Applicator for applying a fluid to a substrate and machine with such an applicator

Abstract

The invention relates to an applicator (01) for coating a substrate (B) with a fluid (L) comprising a first cylinder (02) which forms an application gap with a second cylinder (03) in which the substrate (B) to be guided through the application gap and coated is or can be supplied with the fluid (L) on the side facing the first cylinder (02), wherein the first cylinder (02) can be supplied with the fluid (L) to be applied on its outer surface directly or indirectly by means of a feed device (04).The feed device (04) comprises a first roller (06) and a downstream second roller (07), which form a first gap (11) between them with a gusset above it, wherein a fluid storage chamber (12) is provided in the gusset between two axially spaced side walls (13), and wherein the respective side wall (13) laterally delimiting the fluid storage chamber (12) comprises a sealing surface (18.1) facing the roller shell surface towards one of the two rollers (07; 06) forming the first gap (11), which has a contour corresponding to the roller shell surface and together with the roller shell surface forms a seal against lateral passage of the fluid (F).The feed device (04) has a third roller (09) downstream of the second roller (07) forming a second gap (21) with the second roller (07), wherein the side wall (13) has a sealing surface (18.1; 18.3) with a contour corresponding to the roller curvature and interacting with the roller shell of the second roller (07) as a seal above the second gap (21) and / or a sealing surface (19.3) facing the end face of the third roller (08) and interacting with the end face of the ball of the third roller (08) as a seal above the second gap (21).

Description

[0001] The invention relates to an applicator for applying a fluid, in particular a lacquer, to a substrate - in particular a flat substrate - and to a machine with such an applicator according to the preamble of claim 1 or 10.

[0002] In industrial metal printing, metal sheets are often coated over the entire surface or part of the surface in question in a single process step, e.g. to protect the respective surface of the metal sheets in question or at least a previously printed image and / or e.g. to create a white ground and / or a gloss effect, by applying at least one fluid, e.g. painted over the entire surface or part of the surface by means of a coating unit or coated in some other way. The fluid to be applied to at least one surface, i.e. to the top and / or bottom of the metal sheets in question, is e.g. in the form of a varnish, wherein the application of the fluid is generally subjected to a subsequent drying process. In addition to applying a varnish, an application of another, in particular viscous, fluid, such as glue, is also conceivable in an application unit relating to the invention.

[0003] EP 0 736 329 A2 discloses a device for supplying the coating cylinder of a coating machine with a coating film, wherein a coating reservoir in the gusset above a roller gap between a first coating unit roller and a second coating unit roller is laterally delimited by two side parts, referred to as sliding walls, which are pressed onto the end faces of the two rollers by compression springs.

[0004] CN 110732453 A relates to a double-sided coating device with a first roller forming a first nip with a second roller, wherein the second roller, in turn, forms a second nip with a third roller. In the nip above the first nip, a storage space is formed between two side plates. The side plates, with their corresponding shape, extend into the nip and form respective sealing surfaces with the lateral surfaces of the first and second rollers.

[0005] DE 10 2014 111 943 A1 discloses an adhesive application device for applying adhesive to a material web, comprising a first roller and a second roller forming a first roller gap with the first roller, wherein an adhesive reservoir is formed in the gusset above the roller gap. The reservoir space is bounded on both sides by end walls, each of which forms sealing surfaces with an end face of the first roller and a peripheral portion of the second roller. The second roller, together with a counterpressure roller, forms an application gap through which the material web passes.

[0006] An applicator for coating a substrate is also known, for example, from US 2001 / 027747 or CN 105618340 or CN 204869980.

[0007] The invention is based on the object of creating an application unit, in particular a coating unit, for applying a - in particular flat - substrate with a fluid, in particular paint, as well as a machine with such an application unit, in particular a coating unit.

[0008] The object is achieved according to the invention by the features of claim 1 and 10 respectively.

[0009] The advantages achievable with the invention consist, in particular, in the fact that a lateral leakage of, for example, viscous fluid, in particular paint or glue, or possibly other viscous media, in a fluid path for supplying the fluid to the application or coating cylinder is prevented if possible, or at least kept to a minimum. This saves maintenance and cleaning effort and potentially prevents contamination-related malfunctions during machine operation.

[0010] In particular, leakage through lateral gaps, such as those that can occur when a sidewall is in contact with a roll end face, is minimized or even eliminated. Such gaps can occur not only, but especially, when two adjacent rolls are to be sealed at the end face by an inclined sidewall, but the roll bodies do not align exactly due to tolerances in position and / or width, for example.

[0011] An application unit, in particular a coating unit, particularly suitable for the invention for applying a fluid, in particular a paint, to a particularly flat, e.g. web-shaped or preferably sheet-shaped, substrate, in particular metal sheets, comprises a first cylinder, e.g. an application or coating cylinder, which, with a second cylinder, e.g. an impression cylinder, forms an application gap, in particular a coating gap, in which the substrate to be guided through the gap and to be coated therein is or can be coated with the fluid, in particular a paint, on the side facing the first cylinder. A flat substrate is understood here and below to be a substrate whose width and length are many times greater than their thickness, e.g. by at least a factor of 10, in particular at least a factor of 100. The first cylinder is - if necessary.Can be supplied with the fluid to be applied, in particular paint, directly or indirectly via one or more cylinders by a supply device on its outer surface, wherein the supply device comprises a first roller and a downstream second roller, which form a first gap between them with an overlying gusset in which a fluid storage space, in particular a paint storage space, is formed between two axially spaced-apart side walls. This is thus delimited, for example, by the outer surfaces of the rollers on the one hand and by side walls on both sides on the other.

[0012] The respective side wall laterally delimiting the fluid or paint supply space comprises, towards one of the two rollers forming the first gap with each other, in particular towards the second roller, a sealing surface facing the roller shell surface of this roller, which sealing surface has a contour corresponding to the roller shell surface and, together with the roller shell surface, forms a seal against a - e.g. at least unhindered - lateral passage of the fluid or paint.

[0013] The second roller then forms a second gap with a third roller provided downstream of the second roller in the feed device, wherein this third roller, which also conveys fluid, for example, is in particular part of the fluid-conducting roller train of the feed device and is or will be supplied with fluid by the second roller during operation. The side wall has a sealing surface above the second gap that interacts with the roller shell of the second roller as a seal and has a contour corresponding to the roller curvature and / or a sealing surface facing the end face of the third roller and interacting with the end face of the barrel of the third roller as a seal above the second gap. The barrel length of the third roller is, for example, shorter than the barrel length of the second roller.

[0014] In an advantageous embodiment, the side wall laterally delimiting the fluid or paint supply chamber comprises, on a side of the other of the two rollers delimiting the fluid or paint supply chamber, in particular the first roller, facing the end face of the roller barrel, a sealing surface which, together with an end face of the roller barrel of this other, in particular first, roller, forms a seal against a radial passage of the fluid, in particular paint.

[0015] Preferably, a barrel length of that roller, in particular of the second roller, whose lateral surface forms the seal with the sealing surface of the side wall facing the lateral surface, is greater than the barrel length of the roller, in particular of the first roller, which forms a seal with the sealing surface of the side wall facing the front side with an end face of its barrel.

[0016] Embodiments of the invention are illustrated in the drawings and are described in more detail below.

[0017] They show: Fig. 1 is a side view of an application unit designed as a coating unit with an application cylinder, in particular a coating cylinder, an impression cylinder and a feed device; Fig. 2 is an oblique view of the application unit designed as a coating unit, wherein the side wall according to the invention has been masked out to show the different bale widths; Fig. 3 is an enlarged section of the feed device in an oblique view; Fig. 4 is a detailed view of a side wall provided against a fluid or paint outlet; Fig. 5 is a detailed view of a holder pressing the side wall towards the roller end face.

[0018] An application unit 01, designed in particular as a coating unit 01, for applying a, for example, sheet-shaped, substrate B, e.g. substrate sheets B, in particular metal panels B, with a fluid L designed in particular as a paint L, comprises a first cylinder 02, in particular a coating cylinder 02, which serves in particular for fluid or paint application, which, with a second cylinder 03, acting in particular as an impression cylinder 03, forms a gap, e.g. a coating or painting gap, in which the substrate B, which is guided through the gap and is to be applied or painted, is or can be applied, in particular painted, with the fluid L or paint L on the side facing the cylinder 02, in particular the painting cylinder 02. The first cylinder 02 is directly or optionallycan be supplied with the fluid L to be applied, in particular the paint L, from a supply device 04 via one or more further cylinders on its outer surface.

[0019] Although the application unit 01 is described below based on its preferred embodiment as a coating unit 01, the teaching can also be generalized to other application units 01 for applying - in particular flat - substrates with - in particular a viscous - fluid.

[0020] For this purpose, the feed device 04 comprises at least a first roller 06, e.g. feed or press-off roller 06, and downstream, i.e. viewed in the direction of fluid flow, directly following a second roller 07, which forms a first gap 11, e.g. metering gap 11, with the first roller 06. Above the first gap 11, a gusset is formed between the roller shells of the first and second rollers 06; 07. The gusset forms, between the shell surfaces and the mutually facing sides of two axially, i.e. viewed in the axial direction of the first and / or second roller 06; 07, spaced apart from one another - e.g. single-part or multi-part - side parts 13, in particular side walls 13, over a width which is limited by the distance between the side walls 13, a fluid storage space 12, e.g. B. paint supply room 12. The fluid L is added to this, e.g.supplied via a line system and forms a fluid reservoir there, also referred to as a paint reservoir. The maximum fill level of the fluid reservoir 12 can be limited, for example, by a lowest point on the end side walls 13 or by the rollers 06; 07 with their upper apex line that is lower, or preferably by an overflow 14, e.g. in the form of an opening 14 or channel 14, in at least one of the two side walls 13, which ensures a constant fill level - e.g. in the event of an operationally excess fluid supply via a line (not shown). Flowing fluid L can, for example, be circulated directly from the overflow 14 or, after being collected in a collecting container 16, e.g. via a line 17. The respective side wall 13 can, for example, be designed in one or more parts.

[0021] The side wall 13, which is stationary during operation, must seal the fluid or paint storage chamber 12 formed above the rotating rollers 06; 07 and, if applicable, a further path of the fluid L via rotating rollers 06; 07 to the outside as well as possible, ideally completely. Since complete sealing of the parts moving relative to one another is almost impossible - at least at a reasonable cost - the term "sealing" shall be understood below not only to mean complete sealing but also to mean sealing or preventing the passage of at least a significant or undisturbed flow or outflow of the fluid F according to the usual technical understanding.

[0022] The side wall 13 which laterally delimits the paint supply chamber 12 is sealed against lateral passage of the fluid F - e.g. in the above sense - towards one of the two rollers 07; 06 forming the first gap 11 together, in particular towards the second roller 07, by a sealing surface 18.1 which cooperates with the roller shell surface and has a contour on the side facing the roller shell surface which corresponds to the roller shell surface.

[0023] For this purpose, the side wall 13 preferably has at least one first section 13.1, which has a sealing surface 18.1 facing the roll shell and corresponding to the curvature of the roll shell, extending over a circumferential section of at least one of the two rolls 07; 06 forming the first gap 11, in particular the second roll 07, in a circular arc that extends at least from the first gap 11 to the maximum fill level. This sealing surface 18.1, together with the roll shell section opposite the sealing surface 18.1, forms a seal during operation, in particular an axial seal that at least inhibits the passage of fluid L in the axial direction. The sealing surface 18.1 can be in sliding contact with the roll shell surface - which rotates underneath it in particular during operation - over at least one section width in the axial direction, or can form a gap with the roll shell surface in the manner of a gap seal, for example, less than 1 mm, e.g., at most 0.5 mm.The side wall 13, at least in this first section 13.1, extends at a height viewed in the axial direction such that at least its sealing surface 18.1 lies within the barrel width b07; b06 of the respective roller 07; 06 or at least overlaps it with its sealing surface 18.1. The barrel width b07; b06 of the respective roller 07; 06 is thus, for example, greater than a width of the fluid supply chamber 12—and thus, for example, also greater than a maximum effective working width of the coating unit 01.

[0024] The side wall 13 is preferably further designed such that it is sealed against the passage of the fluid in the radial direction - e.g. in the above sense - with respect to one roller 07; 06, in a first advantageous embodiment e.g. the second roller 07, in the above-mentioned manner by a sealing surface 18.1 which interacts with the roller shell surface of this roller 07; 06 and has a contour corresponding to the roller shell surface, and with respect to the other roller 06; 07, in particular the first roller 06, by a sealing surface 19.2 which interacts with an end face of the roller barrel of this other roller 06, 07. The barrel width b07; b06 of the roller 07; 06 sealed via the shell surface, e.g. the second roller 07, is greater than the barrel width b06; b07 of the other rollers 06; 07 sealed via the front side, e.g. the first roller 06.

[0025] For this purpose, the side wall 13 is designed, for example, in such a way that a first section 13.1 forms an axial seal with a roll shell section of one of the rolls 07; 06, in a first advantageous embodiment, for example the second roll 07, in the above-mentioned manner, but a second section 13.2 of the side wall 13 laterally delimiting the fluid storage space 12 runs on the end face of the roll barrel of the other roll 06; 07, for example the first roll 06, and the end face of this other roll 06; 07, viewed in an axial projection, overlaps at least in a circumferential section which extends at least from the first gap 11 to the maximum fill, wherein a sealing surface 19.2 of the second section 13.2 located in the region of the overlap, together with an opposite surface of the roll barrel end face, forms a seal, in particular a seal which prevents the passage of fluid L in the radial direction between the roll barrel end and the sealing surface 19.2 of the second section 13.2 inhibiting seal. The sealing surface 19.2 is preferably in sliding contact with the roll barrel end face - particularly rotating past it during operation - over at least one section width in the radial direction of the respective roll 06; 07, or forms a gap with it of, for example, less than 1 mm, e.g., at most 0.5 mm. The side wall 13, at least in this second section 13.2, runs with its side facing the roll 06; 07, viewed in the axial direction, directly adjacent to the barrel end face, or else axially spaced therefrom by the above-mentioned gap dimension and / or in a plane running perpendicular to the axial direction. The barrel width b06; b07 of the end-sealed roll 06; 07 determines, for example, the width of the fluid supply chamber 12 - and thus also corresponds, for example, to the maximum effective working width of the coating unit 01.

[0026] In an alternative embodiment, for example, an axial seal as described above is formed in the above-mentioned manner on the first roller 06 by the first section 13.1, and the end seal is formed on the end face of the second roller 07. The above is to be transferred accordingly.

[0027] The aforementioned sections 13.1; 13.2 of the side wall 13 do not have to be assigned to structurally different and / or offset side wall parts, but can be sub-regions of the same one-piece and / or continuous side wall 13 or of the same one-piece and / or continuous side wall part.

[0028] By sealing the paint supply chamber at the front against one, in particular the first, roller 06; 07 in conjunction with the circumferential sealing against the other, in particular the second roller 07; 06, play in the front seal of one roller 06; 07 can be prevented, which can arise, for example, in the case of a front seal of both adjacent rollers 06; 07 due to tolerances in the roller widths b06; b07 or in the assembly.

[0029] In one - for example in the figures Fig. 1 to Fig. 3In the embodiment of the feed device 04 with three rollers 06; 07; 08 shown, the first roller 06 forms with the second roller 07, e.g. as a metering roller 07, the metering gap 11 which serves for pre-metering and is also referred to as the pre-metering gap 11, while the second roller 07 forms with a third roller 08 of the feed device 04 a second gap 21, e.g. the - in particular ultimately decisive - metering gap 21. The above exemplary embodiments for the formation of the seals 18.1; 19.2 by the first and second section 13.1; 13.2 are, with regard to the first and second roller 06; 07, based on the embodiment preferably with three rollers 06; 07; 08 designed to apply feed device 04 - basically regardless of whether and if so in what way a lateral seal is also provided in the area of the second gap 21, but preferably in a configuration set out below.

[0030] In the embodiment with three rollers 06; 07; 08, a circumferential sealing of the gusset located above the second gap 21 against the third roller 08 can generally be provided in the above-mentioned manner, wherein the correspondingly designed first section 13.1 or a further section of the side wall 13 continuing the first section 13.1 can have an axial seal that interacts with a roller shell section for lateral sealing against the third roller 08. The above-mentioned design of such an axial seal and a barrel width b08 enlarged for this purpose are to be applied accordingly.

[0031] Preferably, however, in the design of the feed device 04 with three rollers 06; 07; 08, a side wall 13 - e.g. one-part or multi-part - is provided, which seals the varnish supply space 12 towards the first roller 06 in the above-mentioned manner by means of a sealing surface 19.2 interacting with the end face of the barrel of the first roller 06 and towards the second roller 07 in the above-mentioned manner by means of a sealing surface 18.1 interacting with the roller shell of the second roller 07, and which seals the gusset above the second gap 21 towards the second roller 07 likewise by means of a sealing surface 18.1; 18.3 interacting with the roller shell of the second roller 07 with a corresponding contour and / or towards the third roller 08 by means of a sealing surface 19.3 interacting with the end face in the above-mentioned sense. The above is intended to form such a frontal seal and to produce a smaller or larger seal than the second roller 08.a bale width b08 corresponding to the maximum possible effective working width.

[0032] In an advantageous embodiment which is particularly relevant for three rollers 06; 07; 08 and has an axial seal provided on a circumferential section of the second roller 07, i.e. with the sealing surface 18.1 interacting with the roller shell of the second roller 07, this seal does not only extend over a circumferential section of the second roller 07 which is involved in the upper gusset between the first and second rollers 06; 07, but - e.g. continuously or possibly with one or more interruptions or connection points - at least as far as the next gap 21 downstream, i.e. for the embodiment with three rollers 06; 07; 08 to the gap 21 of the second roller 07 with the third roller 08. The seal formed on the second roller 07 by the interaction of the sealing surface 18.1 with the roller shell can in principle be formed by a first section 13 extending over the entire circumferential section from the first gap 11 to the subsequent gap 21.1 and / or be designed with a sealing surface 18.1 extending over this circumferential section.

[0033] Preferably, however, the sealing surface 18.1; 18.3 which interacts with the roll shell of the second roll 07 and extends, for example, to the second gap 21 is designed in several parts, in particular in two parts, wherein the first section 13.1 extending from the height of the first gap 11 is continued by a further section 13.3 with a design comparable to the above sealing surface 18.1, which extends with a sealing surface 18.3 curved according to the roll contour at least down to the level of the subsequent gap 21 and is arranged on the first section 13.1 so that it is detachable or preferably pivotable about an axis A parallel to the axis of rotation of the second roll 07. Such a detachably or pivotably provided third section 13.3 is encompassed, for example, by a separate side wall part which is detachably and / or pivotably relative to the side wall part which surrounds the first and second sections 13.1; 13.2 comprising side wall part.Pivoting the third section 13.3 can be actuated via a lever 22 and / or the third section 13.3 can be preloaded towards the roller surface by a spring element 23. This can be achieved, for example, by a pair of handles 22, 24 arranged in a pincer-like manner, with one of the handles 24 being rigidly provided on the first section 13.1 and the other handle 22 being formed by the pivotable lever 22, which is preloaded, for example, via the spring element 23 designed, for example, as a compression spring 23. By actuating the lever 22, the third section 13.3 can be pivoted away from the roller shell surface, thus enabling simplified removal - e.g., for cleaning or maintenance purposes - despite the large circumferential area.

[0034] In an embodiment of the feed device 04 with three rollers 06; 07; 08, the third roller 08 acts, for example, as an application roller 08 or is designed as such, by means of which the first cylinder 02 can be subjected to the fluid L on its outer surface.

[0035] The above-mentioned sections 13.1; 13.2, 13.3 are formed, at least in the region of their sealing surfaces 18.1; 18.3; 19.2; 19.3, from a plastic, e.g., from a plastic with good conformability and / or as abrasion-resistant as possible, e.g., from polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), or polyoxymethylene (POM). In an advantageous embodiment, the single- or multi-part side wall 13 is formed from a single- or multi-part plastic plate, which is supported by a metal carrier 26 for stability reasons.

[0036] At least the surface of the roller 07, in particular the second roller 07, which contributes to the formation of an axial seal with its lateral surface, is made of a wear- and / or corrosion-resistant and / or coated steel, for example a heat-treated steel such as steel 45, at least in the region of its barrel that interacts with the sealing surface 18.1; 18.3 of the side wall 13.

[0037] The section 13.2 sealing the front side of the first roller 06 can, for example, extend from the first gap 11 in the direction of rotation over more than 45°, preferably more than 90°, of the circumferential region of the first roller 06 and / or have a wiper 34, e.g. an elastic and / or compressible wiper lip, embedded in a groove of the side wall 13 in a region lying more than 45°, in particular more than 90°, behind the first gap 11 in the direction of rotation.

[0038] The side wall 13 can be pressed, via the support 26 if necessary, directly or indirectly via one or more adjusting elements 27, for example spring elements 27, such as compression springs 27 or possibly pneumatic cylinders, or possibly other force transmission means such as adjusting eccentrics or toggle lever mechanisms, with the respective sealing surface 19.2; 19.3 against the end face of the respective roller 06; 07, 08 sealed on the end face, in particular the first and possibly third roller 06; 08. The respective compression spring 27 is supported directly or preferably indirectly via a holder enabling axial displacement of the compression springs 27 on a side frame 09 of the coating unit 01. The holder 28 is mounted, for example, via rockers 29 on the side frame 09 or on a base 33 fastened to the side frame 09 and can be moved, for example, via an adjusting mechanism 32 - preferably manually via a lever 31 - in the direction of the rollers 06; 07; 08 and away from them.The bracket 28 and the side wall 13 are connected to each other, for example, in a form-fitting manner such that they can be released from each other by an axial relative movement, but are fixed in their relative movement perpendicular to this, or at least their freedom of movement is restricted. This can be achieved by bolts running axially in guides or by bolts embedded in . Fig. 5 Invisible recesses can be realized in the rear of the holder, into which the spring elements 27 engage when the holder 29 is in the adjusted state. The adjusting mechanism 32 can, for example, be formed by a mechanism based on a spiral guide, the rotatable part of which can be pivoted, for example, via the lever 31.

[0039] The above-mentioned singular reference to the "side wall" applies in particular to both side walls, provided that the side walls 13 are provided in their construction and / or their fastening and / or the interaction of their sealing surfaces 18.1, 18.3; 19.2; 19.3 with the rollers 06, 07; 08 so as to be mirrored to one another about a plane perpendicular to the roller axes.

[0040] In the preferred embodiment of the coating unit 01 as a coating unit 01 applying metal panels B or as a coating unit 01 for coating metal panels B, the substrate path leading through the coating gap is flat or leads over a rotation angle on the circumference of one of the cylinders 02; 03 involved in the coating gap of a maximum of 30°, in particular a maximum of 20°.

[0041] The outer surface of the painting cylinder preferably has elastic material in the region of the circumference, ie is formed by an elastic material, e.g. rubber, in the region of the outer surface or has a cover with an elastic surface, e.g. rubber, on a cylinder body.

[0042] The above-mentioned coating unit 01 can be part of a sheet-handling and / or processing machine, e.g. a coating machine, in particular a coating unit 01 of a metal panel coating machine, to which, on the input side, e.g. via a sheet feed, e.g. already printed substrate sheets B, in particular metal panels B, are fed, coated in the machine, preferably dried by means of a downstream dryer, and then laid out - e.g. as a stack. However, it can also be part of an inline production line which, in the transport path of the substrate sheets B or metal panels B, upstream of the coating unit 01, additionally comprises one or more printing units and optionally at least one dryer for intermediate drying of applied printing ink.

[0043] In a preferred embodiment as a coating or painting plant 01 for sheet metal working and / or processing, sheet metal panels B to be processed, in particular to be painted and possibly printed beforehand, have a format of, for example, between 500 mm x 650 mm and 1,000 mm x 1,250 mm and each have a sheet thickness of, for example, between 0.1 mm and 1.5 mm, preferably between 0.14 mm and 0.5 mm. Each individual sheet metal panel B, depending on its format and material - whether made of tinned sheet steel or tin-free sheet steel or aluminum - can therefore have a mass of, for example, a few hundred grams up to a few kilograms, for example from at least 300 grams up to five kilograms or more. In particular in the production of sheet metal packaging, i.e. in sheet metal packaging printing, sheet metal panels B of this type are manufactured industrially in mass production at a production speed of several thousand sheet metal panels B per hour, e.g. B. of at least 6.000 metal sheets B per hour or even 9,000 metal sheets B per hour coated, in particular painted and, if necessary, printed beforehand. List of reference symbols

[0044] 01Applicator, coating unit 02First cylinder, coating cylinder 03Second cylinder, impression cylinder 04Feed device 05- 06First roller, feed roller, pressure roller 07Second roller, metering roller, application roller 08Third roller, application roller 09Frame 10- 11First gap, metering gap, pre-metering gap 12Fluid supply chamber, coating supply chamber 13Side part, side wall 13.1First section 13.2Second section 13.3Third section 14Overflow, opening, gutter 15- 16Collecting container 17Line 18.1Sealing surface 18.3Sealing surface 19.2Sealing surface 19.3Sealing surface 20- 21Second gap, metering gap 22Lever, handle 23Spring element, compression spring 24Handle 25- 26Carrier 27Adjusting element, spring element, compression spring 28Bracket 29Swing arm 30- 31Lever 32Adjusting mechanism 33Base 34Wiper b06Ballenbreite b07Ballenbreite b08Ballenbreite AAchse BSubstrat, Substratbogen, Blechtafel LFluid, Lack

Claims

1. Application unit (01) for coating a substrate (B) with a fluid (L), comprising a first cylinder (02) which, together with a second cylinder (03), forms an application nip in which the substrate (B) that is to be guided through the application nip and coated is or can be acted upon with the fluid (L) on the side facing toward the first cylinder (02), wherein the first cylinder (02) can be directly or indirectly acted upon, on the lateral surface thereof, by a supply device (04) with the fluid (L) to be applied, wherein the supply device (04) comprises a first roller (06) and a downstream second roller (07), which between them form a first nip (11) with a gusset located thereabove, wherein a fluid reservoir (12) is provided in the gusset between two axially spaced-apart side walls (13), and wherein the respective side wall (13) laterally delimiting the fluid reservoir (12) comprises, toward one of the two rollers (07; 06) that together form the first nip (11), a sealing surface (18.1) facing toward the roller lateral surface, which sealing surface has a contour corresponding to the roller lateral surface and together with the roller lateral surface forms a seal against lateral passage of the fluid (L), wherein the supply device (04) comprises, downstream of the second roller (07), a third roller (08) which forms a second nip (21) with the second roller (07), characterized in that the side wall (13) comprises a sealing surface (18.1; 18.3), which cooperates as a seal with the roller lateral surface of the second roller (07) above the second nip (21) and has a contour corresponding to the roller curvature, and / or comprises a sealing surface (19.3), which faces toward the end face of the third roller (08) and cooperates as a seal with the end face of the barrel of the third roller (08) above the second nip (21).

2. Application unit according to claim 1, characterized in that the side wall (13) laterally delimiting the fluid reservoir (12) comprises, on a side facing toward the end face of the roller barrel of the other of the two rollers (06; 07), a sealing surface (19.2) which, together with an end face of the roller barrel of this other roller (06; 07), forms a seal against radial passage of the fluid.

3. Application unit according to claim 2, characterized in that the side wall (13) is designed in such a way that it forms the seal with the roller lateral surface of the second roller (07) on a first portion (13.1) and forms the seal with the end face of the roller barrel of the first roller (06) on a second portion (13.2).

4. Application unit according to claim 2 or 3, characterized in that a barrel length (b07; b06) of the roller (07; 06), the lateral surface of which forms the seal with the sealing surface (18) of the side wall (13) that faces toward the lateral surface, is greater than the barrel length (b06; b07) of the roller (06) which, with an end face of its barrel, forms a seal with the sealing surface (19) of the side wall (13) that faces toward the end face.

5. Application unit according to claim 1, 2, 3 or 4, characterized in that the sealing surface (18.1; 18.3) that cooperates with the roller lateral surface of the second roller (07) is formed of two parts, and in that a first portion (13.1) of the side wall (13), which seals the fluid reservoir (12) with respect to the roller lateral surface of the second roller (07), bears a first part of the sealing surface (18.1) that cooperates with the lateral surface, said first portion being continued by a further portion (13.3), which extends with a sealing surface (18.3), curved in a manner corresponding to the roller contour, at least down as far as the level of the subsequent nip (21) and is arranged on the first portion (13.1) in such a way as to be detachable or pivotable away from the lateral surface about an axis (A) parallel to the axis of rotation of the second roller (07).

6. Application unit according to claim 1, 2, 3, 4 or 5, characterized in that the side wall (13) is supported directly or indirectly against a side frame (09) of the application unit (01) by way of at least one spring element (27) in such a way that it experiences a force in the direction of the end face of the roller barrel of at least the first roller (06) and / or is pressed with its sealing surface (19.2) against the end face of the roller barrel of at least the first roller (06).

7. Application unit according to claim 6, characterized in that the at least one spring element (27) is held on a mount (28), which is coupled to the side frame (09) in an axially displaceable manner.

8. Application unit according to claim 1, 2, 3, 4, 5, 6 or 7, characterized in that the application unit (01) is designed as an application unit (01) for acting upon substrate (B) in the form of metal sheets (B) and has a substrate path leading through the application nip, which substrate path is planar or leads over a maximum rotation angle of 30° on the circumference of the first or second cylinder (02; 03).

9. Application unit according to claim 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that the application unit (01) is designed as a varnishing unit (01), by which the substrate (B) can be acted upon with a fluid (L) formed by varnish (L).

10. Machine for acting upon metal sheets (B) with a fluid (L), to which metal sheets (B) that have already been printed or are yet to be printed can be fed on the inlet side, said machine comprising at least one application unit (01), by which the metal sheets (B) can be acted upon with a fluid (L) on at least one of the sides thereof, and comprising a delivery, in which the metal sheets (B) acted upon with fluid (L) can be placed into piles, characterized by the application unit (01) being designed according to any one of claims 1 to 9.

11. Machine according to claim 10, characterized in that at least one printing unit is arranged upstream of the at least one application unit (01) in the substrate path, and / or at least one dryer is arranged downstream thereof.

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