thermoplastic resin and at least one compound or oligomer that enhances the web's electret properties.

Abstract: Disclosed is an improved filter formed from a non-dielectric material which has been coated with a dielectric material and electret treated by, for example, DC corona discharge treatment. Also disclosed is a method for the formation of the filter.

Abstract: Honeycomb filters for the filtration of molten metal streams comprise a triangular cell cross-section in combination with specified cell density, cell wall thickness, filter open frontal area and geometric surface area, thereby offering improved filtration performance when compared with similar filters of square or circular cell design.

Abstract: A silica embedded metal hydride composition and a method for making such a composition. The composition is made via the following process: A quantity of fumed silica is blended with water to make a paste. After adding metal hydride particles, the paste is dried to form a solid. According to one embodiment of the invention, the solid is ground into granules for use of the product in hydrogen storage. Alternatively, the paste can be molded into plates or cylinders and then dried for use of the product as a hydrogen filter. Where mechanical strength is required, the paste can be impregnated in a porous substrate or wire network.

Abstract: A filter insert. The filter insert includes an accordion fold pack that is made of a filter material and is joined to a filter frame. The material of the filter frame is injected in a flowable state into the folds of the accordion fold pack which are open in the on-coming flow direction of the medium to be filtered. The material is subsequently hardened during automatic claw fixation with the fold walls. The entire peripheral edge of the accordion fold pack sealingly overlaps the outer boundary surfaces of the filter frame, and is designed as a sealing device.

Abstract: A unique filtration device (10) which continuously removes gas phase contaminants from an air stream through the use of partially hollow wicking fibers (20) impregnated with a fine solid carbon powder (18) or zeolites and formed into a fiber filter (12) with a selected chemisorptive liquid applied to one side of the fiber filter (12) and large carbon particles (19) applied to the other side of the fiber filter (12). The air stream to be cleaned is directed through filter element (12) which can capture the gas phase contaminants. The wicking fibers (20) include internal longitudinal cavities (22) filled with the fine carbon powder (18) and each having a relatively small longitudinal extending opening (24).

Abstract: An electrostatic filter includes a fibrous component including a mixture of wool and synthetic fibers and a resinous component including a perfluoroalkyl acrylate copolymer resin and a p-tert-butylphenol formaldehyde resin, which resinous component is adhering to the fibrous component, both of the fibrous substrate component and the resinous component being in electrostatically charged conditions.

Abstract: A filter bag assembly and method and machinery to form the same wherein spaced opposed filter bag panels are connected together by transversely extending preselectively sized binder strips fastened selectively at opposed ends to the spaced filter panels to restrain outward inflation of the filter bag.

Abstract: A supported gas separation membrane for separating a particular component from a mixture of gases, a process for its manufacture and the use of the membrane in the separation of gases are provided in which the supported gas separation membrane comprises (a) a porous polymeric support layer and (b) an asymmetric gas separation membrane layer formed from a polyimide having repeating units of the general formula: ##STR1## wherein R is: ##STR2## and x is an integer.

Abstract: A method of manufacturing ceramic filter media for water filters involves the steps of mixing a plurality of raw ceramic materials and a plurality of extrusion-aid materials to form a mixture of constituent materials, extruding the constituent materials to form tubular filter media, drying the tubular filter media, and firing the tubular filter media to create ceramic tubular filter media. The step of drying the tubular filter media preferably comprises placing the tubular filter media on top of rotating rollers which dries the tubular filter media evenly and preserves the desired characteristics of the tubular filter media.

Abstract: A hydrogen-selective thin Pd/40% Cu membrane as for use as a wall connecting high and low pressure chambers of a hydrogen generator, comprising the foil having its edge area diffusion-bonded to a copper-surfaced metallic frame; and a method of preparing the same.

Abstract: A unique filtration device (10) which continuously removes gas phase contaminants from an air stream through the use of partially hollow wicking fibers (20) impregnated with a fine solid powder and a selected chemisorptive liquid (18) which can capture the gas phase contaminants. The wicking fibers (20) are generally disposed to extend in the same direction and are formed into a filter element (12). The air stream to be cleaned is directed through filter element (12). The wicking fibers (20) include internal longitudinal cavities (22) filled with a fine powder and each having a relatively small longitudinal extending opening (24). The wicking fibers (20) are filled with the selected contaminant removing chemisorptive liquid through capillary action by which the individual wicking fibers (20) rapidly draw the selected chemisorptive liquid, with which they come into contact, through the internal cavities (22).

Abstract: A conical filter device inserts into a duct having flow passing from upstream to downstream. The filter device includes fluted filter media having flutes formed therein and a housing. The filter forms a seal between the outer edge of the filter at the downstream side and the housing. The upstream face of the filter is conical shaped in a first embodiment and frusto-conical in a second embodiment with the housing roughly corresponding to the shape of the filter. The filter elements are formed by winding layers of filter media to form a circular cross-section. The elements are moved axially as they are wound or placed on a shaping form while the sealant is still pliable to shape the element.

Abstract: A compact canister assembly for containing a filter media. The assembly includes an outer metal container, an inner structure of filter media and an inner metal container for insertion into an open end of the outer metal container and over the inner structure of the filter media. The inner metal container has an end exposed at the open end of the outer metal container and an end structure closing the end of the outer metal container opposite the end receiving the inner metal container. An end structure is also provide for closing the exposed end of the inner container. The end structures include at least one layer of an air permeable material that permits air flow through said layer and through the inner structure of filter media while retaining the filter media within the canister assembly. The inner structure of filter media is longer than the combined length of the metal containers when they are telescoped together to compact the filter media within the telescoped containers.

Abstract: A filter and method and apparatus for manufacturing the filter. The filter includes a first filter layer and a second filter layer. The first and second filter layers are joined by a ribbon. The ribbon is attached to the first filter layer and the second filter layer through ultrasonic welding. The apparatus includes first and second ultrasonic welders for attaching the first filter layer to one end of the ribbon and the second filter layer to the other end of the ribbon.

Abstract: A filter insert (1A) for a fluid filter with an outer square or hollow cylindrical shape has a plurality of continuous zigzag folded walls (5) made of a fluid-permeable material (2) and provided in the plane of at least part of the folded walls with stiffening embossed depressions (3) and/or projections for keeping the walls folded. The depressions and/or projections of adjacent folded walls are interconnected at least in part and supported on each other. Stiff spacers are provided between the depressions or projections in at least part of their length for interconnecting them and supporting them on each other.

Abstract: A method is provided for specifying and altering the electrical properties of fibers and fabrics. This allows the prescription of filter media prepared from these constituents for consistently optimum or near optimum performance in the collection of particulate matter. The method may include the steps of determining the triboelectric properties of fabrics having other desirable filter media characteristics, modifying the triboelectric properties of these fabrics as needed to preferentially selected properties and utilizing, selectively, modified fabrics as the filter medium for optimally attracting gas entrained electrically charged particles to the surface of the filter. The modification of the triboelectric properties may be realized chemically or by dyeing the fibers and fabric.

Abstract: A filtering cartridge made of compacted and sintered particles is manufactured from a powder consisting of chromium or a chromium alloy with at least 70% Cr by weight and a particle size of the chromium particles between 160 .mu.m and 500 .mu.m. Filtering cartridges of this type can be used advantageously, particularly in gas clarification for energy production by biomass gasification or coal gasification, in cracking processes in the petroleum industry, as well as for the production of melamine resin.

Abstract: A filter is provided. The filter includes a first layer of a non-blocking screen and a second layer of the non-blocking screen disposed against and in direct contact with the first layer, said first and second layers together forming a filter.

Abstract: A porous permeable molded body designed especially for use in the removal of diesel soot particles from the exhaust gas of diesel engines is disclosed. The body includes an alternatingly closed honeycombed body made of silicon carbide and possessing the following features:______________________________________ wall thickness: 1.25 .+-. 0.5 mm; porosity: 55 to 60%; average pore diameter: 25 to 70 .mu.m; specific permeability: 20 to 100 nPm. ______________________________________In the production method, a starting powder of silicon or a mixture of silicon with portions of silicon carbide and/or carbon is combined with an organic binding agent that can be coked and molded into a green body. This is then subjected to a coking fire in an inert-gas atmosphere; the molded body obtained in this manner is then heated in the presence of nitrogen or a nitrogenous inert gas to a temperature where free silicon is converted with the carbon, in a reaction firing, to silicon carbide.

Abstract: An apparatus for generating negative ions includes two casings which are coupled each other and respectively have an outer thread on one end thereof, a lid which is fastened to the coupled casings, an electrode rod disposed within the coupled casings, an electrode plate disposed within the coupled casings, a circuit board which is disposed within the combined casings and connected to the electrode rod and the electrode plate and having at least one high voltage discharging plate, a high voltage generator which is connected to the circuit board and the high voltage discharging plate, and a plurality of ventilation slots which are respectively defined in the casings and the lid, such that the apparatus can be easily assembled, installed and utilized as an independent unit.

Abstract: A high-porosity metallic membrane element comprising a sintered element having at least about 55% porosity, the sintered element comprising a matrix of substantially interconnected pores, each of the pores being defined by a plurality of dendtritic metallic particles. A preferred form is made from pure nickel, preferably filamentous nickel powder. The high-porosity metallic membrane element, comprising the aforementioned sintered element having at least about 55% porosity, can be sealed within a filter housing to produce a highly porous filter device with a filtered fluid flow path through the metal membrane element. Also disclosed is a method of making the high-porosity metallic membrane element which includes depositing by air-laying techniques a substantially uniform low-density bed of a sinterable dendritic material into a mold suitable for applying compressive force thereto, compressing the low-density bed of sinterable dendritic material to form a green form, and sintering the green form.