Abstract: A paper-feeding roller including a rubber composition containing short fibers in which the short fibers has an average fiber diameter not less than 10 ?m nor more than 100 ?m and an average fiber length not less than 0.01 mm nor more than 4 mm. At least one part of all of the short fibers is radially oriented at an angle not less than 10 degrees nor more than 90 degrees with respect to a plane which contacts a surface of the paper-feeding roller, with one end of each of the radially oriented short fibers disposed exposably on the surface of the paper-feeding roller.

Abstract: A developing device has a developer bearing member, a housing adapted to accommodate a developer, and a supply roller adapted to supply the developer within the housing for the developer bearing member. The supply roller has an outer circumferencial foam layer made of resin or rubber. The foam layer has an air permeability of 150-200 ml/cm2/s, a hardness of 50-200 N, and an average cell density of 20-40 per 25 mm width.

Abstract: The invention concerns a roll of strip of elastomer material reinforced with parallel steel cords. The roll of strip differs from the prior art that it is intentionally not flat when unrolled: it has obtained a permanent preformation so as to take a helical shape when unwound. Such a strip is particularly useful for reinforcing substantially cylindrical objects such as tubes or pillars. Methods to produce such kind of strips are also presented.

Abstract: The present invention intends to provide a method of producing a developing roller capable of providing high-quality electrophotographic images under a variety of environments. The method of producing a developing roller according to the present invention is a method of producing a developing roller having a mandrel, a resin layer on the outer periphery of the mandrel, and a surface layer on the outer periphery of the resin layer, the method including the step of curing a mixture containing a carbon black, a specific diol, and a specific isocyanate compound to form the surface layer.

Abstract: To provide an electrophotographic developing member which can both be kept from the sticking of a developer and be kept from being deformed by its contacting members, and can form stable images over a long period of time. An electrophotographic developing member characterized in that its surface layer satisfies the following expressions (1) to (3) where the average crosslinking density in each region of up to 100 nm in depth, from 100 nm to 200 nm in depth and from 200 nm to 300 nm in depth from the surface of the surface layer is represented by C1, C2 and C3 (mol/cm3), respectively: C3<C2<C1;??(1) C3×1.3?C1?C3×5.0; and??(2) 2.0×10?4?C3?7.0×10?4.

Abstract: An aircraft conveyor system comprising an aircraft including an aircraft cargo storage bay; and a roller mounted within the aircraft cargo storage bay, the roller including a one-piece integral body having a cylindrical shape, the entirety of the body being made solely out of a single piece of polymeric material, said body having a length extending from a first outermost end to a second outermost end and a diameter and a first and second exterior shoulders at the ends, said body including an aperture extending longitudinally along and through the center of said body from the first outermost end to the second outermost end, the aperture sized to rotatably receive an axle therethrough, the axle being for mounting the roller within the aircraft cargo storage bay, wherein the roller has a burn rate of less than 4.0 inches per minute.

Abstract: The invention offers an OA apparatus roller that has a surface layer formed by applying fluororesin and baking it, that has various excellent properties with-out impairing the parting ability and thermal conductivity, and that is suitable for mass production. An OA apparatus roller is produced by forming an elastic layer and a surface layer in this order on a core metal. In the roller, the surface layer is composed of a plurality of fluororesin layers and has a thickness of 6 to 30 ?m. An OA apparatus roller has a structure in which of the multiple fluororesin layers forming the surface layer, at least one layer is a fluororesin layer containing filler. An OA apparatus roller has a structure in which of the multiple fluororesin layers forming the surface layer, the outer-most layer is a fluororesin layer containing no filler and at least one layer other than the outermost layer is a fluororesin layer containing filler.

Abstract: A conductive roller which can form images of consistent quality and does not cause image failures such as formation of blank spots and a method for inspecting the roller. The conductive roller having a metallic core and at least one rubber elastic layer provided on the outer peripheral surface of the core, the rubber elastic layer being formed from a conductive rubber to which conductivity has been imparted by carbon powder, wherein the conductive roller satisfies the relationship represented by formula (1): Zr/Zc?5??(1), wherein Zr (?) represents a resistance component and Zc (?) represents a capacitive reactance component, the resistance component Zr (?) and the capacitive reactance component Zc (?) being calculated respectively from impedance Z (?) and phase difference ?, when the impedance Z (?) is measured upon application of an AC voltage of 0.2 V at a frequency of 1 Hz to the rubber elastic layer.

Abstract: A conductive rubber roller comprising a conductive core material and provided thereon a rubber layer; the rubber layer being formed by using a rubber composition containing as rubber components at least a polar rubber and an ethylene oxide-propylene oxide-allyl glycidyl ether terpolymer; the ethylene oxide-propylene oxide-allyl glycidyl ether terpolymer having a melt peak temperature of from 20 to 30° C. and a melt enthalpy change ?H of from 40 to 70 mJ/mg as measured with a differential scanning calorimeter; and the allyl glycidyl ether in the ethylene oxide-propylene oxide-allyl glycidyl ether terpolymer being in a copolymerization ratio of from more than 10 mol % to 20 mol % or less.

Abstract: A rubber component containing at least one of diene rubber and ethylene-propylene-diene rubber is dynamically crosslinked. Thereby the rubber component is dispersed in a mixture of a thermoplastic elastomer and a thermoplastic resin. An ethylene oxide-propylene oxide-allyl glycidyl ether and an anion-containing salt having fluoro groups and sulfonyl groups are added to the elastomer composition to obtain a conductive dynamically crosslinked thermoplastic elastomer composition. A mixture of the obtained conductive dynamically crosslinked thermoplastic elastomer composition and a micro-capsule composed of a polymer, having acrylic groups, which forms an outer shell thereof is molded to obtain a conductive roller having Shore A hardness specified in JIS K6253 not more than 40 measured at 23° C.

Abstract: A metal rolling pin system includes a metal rolling pin formed from a cylindrical metal body having a hollow core. A removable cylinder is disposed inside the core and is filled with a freezable material such as a cellulose gel material. The rolling pin may also have insulating material inside the core to prevent condensation. A silicone sleeve fits over the metal outside of the pin to keep the dough or pastry from sticking. The rolling pin system has more than one core to assure that there is always a frozen core to keep the pin and dough cold.

Abstract: The invention provides a plastic-sheathed roller, typically a tension roller of plastic for a belt drive. The roller comprises a wheel comprising an inner ring and an outer ring that are connected through radially oriented ribs arranged spaced apart on a periphery and through a central web. The wheel is mounted for rotating through a rolling bearing on a carrier element, while being supported through a running surface on a belt of the belt drive, and injection gates for injection molding are arranged distributed on a lateral surface while being spaced apart angularly non-uniformly from one another.

Abstract: A sheet feed roller prolonging sustainability of sheet feeding capability even if crushed powders are scattered. The sheet feed roller comprises a hub and an elastic layer provided on an outer peripheral surface of the hub, wherein plural grooves axially extend at specific intervals circumferentially on an outer peripheral surface of the elastic layer, a textured surface comprising mountain portions and a valley portion is formed on an outer peripheral surface of the elastic layer except for the grooves, and on bottom surfaces and wall surfaces of the grooves, a ratio of a total area of the bottom surfaces of the grooves to a total area of the outer peripheral surface of the elastic layer except for the grooves is 10% to 20%.

Abstract: Disclosed is a fixing roller which comprises a core 16, a porous material layer 22 disposed in surrounding relation to an outer peripheral surface of the core 16, and a thin-walled metal sleeve 26 covering an outer peripheral surface of the porous material layer 22. The porous material layer 22 comprises a closed cell-type silicone elastomer. The present invention provides a fixing roller capable of ensuring enhanced durability and maintaining a usable state over long periods under the condition of being actually driven and rotated.

Abstract: A rolling pin including a core, a silicone-containing jacket over the core defining a rolling surface. The jacket may be of such length and so positioned on the core as to define end regions of the jacket extending beyond the ends of the core; the jacket end regions being folded inward over the ends of the core; a cap securing to the core each folded inward end region of the jacket. A handle may be at each end of the core.

Abstract: An elastic roll cover for manufacturing or finishing of a fiber web material has at least one layer of rubber mixture, wherein the at least one layer of rubber mixture contains synthetic fiber polymer in powder form.

Abstract: An object of the present invention is to provide a fixing member which includes a surface layer including fluorine rubber having an ether bond and a polysiloxane having a polyether structure, and which has excellent adhesion between the surface layer and a substrate. A fixing member is provided including a substrate, an adhesion layer and a surface layer disposed in contact with the adhesion layer, wherein the surface layer includes fluorine rubber having an ether bond and a polysiloxane having a polyether structure, and wherein the adhesion layer contains a polyorganosiloxane resin and an existence ratio of carbon combining with oxygen to silicon combining with oxygen in the adhesion layer is 1.0 or more and 20.0 or less.

Abstract: An apparatus for charging an image transfer surface in an image transfer device includes a support member and a conductive polymer material surrounding an outer periphery of the support member. An inner portion of the conductive polymer material is loaded with a supplemental conducting agent, and an outer portion of the conductive polymer material is substantially free of the supplemental conducting agent.

Abstract: The invention offers an OA apparatus roller that has a surface layer formed by applying fluororesin and baking it, that has various excellent properties without impairing the parting ability and thermal conductivity, and that is suitable for mass production. An OA apparatus roller is produced by forming an elastic layer and a surface layer in this order on a core metal. In the roller, the surface layer is composed of a plurality of fluororesin layers and has a thickness of 6 to 30 ?m. An OA apparatus roller has a structure in which of the multiple fluororesin layers forming the surface layer, at least one layer is a fluororesin layer containing filler. An OA apparatus roller has a structure in which of the multiple fluororesin layers forming the surface layer, the outermost layer is a fluororesin layer containing no filler and at least one layer other than the outermost layer is a fluororesin layer containing filler.

Abstract: An electroconductive rubber roller constituted of an electroconductive metal core and an electroconductive crosslinked rubber layer including an epichlorohydrin-based rubber, wherein the epichlorohydrin-based rubber is at least one copolymer selected from the group consisting of an epichlorohydrin-ethylene oxide copolymer and an epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer. The ethylene oxide unit in the epichlorohydrin-based rubber is in a content of 40 to 90 mol %, and, the electroconductive crosslinked rubber layer has a heat quantity (enthalpy: ?H) 5 mJ/mg or less as measured by a differential scanning calorimetry (DSC) and indicated by a peak appearing within a range of ?20 to 150° C.

Abstract: A compliant roller assembly comprising an elastomeric tube for rolling along a surface, which tube is inherently compliant to irregularities in the surface. Within the tube but smaller than the inner diameter thereof is a core apparatus comprising a non-rotating mounting element supportive of a plurality of idle rollers, extending from the mounting element in the direction of tube travel, the idle rollers making contact with the inner wall of the tube, preferably at a line orthogonal to the contact line of the tube with the surface being rolled. In a preferred embodiment, the core apparatus exerts no force vector toward the surface being rolled, the weight of the elastomeric tube itself exerting sufficient force.

Abstract: A heat fixing roll or belt having a silicone rubber layer which is formed by curing a silicone rubber composition comprising (A) 100 pbw of an organopolysiloxane having at least two silicon-bonded alkenyl radicals in a molecule, (B) 20-500 pbw of a metallic silicon powder having an average particle size of up to 100 ?m, and (C) an effective amount of a curing agent. The silicone rubber layer has a high heat conductivity and long-term temperature durability.

Abstract: A development roller is provided which can ensure a desired surface roughness and roller hardness even when an elastic layer has not sufficient solvent resistance and which can be preferably used for a long period of time without generating any peeling of a coating film during a continuous long operation. In the development roller, an underlying conductive layer having at least one sublayer and a surface resin layer are provided on the elastic layer in that order. The elastic layer is formed of a foam material having a closed cell structure, the underlying conductive layer is formed from a water-based paint containing a conductive agent, and one of the sublayers of the underlying conductive layer that is in contact with the elastic layer is at least primarily composed of a chloroprene-methacrylic acid copolymer.

Abstract: A process produces a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press fitted into the foamed rubber tube without using any adhesive.

Abstract: A charging roll includes a shaft and an ionically conductive elastic layer formed around the shaft. The ionically conductive elastic layer is formed of a rubber composition free of any electron-conductive agent and containing 0.7 to 1.0 parts by weight of a peroxide cross-linking agent per 100 parts by weight of an ion-conductive rubber. The ion-conductive rubber is formed of at least one of an epichlorohydrin rubber and a nitrile rubber, and a percentage of a rubber component in the ionically conductive elastic layer measured by thermogravimetric analysis is 90% or more by weight.

Abstract: [Task] It is provide an electrical conductive roller capable of forming an elastic layer cheaply to largely reduce a product cost without sacrificing a dimensional precision of an outer periphery. [Solution Means] An electrical conductive roller 1 comprises a shaft member 2 born at both end portions in a lengthwise direction thereof, and one or more elastic layers 3 arranged on a radially outside thereof, wherein each elastic layer has a glass transition point of not higher than ?40° C., and at least one of the elastic layers is constituted with a ultraviolet curing type resin containing an electrically conducting agent and a ultraviolet initiator.

Abstract: A conductive thermoplastic elastomer composition including a continuous phase and first and second uncontinuous phases. The continuous phase and the first and second uncontinuous phases form a sea-island structure; and the first and second uncontinuous phases independently forming island structures. In this structure, the continuous phase contains a composition (A) which is a mixture of a thermoplastic elastomer and a thermoplastic resin; the first continuous phase contains a rubber component (B) containing at least one of diene rubber and ethylene-propylene-diene rubber; and the second continuous phase contains an ethylene oxide-propylene oxide-allyl glycidyl ether copolymer containing an anion-containing salt having a fluoro group and a sulfonyl group (component (C)).

Abstract: In a roller member having at least a mandrel and a conductive elastic layer provided on the peripheral surface of the mandrel, the roller member has a surface roughness Rz jis 94 of from 0.5 ?m to 10 ?m, and the roller member contains voids in the vicinity of its surface. Substantially all of the voids have an average internal diameter of from 10 ?m to 400 ?m and an aspect ratio of from 1.3 or more to 10.0 or less, and having an angle of from 0° or more to 45° or less as an acute angle between an axis that takes the maximum internal diameter of each of the voids and a tangent to a concentric circle of the roller member at the center of each of the voids.

Abstract: A system and method for personalizing cards and other secure identification documents. The card personalization system and method provide improved data integrity, system reliability, and system performance. Improvements to card handling and processing within the modules, improved card transfer between modules, improvements to control of the modules, and other improvements are set forth, all of which contribute, individually and collectively, to achieving these goals.

Abstract: A paper-feeding roller (3) including a core (2) and a rubber roll (1) mounted on a peripheral surface of the core (2). The rubber roll (1) has a three-layer construction composed of an inner layer (11), an intermediate layer (12), and an outer layer (13). The inner layer (11), the intermediate layer (12), and the outer layer (13) are a non-foamed layer respectively. The JIS-A hardness of the inner layer (11) is set to not more than 10 degrees. The JIS-A hardness of the outer layer (13) is set to a range of 25 to 60 degrees.

Abstract: An electroconductive roller including an electroconductive cellular material layer, comprised of a polyurethane composition, which has an average foamed cell diameter not more than 100 ?m and a variation ?D of the foamed cell diameter not more than 50 ?m. The electroconductive roller has a hardness variation ?Hs not more than 8 degrees and a circumferential non-uniformity index RMAX/RMIN in an electric resistance thereof not more than 1.3. The electroconductive cellular material layer is made of a thermosetting one-part polyurethane composition. And the polyurethane composition is cured instantly at a temperature not less than a thermosetting critical temperature for curing thereof, after it is foamed by a mechanical foaming method.

Abstract: A roller (1) for forming noodles and the like (W) comprises a roller body (2), an intermediate layer (4) and a fluoropolymer layer (3). The intermediate layer (4) is formed from a thermally sprayed material with open cells such as a ceramic. The open cells of the intermediate layer (4) permit intrusion of fluoropolymer therein. The intermediate layer (4) binds the surface of the roller body (2) with the fluoropolymer layer (3).

Abstract: An electrophotographic fixing member is provided, which is excellent in toner releasability and hard to change in rubber elasticity of a silicone rubber elastic layer. The fixing member is laminated with a substrate, a cured silicone rubber layer, a cured silicone rubber adhesive layer and a fluorine resin layer, wherein when infrared light absorption strength ratios (1020 cm?1/1260 cm?1) at 1020 cm?1 and 1260 cm?1 determined by sampling the portions of 5 ?m and 20 ?m from the outer surface of the cured silicone rubber layer are taken as ?(5) and ?(20), respectively, a relationship of ?(5) and ?(20) satisfies 1.03??(5)/?(20)?1.30 and ?(20) is 0.8 or more and 1.2 or less.

Abstract: The invention relates to a sleeve, particularly a rubber blanket sheath, for a printing machine. The sleeve (10) has a two-layer structure comprising an internal layer designed as support layer (11), and an external layer designed as cover layer (12) and used for the print transfer, with the external or cover layer (12) being connected directly to the internal or support layer (11). A three layer composite sheath also is disclosed.

Abstract: An electrical conductive roller comprises a shaft member, an elastic layer disposed on an outer side of the shaft member in a radial direction and at least one resin coating layer disposed on an outer side of the elastic layer in the radial direction, wherein a resin coating layer at least adjacent to the elastic layer is made of a ultraviolet-cured resin formed by curing a paint for the resin coating layer comprising (A) a (metha)acrylate oligomer, (B) a (metha)acrylate monomer and (C) a photopolymerization initiator through irradiation of ultraviolet rays, and having an elongation at break of not less than 80%.

Abstract: A fuser member having a substrate, an outer layer with a fluoropolymer, and a release agent material coating on the outer layer, wherein the release agent material coating contains (a) a blend with a mercapto functional release agent having the following formula II: wherein A represents —R4—X, wherein R4 represents an alkyl group having from about 1 to about 10 carbons, X represents —SH; R1 and R2 are the same or different and each is selected from the group consisting of an alkyl having from about 1 to about 25 carbons, an aryl having from about 4 to about 10 carbons, and an arylalkyl; R3 is selected from the group consisting of an alkyl having from about 1 to about 25 carbons, an aryl having from about 4 to about 10 carbons, an arylalkyl, and a substituted diorganosiloxane chain having from about 1 to about 500 siloxane units; b and c are numbers and are the same or different and each satisfy the conditions of 1?b?10 and 10?c?1,000 d and d? are numbers and are the same or different and are 2 or 3, and e

Abstract: In order to manufacture a discharging roller which discharges a recording medium from a recording apparatus, there are a first die formed with a first recess extending in an axial direction of a shaft portion of the discharging roller, and a second die formed with a second recess extending in the axial direction. The first die and the second die are combined such that the first recess and the second recess face to form a continuous cavity. Synthetic resin is injected into the cavity to mold a bore portion of the shaft portion.

Abstract: A rubber roller, for use in an image-forming apparatus, which is formed by molding a rubber composition into the shape of a roller. In the rubber roller, a complex elastic modulus E* of rubber and a surface roughness Rz of the rubber roller satisfy a relationship indicated by an equation (1) shown below; and a hardness change of the rubber is set to not more than five points when the rubber ages at 70° C. for eight days: 7×Ln E*?0.12×Rz+3.0?10.

Abstract: This invention relates to a polymer sleeve including a polymer sidewall and a ceramer outer coating and a method for producing the polymer sleeve for use with a blanket cylinder in an electrophotographic process.

Abstract: Rolls having a polyurethane elastomer formed from a polyurethane mixture, wherein the polyurethane mixture comprises polydiene, tri-functional polyol curative, an additional graft polymer curative having a molecular weight of at least about 800 and comprising diol, polyol, diamine, polyamine or a combination thereof, conductive modifier, antioxidant, and hydrolytic stabilizer. Methods of forming such rolls include casting the polyurethane mixture, followed by curing, then demolding, grinding to desired dimensions and baking such that the outer layer of the cured roll is oxidized.

Abstract: A fuser member with a supporting substrate having an outer surface layer of a fluoroelastomer, and the fluoroelastomer outer surface layer is prepared by: a) dissolving a fluoroelastomer; b) adding and reacting a biphenyl compound and an amino silane having amino functionality to form a homogeneous fluoroelastomer solution; and c) subsequently providing a surface layer of the resulting homogeneous fluoroelastomer solution to the supporting substrate.

Abstract: Disclosed is a fuser member comprising a substrate, a layer thereover comprising a polymer or an elastomer, and, on the layer, a coating including mercapto- and amino-functionalities comprising from about 0.05 mole percent to about 1.00 mole percent mercapto groups and from about 0.0001 mole percent to about 0.06 mole percent amino groups, wherein the ratio of mercapto to amino mole percent values is at least 2. The layer preferably is a fluoropolymer or fluoroelastomer filled with a metal oxide (CuO, Al2O3, etc.).

Abstract: A developing roller composed of a rubber member including not less than two vulcanized rubber layers including a surface layer and a base layer. A hardness of the surface layer is set higher than that of the base layer. The hardness of the base layer is set to not more than 60 degrees in a JIS A hardness. A hardness of a laminate of all layers including the base layer and the surface layer is set to not more than 70 degrees in the JIS A hardness. An electric resistance value of the laminate is set to not more than 1010?, when the electric resistance value is measured by applying a voltage of 100V to the laminate at a temperature of 10° C. and a relative humidity of 20%.

Abstract: A semi-conductive roll is provided including a shaft, a low-hardness base layer formed on an outer circumferential surface of the shaft, and a coating layer formed by coating the low-hardness base layer radially outwardly. The coating layer includes one of a rubber material and an elastomer material that is crosslinked by at least one resin crosslinking agent.

Abstract: A sheet feeding roller, available at a lower cost, having lower hardness with securing both abrasion resistance and sustainability of friction coefficient. The sheet feeding roller comprises a hub, an inner layer provided on an outer peripheral surface of the hub, and an outer layer provided on an outer peripheral surface of the inner layer, the inner layer and the outer layer are formed by an unfoamed cured body of thermosetting urethane rubber wherein the outer layer is harder than the inner layer.

Abstract: A developing roller including a semiconductive rubber member having not less than two vulcanized layers including a base layer composed of a vulcanized electro-conductive rubber composition and a surface layer composed of a vulcanized rubber composition. An electric resistance value of the base layer is set to not more than 107?, when the electric resistance value of the base layer is measured by applying a voltage of 100V thereto at a temperature of 10° C. and a relative humidity of 20%. An electric resistance value of a laminate of all layers including the base layer and the surface layer is set not more than 107? in the same condition as the above-described condition in which the electric resistance value of the base layer is measured.

Abstract: A toner fuser member has a substrate, on which is formed a toner release surface layer from a composition that includes: about 95 wt. % to about 99.9 wt. % of a cross-linked, glycidyl end-capped bisphenolic polymer having the formula where R1 and R2 are each independently H or an alkyl group containing 1 to about 4 carbon atoms, and R3 and R4 are each independently H, F, or an alkyl group containing 1 to about 4 carbon atoms, Z is a carbonyl cross-linking group, and x is an integer from 1 to about 10; and about 0.01 wt. % to about 5 wt. % of a perfluoroalkylsubstituted glycidyl-reactive compound having the formula where R5 is H or F, Q is OH or SiR6R7R8, R6, R7, and R8 being independently selected from the group consisting of Cl, OH, an alkyl group containing 1 to about 4 carbon atoms, an alkoxy group containing 1 to about 4 carbon atoms, an acyloxy group containing 2 to about 4 carbon atoms, and an amino group containing 0 to about 4 carbon atoms; and n is an integer from 1 to about 15.

Abstract: An industrial roll includes: a substantially cylindrical core and a cover overlying the adhesive layer. The cover typically comprises a polymeric top stock layer which comprises a mixture of a polymeric material and at least one of a piezochromic material and a thermochromic material. In this configuration, the pressure and/or temperature experienced by the roll cover at any location thereon can be determined visually, without the need for external equipment.

Abstract: A roll cover particularly suitable for a fuser roll has an intermediate layer on the roll body and an outer surface layer including heat transfer bodies therein. The intermediate layer is a graphite sheet having legs extending along the axial extent of the roll body. The outer layer has graphite fibers embedded therein, the graphite fibers extending axially with respect to the roll.

Abstract: A circular-shaped metal structure is fabricated by plastic-working and has a wall thickness in the range of 0.03 mm to 0.09 mm both inclusive. A film composed of one of (a) silicon and fluorocarbon resin and (b) copper is coated on a surface of the circular-shaped metal structure.