DE102011075600B4 - Dampening unit of an offset printing unit - Google Patents

Abstract

Dampening unit (07) of an offset printing unit (01), the dampening unit (07) having at least one first chamber and at least one dampening solution source (13) arranged in the at least one first chamber and at least one roller (09 ; 11), wherein the at least one first chamber has at least one first opening (28) which extends from the at least one roller (09; 11) delimiting the at least one first chamber except for a first, the at least one first opening (28 ) circumferential gap is closed, the first gap surrounding the at least one first opening (28) by the at least one roller (09; 11) delimiting the at least one first chamber and a first circumferential opening (28) Edge of the at least one first chamber on the other hand is limited and wherein in the circumferential direction of the at least one roller (09; 11) delimiting the at least one first chamber adjacent to the at least one first chamber rt at least one second chamber of the dampening unit (01) is arranged, which has a second opening (41) which is formed by at least one roller (09; 11) is closed except for a second, the second opening (41) circumferential gap, the second, the second opening (41) circumferential gap by the at least one, the at least one second chamber delimiting roller (09; 11) on the one hand and a the second opening (41) circumferential second edge of the at least one second chamber is on the other hand limited and wherein the at least one dampening solution source (13) has at least one spray nozzle, characterized in that the at least one second chamber in addition to the second opening (41) and at least a drain opening has at least one vent opening (29) and that the at least one first opening (28) has a first cross-sectional area and the at least one vent opening (29) has a total second cross-sectional area which is greater than 1% of the first cross-sectional area of the at least one first opening (28).

Description

The invention relates to a dampening unit of an offset printing unit according to the preamble of claim 1.

Rotary offset printing machines frequently use dampening systems which apply a dampening solution to corresponding offset printing plates in order to ensure reliable separation of ink-transferring and ink-non-transferring areas of the printing plates. There are a number of different types of dampening systems that are used for this purpose, in particular contact dampeners and contactless dampeners. One design of a non-contact dampening unit is a spray dampening unit in which the dampening solution is sprayed by means of a series of spray nozzles onto the printing plates or in particular onto a roller which is in direct contact or via other rollers with the printing blocks arranged on a forme cylinder.

Such a contactless dampening unit and in particular spray dampening unit has the advantage that no backflow of possibly soiled dampening solution and in particular no inflow of printing ink from the printing forme into a dampening solution supply is possible. Since the dampening solution is sprayed by means of the nozzles, a fine mist of fountain solution droplets often results. In printing presses, which are comparatively generous in terms of their spatial arrangement, this mist of droplets of fountain solution can be removed relatively easily. In compact built printing presses, however, the problem arises that dampening solution condenses in areas of the printing press in which this is undesirable, which in the long term can lead to problems in the form of impurities and / or corrosion. This can lead to failures due to malfunction and / or maintenance work as well as to increased spare parts consumption.

By the US Pat. No. 6,050,186 A , the DE 10 2007 015 401 A1 and the DE 101 62 788 A1 In each case, a dampening unit of an offset printing unit is known, wherein the dampening unit has a chamber and at least one dampening solution source arranged in the at least one first chamber and a roller bounding the chamber, wherein the chamber has a first opening which extends from the roller delimiting the chamber is closed except for a first, the first opening circumferential gap, wherein the first, the first opening circumferential gap is limited by the chamber bounding roller on the one hand and the first opening circumferential edge of the chamber on the other.

By the DE 24 60 021 A1 it is known to arrange side shields in an otherwise open system next to spray nozzles to prevent overspray into undesirable areas, the side shields are adapted in their contours to two rollers.

By the DE 10 2006 022 522 A1 a device is known for applying a liquid to a roller, the device having a first chamber and a first chamber disposed in a liquid source and a, the first chamber bounding roller, wherein the first chamber having an opening which of the first chamber bounding roller except for a first, which is closed at least a first opening circumferential gap. Suction air influences an expansion of a liquid column protruding from the first chamber and contacting the roller.

By the EP 0 609 693 A1 and the US 3,199,028 A in each case a dampening unit of an offset printing unit is disclosed, wherein the dampening unit has a first chamber and at least one fountain solution source arranged in the first chamber and at least one roller bounding the first chamber, wherein the first chamber has a first opening which extends from the first the first chamber bounding roller is closed except for a first, the first opening circumferential gap, wherein the first, the first opening circumferential gap is bounded by the first chamber limiting roller on the one hand and a first opening surrounding the first edge of the at least one first chamber on the other and wherein in the circumferential direction of the first chamber bounding roller of the first chamber adjacent to at least a second chamber of the dampening unit is arranged, which has a second opening, of at least one, the at least one second chamber bounding roller to a second, the second opening circulating Gap is closed, the two Ite, the second opening circumferential gap through the at least one, the at least one second chamber limiting roller on the one hand and the second opening encircling second edge of the at least one second chamber on the other hand is limited and wherein the at least one fountain solution source has at least one spray nozzle.

By the JP 1 009 737 A a dampening unit of an offset printing unit is known, wherein the dampening unit has at least a first chamber. From the first chamber humid air flows to a roller. From a second chamber further air flows to the roller. Through a third chamber, air is sucked from the roller.

The invention has for its object to provide a dampening unit of an offset printing unit, in which an overpressure in the at least one first chamber is selectively prevented and thereby an unwanted escape of fountain solution droplets prevented together with excess air in a designated area and thus a better removal of dampening drops is possible

The object is achieved by the features of claim 1.

In the invention, in the circumferential direction of at least one, at least a first chamber bounding roller at least a first chamber adjacent at least a second chamber of a dampening unit is arranged, which has a second opening of at least one, the at least one second chamber bounding roller until is closed to a second, the second opening circumferential gap, and in which the second, the second opening circumferential gap through the at least one, the at least one second chamber limiting roller on the one hand and a second edge surrounding the second edge of the at least one second chamber on the other is limited, there is a particular advantage in that fountain solution droplets preferably emerge from the at least one first chamber in a circumferential direction because of the rotation of the at least one first chamber limiting roller and that at least one second chamber is arranged at a corresponding exit point. Thus, the at least one first chamber can be specialized in a supply of dampening solution and the at least one second chamber can be specialized in a removal of excess dampening solution, which increases a respective effectiveness of the components and thus of the entire dampening unit. In an embodiment in which a part of the first peripheral edge is identical to a part of the second circumferential edge, this advantage is further enhanced because there is no unwanted escape path for fountain drops.

Since the at least one first chamber or in one embodiment additionally at least one second chamber apart from the at least one first opening and / or at least one outflow opening and / or at least one supply line has at least one first vent opening, there is in particular an advantage in that an overpressure in the at least one first chamber is selectively prevented and thereby an unwanted escape of fountain solution droplets is prevented together with excess air in a non-designated area.

In an embodiment in which the at least one first vent opening is not arranged at a lowest point of the at least one first chamber, there is in particular an advantage in that it may be reserved for the lowest point of a drain opening from which liquid fencing agent is removed , which is easier to handle, as drop-shaped, dissolved in air dampening solution. Thus, only a relevant proportion of dampening solution needs to be specially treated. This advantage results in particular when the at least one first vent opening is arranged in addition to at least one outflow opening arranged at at least one lowest point of the at least one first chamber.

Since the at least one first opening has a first cross-sectional area and the at least one first vent opening has an entire second cross-sectional area that is greater than 1% of the first cross-sectional area of the at least one first opening, there is an advantage in particular in that a larger cross-sectional area of the vent opening reduces a flow resistance and thereby allows a better removal of fountain solution drops.

In an embodiment in which the at least one first vent opening is delimited outside the at least one first chamber by at least one guide device, there is an advantage in particular that droplets of fountain solution leaving the at least one chamber can be kept away from corresponding areas of the printing unit. More preferably, the at least one guide device is designed as a tubular guide device, so that a targeted removal and in particular a reprocessing of the fountain solution droplets is made possible. This saves dampening solution and therefore costs. More preferably, the at least one guide device is connected to a suction device, so that an overpressure can be excluded and an even better removal of fountain solution drops is guaranteed.

In one embodiment, in which the at least one dampening solution source has at least one drop generator designed as a spray nozzle, there is, in particular, an advantage in that dampening solution can be applied very selectively to specific areas, for example, lateral surfaces of rolls of the dampening unit.

In an embodiment, in which the first, the at least one first opening circumferential gap is bounded by at least two, the at least one first chamber bounding rollers on the one hand and the at least one first opening encircling the first edge of the at least one first chamber on the other hand, and in the Preferably, a nip, more preferably an incoming nip the at least one first chamber is arranged at least partially limiting, there is in particular an advantage that by the interaction of the at least one chamber with the nip of the two rolls such a range of dampening of the at least one chamber is enclosed in the particularly simple and very many drops of fountain solution are introduced, for example, by entrainment of an air layer through the rotating rollers. As a result, the at least one chamber can be used particularly effectively for collecting and / or removing drops of fountain solution.

In an embodiment in which at least one drip catcher is arranged in at least one of the at least one first vent opening and / or in the at least one tubular guide device and which is provided with a plurality of meshes and / or open pores and / or flow passages Gas and / or liquids through-flow component is formed, there is an advantage in particular that dampening solution can be collected and transported particularly effectively, since such a drip provides a large surface, can attach to the fountain solution droplets.

In one embodiment, in which at least one drip and / or at least one guide device is designed as a cold trap and / or has at least one cold trap, there is in particular an advantage in that a condensation of dampening solution is enforced and thus excess dampening solution even more effective from the printing unit can be removed.

In an embodiment in which the at least one first chamber, apart from the at least one first opening and / or at least one outflow opening and / or at least one inflow opening, has at least three ventilation openings, which with respect to the at least one roller bounding at least one first chamber Axial direction are arranged side by side, there is in particular an advantage in that a plurality of vents for a particularly uniform removal of fountain solution droplets and thereby ensure a particularly uniform supply of fountain solution.

In an embodiment in which the at least three vent openings are arranged closer to at least one drop generator than at the at least one first opening, there is in particular an advantage in that essentially only drops of fountain solution which are already no longer in the vicinity of a person to be moistened Surface, through the vents escape, so not unnecessarily much dampening solution must be used.

In an embodiment in which each point of the first edge circumscribing the at least one first opening is located at most 10 mm away from the at least one roller bounding the at least one first chamber, and preferably each point of a second edge encircling a second opening is at most 10 mm from At least one, at least a second chamber limiting roller is arranged away, there is in particular an advantage that less air and in particular less drops of fountain solution from the at least one first and / or second chamber can escape uncontrollably into the printing unit by a narrower gap.

In one embodiment, in which the at least one roller delimiting at least one first chamber is a wet rubbing roller and / or a smoothing roller, there is in particular an advantage in that dampening solution is applied directly to such rollers, which ensure a further distribution of the dampening solution in the dampening unit anyway have to be brought into contact with dampening solution, whereby a particularly effective application of dampening solution is made possible.

In an embodiment in which at least one inner shield is arranged in such a way that each rectilinear connection of at least one spray nozzle with the at least one vent opening has at least one point of intersection with the at least one inner shield, there is in particular an advantage in that the fountain solution droplets in each case surround the surroundings to be moistened roll, whereby a deposit on the roll surface is more likely and a fountain solution thus more effective.

In an embodiment in which the second gap surrounding the second opening is delimited by at least two rollers delimiting at least one second chamber on the one hand and the second edge of the at least one second chamber surrounding the second opening on the other hand, there is an advantage in particular unnecessarily many parts are avoided and the gap is made very tight.

In an embodiment in which the at least one second chamber has at least one vent opening in addition to the second opening and / or at least one drain opening, there are advantages analogous to the embodiment in which the at least one first chamber or in one embodiment apart from the at least one The first opening and / or at least one outlet opening and / or at least one supply line has at least one first vent opening.

In one embodiment, in which the at least one second chamber and / or the at least one guide device is connected to a suction device, there is in particular an advantage in that an overpressure can be avoided particularly effectively.

In one embodiment, in the axial direction relative to the at least one roller delimiting at least one first chamber, a plurality of first chambers are juxtaposed and / or a plurality of second chambers are juxtaposed and a separator is arranged between each two first chambers and / or between each two second chambers a separator is arranged, in particular, an advantage is that a partial shutdown of the dampening unit is possible, which serves to save dampening solution, energy and costs.

In one embodiment, in which a contour of the separating devices is adapted to radial dimensions of the at least one roller delimiting at least one first and / or second chamber, there is in particular an advantage in that corresponding chambers are thereby made particularly dense, which likewise comprises dampening solution, Saves energy and costs.

In an embodiment in which a delimiting tissue and / or delimiting mesh and / or delimiting grid extend between edges of side shields and / or edges of the separating devices and on one side of the delimiting tissue and / or delimiting mesh that faces away from the at least one second chamber In particular, there is an advantage that the at least one drip is arranged particularly close to the roll surface, which increases its effectiveness without impairing the roll and / or boundary grid of the at least one drip.

A preferred use of air-purged spray nozzles prevents soiling and malfunction.

Last but not least, the optimization of the dampening systems also serves to increase the print quality of coldset and semi-commercial productions.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Show it:

1 a schematic representation of a printing unit with four double printing units, each with two dampening units;

2 a schematic representation of a dampening unit according to the prior art;

3 a schematic representation of a dampening unit with three vents;

4 a schematic representation of a dampening unit with guide device;

5 a schematic representation of a dampening unit with second chamber;

6 a schematic representation of a dampening unit with second chamber and separating devices.

A printing unit 01 a printing machine designed as a rotary offset printing machine, for example, rotary-rotary offset printing machine is offset printing unit 01 called. The offset printing unit 01 has at least one form cylinder 02 at least one transfer cylinder in contact therewith 03 and at least one with this transfer cylinder 03 interacting arranged impression cylinder 04 on. The press is designed for wet offset printing. The at least one forme cylinder 02 is preferred as a plate cylinder 02 educated. The at least one transfer cylinder 03 is preferred as a blanket cylinder 03 educated. In double printing units are usually two transfer cylinders 03 each other as an impression cylinder 04 serving arranged. Between the transfer cylinder 03 and the impression cylinder 04 At least in a printing operation, a printing material, for example paper and in particular a printing material web, for example a paper web, is guided through. The transfer cylinder 03 transmits at least one print image on the substrate at each of its revolutions. The printing unit 01 also has at least one inking unit 06 and at least one dampening unit 07 on.

The printing unit 01 For example, one, two, three, five, seven, eight, especially four or six printing plates may be wide. Ie. the form cylinder 02 , the impression cylinder 04 and the transfer cylinder 03 have an axial length of a corresponding number, in particular of four or six printing plates. The form cylinder 02 , the impression cylinder 04 and the transfer cylinder 03 have a length in the circumferential direction of, for example, one or two printing plates. Each printing plate preferably corresponds in size and its transferable printed image in each case in size and / or shape of a standing newspaper page in a broadsheet format or two horizontal newspaper pages in a tabloid format. There are also other formats conceivable, for example, printing plates with the width of two stationary newspaper pages in broadsheet format or printing plates, at least 90% of a lateral surface of the forme cylinder 02 cover.

The described dampening unit 07 is particularly suitable for simple printing units 01 . Double printing units 01 and satellite printing works 01 , The dampening unit 07 is designed so that it applies a fountain solution contactless and / or can apply, for example as a brush dampening unit 07 or as a Schleuderfeuchtwerk 07 , preferably as a spray dampening unit 07 , The dampening unit 07 has at least one dampening solution source 13 on, for example, as a spray bar 13 and / or spray box 13 is trained. Each dampening solution source 13 has at least one drop generator. The at least one drop generator can be designed as at least one spray nozzle. Preferably, a plurality of spray nozzles, not shown here, are in the spray bar 13 and / or spray box 13 arranged and spray in the operating case, the dampening solution to at least one, and preferably exactly one example, as a dampening rubbing roller 09 trained roller 09 of the dampening unit 07 on. Preferably, the spray nozzles are designed as compressed air-sprayed spray nozzles. This means that the spray nozzles each have at least one nozzle opening from which the dampening solution exits, preferably in the form of finely distributed droplets, and on the other hand each have at least one nozzle opening from which compressed air exits. This compressed air prevents ink and / or dirt and / or fountain solution attaches unwanted to the spray nozzle and / or dries. In this case, at least one nozzle opening can be arranged opening into a channel in front of at least one further nozzle opening, so that a mixture of compressed air and dampening agent ultimately flows out of at least one common nozzle opening. The spray nozzles preferably produce fountain solution droplets in that compressed air and dampening solution are conveyed under pressure through the at least one nozzle opening. It is also possible to arrange the at least one drop generator designed as an ultrasonic atomizer. Such ultrasonic generators produce drops of fountain solution, but they emit less directed on average. However, the directional ejection through the spray nozzles improves the application of dampening solution to corresponding target surfaces.

That on the at least one wet rubbing roller 09 Sprayed dampening solution is taken directly from the wet rubbing roller 09 and / or via at least one further, for example as a smoothing roll 11 trained roller 11 of the dampening unit 07 on as a dampening roller 08 trained roller 08 and from there to the form cylinder 02 transfer. The as a wet rubbing roller 09 trained roller 09 and as a smoothing roll 11 trained roller 11 form a nip 12 , At least one dampening roller 08 of the dampening unit 07 So at least temporarily with the at least one forme cylinder 02 in preferably rolling contact. As damp rubbing rollers 09 trained rollers 09 are arranged executable in the axial direction oscillating movements. In particular, form rollers 09 ; 11 of the dampening unit 07 nips 12 , About the just described, rotating in printing operation rolls 08 ; 09 ; 11 of the dampening unit 07 the dampening solution reaches the form cylinder 02 , A connection path from the dampening solution source 13 to the form cylinder 02 , along which fencing agent can be transferred by direct contacts, may also have more or fewer rolls than indicated in this example.

The rollers 08 ; 09 ; 11 of the dampening unit 07 have in their respective axial direction a length preferably in a range of 500 mm to 2,600 mm, in particular in the range of 1,400 mm to 2,400 mm. Their outer diameter is preferably in the range between 50 mm and 300 mm, preferably between 80 mm and 250 mm.

In the direction of rotation of the forme cylinder 02 seen after a contact point between dampening roller 08 and form cylinder 02 lie one or more rolls 16 of the inking unit 06 , For example, inking rollers 16 to the form cylinder 02 at. At these inking rollers 16 again lies at least one cylinder 17 , For example, inking cylinder 17 At the preferred turn at least one roller 18 , For example, a Farbstromtrennwalze 18 , is present. The at least one, in an oscillating movement in the direction of its axes of rotation exporting manner arranged at least one Farbreibzylinder 17 is preferably provided with its own drive for rotation while the Farbstromtrennwalze 18 and an at least temporarily applied roller 19 , in particular ink roller 19 as well as the inking rollers 16 preferably in frictional contact with its adjacent rolls 19 and / or cylinders 17 and thereby driven to rotate. The as a paint roller 19 designated roller 19 can also be a film roller 19 or a squeegee roller 19 his or with one as a film roller 22 or squeegee roller 22 trained roller 22 or a color ductor 22 directly or indirectly in contact. For the invention is a number of rolls 16 ; 19 ; 22 and / or cylinders 17 of the inking unit 06 and an embodiment of a color source 21 as a color supply 21 and / or chambered doctor blade 21 and / or color box 21 of at most subordinate importance, therefore, it will not be discussed further here. A transfer path of the ink in the printing operation, along which ink can be transferred by direct contacts, leads from the color supply 21 over the rotating rollers described above 16 ; 18 ; 19 ; 22 and / or cylinders 17 of the inking unit 06 on the form cylinder 02 , A connection path from the color stock 21 to the form cylinder 02 may also contain more or fewer rolls than indicated in this example. There may be rollers in the printing unit 01 be included, at least temporarily, a printing ink and / or dampening solution transferring and / or transferable connection between dampening unit 07 and color stock 21 bypassing the forme cylinder 02 create.

The rollers 16 ; 18 ; 19 ; 22 and / or cylinders 17 of the inking unit 06 have in their respective axial direction preferably a length in the range of 500 mm to 2,600 mm, more preferably in the range of 1,400 mm to 2,400 mm. Their outer diameter is preferably in the range between 50 mm and 300 mm, more preferably between 80 mm and 250 mm. The ink separation roller 18 preferably has a lateral surface made of an elastic material, for example of a rubber.

In the above and below is to be understood as a soft surface, a surface, for example made of an elastomeric material, preferably made of rubber, in particular of a material having a hardness between 20 and 40 Shore A, and a hard surface, for example, a ceramic or a chromium-containing Material, wherein z. B. on a roll core of a metallic material, a coating of a chromium-containing material is applied. Also a roller coated with a hard plastic, especially Rilsan 08 ; 09 ; 11 is used as a roller in the context of this disclosure 08 ; 09 ; 11 with a hard surface or as a hard roller 08 ; 09 ; 11 Understood.

The at least one drop generator of the dampening solution source 13 dampening solution is arranged ejectable in at least one direction, which preferably has a greater vertically upward component, as an optional horizontal component. The dampening solution source 13 preferably has a plurality of drop generators, preferably spray nozzles. The spray nozzles are in a first housing 23 arranged, which preferably over the entire width of the dampening unit 07 extends. Inside the first case 23 At least a first chamber is formed. The at least one dampening solution source 13 is thus arranged in the at least one first chamber. Several and preferably all droplet generators are preferably spaced apart in an axial direction and more preferably arranged equidistantly next to each other, the axial direction being a roller delimiting at least one roller, which defines at least one first chamber 09 ; 11 is related axial direction.

In the following, only spray nozzles are described as drop generators, but the invention can be applied to other types of drop generators, such as ultrasonic atomizers. Each activated spray nozzle preferably generates a spray cone of dampening solution, wherein adjacent spray cone can partially overlap in their geometric extension. Between each two adjacent spray nozzles is preferably a respective separation device 24 or shielding device 24 arranged as a partition plate 24 , for example as a separating plate 24 , in particular as a perforated plate 24 , z. B. perforated plate 24 can be trained. Such separators 24 prevent an actual overlap of adjacent spray cones and thus ensure that each spray nozzle only one area of the opposite roller 09 moistened. By such separators 24 the at least one first chamber is divided into a plurality of first chambers. In this way, a plurality of first chambers are arranged. Preferably, the at least one separating device 24 arranged so that in the axial direction with respect to the at least one, the at least one first chamber bounding roller 09 ; 11 a plurality of first chambers are arranged side by side. Preference is given to a plurality of separation devices 24 in the axial direction with respect to the at least one roller bounding the at least one first chamber 09 ; 11 arranged side by side.

The separation devices 24 are inside the first case 23 preferably on the first housing 23 self-attached. The separation devices 24 have at their the roll train of dampening 07 facing the end of each edge 38 on, the at least one roller 09 ; 11 of the dampening unit 07 is facing. This edge 38 preferably has a contour which corresponds to the at least one radius of the at least one roller bounding the at least one first chamber 09 ; 11 is adjusted. Between every two separating devices 24 Instead of a single spray nozzle, two spray nozzles or more than two spray nozzles may also be arranged. Preferably, distances between the separating devices correspond 24 a width in the axial direction of pages to be printed, for example, a width of a standing page in the broadsheet format. The spray nozzles are preferably formed individually operable. As a result, the amount of dampening agent to be applied is sectionally adjustable in the axial direction, that is controllable and / or controllable. The spray nozzles can preferably be operated continuously and / or discontinuously, in particular periodically and / or according to current requirements.

The first case 23 preferably has two first side shields 26 on which the at least one first chamber within the first housing 23 in one on the form cylinder 02 limit axial direction. The first side shields 26 preferably each have an edge 27 on, the at least one roller 09 ; 11 of the dampening unit 07 is facing. This edge 27 preferably has a contour which corresponds to the at least one radius of the at least one roller bounding the at least one first chamber 09 ; 11 is adjusted. A roller bounding at least a first chamber 09 ; 11 is a roller 09 ; 11 characterized in that the at least one first chamber has at least one first opening 28 which, of the at least one, the at least one first chamber bounding rollers 09 ; 11 except for a first, the first opening 28 circumferential gap is closed. At the same time, the first, the first opening becomes 28 circumferential gap through the at least one, the at least one first chamber limiting roller 09 ; 11 on the one hand and the first opening 28 circumscribing first edge of the at least one first chamber on the other hand limited. The mentioned edges 27 The side shields form subsections of the at least one first edge. On at least one, at least a first chamber bounding roller 09 ; 11 is applied by means of at least one spray nozzle at least temporarily dampening, in particular without the interposition of other rolls. For example, a roller bounding the at least one first chamber 09 the wet rubbing roller 09 , which is sprayed directly from the at least one spray nozzle. It is also conceivable that the spray nozzles on a nip 12 are directed, for example, a nip 12 between the dampening roller 09 and the calender roll 11 ,

The at least one first chamber and / or at least one second chamber described below preferably has apart from the first opening 28 and / or at least one outflow opening and / or at least one supply line at least one first vent opening 29 on. The at least one first vent opening 29 serves to remove air and / or dampening solution, in particular floating in the air fountain solution droplets. The at least one first vent opening 29 Prevents that formed by the introduced compressed air within the first chamber, an overpressure, which could happen, because on the one dampening agent is additionally transported into the at least one first chamber and there, on the other hand, the compressed air-enclosed spray nozzles an air volume in addition to the at least one first chamber inside transport. The at least one first chamber is apart from the at least one first vent opening 29 relatively dense, in order to prevent an uncontrolled distribution of drops of fountain solution. This is the first case 23 and in particular the at least one first chamber arranged such that each point of the first opening 28 circumferential first edge at most 10 mm from the at least one, the at least one first chamber bounding roller 09 ; 11 is arranged remotely. The pressure would be uncontrolled without countermeasures through existing openings, in particular through the first opening 28 emerge from the at least one first chamber. This would cause a large amount of enriched with dampening water uncontrolled in the printing unit 01 penetration. Preferably, the at least one first chamber apart from the at least one first opening 28 and / or at least one outflow opening and / or at least one inflow opening at least two, more preferably at least three vents 29 with respect to the at least one roller bounding the at least one first chamber 09 ; 11 are arranged side by side in an axial direction. Preferably, the at least three vents 29 arranged closer to each at least one drop generator, as at the at least one first opening 28 , Preferably, the at least one vent opening 29 arranged lower than the at least one first opening 28 , As a result, gravity promotes a removal of excess fountain solution droplets from the at least one first chamber.

The at least one first vent opening 29 is preferably at a location of the first housing 23 arranged, the at least one, the at least one first chamber bounding roller 09 ; 11 turned away. In particular, the at least one first vent opening 29 one from the first opening 28 different opening 29 , The at least one first vent opening 29 is preferably arranged to an area outside the at least one first chamber, which can be easily vented and / or ventilated. In this way, the mist formed by the fountain solution droplets after its exit from the at least one first vent opening 29 swiftly from the first housing 23 and from the printing unit 01 be removed. The at least one vent 29 is preferably not located at a lowest point of the at least one first chamber. At such a lowest point of the at least one first chamber, at least one outflow opening is preferably arranged. This means that preferably the at least one vent opening 29 in addition to at least one, is arranged at the at least one lowest point of the at least one first chamber arranged discharge opening. Preferably, the at least one vent opening 29 an overall second cross-sectional area greater than 1% of a first cross-sectional area of the first opening 28 , more preferably greater than 5% and even more preferably greater than 20%.

Preferably, the at least one vent opening 29 outside the at least one first chamber of at least one guide device 31 limited. The at least one first guide device 31 can, for example, as at least a first baffle 31 be educated. The at least one first guide device 31 delimits a discharge path of the air enriched with drops of fountain solution, which passes through the at least one first vent opening 29 from the at least one first chamber and preferably from the first housing 23 exit. The at least one guiding device 31 is preferred as at least a tubular guide device 31 formed, for example as at least one pipe 31 and / or as at least one hose 31 and / or as at least one shaft 31 , The at least one vent 29 is preferably directly or via the at least one guide device 31 connected to a first suction device, for example a pump and / or a fan. The first suction device is preferably designed to generate and / or generate a negative pressure. The first suction device thereby causes a removal of almost all excess dampening solution.

By the rotation of the at least one first chamber bounding roller 09 ; 11 is always an air film around a cylindrical surface of this roller 09 with the roller 09 ; 11 carried. This air film comes into contact, at least within the at least one first chamber, with the air enriched with the mist of fountain solution drops. By the further rotation of this roller 09 It could happen that the air film transported a part of this dampening-enriched air from the at least one first chamber.

In order to prevent this, the at least one first chamber is preferably so far in the circumferential direction of the at least one roller bounding the at least one first chamber 09 ; 11 extended that at least two rolls 09 ; 11 the at least one first chamber are arranged delimiting. That means the first, the first opening 28 circumferential gap through at least two, the at least one first chamber bounding rollers 09 ; 11 on the one hand and the first opening 28 circumferential first edge of the at least one first chamber is bounded on the other. In other words, this means that at least one by two rollers 09 ; 11 formed nip 12 , preferably an incoming nip 12 the at least one first chamber is arranged at least partially delimiting. An incoming nip 12 is a nip 12 in which involved roll surfaces towards each other in the nip 12 are arranged incoming. In this case, the edges point 27 the first side shields 26 preferably contours, in part the radius of the one, preferably as a wet rubbing roller 09 trained and partly the radius of the other, preferably as a smoothing roll 11 trained, the at least a first chamber bounding rollers 09 ; 11 are adjusted. An adaptation of a contour is preferably to be understood that the contour in the axial direction with respect to the at least one first or second chamber limiting roller 09 ; 11 considered corresponds to a circular arc whose radius is preferably at most 10 mm, more preferably at most 6 mm greater than the radius of the at least one first or second chamber bounding roller 09 ; 11 , The nip 12 can in principle also be used as an expiring nip 12 be formed, in which case the directions of rotation of the rollers involved 09 ; 11 are turned over.

Alternatively or in addition to the separation devices 24 is preferably at least one inner shield 39 arranged. The at least one inner shield 39 preferably extends substantially in the axial direction with respect to the at least one roller bounding the at least one first chamber 09 ; 11 , That means that at least one inner shield 39 has an extension in this axial direction, which is greater than an extension in a direction which is perpendicular to the axial direction. The at least one inner shield 39 is preferably arranged such that each rectilinear connection of the at least one spray nozzle with the at least one vent opening 29 at least one point of intersection with the at least one inner shield 39 having. This will cause a short circuit between the spray nozzle and the vent 29 avoided and an air flow from the nozzle openings to the at least one vent 29 as close as possible to the at least one, the at least one first chamber bounding roller 09 ; 11 guided along. As a result, not only fountain solution directly from the spray nozzles is actively sprayed onto the roll surface, but also other fountain solution droplets, for example those which undesirably spray away laterally and / or those which have been produced by ultrasonic atomizers, are effectively conveyed onto the roll surface.

Preferably, the at least one inner shield extends 39 over the entire axial length of the at least one chamber. Preferably, this extends at least one inner shield 39 up to a distance of at most 10 mm to the at least one, the at least one first chamber limiting roller 09 ; 11 approach. As a result, the at least one first chamber is divided into two parts. The one part further corresponds to the at least one first chamber and contains the at least one dampening solution source 13 , The other part forms at least a second chamber and contains the at least one vent opening 29 , It is also possible that both the at least one first chamber and the at least one second chamber each have at least one vent opening 29 exhibit.

It is not important whether the at least one first chamber and the at least one second chamber consist of common components, for example the at least one inner shield 39 and / or common or separate side shields 26 ; 36 is constructed. Depending on the space available, a housing can pass through an intermediate wall, ie an inner shield 39 be shared or it may be a second housing 33 to a first housing 23 be grown or a second housing 33 can be perfect independent and independent of a first housing 23 be arranged. In the following, without loss of generality, an embodiment is described in which a second housing 33 directly to the first housing 23 is arranged adjacent. The second housing 33 includes the at least one second chamber. Preferably, the first housing 23 and the second housing 33 a common, the at least a first chamber of the first housing 23 from the at least one second chamber of the second housing 33 separating boundary 39 on, for example, as a boundary plate 39 can be trained. This limit 39 is the previously described, as close as possible brought up to the roll surface inner shield 39 , The second housing 33 is related to a direction of rotation of the at least one, the at least one first chamber bounding roller 09 downstream of the first housing 23 and in particular arranged downstream of a target area of the spray nozzles. As a result, in the direction of rotation of the at least one, the at least one first chamber bounding roller passes 09 transported and enriched with fountain solution droplets air after their exit from the at least one first chamber of the first housing 23 through the first opening 28 directly into the at least one second chamber of the second housing 33 , The second housing has 33 two second side shields 36 on.

The two second side shields 36 of the second housing 33 limit the at least one second chamber of the second housing 33 in the on the form cylinder 02 related axial direction. The second side shields 36 preferably each have an edge 37 on, the at least one roller 09 ; 11 of the dampening unit 07 is facing. This edge 37 preferably has a contour which corresponds to the at least one radius of the at least one with the second housing 33 interacting roller 09 ; 11 is adjusted. One with the second housing 33 cooperating roller 09 ; 11 is a roller 09 ; 11 on which a second opening 41 of the second housing 33 is directed. For example, with the second housing 33 cooperating rolls 09 ; 11 the wet rubbing roller 09 and the smoothing roller 11 on their common nip 12 the second opening 41 of the second housing 33 is preferably aligned. In this case, the edges point 37 the second side shields 36 Contours on, in part, the radius of the dampening roller 09 and partly the radius of the calender roll 11 are adjusted. The at least one second chamber of the second housing 33 is preferred except for the second opening 41 and preferably at least one vent opening 29 and / or at least one discharge opening in all directions closed, which is perpendicular to the axis of rotation of the forme cylinder 02 are oriented. In each case a first side shield 26 and a second side shield 36 are preferred as a continuous side shield 26 ; 36 educated.

Overall, therefore, results in this embodiment that in the circumferential direction of the at least one, the at least one first chamber bounding roller 09 ; 11 the at least one first chamber adjacent at least one second chamber of the dampening unit 07 is arranged, which has a second opening 41 that of at least one, the at least one second chamber bounding roller 09 ; 11 except for a second, the second opening 41 circumferential gap is closed. The second, the second opening 41 circumferential gap is preferred by the at least one, the at least one second chamber bounding roller 09 ; 11 on the one hand and the second opening 41 encircling second edge of the at least one second chamber on the other. More preferably, a part of the first circumferential edge is identical to a part of the second circumferential edge, for example the part of the edge which is an edge of the boundary 39 and / or the inner shield 39 is. In this case too, it is preferable for each point to be the first opening 28 circumferential first edge at most 10 mm from the at least one, the at least one first chamber bounding roller 09 ; 11 is arranged remotely. More preferably, alternatively or additionally, that each point of the second opening 41 circumferential second edge at most 10 mm from the at least one at least one second chamber bounding roller 09 ; 11 is arranged remotely. Because the limit is preferred 39 not exactly in a nip 12 protrudes, is preferably at least one roller 09 ; 11 formed both the at least one first chamber and the at least one second chamber limiting. Preferred are in the axial direction with respect to the at least one, the at least one second chamber bounding roller 09 ; 11 a plurality of second chambers arranged side by side and by at least one separating device 34 or shielding device 34 separated from each other. The at least one separating device 34 is for example partition plate 34 or separating plate 34 or perforated plate 34 or perforated plate 34 educated. The at least one separating device 34 indicates at her the roll train of the dampening unit 07 facing the end of each edge 42 on, the at least one roller 09 ; 11 of the dampening unit 07 is facing. This edge 42 preferably has a contour which corresponds to the at least one radius of the at least one roller bounding the at least one second chamber 09 ; 11 is adjusted.

In this embodiment, neither the at least one first nor the at least one second chamber in any form needs to be spaced from a nip 12 be limited. However, it is preferred that at least one by two rollers 09 ; 11 formed nip 12 , preferably an incoming nip 12 the at least one second chamber is arranged at least partially delimiting. In the incoming nip 12 collects entrained, fountain solution containing air particularly well and can be particularly effective through the at least one vent 29 the at least one second chamber are purposefully removed. Therefore, it is preferable that the second, the second opening 41 circumferential gap through at least two, the at least one second chamber limiting rollers 09 ; 11 on the one hand and the second opening 41 circumscribing second edge of the at least one second chamber on the other hand limited.

Everything already to vents 29 described applies regardless of whether they are associated with at least a first chamber or at least a second chamber and / or if there are any second chambers. In particular, corresponding guide devices are also preferred here 31 and / or suction and / or drip arranged and / or trained.

It is preferred in addition to the at least one first guide device 31 that is associated with the at least one vent 29 the at least one first chamber is arranged, arranged at least one second guide device, for example at least one second guide plate. The at least one second guide device correspondingly delimits a discharge path of the air enriched with fountain solution drops, which flows through the at least one ventilation opening 29 from the second housing 33 and / or exiting from the at least one second chamber. Preferably, the at least one second guide device is likewise designed as at least one pipe and / or as at least one hose and / or as at least one shaft. The at least one second guide device is preferably connected to a second suction device, for example a pump and / or a ventilator. The second suction device is preferably designed to generate a negative pressure and / or capable of generating. The second suction device thereby causes a removal of almost all excess dampening solution. Preferably, the first and the second suction device are identical. That through the at least one vent 29 From the at least one first and / or the at least one second chamber removed dampening solution can in a manner not shown again the dampening solution source 13 be forwarded. It is preferred between the leaving de at least a first and / or the at least one second chamber and the re-supply to the dampening solution source 13 reconditioned.

Regardless of how many first and / or second chambers are arranged and regardless of whether a nip 12 a first and / or a second chamber is arranged limiting, preferably at least one drip is arranged. The at least one drip is preferably in the at least one vent opening 29 the at least one first and / or second chamber and / or in the at least one tubular guide device 31 and / or in the at least one second chamber fluidically before the at least one vent opening 29 arranged. The at least one drip is designed as a component having a multiplicity of meshes and / or open pores and / or flow passages, through which gases and / or liquids can flow. A multiplicity of meshes and / or open pores and / or flow passages are to be understood as meaning preferably at least 5, more preferably at least 50 and even more preferably at least 200 meshes and / or open pores and / or flow passages. The at least one drip made of a permeable and / or porous material. The at least one drip preferably has a particularly high surface area per volume, preferably greater than 10 cm 2 per cm 3 (more than ten square centimeters per cubic centimeter), more preferably greater than 50 cm 2 per cm 3 (more than 50 cm 2) Square centimeters per cubic centimeter).

The mode of action of the at least one drip is based on the fact that an air mass emerging from the first inner volume strips and / or preferably penetrates the at least one drip. In this case, smaller drops of fountain solution, which are contained in the air mass emerging from the first inner volume, deposit on the surface of the at least one drip catcher. By successive addition of smaller drops of fountain solution, at least one drop catcher forms larger drops of fountain solution and / or a dampening solution film. If an amount of dampening agent deposited onto the at least one drip catcher is exceeded, the deposited dampening solution flows along the surface of the at least one drip trapped by gravity and / or larger droplets of moisture solution drop, which drop and / or flow downwards into a drip area following gravity. The accumulation of the drops of fountain solution can be improved by cooling the at least one drip at least partially relative to its surroundings. As a result, a condensation of the fountain solution droplets is promoted and thus an amount of dampening agent accumulating on the at least one drip catcher and flowing away from it is increased. It is important that the deposited dampening solution can drain, so that no equilibrium state forms in which just as much dampening solution evaporates from the surface of the at least one drip, as is attached to her.

The at least one drip preferably has at least one fabric and / or mesh and / or grid and / or metal wool volume. The at least one fabric and / or net and / or grid and / or metal wool volume consists of contacting and / or interconnected webs and arranged between the webs stitches and / or flow passages. More preferably, the at least one drip more layers of the at least one fabric and / or mesh and / or grid. The at least one fabric and / or mesh and / or grid preferably has a mesh size of 0.05 mm to 0.75 mm and more preferably of 0.10 mm to 0.40 mm and preferably has a web diameter of 0.05 mm to 2 mm and more preferably from 0.05 mm to 0.5 mm. The at least one fabric and / or mesh and / or grid and / or metal wool volume preferably consists of a stainless material, for example a plastic or a metal alloy and preferably made of stainless steel.

The at least one drip may also be made of a porous material having a three-dimensional structure of interconnected pores, wherein the pore system is also open to the outside. A pore size and / or a pore distribution and / or a specific surface per volume are preferably adapted to a dampening solution concentration and / or a flow rate and / or a dampening solution quantity flowing through a volume unit of the drip per unit time. The porous material is preferably made of a stainless material, for example a plastic or a metal alloy and preferably made of stainless steel. Preferably, the porous material is formed as a sponge and / or a foam, in particular metal foam and / or as a filter mat of intertwined and / or pressed fibers and / or a metal wool.

The porous material is preferably delimited from an environment by a limiting fabric and / or a delimiting network and / or a delimiting grid, in particular in one direction onto the at least one roller bounding the at least one second chamber 09 ; 11 , More preferably, this boundary fabric and / or boundary mesh and / or boundary grid on a mesh size of 1 mm to 10 mm and / or this boundary fabric and / or boundary mesh and / or boundary grid has a web diameter of 0.2 mm to 2 mm. This limiting fabric and / or limiting net and / or limiting grid is preferably in its shape to the roller bounding the at least one second chamber 09 ; 11 customized. More preferably, this boundary fabric and / or boundary mesh and / or boundary grid extends between the edges 37 the second side shields 36 and / or the edges 42 the separating devices 34 , these edges 37 ; 42 as described above, each have a contour which corresponds to the at least one radius of the at least one roller bounding the at least one second chamber 09 ; 11 is adjusted. The separation devices 34 then support the perimeter fabric and / or perimeter net and / or perimeter fence. But it is also possible, the limiting fabric and / or limiting network and / or limiting grid at a greater distance from the at least one, the at least one second chamber bounding roller 09 ; 11 within the at least one second chamber and / or the at least one guide device 31 and / or at the at least one vent opening 29 to arrange, so that an arrangement of the boundary tissue and / or boundary mesh and / or boundary grid must be less precise and less susceptible to interference.

Preferably, at least the porous material is interchangeably arranged, for example for maintenance. For this purpose, it is preferably the second housing 33 taken and / or the entire second housing 33 together with the porous material from the printing unit 01 away.

Such a drip may also be at other locations within the printing unit 01 be arranged, preferably in such places, which must be traversed inevitably enriched with dampening agent droplets air masses.

Preferred is in the first housing 23 and / or in the second housing 33 in the region of the at least one vent opening 29 and / or arranged in the region of the fabric and / or mesh and / or grid and / or in the region of the porous material at least one cold trap. A cold trap has a surface which is colder than an environment and which in particular is colder than the air containing the fountain solution droplets contained in the first housing 23 and / or in the second housing 33 is arranged. At this surface, fountain solution drops can condense and be discharged into a collection container. More preferably, the fabric and / or mesh and / or grid and / or metal wool volume and / or the porous material and / or the boundary fabric and / or boundary mesh and / or boundary grid is designed as a cold trap. For cooling the cold trap, at least one Peltier element is preferably arranged, preferably on the fabric and / or mesh and / or grid or the porous material. At least one guiding device is preferred as an alternative and / or in addition to the at least one drip catcher 31 cooled.

LIST OF REFERENCE NUMBERS

01

Printing unit, offset printing unit, double printing unit, satellite printing unit

02

Form cylinder, plate cylinder

03

Transfer cylinder, blanket cylinder

04

Impression cylinder

05

06

inking

07

Dampening unit brush dampening unit, centrifugal dampening unit, spray dampening unit

08

Roller, dampening roller

09

Roller, wet rubbing roller

10

11

Roller, smoothing roller

12

Nip, incoming

13

Dampening agent source, spray bar, spray box

14

15

16

Roller, inking roller

17

Cylinder, inking cylinder

18

Roller, ink separation roller

19

Roller, ink roller, film roller, squeegee roller

20

21

Color source, ink supply, chamber doctor blade, ink fountain

22

Roller, film roller, squeegee roller, ink ductor

23

Housing, first

24

Separating device, shielding device, separating plate, separating plate, perforated plate, perforated plate

25

26

Side shield, first

27

Edge ( 26 )

28

Opening, first

29

Opening, vent

30

31

Guide, first, baffle, tube, hose, shaft

32

33

Housing, second

34

Separating device, shielding device, separating plate, separating plate, perforated plate, perforated plate

35

36

Side shield, second

37

Edge ( 36 )

38

Edge ( 24 )

39

Shield, inner, limit, boundary plate

40

41

Opening, second

42

Edge ( 34 )

Claims (8)

Dampening unit ( 07 ) of an offset printing unit ( 01 ), whereby the dampening unit ( 07 ) at least one first chamber and at least one, in the at least one first chamber arranged dampening solution source ( 13 ) and at least one roller bounding at least a first chamber ( 09 ; 11 ), wherein the at least one first chamber has at least one first opening ( 28 ) spaced from the at least one roller defining the at least one first chamber ( 09 ; 11 ) except for a first, the at least a first opening ( 28 ) circumferential gap is closed, wherein the first, the at least one first opening ( 28 ) circumferential gap through the at least one, the at least one first chamber limiting roller ( 09 ; 11 ) on the one hand and the at least one first opening ( 28 ) circumferential first edge of the at least one first chamber on the other hand is limited and wherein in the circumferential direction of the at least one, the at least one first chamber bounding roller ( 09 ; 11 ) of the at least one first chamber adjacent at least one second chamber of the dampening unit ( 01 ) is arranged, which has a second opening ( 41 ) of at least one, the at least one second chamber bounding roller ( 09 ; 11 ) except for a second, the second opening ( 41 ) circumferential gap is closed, wherein the second, the second opening ( 41 ) circumferential gap through the at least one, the at least one second chamber bounding roller ( 09 ; 11 ) on the one hand and a second opening ( 41 ) circumferential second edge of the at least one second chamber on the other hand is limited and wherein the at least one dampening solution source ( 13 ) has at least one spray nozzle, characterized in that the at least one second chamber in addition to the second opening ( 41 ) and at least one drain opening at least one vent opening ( 29 ) and that the at least one first opening ( 28 ) has a first cross-sectional area and the at least one vent opening ( 29 ) has an entire second cross-sectional area that is greater than 1% of the first cross-sectional area of the at least one first opening (FIG. 28 ). Dampening unit according to claim 1, characterized in that a part of the first peripheral edge is identical to a part of the second circumferential edge. Dampening unit according to claim 1, characterized in that each point of the at least one first opening ( 28 ) circumferential first edge at most 10 mm from the at least one, the at least one first chamber bounding roller ( 09 ; 11 ) is located away. Dampening unit according to claim 1, characterized in that each point of the second opening ( 41 ) peripheral edge at most 10 mm from the at least one, the at least one second chamber bounding roller ( 09 ; 11 ) is located away. Dampening unit according to claim 1, characterized in that at least one roller ( 09 ; 11 ) is formed bounding both the first chamber and the second chamber. Damping unit according to claim 1, characterized in that the second, the second opening ( 41 ) circumferential gap by at least two, the at least one second chamber limiting rollers ( 09 ; 11 ) on the one hand and the second opening ( 41 ) circumferential second edge of the at least one second chamber on the other hand is limited. Dampening unit according to claim 1, characterized in that the at least one second chamber is connected to a suction device. Dampening unit according to claim 1, characterized in that in the at least one vent opening ( 29 ) is arranged on at least one SteIle at least one drip, which is designed as a a plurality of meshes and / or open pores and / or flow passages having, through which gases and / or liquids can flow.

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