Abstract: A cleaning card for use in cleaning internal surfaces of a machine-reading mechanism includes a substrate having plurality of discrete raised areas in opposed surfaces thereof. The discrete raised areas each include a peak and a peripheral wall having an edge remote from the peak, and the peak of each raised area is farther from a central plane of the card than the edge of the peripheral wall remote from the peak. Relief means are provided in the substrate for preventing the peaks of at least some of the discrete raised areas from flattening toward the central plane to an extent that such peaks will not effectively engage and clean desired internal surfaces of a machine-reading mechanism when the cleaning card moves in the machine direction in other than a single, substantially linear plane.

Abstract: A doctor blade holder is disclosed that includes first and second members as well as position adjustment means. The first member includes a plurality of first member mounting structures that are integrally formed with the first member and are mutually spaced apart from one another along an elongated direction that is parallel with an elongated edge of a doctor blade. The second member is coupled to the first member, at least in part, by a plurality of second member mounting structures that are mutually spaced apart from one another along the elongated direction that is parallel with the elongated edge of the doctor blade. The position adjustment means is for adjusting the relative positions of the first member and the second member while the first member is coupled to the second member, at least in part, by the plurality of first member mounting structures and the plurality of second member mounting structures.

Abstract: A metal strip casting apparatus and method of casting metal strip include assembling a pair of counter-rotatable casting rolls positioned laterally forming a nip between for casting, and assembling a pair of brush rolls, each of the brush rolls associated with one of each of the casting rolls. Each brush roll includes at least one spaced apart brush line extending substantially along the axial length of the casting roll. The brush lines may form a spiral, zigzag, wave or crisscross array about the brush roll. The brush roll may include one or more staggered rings with regularly or irregularly spaced apart bristles which form the brush lines. The brush lines may be between 10 to 50 mm apart and separated by between 2 mm to 45 mm of open space. The brush lines may be one line per 10 mm to 90 mm of axial length of brush roll.

Abstract: A method and apparatus for removing ice from overhead utility power lines which includes a tool having an extendable pole with an ice removing roller having an annular outer channel rotatably supported on the pole. The pole is extendable for enabling a user to place the roller over an ice-laden utility power line while standing on the ground, and then is movable along the power line by the workmen while standing on the ground or walking along a line parallel to the power line for removing ice from the line.

Abstract: A roll cleaning apparatus for a paper making machine has a cleaning member that is mounted to a support member that extends lengthwise relative to a first roll. The cleaning member has a pad and is moveable between an engaged position against the roll during operation, and a disengaged position spaced away from the roll in a non-operating condition. The roll cleaning apparatus includes a drive connected to cause linear reciprocation of the cleaning member and a drive or actuator mounted to move the cleaning member between the engaged and disengaged positions, and operable to bias the cleaning member against the roll in use.

Abstract: A method in connection with coating, comprising a running web (8) arranged to be coated with a coating mix (11), coating means (1) arranged in connection with said web (8), a coating surface (6, 7) at the coating means (1) and arranged in contact with said web (8) to dose said coating mix (11), and said coating means (1) being provided with at least a first coating surface (6) and a second coating surface (7), in such a way that it is possible at said running web (8) to switch between the one (6) and the other (7) surfaces while at least one of said surfaces (6, 7) is in an active contact position.

Abstract: A blade for creping a paper web from a dryer surface is provided, said blade having a sliding surface facing the dryer surface during use of the blade, a web impact surface upon which the paper web impacts during creping, and a working apex formed between the sliding surface and the web impact surface, wherein the working apex is located no more than 30 percent of the total blade thickness away from a neutral fiber of the blade. Preferably, the working apex of the inventive creping blade is located at or close to the neutral fiber of the blade. A method for manufacturing the blade is also disclosed.

Abstract: A mechanical apparatus maintains and/or cleans support strips of a workpiece support that forms a support plane for supporting workpieces. The mechanical apparatus includes a transport device for moving the workpiece support along a transport axis X and a service device that has a tool for processing the support strips. The service device is movable by means of a mechanical movement unit along a movement axis Y that is arranged at an angle relative to the transport axis X and/or along a movement axis Z that is arranged at an angle relative to the transport axis X and that is different from the movement axis Y, with the movement of the workpiece support along the transport axis X and the movement of the service device along the movement axis Y and/or along the movement axis Z being controllable in a coordinated manner by means of a control unit.

Abstract: A confectionery composition comprises a convoluted chocolate sheet having fold lines arranged generally along a first direction and having at least one region of weakness. The or each region of weakness extends along the full width of the chocolate sheet substantially in a single plane transverse to the first direction. Also provided are scraper blades for removing chocolate from a roller to form a chocolate sheet, and apparatus and methods for producing the confectionery composition described.

Abstract: An apparatus for automatically removing webbing remnants from unwound cores without damaging the surfaces or ends of the cores. The core cleaning apparatus includes a frame that carries an overhead bridge crane and a cutter frame supporting a movable cutting blade. The overhead crane includes a pair of opposed plugs designed to engage the open ends of the spent core. The cutter frame includes a cutter assembly that has automatically driven horizontally the length of the material webbing of the spent core, thereby cutting excess material webbing from the spent core. The entire operation is managed by a programmable controller without operator intervention.

Abstract: A regenerated elastic rollers manufacturing process is provided. The process includes the step of removing an agglutinated stain of toner adhered to the surface of an elastic roller including a mandrel and an elastic layer. The step further includes the steps of: (1) pressing a pressing roller against the surface of the elastic roller so as to crack the agglutinated stain on the surface of the elastic roller; and (2) removing the agglutinated stain cracked in the step (1) from the surface of the elastic roller by means of an adhesive roller.

Abstract: A doctor apparatus for a web forming machine for doctoring a moving surface with the doctor apparatus (10) has a blade (16), a blade holder (14) to which the blade (16) is adapted, a frame component (12) to which the blade holder (14) is adapted, and a loading element (23) arranged between the frame component (12) and the blade holder (14) for loading the blade holder (14) and further the blade (16). The loading element (23) is tied to both the frame component (12) and the blade holder (14). The invention also relates to a blade holder (14) and a method for a web forming machine for doctoring a moving surface (26).

Abstract: A lubricant applying device that faces a rotatable body, and that applies a solid lubricant to the rotatable body, includes: a lubricating roll in which the solid lubricant for application is formed into a circular sectional shape around a rotatable support shaft, and that is contacted with the rotatable body; and a pressing mechanism that presses the lubricating roll toward the rotatable body, wherein the lubricating roll that is pressed against the rotatable body by the pressing mechanism applies the lubricant in a state where the lubricating roll is not rotated relative to the rotatable body, and, when a rotational torque due to the contact with the rotatable body exceeds a predetermined value, the lubricating roll is rotated in accordance with rotation of the rotatable body.

Abstract: A coverage robot includes a chassis, a drive system, and a cleaning assembly. The cleaning assembly includes a housing and at least one driven cleaning roller including an elongated core with end mounting features defining a central longitudinal axis of rotation, multiple floor cleaning bristles extending radially outward from the core, and at least one compliant flap extending radially outward from the core to sweep a floor surface. The flap is configured to prevent errant filaments from spooling tightly about the core to aid subsequent removal of the filaments. In another aspect, a coverage robot includes a chassis, a drive system, a controller, and a cleaning assembly. The cleaning assembly includes a housing and at least one driven cleaning roller. The coverage robot includes a roller cleaning tool carried by the chassis and configured to longitudinally traverse the roller to remove accumulated debris from the cleaning roller.

Abstract: A cleaning mechanism for cleaning one or both side surfaces of a plastic card substrate prior to a processing operation occurring on the cleaned side surface. The cleaning mechanism is designed so that two cleaning rollers, one cleaning roller on a first cleaning station and one cleaning roller on a second cleaning station, are simultaneously cleaned by a single cleaning tape assembly.

Abstract: Creping and cutting procedure and equipment, for paper manufacture which consists of a creping doctor (1) carrying a blade (2) which carries out the creping; a support plate (12) which can pivot on a pivot shaft (5) in the geometrical center of which the creping blade (2) works; primary means of actuation (3) which through the support plate (12) cause the rotation of the creping doctor (1) on a pivot shaft (4); and secondary means of actuation of variation of angle (6) which act on the support plate (12) and cause its rotation on a pivot shaft (5) ; in such a way that it is possible, with only two doctors (1), (7) to carry out the maneuvers of creping, blade changing, cutting and cleaning.

Abstract: A method for cleaning a circumferential surface of a cylinder of a printing press provides for improved cleaning to be achieved during a short time. In order to clean the circumferential surface, a cleaning fluid is first applied to the circumferential surface. In order then to remove contaminants, the contaminants a broken up mechanically after the cleaning fluid is applied and before a cleaning apparatus acting on the circumferential surface is set into operation.

Abstract: A protective material block including a metal soap, wherein the surface of the protective material block has an X-ray diffraction pattern wherein a ratio (P2/P1) of a maximum peak height (P2) on a surface separation of from 3.6 to 5.0 ? to a maximum peak height (P1) on a surface separation of from 11 to 16 ? not greater than 0.5.

Abstract: A photoconductor drum cleaning apparatus in an electrophotographic printer is disclosed which is simple in makeup, which allows a wiping roll to be rotated to follow rotation of the photoconductor drum is rotated and to be serviced for a prolonged life and is capable of performing an improved cleaning operation.

Abstract: The present invention relates to a cleaning device that allows the obtaining of a high level of removal performance while reducing wear between a plate-shaped elastic member and a cleaning-targeted surface moving member, while also being able to stably maintain the contact status between the surface moving member and the plate-shaped elastic member, and an image forming apparatus and a process cartridge provided therewith.

Abstract: In one embodiment, the present invention includes a protective member to be adapted about a roller of a moving assembly and to ride along a path of the roller. In this way, debris is prevented from contacting the roller. In one particular embodiment, the protective member may have an internal portion with a frusto-circular shape.

Abstract: A roll polishing apparatus that can suppress cracks on a strip. The roll polishing apparatus includes brush rolls which face outer periphery of chilled rolls over an axial length of the chilled rolls, respectively, cylinders which urge the brush rolls wholly to the chilled rolls, respectively, and cylinders which deform the brush rolls in conformity to crowns of the chilled rolls, respectively. By these elements, wires of the brush rolls are uniformly contacted on outer peripheries of the chilled rolls to wipe off oxides adhering to the outer peripheries of the chilled rolls.

Abstract: Doctor blade for the paper industry, comprising a scraping plate (1) and holding means (p) for the scraping plate which in turn are held by a frame (a) the ends of which are securely fastened (2) by two fastening points (pf) to a stationary structure (f), characterized in that it comprises: a) mechanical means for adjustable fastening (3) between at least one end (2) of the frame and the stationary structure (f) in such a way that the distance (d) between the two fastening points (pf) can be varied by the user; and b) means for incorporating an additional mass (5) in adjustable quantities.

Abstract: A scraper for scraping and/or cleaning, especially for scraping and/or cleaning of units for the production and/or treatment of a fibrous material web, and preferably for scraping and/or cleaning of drying cylinders, including a composite material which includes a resin matrix material with fibers embedded therein. Copper and/or at least one copper alloy are mixed into the resin matrix material. The resin matrix material may be substituted at least partially by silicone modified epoxy resin.

Abstract: The invention relates to a device for placing a brush (1) against rollers (2), for example in roll stands, in particular against the working and/or support roller of a roll stand for the hot rolling of aluminium, wherein the brush (1) is mounted on a pivot lever and can be placed in contact against the roller (2) by means of a placement device (3) which exerts a placement force. It is provided here according to the invention that the placement device (3) for the brush (1) comprises at least one adjusting element (5) which is arranged so as to be rotatable with respect to the pivot lever (12) and which is operatively connected to the pivot lever by means of a force transmission element (4).

Abstract: The present invention provides a cleaning device including a cleaning member that cleans a surface of a rotating cylindrical element to be cleaned, and whose length in a longitudinal direction is longer than a length of the maximum operating region of the element to be cleaned, a length of a contact part of the cleaning member at which the cleaning member contacts with the element to be cleaned being shorter than the length in the longitudinal direction of the cleaning member, and the contact part being moved in the longitudinal direction of the element to be cleaned.

Abstract: A gravure coating apparatus is provided for forming a stripe-shaped coating film by means of a gravure roll having a groove between plate cylinders. The apparatus has a scraping member having: side edges each of which contacts an edge surface of one of the plate cylinders so as to be approximately aligned along the radial direction of the gravure roll and scrapes a coating solution on the edge surface; a groove-like passage for discharging the coating solution, the groove-like passage being formed in a generally central portion of the inner peripheral surface along the bottom surface of the groove so as to be aligned along the rotation direction of the gravure roll; and a tapered surface which guides the coating solution from the edges to the groove-like passage. The scraping member is disposed in the groove, whereby the coating film formed by the plate cylinders is made uniform over the entire surface using a simple configuration.

Abstract: A film for cleaning guide rollers of escalator can be detachably stuck over a predetermined length in a direction of transporting of a handrail belt, to the endless handrail belt which is guided and transported by guide rollers installed at a lower side of steps of an escalator (E) and a belt guide which is installed at an upper side of the steps, and includes a removing film layer which scrapes substances adhered to an outer circumferential surface of the guide rollers.

Abstract: A cleaning device includes a cleaning blade, a receiving member, an inlet seal, an adhering member, and an end seal. The cleaning blade is brought into contact with a photosensitive drum to remove residual toner therefrom. The receiving member receives the residual toner. The inlet seal guides the residual toner to the receiving member. The adhering member adheres the inlet seal to the receiving member. The end seal is arranged along the end portions of the cleaning blade and the inlet seal. The inlet seal covers the end seal and extends out from the end seal in its longitudinal direction.

Abstract: A doctor assembly is disclosed for use in a paper-making machine. The doctor assembly includes a doctor blade holder into which a doctor blade may be inserted and the doctor blade holder includes a pressure plate, pressure adjustment system, a support tray, and a bracket in accordance with an embodiment. The pressure plate is for supporting and aligning the doctor blade in a cross machine direction for application to a machine roll. The pressure adjustment system is for adjusting the pressure applied to the machine roll by the doctor blade, said pressure adjustment means including at least one fluid reservoir having a wall that contacts the pressure plate. The support tray for supporting the at least one fluid reservoir, and the support tray includes at least one bracket alignment feature. The bracket is attached to the support tray for pivotal attachment to the pressure plate.

Abstract: A cleaning card for use in cleaning internal surfaces of machine components includes a substrate having a central plane between opposed surfaces thereof, a machine direction dimension defined between opposed end edges and a transverse direction dimension defined between opposed side edges. The substrate includes an embossment forming angled, substantially non-collapsible, elongate raised ridges on opposite sides of the cleaning card substrate, with the raised ridges being oriented at an angle to the machine direction for incrementally wiping transversely across the internal surfaces to be cleaned, which can include peripheral surfaces of idler rolls. Preferably the opposed surfaces of the substrate each have a plurality of discrete, raised and collapsible working areas for engaging and cleaning internal surfaces of machine components.

Abstract: According to one embodiment, A cleaning device includes a cleaning blade, a support section, a container and an elastic sheet. the support section supports the cleaning blade while pressing an end portion of the cleaning blade to a cleaning object surface. the container has an opening portion at a side opposite to the cleaning object surface and contains a removal object scraped from the cleaning object surface by the cleaning blade. one end of the elastic sheet is fixed to a peripheral portion of the opening portion of the container. the other end of the elastic sheet is in contact with a non-opposite surface as a surface of the cleaning blade at a side not opposite to the cleaning object surface. the elastic sheet guides the removal object scraped from the cleaning object surface by the cleaning blade into the container.

Abstract: The invention relates to a scraper blade holding device comprising a mounting unit into which a scraper blade is normally inserted. According to the present invention a scraper blade carrier, which has in its region projecting out of the mounting unit fastening means for a scraper blade, is inserted into the mounting unit. This has the advantages that scraper blades with reduced dimensions can be used.

Abstract: An apparatus for cleaning a rubbing cloth disposed on an alignment roller includes: a first support member to be disposed parallel to the alignment roller; a second support member to be disposed parallel to the alignment roller and spaced apart from the first support member at a predetermined distance; and a cleaning cloth disposed on and extending between the first and second support members. The cleaning cloth cleans the rubbing cloth by rubbing.

Abstract: A paper making machine may having heated rolls for making high clay content papers. A roll cleaning apparatus may be mounted to the paper making machine. The roll cleaning apparatus may have a cleaning member that is mounted to a support member that extends lengthwise relative to a first roll of the paper making machine. The cleaning member may be a pad having a substantial area of the surface of the roll may be contacted. The cleaning member may be movable between an engaged position against the roll during operation, and a disengaged position spaced away from the roll in a non-operating condition, such as when replacement of the cleaning member is desired. The roll cleaning apparatus may include a drive connected to cause linear reciprocation of the cleaning member. The roll cleaning apparatus may have a drive or actuator mounted to move the cleaning member between the engaged and disengaged positions, and may be operable to bias the cleaning member against the roll in use.

Abstract: The invention relates to a method for shaping a roll cleaning brush (1), particularly for working rolls, for use in metal and, in particular, aluminum hot strip mills, comprising a brush lining (2). The inventive brush also comprises a supporting base body (3), which is mounted at one end and which is provided with the brush covering (2) attached thereto, said brush covering being pressed against the roll (4) with a settable force or defined insertion depth in order to have a cleaning effect. In order to achieve a uniform contact pressure, the shape of the cleaning brush (1) or of the brush covering (2) is matched according to the shape of the roll (4) whereby setting, between the roll and the brush covering or cleaning brush, a contact pressure that is as uniform as possible over the entire surface length of the roll. The invention also relates to a correspondingly contoured cleaning brush (1).

Abstract: In a device for cleaning chilled rolls that can keep higher cleanliness of a brush, a brush includes a rotatable cylindrical barrel including a number of suction through-holes extending from an outer periphery to inside, the barrel extending in parallel with an axis of the roll, grouped cleaning wires implanted on the outer periphery of the barrel and forming a helical bank extending from one end to the other end of the barrel for cleaning of the roll, and a dust suction port at one end of the barrel and in communication with an inner space of the barrel, the dust suction port being connected to an exhaust mechanism.

Abstract: A doctoring system is disclosed for cleaning a moving surface in a papermaking machine, and the doctoring system includes a doctor blade and fluid assist system. The doctor blade is coupled to a doctor blade holder, and the doctor blade holder is coupled to a doctor-back. The fluid assist system is for providing a fluid under positive pressure that is higher than atmospheric pressure. The fluid is directed in a direction generally opposite a direction of movement of the moving surface such that fluid of high momentum is provided to impinge on water resident within the moving surface and adjacent a leading edge of the doctor blade during movement of the moving surface.

Abstract: A paper making machine may having heated rolls for making high clay content papers. A roll cleaning apparatus may be mounted to the paper making machine. The roll cleaning apparatus may have a cleaning member that is mounted to a support member that extends lengthwise relative to a first roll of the paper making machine. The cleaning member may be a pad having a substantial area of the surface of the roll may be contacted. The cleaning member may be movable between an engaged position against the roll during operation, and a disengaged position spaced away from the roll in a non-operating condition, such as when replacement of the cleaning member is desired. The roll cleaning apparatus may include a drive connected to cause linear reciprocation of the cleaning member. The roll cleaning apparatus may have a drive or actuator mounted to move the cleaning member between the engaged and disengaged positions, and may be operable to bias the cleaning member against the roll in use.

Abstract: A machine-actuating mechanism cleaning card includes a substrate having a central plane between opposed surfaces, a machine direction dimension between opposed end edges and a transverse direction dimension between opposed side edges. The opposed surfaces each have a plurality of discrete raised areas arranged in transversely extending rows. At least some of the discrete raised areas in at least some of the transversely extending rows extend outwardly on each side of the central plane. The discrete raised areas each include a peak and a peripheral wall joined at one edge to the peak and having an opposed edge that is closer to the central plane than the peak. The cleaning substrate has an effective thickness that is greater than the nominal thickness. Methods of making cleaning cards also are part of the invention.

Abstract: A creping foil having a machine direction, cross machine direction, and Z-direction normal to a plane formed by machine direction and cross machine directions. The creping foil also has a front face, back face, and bottom side. The front face has one or more top conduits with one or more upper pipes integrally mounted therein. The one or more upper pipes are rotatable about an axis in the cross machine direction and have one or more upper diameter holes. The bottom side has one or more bottom conduits with one or more lower pipes integrally mounted therein. The one or more lower pipes are rotatable about an axis in the cross machine direction and have one or more lower diameter holes.

Abstract: A device for the detachable fixing of a holder for a doctor blade located in a paper production plant, it being possible for the doctor blade, which is assigned to a supporting or guiding roll for the wire, for the felt or for the paper web, to be set in its position with respect to the supporting or guiding roll by way of an actuating device and, furthermore, it being possible for the holder for the doctor blade to be displaced on a support for the holder by way of a guide at least approximately in the axial direction of the supporting or guiding roll and fixed on the support in the operating position. A pressure hose is disposed between the holder for the doctor blade and the support. The pressure hose allows the holder for the doctor blade to be clamped to the support.

Abstract: A cleaning device and a blade which is provided in the cleaning device and which has an edge portion to be pressed against a surface of a photoreceptor, so as to scrape toner are arranged so that: the blade includes (a) a blade main body constituting a main body portion of the blade and (b) a fluorocarbon resin layer formed in an edge portion, which is to make contact with the photoreceptor, of the blade main body, the fluorocarbon resin layer being made of a resin material, the resin material being filled in irregularities of a smooth surface of the blade main body. With this, even when the cleaning device is provided in a high-speed machine using small-particle toner with no corner, it is possible to extend the life of the photoreceptor without reducing a cleaning property.

Abstract: A blade of a cleaning device includes two surfaces: an upstream side surface and a downstream side surface. The two surfaces adjoin each other with respect to a contact edge of the blade. The upstream side surface has a longer dimension in the direction orthogonal to the contact edge than that of the downstream side surface. A horizontal portion of a blade holder that restricts a warp in the blade is bonded on an opposed surface to the upstream side surface of the blade. The blade is held via the horizontal portion with a vertical portion of the blade holder supported by the main body of the cleaning device in a downstream of a normal line to a contact point on a photoconductor surface in contact with the contact edge, in the photoconductor-surface moving direction.

Abstract: The present invention relates to a doctor blade comprising: a body having a thickness, a sharp leading side, a trailing side, and working end comprising a bevel surface, wherein the bevel surface is defined by a leading edge and a trailing edge, and wherein the Ra of the bevel surface is from about 1 ?-in to about 7 ?-in.

Abstract: A roll cleaning apparatus having a cleaning member mounted to a support member that extends lengthwise relative to a first roller of the machine. The cleaning member has a brush having a substantial area to place against the surface of the roll. The cleaning member may be movable between an engaged position against the roll during operation, and a disengaged position spaced away from the roll in a non-operating condition, such as when replacement of the cleaning member is desired. The roll cleaning apparatus may include a drive connected to cause linear reciprocation of the cleaning member. The roll cleaning apparatus may have a drive or actuator mounted to move the cleaning member between the engaged and disengaged positions, and may be operable to bias the cleaning member against the roll in use. The roll cleaning member may have a contact head that includes an array of abrasive bristles.

Abstract: A cleaning apparatus suitable for cleaning a roll coating machine is described, the cleaning apparatus having one or more rolls and including: a cleaning means; and a support chassis for supporting the cleaning means adjacent the one or more rolls. A roll coating machine is also described, which includes a cleaning apparatus, comprising a cleaning means; and a support chassis for supporting the cleaning means adjacent the one or more rolls.

Abstract: The invention relates to a scraper blade holding device which comprises a cover plate and a base plate. The cover plate and the base plate are pivotable relative to one another about an axis. The axis is formed by a bearing tube, which is a component of the base plate and is arranged in an end region of the base plate.

Abstract: A self-retaining scraping device for continuously cleaning work rolls of a roller leveler assembly has a first wall having two angled or curved portions and a straight portion extending between the angled portions; and a second wall having two angled or curved portions and a straight portion extending between the angled portions. The first wall and second wall are connected to each other via the straight portions. The angled or curved portions of the first wall extend in an opposite direction from the angled or curved portions of the second wall. The scraping device is inserted between adjacent work rolls and has multiple scraping edges contacting outer surfaces of the work rolls to continuously clean the work rolls. The scraping device is supported by the work rolls.

Abstract: A cleaning card for use in cleaning internal surfaces of machine components includes a substrate having a central plane between opposed outer surfaces, a machine direction dimension defined between opposed end edges and a transverse direction dimension defined between opposed side edges. The opposed surfaces have a plurality of discrete raised working areas for engaging and cleaning internal surfaces of the machine components. The working areas each include a peak and a peripheral wall having an edge remote from the peak and the peak of each raised working area is further from the central plane than the edge of the peripheral wall remote from the peak. The cleaning card substrate has an effective working thickness that is greater than the nominal thickness between the opposed surfaces.