HK1088867A - Method for washing an anilox inking unit of a printing press - Google Patents

Description

Method for cleaning an anilox inking unit of a printing press

Technical Field

The invention relates to a method for cleaning an Anilox inking unit of a printing press, wherein a detergent is applied to the Anilox inking unit. The invention also relates to a printing press for carrying out the method.

Background

Such a process is described in DE 102004005576 a 1. However, in this prior art method, the distribution of the detergent in the anilox inking unit is unsatisfactory.

Disclosure of Invention

The object of the present invention is therefore to provide a method for cleaning an anilox inking unit, by means of which a rapid distribution of the washing agent throughout the anilox inking unit is ensured.

This object is achieved by the method according to the invention for cleaning an anilox inking unit of a printing press, wherein a washing agent is applied to the anilox inking unit, wherein the washing agent is applied to the anilox inking unit by a wetting device or a part of the wetting device.

Further configurations of the process according to the invention are listed below.

In a further embodiment, the washing agent is sprayed or misted onto a dampening roller and/or onto a dampening roller of the dampening device which rests only on the dampening roller. The dampener roll may be a dampening roll and not resting on other rolls than the dampening roll.

In a further embodiment, the washing agent is fed from the dampening unit via a bridge roller into the anilox inking unit. The bridge roller defines the direction of the detergent flow from the wetting device to the inking device.

In a further development, the bridge roller rests on the dampening roller and on an inking roller only in the cleaning mode. In the printing mode of operation, the bridge roller does not rest on the ink form roller.

In a further development, the dampening roller is pressed away from the plate cylinder of the printing press in the cleaning mode. However, in the printing mode of operation, the dampening roller presses against the plate cylinder.

In a further embodiment, the washing agent is transferred from the inking roller via the anilox roller and at least one first inker roller resting on the anilox roller to a further inker roller and scraped off from the further inker roller. The further inker roller rests on the first inker roller.

The invention also relates to a printing press which is designed to carry out the method according to the invention or corresponds to one of the further embodiments.

Further structurally and functionally advantageous configurations can be taken from the following description of a preferred embodiment and its drawings.

Drawings

The only figure shows a printing unit comprising an anilox inking unit and a dampening unit for wet offset printing.

Detailed Description

A printing press 1 for offset printing comprises a printing unit, which is provided with a plate 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 form roller 7, which are of the same diameter as the plate cylinder 2. Furthermore, the anilox inking unit 4 comprises a first roller 8, a second roller 9 and a third roller 10. The first roller 8 and the second roller 9 rest on the anilox roller 6, and the third roller 10 rests on the first roller 8 and the second roller 9.

The ink form roller has a tensioning device 11 for tensioning an rubber blanket 12 located in the cylinder channel 29 of the ink form roller 7.

The first roll 8 and the second roll 9 each have a rubber-elastic roll cover 13 and are responsible for template-free (schablonierfrei) printing. These rubber-elastic roller coverings 13 are advantageous in the cleaning mode of the printing press 1 in that these roller coverings 13 are temporarily pressed into the depressions (pits or grooves) of the screen structure of the screen roller 6 and, when subsequently detached from the screen structure, exert a suction effect by which printing ink located in these depressions is drawn out of them. In certain applications only one of the two rollers 8, 9 needs to be provided.

The third roll 10 has a metallic hard circumferential surface formed by a layer 14 of nylon 11 type polyamide fibres. The third roller 10 is an oscillating distributor roller (Farbreibwalze) which runs axially and is driven in rotation by means of a positive connection, i.e. by means of a coaxially arranged gear wheel which is connected in a rotationally fixed manner to the third roller 10. In certain applications, axial, oscillating movement of the third roller 10 is not absolutely necessary.

In addition, the anilox inking unit 4 comprises an ink blade 15 which rests on the anilox roller 6 and receives a reserve of printing ink 16.

The dampening device 5 comprises a fountain roll 17 in a fountain 18, a metering roll 19, a backing roll 20 and an axially oscillating dampening vibrator roll 21. When the printing press 1 is operating in a printing mode (not shown in the figures), the metering roller 19 rests as a transfer roller against the fountain roller 17 and simultaneously against the dampening roller 20. In the cleaning mode, the metering roller 19 is at least initially disengaged from the dampening roller 20, as shown. The dampening rollers 21 rest only on the dampening rollers 20 and do not absolutely need to be axially dampened in certain applications.

A bridge roller 22 is mounted in a selectively adjustable manner in a first position 22.1 and a second position 22.2. In the first position 22.1, indicated by dashed lines, the bridge roller 22 rests only on the dampening roller 20 and the bridge roller 22 is pressed away from the inking roller 7. The bridge roller 22 occupies a first position 22.1 in the printing mode of operation and a second position 22.2 only in the cleaning mode. In the second position 22.2, which is indicated by a solid line, the bridge roller 22 rests against the dampening roller 20 and simultaneously against the inking roller 7, so that in the cleaning mode the dampening unit 5 is connected to the anilox inking unit 4 via the bridge roller 22.

In the cleaning mode, a system is used which comprises a spray or spray device 23 for applying cleaning agent into the moistening device 5 and a cleaning blade 24 with a collecting groove 25 arranged thereunder. The spraying or atomizing device 23 comprises a detergent spray pipe 26 and a water spray pipe 27, wherein in the region of an entry wedge formed by the dampening roller 20 and the dampening roller 21, one spray pipe 26 or 27 is aligned on one of the two rollers 20, 21 and the other spray pipe is aligned on the other of the two rollers. The spraying or misting device 23 thus sprays detergent and water into the inlet wedge. The purge scraper 24 is engaged against the third roller 10 in the cleaning mode and disengaged therefrom in the printing mode of operation. The pressing and releasing of the cleaning blade 24 is effected by its deflection about a pivot joint 28.

During cleaning of the anilox inking unit 4, the printing press 1 operates as follows:

first, the dampening roller 20 is pressed away from the plate cylinder 2 and the bridge roller 22 is pressed against the ink form roller 7 (second position 22.2). Further, the metering roller 19 is pressed away from the dampening roller 20.

The washing agent is then applied in a plurality of spray intervals by means of a spray or spray device 23 during operation of the printing press 1 between the dampening rollers 20 and the dampening rollers 21. Particularly effective cleaning is achieved by spraying or beaming the washing agent alternately with water onto the rollers 20, 21 forming the inlet wedge by means of a spraying or misting device 23. However, in certain applications, water is not required, so that the water jet 27 can be dispensed with in this case.

Since the rollers roll against each other, which is symbolically indicated in the figure by the arrow giving the direction of rotation of the rollers, the detergent is distributed throughout the anilox roller inking unit 4 and is transported all the way to the third roller 10. In this case, the detergent flows through the bridge roller 22 onto the form roller 7, from there onto the anilox roller 6 and from there through the first roller 8 and the second roller 9 onto the third roller 10.

Once the detergent reaches the third roller 10 in a sufficient amount, the purge scraper 24 is pressed against the third roller 10 and the printing ink-detergent mixture is scraped off the third roller 10. The scraped-off printing ink-detergent mixture is collected in a collecting tank 25. During the scraping, new detergent continues to be sprayed into the moistening device 5.

The operator of the printing press 1 can optionally set a "plate cylinder washing" program on the press, whereby the ink form rollers 7 are pressed against the plate cylinder 2 during the above-mentioned washing process, as shown in the figure. In this case, the inking roller 7 rests on the anilox roller 6 and simultaneously on the plate cylinder 2 in the cleaning mode. In this way, the detergent reaches not only from the form roller 20 through the bridge roller 22 onto the form roller 7, but also from the form roller 7 onto the plate cylinder 2.

At the end of the cleaning process, the detergent supply is first terminated, the cleaning blade 24 is later disengaged from the third roller 10, and the metering roller 19 is then pressed against the dampening roller 20 and the plate cylinder 2, so that the latter is cleaned by the dampening solution of the dampening unit 5 before the printing operation begins.

List of reference numerals

17 fountain roller of printing machine

2 printing plate cylinder 18 bucket

3 blanket cylinder 19 metering roll

4 anilox roller inking unit 20 dampening roller

5 wetting device 21 dampening rollers

6 Anilox roll 22 bridge roll

7 form roller 22.1 first position

8 first roll 22.2 second position

9 second roll 23 spraying or misting device

10 third roller 24 cleaning blade

11 tensioning device 25 collecting tank

12 rubber cloth 26 detergent injection pipe

13 roll coating 27 spray pipe

14 nylon 11 type polyamide fiber layer 28 rotating hinge

15 ink scraper 29 cylinder channel

16 reserve printing ink

Claims (7)

1. Method for cleaning an anilox roller inking device (4) of a printing press (1), wherein a detergent is applied to the anilox roller inking device (4), characterized in that: the washing agent is applied to the anilox inking unit (4) by a wetting unit (5) or a part of the wetting unit (5).

2. A method according to claim 1, characterized in that: the washing agent is sprayed or misted onto a dampening roller (20) and/or a dampening unit roller (21) of the dampening unit (5) which rests only on the dampening roller (20).

3. A method according to claim 2, characterized in that: the detergent is fed from the wetting device (5) through the bridge roller (22) into the anilox inking unit (4).

4. A method according to claim 3, characterized in that: the bridge roller (22) rests on the dampening roller (20) and on one inking roller (7) only in the cleaning mode.

5. The method according to claim 4, characterized in that: in the cleaning mode, the dampening roller (20) is pressed away from the plate cylinder (2) of the printing press (1).

6. A method according to claim 4 or 5, characterized in that: the washing agent is transferred from the inking roller (7) via the anilox roller (6) and at least one first inker roller (8; 9) resting on the anilox roller (6) to a further inker roller (10) resting on the first inker roller (8; 9) and scraped off from the further inker roller (10).

7. Printing press (1) configured to carry out a method according to one of claims 1 to 6.