Method for washing an anilox inking unit of a printing press

Abstract

Method for washing an anilox inking unit (4) of a printing press (1), wherein a washing agent is introduced into the anilox inking unit (4) via a dampening unit (5) or a part of the dampening unit (5), characterized by that the washing agent is jetted or sprayed onto a dampening roller (20) and / or a dampening unit roller (21) of the dampening unit (5) which is only adjacent to the dampening roller (20) and is conveyed from the dampening unit (5) via a bridge roller (22) into the anilox inking unit (4), and that the bridge roller (22) rests against a dampening forme roller (20) and rests against an inking roller (7) only in a cleaning mode.

Description

[0001] The present invention relates to a method for washing an anilox inking unit of a printing press, wherein a washing agent is introduced into the anilox inking unit, according to the preamble of claim 1.

[0002] Such a process is described in DE 10 2004005 576 A1. However, in this prior art process, the distribution of the washing agent in the anilox inking unit is unsatisfactory.

[0003] EP 0 839 652 A2 describes a method for cleaning cylinders and rollers in a printing press, in which cleaning fluid is sprayed with a spray device that is assigned to an inking roller train.

[0004] US 3,701,316 A describes a printing machine in which washing agent is introduced into a dampening unit via an inking unit.

[0005] DE 36 06 007 A1 describes a cleaning device in which washing agent is sprayed onto a dampening roller which is in contact with two dampening application rollers.

[0006] DE 38 26 222 A1 describes a dampening unit in which the application is effected by lowering and immersing an application roller into a tub containing cleaning fluid.

[0007] Therefore, the object of the invention is to provide a method for washing an anilox inking unit, in which method a rapid distribution of the washing agent throughout the entire anilox inking unit is ensured.

[0008] This object is achieved by a method having the features of claim 1.

[0009] Advantageous developments of the method according to the invention are mentioned in the subclaims.

[0010] In a further development, the dampening forme roller is disengaged from a printing form cylinder of the printing press in cleaning mode. However, in printing mode, the dampening forme roller is engaged with the printing form cylinder.

[0011] In a further development, the detergent is conveyed from the ink application roller via an anilox roller around at least one first inking unit roller adjacent to the anilox roller to another inking unit roller, and is doctored off by the other inking unit roller. The other inking unit roller is adjacent to the first inking unit roller.

[0012] Further constructively and functionally advantageous developments emerge from the following description of a preferred embodiment and the associated drawing.

[0013] The only figure shows a printing unit that includes an anilox inking unit and a dampening unit for wet offset printing.

[0014] A printing press 1 for offset printing comprises a printing unit with a printing form cylinder 2, a blanket cylinder 3, an anilox inking unit 4, and a dampening unit 5. The anilox inking unit 4 comprises an anilox roller 6 and an ink forme roller 7, which are the same diameter as the printing form cylinder 2. The anilox inking unit 4 also comprises a first roller 8, a second roller 9, and a third roller 10. The first roller 8 and the second roller 9 bear against the anilox roller 6, and the third roller 10 bears against the first roller 8 and the second roller 9.

[0015] The ink form roller has a tensioning device 11 for tensioning a rubber blanket 12, which sits in a cylinder channel 29 of the ink form roller 7.

[0016] The first roller 8 and the second roller 9 each have a rubber-elastic roller cover 13 and ensure stencil-free printing. The rubber-elastic roller covers 13 are advantageous in a cleaning mode of the printing press 1, in that the roller covers 13 temporarily press into the depressions (cups or grooves) of the screen structure of the screen roller 6 and, upon subsequent release from the screen structure, exert a suction effect, which expels printing ink sitting in the depressions. In certain applications, only one of the two rollers 8, 9 needs to be present.

[0017] The third roller 10 has a metallic-hard peripheral surface formed by a Rilsan layer 14. The third roller 10 is an axially oscillating ink distribution roller and is rotationally driven by a positive connection, i.e., via a coaxially arranged gearwheel that is rotationally fixedly connected to the third roller 10. In certain applications, the axial oscillating movement of the third roller 10 is not absolutely necessary.

[0018] Furthermore, the anilox inking unit 4 comprises an ink doctor blade 15, which rests on the anilox roller 6 and holds a printing ink supply 16.

[0019] The dampening unit 5 comprises a fountain roller 17 in a dampening box 18, a metering roller 19, a dampening forme roller 20, and an axially oscillating dampening distribution roller 21. The metering roller 19 acts as a transfer roller against the fountain roller 17 and simultaneously against the dampening forme roller 20 when the printing press 1 is running in a printing mode (not shown in the drawing). In cleaning mode, the metering roller 19 is at least initially separated from the dampening forme roller 20, as shown. The dampening distribution roller 21 is in contact exclusively with the dampening forme roller 20 and, in certain applications, does not necessarily need to oscillate axially.

[0020] A bridge roller 22 is mounted so that it can be adjusted to a first position 22.1 and a second position 22.2. In the first position 22.1, which is shown in phantom, the bridge roller 22 rests only on the dampening forme roller 20 and the bridge roller 22 is spaced apart from the inking roller 7. The bridge roller 22 assumes the first position 22.1 in printing mode and assumes the second position 22.2 only in cleaning mode. In the second position 22.2, which is shown in solid line, the bridge roller 22 rests against the dampening forme roller 20 and simultaneously against the inking roller 7, so that in cleaning mode the dampening unit 5 is connected to the anilox inking unit 4 via the bridge roller 22.

[0021] In cleaning mode, a system is used that includes a jet or spray device for introducing a detergent into the dampening unit 5 and a cleaning blade 24 with a collecting tray 25 arranged underneath. The jet or spray device 23 includes a detergent spray pipe 26 and a water spray pipe 27. In the area of ​​an inlet gusset formed by the dampening forme roller 20 together with the dampening distribution roller 21, one spray pipe 26 or 27 is directed at one of the two rollers 20, 21 and the other spray pipe is directed at the other of the two rollers. The jet or spray device 23 thus sprays the detergent and water into the inlet gusset. In cleaning mode, the cleaning blade 24 is engaged with the third roller 10 and disengaged from the latter in printing mode. The cleaning blade 24 is engaged and disengaged by pivoting it about a pivot joint 28.

[0022] The printing press 1 is operated as follows when cleaning the anilox inking unit 4: First, the dampening forme roller 20 is moved away from the printing form cylinder 2, and the bridge roller 22 is positioned against the ink forme roller 7 (second position 22.2). Furthermore, the metering roller 19 is moved away from the dampening forme roller 20.

[0023] With the printing press 1 running, the washing agent is then introduced into the inlet gusset between the dampening forme roller 20 and the dampening distribution roller 21 by means of the jet or spray device 23 in several spray intervals. Particularly effective cleaning can be achieved by spraying or blasting the washing agent alternately with water onto the rollers 20, 22 forming the inlet gusset by means of the jet or spray device 23. In certain applications, however, water is not required, so that in these cases the water spray pipe 27 can be omitted.

[0024] As the rollers roll onto each other, symbolized in the figure by the arrows indicating the direction of roller rotation, the detergent is distributed throughout the anilox inking unit 4 and conveyed to the third roller 10. The detergent flows via the bridge roller 22 onto the inking roller 7, from there onto the anilox roller 6, and from the latter via the first roller 8 and the second roller 9 onto the third roller 10.

[0025] As soon as a sufficient amount of washing agent has reached the third roller 10, the cleaning doctor blade 14 is positioned on the third roller 10, and the ink-washing agent mixture is doctored off the third roller 10. The doctored-off ink-washing agent mixture is collected in the collecting tray 25. During the doctoring process, fresh washing agent continues to be sprayed into the dampening unit 5.

[0026] The operator of printing press 1 can optionally set the "Clean Printing Form Cylinder" program on the latter, so that during the cleaning process described above, the ink form roller 7 is positioned against the printing form cylinder 2, as shown in the drawing. In cleaning mode, the ink form roller 7 rests against the anilox roller 6 and simultaneously against the printing form cylinder 2. In this way, the cleaning agent not only passes from the dampening form roller 20 via the bridge roller 22 to the ink form roller 7, but also from the ink form roller 7 to the printing form cylinder 2.

[0027] At the end of the cleaning process, first the washing agent supply is stopped, a little later the cleaning doctor blade 24 is switched off from the third roller 10 and then the metering roller 19 is switched on to the dampening roller 20 and this is switched on to the printing form cylinder 2 in order to rinse the latter with the dampening solution from the dampening unit 5 before the start of printing operation. List of reference symbols 1 printing machine 2 printing form cylinders 3 blanket cylinders 4 anilox inking units 5 Dampening system 6 anilox roller 7 ink application roller 8 first roller 9 second roller 10 third reel 11 Clamping device 12 rubber blanket 13 Roller cover 14 Rilsan layer 15 paint squeegees 16 printing ink supply 17 Immersion roller 18 Humidity box 19 Dosing roller 20 dampening roller 21 Dampening roller 22 Bridge roller 22.1 first position 22.2 second position 23 Jet or spray device 24 cleaning squeegees 25 drip tray 26 Detergent spray tube 27 Water spray pipe 28 Swivel joint 29 Cylinder channel

Claims

[1] Method for washing an anilox inking unit (4) of a printing press (1), wherein a washing agent is introduced into the anilox inking unit (4) via a dampening unit (5) or a part of the dampening unit (5), characterized by , that the washing agent is jetted or sprayed onto a dampening roller (20) and / or a dampening unit roller (21) of the dampening unit (5) which is only adjacent to the dampening roller (20) and is conveyed from the dampening unit (5) via a bridge roller (22) into the anilox inking unit (4), and that the bridge roller (22) rests against a dampening form roller (20) and rests against an inking roller (7) only in a cleaning mode. [2] Method according to claim 1, characterized by that in the cleaning mode the dampening forme roller (20) is separated from a printing form cylinder (2) of the printing press (1). [3] Method according to claim 1 or 2, characterized bythat the washing agent is conveyed from the inking roller (7) via an anilox roller (6) and at least one first inking unit roller (8; 9) lying on the anilox roller (6) to a further inking unit roller (10) lying on the first inking unit roller (8; 9) and is doctored off by the further inking unit roller (10).

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