EP2087997A1 - Device for cleaning cylinders in a printing press - Google Patents

Abstract

The method involves demand-related applying of washing liquids on a brush roller (5). Demand-related employing and stopping of blades (14) are performed to bring the blades in contact with the brush roller or take out from the contact. A rotation direction of the brush roller is changed during a cleaning process in a phase. The brush roller is rotated in synchronization with a cylinder (6) to be cleaned in another phase, where the brush roller rotates in a counter rotation with the cylinder to be cleaned. Applying of the washing liquids is performed in the former phase. An independent claim is also included for a device for cleaning a cylinder of a printing machine.

Description

The invention relates to a device for cleaning cylinders of a printing press according to the preamble of claim 1.

Accordingly, the present invention relates to an apparatus having a driven brush roller engageable with a cylinder to be cleaned, a doctor for scraping dirt, at least temporarily engaged in the brush roller, and means for applying washing liquids to the brush roller.

Cleaning devices of this type are used to remove deposits and contaminants on cylinders of printing presses, which arise in particular by the intensive contact with the substrates. As far as paper is printed, deposited on the cylinders of the printing press especially paper dust (fibers, coating, fillers, etc.) and printing ink. These deposits affect the cylinders in their functionality. This applies to all cylinders of a printing press, in particular blanket cylinders, impression cylinders, plate or forme cylinders, cooling rollers, guide rollers, ink rollers and dampening rollers in all types of printing machines, in particular newsprint printing machines, commercial web presses and sheetfed presses. For the print quality and the operational safety, it is therefore essential that the cylinders are regularly cleaned of impurities.

An example of a known cleaning device is in EP-A-1 106 354 described. The brush roll, which can be set in rotation by the motor of this device, is set against a cylinder. At the same time washing liquids are applied to the brush roller, so that the adhering to the cylinder impurities are softened and lifted by the rotating brush roller from the cylinder. The dirt picked up by the brush roller is scraped off by a squeegee, which sits in squeegee holders. Below the squeegee a drip tray is provided.

However, direct doctoring of the dirt removed by a brush roller from the surface of the cylinder to be cleaned is not always optimal. Because when doctoring not only the dirt particles are thrown off the brush roller or stripped on the doctor blade, but also the recorded from the brush roller washing liquid. It is therefore necessary for a good cleaning result to use relatively much washing liquid, which, however, contradicts the efficient use of washing liquids.

This is particularly important in heat-set presses where the freshly printed substrate enters a dryer. This works with heat, and the commonly used washing liquids contain a high proportion of volatile hydrocarbons. Especially in heat-set printing machines is usually required that the cleaning of the cylinder surfaces takes place during production. The printing material running through the printing machine thus absorbs washing liquid and then transports it into the dryer. In the dryer, the volatile hydrocarbons evaporate and are heated so that there is a constant risk that the hydrocarbon concentration in the dryer will rise above a safety level. However, since high-quality substrates are used at the same time, especially in heat-set printing presses, care must be taken to ensure that the cleaning of the cylinder surfaces, which inevitably leads to waste, is done as quickly as possible.

However, these two requirements are contradictory: in order to ensure a high level of protection against too high a concentration of volatile hydrocarbons in the dryer, it is necessary to use as little washing liquid as possible. The simultaneous requirement to keep the cleaning cycle as short as possible on the contrary requires the use of relatively much washing liquid, since the time is too short, within which the dirt on the surface of the cylinder can be dissolved. It is therefore particularly true to achieve maximum efficiency in the use of the washing liquid, although this is also a generally desirable target for cleaning devices and methods for all types of printing presses.

For maximum efficiency, it is not necessary to keep the squeegee constantly engaged with the brush roller, but to temporarily remove it from this operation. The washing liquid then remains longer on the brush roller and accordingly has more time to dissolve the contaminants on the surface of the cylinder to be cleaned. It is then less often necessary to apply new washing liquid on the brush roller; the washing liquid consumption drops accordingly with comparable cleaning performance. Examples of cleaning devices with as needed engageable to the brush roller and off this off squeegee can be found in the US-A-5 010 819 and the EP-A-1 743 771 ,

In the JP 20011315313A discloses a method that further increases the efficiency of the use of washing liquid by changing the rotational direction of the brush roller during the cleaning operation. In a first phase, the brush roller rotates in synchronism with the cylinder to be cleaned, which means that the directions of movement of the roller surface and the cylinder surface are rectified at the point of their coincidence. In a second phase, the direction of rotation of the brush roller is reversed so that it then rotates in a counter-rotation with the cylinder to be cleaned, which means that the directions of movement of the surface of the brush roller and the surface of the cylinder to be cleaned are oppositely directed at their point of contact. The application of the washing liquids takes place mainly in the first cleaning phase, ie during synchronization of the brush roller with the cylinder to be cleaned.

The great advantage of this procedure consists in the fact that the relative speed between the brush roller surface and the cylinder surface is reduced when the washing liquids are applied to the brush roller. The washing liquids are therefore transferred virtually lossless from the brush roller to the cylinder surface where they can act and dissolve the pollution, undisturbed by scrubbing effects of the brush roller and thus with a minimum amount of washing liquid to be used. In the second cleaning phase, when the brush roller rotates in the countercurrent with the cylinder to be cleaned, an increased scrubbing effect on the cylinder surface, whereby the loosened contaminants are removed from the cylinder surface and taken away by the brush roller. The efficiency of the use of washing liquids for a given cleaning effect is thus optimized.

The contaminants received by the brush roll generally have a high adhesive force, in particular because of the printing ink contained therein. These sticky properties of the dirt finally scraped off the squeegee can cause dirt to accumulate on the squeegee over time, at least in the areas not directly on the squeegee edge. This is in the EP 0 713 772 A1 has been proposed to free the doctor blade depending on demand by means of a rinsing device.

Now, if there is a possibility of rotation of the brush roller in both directions to increase the efficiency of the use of washing liquid, the high adhesive force of abgerakelten from the brush roller soiling leads to special problems. Because then the dirt on the squeegee are not thrown off in any case only in one direction, but possibly also in the opposite direction. Dirt deposits can thus arise not only on the squeegee itself and in more or less inaccessible corners of a sump, which is formed by the bottom of the housing of the cleaning device, but optionally also above the squeegee in the housing parts located there.

The present invention is therefore based on the object to improve a cleaning device of the type mentioned in terms of their suitability for a procedure in which the brush roller is operated with changing rotational directions.

This object is achieved by a device having the features of claim 1. Preferred embodiments of the device according to the invention are set forth in claims 2 to 10.

In the device according to the invention, a housing with a rear wall, an upper cover and a lower cover and a front opening is provided, which is substantially filled by the brush roller. Such a housing prevents, as known per se, that wash liquids and dirt splash into the environment. The special feature of the cleaning device according to the invention consists in the fact that the interior of the housing, so the space which is bounded by the rear wall, the upper and lower cover and the brush roller, by a separating element, in the simplest case a sheet in an upper washing liquids Ordering space, in which the means for applying washing liquids are arranged on the brush roller, and a lower dirt space in which the doctor blade and the rinsing device are arranged, is divided.

By such a construction of a cleaning device according to the invention it is ensured that the doctoring of dirt in both directions of rotation of the brush roller is possible without affecting the means for applying washing liquids by thrown off dirt. Accordingly, although it is preferred, but not necessary, that a rotational direction of the brush roller is selected when setting the doctor, which ensures that the dirt in the lower cover of the housing, which is preferably designed as a collecting trough, is stripped.

In such a division of the interior of the housing, it offers particular advantages when the rinsing device for the doctor blade is arranged on or in the dirt chamber and this mitspült, so in addition to the squeegee also acts at least on an upper part of the dirt chamber, while the drip pan, ie the lower part of the dirt compartment, usually without such a flush.

Further advantages result in the device according to the invention when the doctor blade is pivotally held to hire them to the brush roller and park it. In this case, the doctor may also be associated with a scraper, which in the simplest case consists of a flexible plate, but may also have other shapes, wherein the scraper rests with a front edge on the doctor blade and slides when pivoting the doctor blade along the surface thereof , As a result, the rinsing process is assisted by the rinsing device according to the invention, since during the sliding of the front edge of the scraper over the doctor surface any dirt stuck there is scraped off, after which he can be easily washed away. As mentioned, this may be highly advantageous because of the normally high tackiness of the soil buildup. The scraper is preferably attached to the rear wall of the housing, so that its front edge, for example due to an elasticity of the scraper makes the pivoting movement of the doctor.

As is known per se, the means for applying washing liquids are designed as spraying devices, which expediently also applies to the flushing device. For applying washing liquids, preferably at least two spray devices are provided, wherein a spray device for applying liquid detergent and a spray device for applying water is provided. Depending on the application, however, only one spraying device or more than two spraying devices can be provided.

For a particularly efficient use of the washing liquids, the spraying devices can also be provided with spray nozzles.

Figur 1

eine schematische seitliche Schnittdarstellung einer erfindungsgemäßen Reinigungsvorrichtung mit einem Teil des zu reinigenden Zylinders in einer ersten Reinigungsphase;

Figur 2

eine Darstellung wie Figur 1 jedoch in einer zweiten Reinigungs-phase;

Figur 3

eine Darstellung wie Figur 1, jedoch in einer dritten Reinigungs-phase;

Figur 4

eine Darstellung wie Figur 1, jedoch in einer vierten Reinigungs-phase.

An embodiment of the cleaning device according to the invention will be described and explained in more detail below with reference to the accompanying drawings. Show it:

FIG. 1

a schematic sectional side view of a cleaning device according to the invention with a part of the cylinder to be cleaned in a first cleaning phase;

FIG. 2

a representation like FIG. 1 however, in a second cleaning phase;

FIG. 3

a representation like FIG. 1 but in a third phase of cleaning;

FIG. 4

a representation like FIG. 1 , but in a fourth cleaning phase.

In the FIG. 1 cleaning device shown comprises a housing 1 with a rear wall 2, an upper cover 3, a lower cover 4, which is designed as a collecting trough, and a brush roller 5. The brush roller 5 is here hired to a partially shown, to be cleaned cylinder 6 and runs with this, as the arrows 7 and 8 symbolize the directions of rotation, in synchronism.

As shown, the brush roller 5 fills the opening of the housing 1 delimited by the upper cover 3 and the lower cover 4 almost completely, so that a maximum splash protection against escape of washing liquids and / or dirt from the interior of the housing 1 in the environment of Cleaning device is guaranteed. The so limited by the rear wall 2, the upper cover 3, the lower cover 4 and the brush roller 5 interior of the housing 1 is divided with a, here formed by a partition plate separating element 9 in two halves, wherein the separating plate 9 of the rear wall. 2 extends almost to the surface of the brush roller 5.

A first spray tube 10 for applying detergent and a second spray tube 11 for applying water to the brush roller 5 are arranged above the partition member 9, so that the upper part of the interior of the housing 1 is a washing liquid application space 12. Below the separator 9 extends in contrast, a dirt chamber 13, in which a doctor blade 14 is arranged, which, if necessary, engages in the brush roller 5 and scrapes dirt from this. The doctor 14 is seated in a doctor blade holder 15 and can be easily replaced accordingly. The squeegee holder 15 is seated on a torsion shaft 16, by means of which it can be pivoted together with the squeegee 14. The pivoting movement makes it possible to set the doctor blade 14 against the brush roller 5 or, as shown here, to turn it off from the brush roller 5 and bring it into a parking position.

A scraper 17 constituted by a flexible plate fixed to the rear wall 2 of the housing 1 and resting on the squeegee 14 only by virtue of its inherent elasticity will be described later in its function.

In the dirt chamber 13, a further spray pipe is finally arranged as a rinsing device 18, which can if necessary spray rinsing liquid on the doctor blade 14.

Both the first spray tube 10 and the second spray tube 11 and the spray tube used as purging 18 are provided with inserted spray nozzles 19 of soft elastic material, which in itself from the EP-A-1 759 846 are known and cause a particularly efficient application of the washing liquids and the rinsing liquid. The rinsing device 18 is in this case, as shown, with distributed over its longitudinal axis, alternately radially offset spray nozzles 19 to flush not only the doctor 14, but also a part of the dirt chamber 13 and the scraper 17 can.

• In Figur 1 wird eine erste Reinigungsphase dargestellt. Die Bürstenwalze 5 rotiert im Gleichlauf mit dem zu reinigenden Zylinder 6, so dass die Relativgeschwindigkeit zwischen der Oberfläche der Bürstenwalze 5 und der Oberfläche des Zylinders 6 minimal ist. Die Rakel 14 befindet sich in der Parkposition, und die Sprühdüsen 19 auf dem ersten Sprührohr 10 sprühen Waschmittel auf die Bürstenwalze 5, während die Sprühdüsen 19 auf dem zweiten Sprührohr 11 Wasser auf die Bürstenwalze 5 aufsprühen. Diese Waschflüssigkeiten werden von der Bürstenwalze 5 auf die zu reinigende Oberfläche des Zylinders 6 übertragen, wobei aufgrund der geringen Relativgeschwindigkeit ein nahezu verlustfreier Übertrag der Waschflüssigkeiten auf die Zylinderoberfläche erfolgen kann. Waschflüssigkeiten, die auf der Bürstenwalze 5 verbleiben, werden an der in der Parkposition befindlichen Rakel 14 vorbei geführt und stehen für den nächsten Umlauf der Bürstenwalze 5 wieder zur Verfügung. Die Waschflüssigkeiten werden in Intervallen aufgesprüht, und zwar jeweils nur etwa so viel, wie die Bürstenwalze 5 auf den Zylinder 6 übertragen kann.

The FIGS. 2 to 4 show the same structure of the cleaning device shown schematically, the individual components are correspondingly provided in accordance with reference numerals. In the Figures 3 and 4 the cylinder to be cleaned 6 is no longer visible, since the cleaning device is turned off here by the cylinder 6. Based on the different representations in the FIGS. 1 to 4 Therefore, the operation of the illustrated embodiment for a device according to the invention can be described:

• In FIG. 1 a first cleaning phase is shown. The brush roller 5 rotates in synchronism with the cylinder 6 to be cleaned, so that the relative speed between the surface of the brush roller 5 and the surface of the cylinder 6 is minimal. The squeegee 14 is in the park position, and the spray nozzles 19 on the first spray tube 10 spray detergent onto the brush roller 5, while the spray nozzles 19 spray water onto the brush roller 5 on the second spray tube 11. These washing liquids are transferred from the brush roller 5 to the surface to be cleaned of the cylinder 6, wherein due to the low relative speed, a virtually lossless transfer of the washing liquids can take place on the cylinder surface. Washing liquids, which remain on the brush roller 5, are guided past the blade 14 located in the parking position and are available again for the next rotation of the brush roller 5. The washing liquids are sprayed at intervals, and in each case only about as much as the brush roller 5 can transmit to the cylinder 6.

After a certain exposure time of the washing liquids to the cylinder 6, the first spray tube 10 and the second spray tube 11 are turned off and the direction of rotation 7 of the brush roller 5 is changed. This results in the contact point of the brush roller 5 and the cylinder 6, a maximum relative speed and thereby a maximum scrub effect, whereby the loosened soiling on the surface of the cylinder 6 are lifted from the brush roller 5. As far as much dirt from the cylinder 6 has to be lifted, the torsion shaft 16 can be simultaneously rotated and thereby the squeegee 14 are brought into engagement with the brush roller 5, so that the dirt can be stripped off the squeegee 14 and thrown into the sump 4. In FIG. 2 On the other hand, a procedure is shown in which the doctor 14 remains in the parking position even in a second cleaning phase. The brush roller 5 thus absorbs the dirt from the cylinder 6, without being able to strip it again at the same time.

After cleaning the cylinder 6, the brush roller 5 is turned off by this and the squeegee 14 employed by pivoting the torsion shaft 16 and the doctor blade holder 15 to the brush roller 5. This situation shows FIG. 3 , Here the squeegee 14 is with its doctor edge in engagement with the brush roller 5, while the brush roller 5 continues in the already in FIG. 2 rotated direction 7 rotates. This is the self-cleaning phase of the device, in which the brush roller 5 is freed from the dirt picked up again. Since there is no longer contact with the cylinder 6, it is no longer necessary to pay attention to the smallest possible consumption of the washing liquids, so that detergent and water are in turn sprayed onto the brush roller 5 by activating the first spraying tube 10 and the second spraying tube 11 to support self-cleaning , These washing liquids are then stripped together with the dirt received by the cylinder 6 on the doctor blade 14 and thrown into the drip pan 4, from where the dirt-washing liquid mixture is derived in a conventional manner.

At the point where the brush roller 5 strikes the squeegee 14, due to the high adhesion ability of the ink contained in the dirt forms a dirt build-up. This one will be in the in FIG. 4 again shown eliminated process phase. Here, the brush roller 5 is stationary and the spray tubes 10 and 11 are turned off. By pivoting the squeegee holder 15 about the torsion shaft 16, the squeegee 14 has been returned to its parking position. In this case, the free, resting on the doctor blade 14 leading edge of the scraper 17 slid along the surface of the doctor blade 14 and scraped them from the aforementioned dirt structure free. The scraped dirt will then, as in FIG. 4 shown rinsed by activating the rinsing device 18 in the drip pan 4. The rinsing device 18 sprays not only rinsing liquid onto the doctor blade 14 and the doctor blade holder 15, but also in some areas into the dirt compartment 13, in particular onto the scraper 17.

Then the device is ready for another cleaning process. The separator 9 ensures, as is apparent from the figures, that scraping off of the squeegee 14 can not get into the washing liquid application space 12, even if the squeegee 14 is employed in a direction of rotation of the brush roller 5, in which the dirt is not is stripped into the sump 4, but up into the dirt chamber 13 into it. In any case, the separating element 9 thus enables the brush roller 5 to be used in both directions of rotation. the same Effect has the flushing device 18 according to the invention, since without this a stripping of the dirt in the dirt chamber 13 in a short time would lead to clogging of the dirt chamber 13.

The present invention further significantly improves and optimizes the use and efficiency of wash liquids in cleaning cylinders of a printing press over the prior art.

Claims (10)

Device for cleaning cylinders of a printing machine, comprising a driven brush roller (5) which can be turned on a cylinder (6) to be cleaned, a housing (1) having a rear wall (2), an upper cover (3) and a lower cover (4) ) and a front opening, which is substantially filled by the brush roller (5), a at least temporarily in the brush roller (5) engaging scraper (14) for stripping of dirt and means (10, 11) for applying washing liquids to the brush roller (5), where
the squeegee (14) is associated with a rinsing device (18) which acts on the squeegee (14) when necessary and removes dirt by a rinsing process,
characterized,
in that the interior of the housing (1) is arranged through a separating element (9) in an upper washing liquid application space (12) in which the means (10, 11) for applying washing liquids to the brush roller (5) and a lower dirt space (13), in which the doctor blade (14) and the rinsing device (18) are arranged, is divided. Device according to claim 1,
characterized,
in that the rinsing device (18) for the doctor blade (14) is arranged on or in the dirt compartment (13) and also acts on at least part of the dirty compartment (13) in addition to the doctor blade (14). Device according to one of claims 1 or 2,
characterized,
that the doctor blade (14) is pivotally held. Device according to claim 3,
characterized,
in that the doctor blade (14) is also associated with a scraper (17) which rests with a front edge on the doctor blade (14) and slides along the surface thereof during pivoting of the doctor blade (14). Device according to claim 4,
characterized,
in that the scraper (17) is fastened to the rear wall (2) of the housing (1). Device according to at least one of claims 1 to 5,
characterized,
in that the lower cover (4) of the housing is designed as a collecting trough for the dirt scraped off by the rotary brush roller (5) by means of the doctor blade (14). Device according to at least one of claims 1 to 6,
characterized,
in that the means (10, 11) for applying washing liquids are spray devices. Device according to claim 7,
characterized,
that at least two spraying devices are present, one spraying device (10) for applying liquid washing agent and a spray device (11) is provided for applying water. Device according to one of claims 7 or 8,
characterized,
in that the spray devices (10, 11) are provided with spray nozzles (19). Device according to at least one of claims 1 to 9,
characterized,
in that the rinsing device (18) is a spray device with spray nozzles (19).

Images