EP0715955B2 - Process for cleaning a cylinder of a rotary printing machine - Google Patents

Abstract

The cleaning device uses a washing roller (2), or a washing cloth, displaced into contact with the cylinder to be cleaned and supplied with a biological cleaning fluid (3) via a spray. The washing cycle and drying cycle are controlled in defined angular positions, accounting for the rotation velocity and rotation direction of the cylinder being cleaned, to obtain effective cleaning and a dry cylinder surface at the end of the drying cycle. The angular positions for the washing and drying cycles may be variable or self-adjustable.

Description

The invention relates to a method for cleaning a cylinder of a rotary printing press. The invention is particularly suitable for cleaning blanket cylinders and Impression cylinders as well as plate cylinders or Forme cylinders, for example in a painting unit.

A method according to the preamble of claim 1 is known from DE 4 216 243 A1.

One method is from DE-AS 1 808 909 known for cleaning a plate cylinder. To achieve a wiping effect for the removal of impurities on the plate cylinder roller lying on the cylinder with different Peripheral speed driven.

EP 0 004 605 A1 is one in one Swivel-mounted washing device with a Wash roller known in the area of the gripper of Printing cylinder has a control curve. About these The control curve is the one applied to a pressure cylinder Washer roller at an angle from the outer surface lifted off so that it does not collide with the grippers.

It is also known from EP 0 548 500 A1 that at the contact point of the washcloth and cylinder a fluid jam consisting of detergent and detached contaminants. The fluid jam will pushed in front of the washcloth in the transport direction and will pass through the cylinder channel conveyed into this, which leads to reduction or Removal of the fluid jam leads. The washcloth is can be variably pressed onto the cylinder surface.

The disadvantage of these solutions is that the hydrodynamic conditions and kinetic friction at the contact point of washing device, in particular with wash roller or washcloth and to too little attention is paid to the cleaning cylinder. So is often at the end of the cleaning process a remaining fluid layer on the entire surface of the cylinder, i.e. the cylinder surface is still not sufficiently dry at the start of printing. This situation occurs particularly with detergents on that have no fast evaporating solvents include, for example, plant-based detergents. There is also a risk that detergent or also water through the spray effect of the nozzles or also through the washing device itself into the cylinder channel reach.

Even the transportation of excess Detergent (including impurities) in the cylinder channel according to EP 0 548 500 A1 has a disadvantageous effect on the print quality of the sheet of the following Print job. The excess of detergent builds up in connection with impurities as Mud in the cylinder channel and especially in relation to the direction of rotation of the printing press at the beginning arranged cylinder channel edge. The excess Detergent increases detergent consumption unnecessarily without improving the cleaning itself. A uncontrolled supply of detergent can float the washing device on the cylinder surface to lead.

From DE 2 613 687 B2 is a blanket cylinder known that in the cylinder channel on both sides of the Channel edges have flattened areas.

The object of the invention is a method for controlled cleaning fluid guidance, especially for organic detergents Basis, such as vegetable oil esters, on a To develop a cylindrical surface that is effective Cleaning and one at the end of the washing process relatively dry cylinder jacket surface guaranteed.

According to the invention that is by the characterizing Part of claim 1 solved. With the method according to the invention it is ensured that the kinetic friction always at the contact point of the washing device and cylinder surface in the form of mixed friction is present. Mixed friction is the mixed form of solids and fluid friction. The effect of floating (Aquaplaning) of the washing device on the cylinder surface if there is too much detergent, this is avoided. , This reduces the detergent consumption and after At the end of the cleaning process there are relatively dry ones Cylinder jacket surfaces in front. Even when using Bio-based detergents, especially from Plant nests, will be an optimal washing result reached because at the end of a washing process the cylinder surface is dry. Because the cylinder channel largely of detergent, water and Contamination is also increased the quality of the sheets in a subsequent print job. The angle-dependent cleaning is suitable for Plate cylinder, blanket cylinder, counter-pressure cylinder and forme cylinders, in particular for painting facilities. The procedure is also suitable for washing equipment with washing rollers, such as. a washing brush or a roller with a softer one Lateral surface (rubber or textile cover) or with a washcloth with a pressure element in Active connection is established. All control processes the washing device take place at certain predetermined Angular positions of the printing press or cylinder to be cleaned. Another advantage of the angle controlled Purification is an entry from Detergent or water into the cylinder channel uncontrolled spraying is prevented. That reduces environmentally friendly the consumption of detergent and water, since not the entire surface of the cylinder must be cleaned.

Fig. 1

ein Druckwerk einer Rotationsdruckmaschine,

Fig. 2

eine Waschwalze in Kontakt mit einem Zylinder,

Fig. 3

einen doppeltgroßen Druckzylinder,

Fig. 4

die Anordnung mit Winkelgeber und Steuerung.

The invention will be explained in more detail using an exemplary embodiment. Show schematically

Fig. 1

a printing unit of a rotary printing press,

Fig. 2

a washing roller in contact with a cylinder,

Fig. 3

a double-sized impression cylinder,

Fig. 4

the arrangement with angle encoder and control.

• Befeuchten/Einsprühen der Waschbürste, einschließlich Dosierung von Waschmittel/Wasser
• Waschvorrichtung an- und abstellen
• Waschbürstenumfangsgeschwindigkeit
• Waschbürstenstopp
• Waschbürstendrehrichtung/Drehrichtungsumkehr
• Zylinderumfangsgeschwindigkeit
• Zylinderdrehrichtung
• Rakeldruck an- und abstellen.

1 shows a printing unit of a multi-color rotary printing press, in which a transfer drum 8 is arranged, which is followed by a printing cylinder 1 in the sheet transport direction. The printing cylinder 1 is adjacent to a blanket cylinder 6 in a known manner, which is in contact with a plate cylinder 7. The plate cylinder 7 has a dampening unit and an inking unit, which are not shown here. Downstream of the impression cylinder 1 is a take-up drum 9, which removes the sheet from the impression cylinder in a known manner and transports it to the delivery arm. A washing device 2 is assigned to the blanket cylinder 6 and the impression cylinder 1. The washing device 2 extends over the full width of the cylinders 1, 6. It essentially consists of a housing which accommodates a washing brush. The washing brush is coupled to its own drive, and the washing device 2 has working cylinders for turning it on and off from the cylinder to be cleaned. A detergent and water supply directed towards the washing brushes and a doctor blade constantly engaged with the washing brush are arranged on the housing. At the lowest point of the housing there is a drain for the cleaning fluid 3 consisting of water and detergent. The washing device 2 with its working cylinders and its spray nozzles is connected in terms of circuitry to a controller, which in turn is coupled in terms of circuitry to an angle sensor (FIG. 5). The angle encoder is preferably integrated in a reac calculator. A sensor is also suitable as an angle encoder. The angle encoder is used to trigger all control processes for the washing device (control of the nozzles and control of the working cylinders) at predetermined angular positions, taking into account the cylinder position (cylinder channel position) or the cylinder peripheral speed. The control processes include:

• Moisten / spray the washing brush, including detergent / water dosage
• Switch the washing device on and off
• Wash brushes peripheral speed
• Wash brushes stop
• Wash brushes rotation / reverse rotation
• Cylinder peripheral speed
• Cylinder direction of rotation
• Switch squeegee pressure on and off.

For example with every cylinder revolution the washing brush is sprayed with a detergent based on a vegetable oil ester or water. To Finish cleaning with detergent that has multiple Cylinder revolutions can be optional with at least one cylinder revolution Washed water. Spraying detergent or water is preferably done before starting the Washing device on the pressure cylinder, so that during the contact of the washing device with the No more detergent or water in the cylinder is supplied, but only the cleaning fluid 3rd is guided as a wedge in front of the washing brush. At this The procedure is for a cylinder revolution Amount of detergent in the area of the print end only still available.

At the end of the washing and drying cycles the speed of the cleaned cylinder is increased. This will dry the cylinder surface accelerated. Especially on the cylinder channel edges any droplets that may still be present are removed by the Centrifugal force thrown off. This contributes to the reduction the start-up waste.

The mode of action is as follows:
The cleaning process consists of a washing process and a drying process.

In an angular position C of the blanket cylinder 6 (in the direction of rotation in front of the cylinder channel 4) the washing device 2 activated by the washing roller is sprayed with detergent. The washing device 2 is in an angular position D on the first Edge (beginning of the cylinder pit 4) on the blanket cylinder 6 employed. The washing roller of the washing device 2 remains based on the angular position D during a rotary movement of the blanket cylinder 6 with its outer surface in contact until it is reached an angular position A. The angular position A is through the area from the end of the print sheet (depending on format) and the angular position B (second channel edge) the cylinder pit 4 limited. During the Contact of the washing roller of the washing device 2 with the outer surface of the blanket cylinder 6 is formed a cleaning fluid wedge consisting of detergent and / or water 3. The fluid wedge 3 is on the outer surface of the blanket cylinder 6 in one by Angular positions D and A formed circle sector before of the washing roller. In the angular position A the washing device with washing roller 2 from Blanket cylinder 6 turned off and the fluid wedge 3 on the remaining lateral surface in one by the Angular positions A and B formed by the circular sector the rotary movement of the blanket cylinder 6 flat distributed landfilled. The blanket cylinder 6 leads during a rotating movement of the washing process from, the cylinder channel 4 also the washing device 2 happens, but without contact. In the field of The washing roller is again at angular position C. Sprayed detergent in the angular position D. hired them to the blanket cylinder 6, in the Angular position A is turned off and the fluid wedge 3 is repeated in the angular position A and B formed circular sector landfilled distributed. This Washing process can be carried out several times, being before or after washing with detergent in the described angular positions of the blanket cylinders 6 can be cleaned with water and the water also in the position A and B formed circular sector is landfilled distributed.

During the drying process, the washing roller becomes the Washing device 2 no longer with detergent or Water sprayed, but preferably constantly during Of your rotation. The washing roller will again in the angular position D on the rotating blanket cylinder 6 hired, remains on the angular position A hired at this until Angular position B. This is in the area of the lateral surface formed by the angular positions A and B. Circular sector the deposited fluid (detergent and Water) from the rotating washing brush. , The rotating one Washing roller of the washing device 2 has opposite the blanket cylinder 6 a higher peripheral speed. The washing roller can in the circle segment the angular positions A and B maintain their direction of rotation or the washing drum is reversed. It is also a movement stop Wash roller possible. This then acts on the outer surface of the rotating blanket cylinder 6 as a doctor blade. The washing device is in the area of the cylinder pit 4 disengaged from the lateral surface, see above that essentially no sludge (detergent, water, Paint / varnish residues, impurities, dust) in the Cylinder pit 4 can be promoted and itself does not build up on the channel edge.

The washing roller can also be yours Maintain direction of rotation, stop this or one Perform movement reversal. In the area of the cylinder pit 4 is the washing device 2 from the blanket cylinder 6 turned off.

A double-sized printing cylinder 1 according to FIG. 3 has two arc-carrying lateral surfaces I and II. Analogous to the example already described, in pre-moistened in an angular position C, in the angular position D the washing device 2 turned on, in the angular position A turned off and dry brushing the The outer surface of the printing cylinder 1 is in the angular position A is employed and at the angular position B. switched off. Since there are two lateral surfaces I and II, can, for example, the jacket surfaces I and II with the Washer 2 are in contact. After preferably a full cylinder revolution (at which all Shell surfaces I, II are cleaned) during the Cylinder 1 rotates, the washing device 2 from the outer surface I set up. In this parking position the rotating washing roller of the washing device 2 in Circle sector of the outer surface I doctored and then hired again to the lateral surface II. The Washing device 2 is after cleaning the outer surface II also employed on the lateral surface I. While the further rotation of the cylinder 1 becomes the washing device 2 parked in the circular area of the lateral surface II and the rotating washing roller is scraped off.

The example described represents only one Training. Likewise, the outer surfaces I, II or other surface areas (for triple and quadruple sizes Cylinders) are cleaned alternately. It is advantageous after at least one cylinder revolution the rotating washing roller in the parked position abzurakeln. It is always a relatively clean one Washer roller with the cylinder surface to be cleaned I and / or II brought into contact

reference numeral

1

pressure cylinder

2

washer

3

fluid

4

cylinder gap

5

flattening

6

Blanket cylinder

7

plate cylinder

8th

transfer drum

9

off drum

I

arch-bearing surface

II

arch-bearing surface

A

angular position

B

angular position

C

angular position

D

angular position

Claims (1)

1. Process for cleaning a cylinder (1, 6) of a rotary printing press with a washing device (2) which can be set against and away from the rotating cylinder (1, 6), which contains a washing roller or a washing cloth which can be sprayed with at least a cleaning liquid, and with a control unit actuating the washing device (2) in angle correlated fashion, characterised in that taking into account the rotational speed and rotational sense of the cylinder (1, 6) to be cleaned, the washing device (2) is controlled dependent on four fixed angular positions A, B, C, D with a washing cycle and a drying cycle,
   that, in the rotational sense of the cylinder (1, 6), in each case

   prior to the front edge of a cylinder channel (4), the angular position C is defined

   at the front edge of the cylinder channel (4) the angular position D,

   at the format defined print end the angular position A, and

   at the rear edge of the cylinder channel (4), the angular position B

   that in the washing cycle the washing device (2) is sprayed with cleaning liquid at the angular position C, set against the cylinder (1, 6) at the angular position D, and set off from the cylinder (1, 6) at the angular position A, and that in the drying cycle the washing device (2) is set against the cylinder (1, 6) at the angular position D and set off from the cylinder (1, 6) in the angular position B.

Images