EP0715955B1 - Process and device 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 and an arrangement for cleaning of 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 of this type is known from DE-AS 1 808 909 for cleaning of a plate cylinder known. To achieve a wiping effect for the removal of impurities on the plate cylinder becomes a cylinder on the cylinder with different Peripheral speed driven.

EP 0 004 605 A1 describes a bearing mounted in a swivel joint Washing device with a washing roller known in the field of Gripper of the printing cylinder has a control curve. About these The control curve is the washing roller attached to a pressure cylinder at an angle from the outer surface so that this not collided with the grippers.

Furthermore, it is known from EP 0 548 500 A1 that the A fluid jam exists between the contact point of the washcloth and the cylinder from detergent and detached contaminants. The fluid jam is pushed in front of the washcloth in the transport direction and is conveyed into the cylinder channel as it passes through it, what to reduce or remove the fluid jam leads. The washcloth is variable on the surface of the cylinder pressable.

The disadvantage of these solutions is that the hydrodynamic Conditions and the movement friction at the contact point of Washing device, in particular with washing roller or washcloth and to too little attention is paid to the cleaning cylinder. So is often a residual fluid layer at the end of the cleaning process on the entire surface of the cylinder, i.e. the cylinder surface is not yet sufficiently dry when printing starts. This situation occurs especially with detergents, that do not contain fast evaporating solvents, for example Plant-based detergent. Furthermore, the Risk of detergent or water due to the spray effect of the Nozzles or through the washing device itself into the cylinder channel reach.

Also the transport of excess detergent (included Impurities) in the cylinder channel according to EP 0 548 500 A1 adversely affect the print quality of the sheet of the subsequent Print job. The excess detergent builds up in Connection with impurities as sludge in the cylinder channel and especially on the in relation to the direction of rotation of the printing press At the beginning arranged cylinder channel edge. The excess Detergent unnecessarily increases detergent consumption without that Improve cleaning yourself. An uncontrolled supply of detergent can for floating the washing device on the cylinder surface to lead.

From DE 2 613 687 B2 a blanket cylinder is known which in Cylinder channel has flats on both sides of the channel edges.

The object of the invention is a method and an arrangement for controlled cleaning fluid flow, especially for detergents on a biological basis, such as vegetable oil esters to develop a cylindrical surface that is effective Cleaning and a relatively dry one at the end of the washing process Guaranteed cylinder surface.

According to the invention that is by the characterizing part of Claims 1 and 13 solved. Further training results from the subclaims. With the inventive method and Arrangement ensures that the kinetic friction is always on the Contact point of 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 too much detergent is avoided. So that the detergent consumption lowered and lie after the cleaning process relatively dry cylinder jacket surfaces. Even when using Bio-based detergents, especially plant nests, an optimal washing result is achieved because at the end the cylinder surface is dry during a washing process. Thereby, that the cylinder channel largely of detergent, water and If contamination is kept free, the quality also increases the sheet for a subsequent print job. The angle-dependent Cleaning is suitable for plate cylinders, blanket cylinders, Impression cylinders and forme cylinders, in particular for painting equipment. The method and the arrangement are also suitable for washing devices with washing rollers, e.g. a washing brush or a roller with a soft surface (rubber or textile Cover) or with a washcloth, which has a pressure element in Active connection is established. All control processes of the washing device take place at certain predetermined angular positions Printing machine or the cylinder to be cleaned. Another The advantage of angle-controlled cleaning is that an entry of Detergent or water in the cylinder channel through an uncontrolled Spraying is prevented. This reduces the environmentally friendly Use of detergent and water, since not all of it Cylinder surface must be cleaned.

Fig. 1

ein Druckwerk einer Rotationsdruckmaschine,

Fig. 2

eine Waschwalze in Kontakt mit einem Zylinder,

Fig. 3

eine weitere Ausbildung von Fig. 2,

Fig. 4

einen doppeltgroßen Druckzylinder,

Fig. 5

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 further embodiment of Fig. 2,

Fig. 4

a double-sized impression cylinder,

Fig. 5

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 multicolor 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 in each case. 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 real-time computer. 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 brush peripheral speed
• Wash brush stop
• Wash brush direction of rotation / reversal of direction of rotation
• Cylinder peripheral speed
• Direction of cylinder rotation
• Switch squeegee pressure on and off.

For example, every time the cylinder turns, the washing brush sprayed with a detergent based on a vegetable oil ester or water. After cleaning with detergent, the can be several cylinder revolutions, is optionally at Washed with water at least one revolution of the cylinder. The Spraying of detergent or water is preferably done before Place the washing device on the pressure cylinder, so that during the contact of the washing device with the pressure cylinder Detergent or water is fed, but only the cleaning fluid 3 is guided as a wedge in front of the washing brush. In this procedure, the is at a cylinder revolution The amount of detergent in the area of the print end is only reduced available.

After the washing and drying cycles, the speed of the cleaned cylinder increased. This will dry the cylinder surface accelerates. Especially on the cylinder channel edges any remaining droplets are thrown off by centrifugal force. This helps to reduce 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 is activated, by spraying the washing roller with detergent. The washing device 2 is in an angular position D on the first edge (Start of the cylinder pit 4) on the blanket cylinder 6. The washing roller of the washing device 2 remains from the Angular position D during a rotary movement of the blanket cylinder 6 with its lateral surface in contact until a Angular position A. The angular position A is through the range of End of the sheet (depending on the format) and the angular position B (second channel edge) of the cylinder pit 4 limited. During the Contact of the washing roller of the washing device 2 with the outer surface the blanket cylinder 6 forms a detergent and / or water existing cleaning fluid wedge 3. The fluid wedge 3 is on the outer surface of the blanket cylinder 6 in one the angular positions D and A formed circle sector in front of the washing roller brought forth. In the angular position A, the washing device turned off with blanket cylinder 6 from the blanket cylinder 6 and the fluid wedge 3 is on the remaining lateral surface in a through the Angular positions A and B formed circle sector by the rotary movement of the blanket cylinder 6 deposited over a large area. Of the Blanket cylinder 6 constantly leads one during the washing process Rotational movement, the cylinder channel 4 also the washing device 2 happens, but without contact. In the area of the angular position C, the washing roller is sprayed again with detergent in the Angular position D is placed on the blanket cylinder 6, it is turned off in the angular position A and the fluid wedge 3 is repeated in the A and B angular positions Circular sector landfilled. This washing process can be performed several times, 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 circular sector formed by angular positions A and B. is deposited over a large area.

During the drying process, the washing roller of the washing device 2 no longer sprayed with detergent or water, but preferably constantly scraped off during your rotation. The washing roller is again in the angular position D on the rotating blanket cylinder 6 turned on, stays on beyond the angular position A. this up to the angular position B. In the area the lateral surface of the formed by the angular positions A and B. Circular sector the deposited fluid (detergent and water) from the rotating washing brush added. In another version can the washing roller also in the circular sector, formed by the Angular positions D, A, remain parked and from the angular position A are placed on the outer surface until they are reached the angular position B and thus only absorb the deposited fluid. The rotating washing roller of the washing device 2 has compared to the blanket cylinder 6 a higher peripheral speed. The washing roller can in the circular segment of the angular positions A and B maintain their direction of rotation or the washing roller receives one Reversal of direction of rotation. It also stops the washing roller from moving possible. This then acts on the outer surface of the rotating Blanket cylinder 6 as a squeegee. The washing device is in the Area of the cylinder pit 4 with the outer surface out of engagement brought so that essentially no sludge (detergent, water, Paint / varnish residues, impurities, dust) in the cylinder pit 4 can be promoted and does not build up on the channel edge.

For cylinders with flats 5 on the cylinder channel 4, the washing device 2 in the angular position A (Fig. 3). The fluid wedge 3 is brought up in front of the washing roller and on the Flattening 5 deposited. When dry brushing the cylinder surface the washing roller of the washing device 2 from about Angular position A brought into contact with the flat 5. Thereby the deposited fluid 3 is taken up by the washing device 2.

The washing roller can also keep its direction of rotation, stop them or reverse the movement. In the field of The cylinder pit 4 is the washing device 2 from the blanket cylinder 6 switched off.

A double-sized impression cylinder 1 according to FIG. 4 has two sheet-bearing ones Lateral surface I and II. Analogous to the one already described Example is pre-moistened in an angular position C, in the angular position D, the washing device 2 started, in the Angle position A is switched off and the outer surface is dry brushed of the impression cylinder 1 is set in the angular position A. and at the angular position B is turned off. Because two outer surfaces I and II are present, for example, the jacket surfaces I and II are in contact with the washing device 2. After preferably a full cylinder revolution (in which all lateral surfaces I, II be cleaned), while the cylinder 1 rotates, the washing device 2 parked from the lateral surface I. In this parking position the rotating washing roller of the washing device 2 in Circle sector of the outer surface I doctored and then to the Shell surface II hired again. The washing device 2 is after Cleaning of the outer surface II also started on the outer surface I. During the further rotation of the cylinder 1, 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 is only an education. Likewise, the outer surfaces I, II or other outer surfaces (with three and four times large cylinders) alternating getting cleaned. It is advantageous after at least one cylinder revolution the rotating washing roller in the parked position to scrape off. So that a relatively clean washing roller is always with the cylinder surface I and / or II to be cleaned in contact brought.

Reference numerals

1

Impression cylinder

2nd

Washing device

3rd

Fluid

4th

Cylinder channel

5

Flattening

6

Blanket cylinder

7

Plate cylinder

8th

Transfer drum

9

Acceptance drum

I.

arch-bearing surface

II

arch-bearing surface

A

Angular position

B

Angular position

C.

Angular position

D

Angular position

Claims (19)

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, 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 fixed angular positions A, B, C, D with a washing cycle and a drying cycle.
2. Process according to Claim 1, characterised in that the set angular positions A, B, C, D are variably adjustable or are adjustable automatically.
3. Process according to Claim 1, characterised in that in the direction of rotation of the cylinder (1, 6) for a sheet guiding cover surface

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

   in the region of the front edge of the cylinder channel (4), i.e. in the region of print start, the angular position D is defined

   in the region of the print end, the angular position A is defined depending upon the format and

   in the region of the rear edge of a cylinder channel (4), the angular position B is defined.
4. Process according to Claims 1 and 3, characterised in that in the washing cycle exclusively at angular position C with the washing device (2) set off, the washing roller or the washing cloth is sprayed with a cleaning liquid (3) such as washing agent, water.
5. Process according to Claims 1 and 3, characterised in that in the washing and drying cycle at the angular position D, the washing device (2) is set against the rotating cylinder.
6. Process according to Claims 1 and 3, characterised in that in the angular position A, the washing device (2) is set off in the washing cycle and in the drying cycle remains set on or is set on.
7. Process according to Claims 1 and 3, characterised in that at the angular position B in the washing and drying cycle, the washing device (2) is set off from the cylinder.
8. Process according to Claims 1 to 7, characterised in that with multiple size cylinders, the washing device (2) is engaged during a first cylinder rotation with a first cover surface (I) dependent upon the angle and is engaged or not engaged with a subsequently following cover surface (II) and after each cylinder rotation, this sequence changes.
9. Process according to Claims 1 to 7, characterised in that with a washing device (2) with a rotating washing roller, this is doctored off correlated with the angle.
10. Process according to Claims 1 to 7 and 9, characterised in that the washing roller rotates with a higher peripheral speed relative to the cylinder (1, 6).
11. Process according to Claims 1 to 7 and 9, characterised in that during the drying process, the washing roller which is engaged with the cylinder (1, 6) in the circular segment of angular positions A and B is stopped or undergoes a reversal of movement.
12. Process according to Claims 1 to 7, characterised in that with cylinders with flattenings (5) in the region of the cylinder channel, the washing device (2) during washing and also during the drying cycle at the angular position A remains set against the cylinder cover surface.
13. Arrangement for carrying out the process according to Claims 1 to 12, characterised in that the washing device (2) is linked with a control which is connected in circuit with an angle transmitter.
14. Arrangement according to Claim 13, characterised in that the angle transmitter differentiates the angular position of the cylinder (1, 6) to be cleaned between one and several cylinder rotations.
15. Arrangement according to Claim 13, characterised in that the control is a learning control.
16. Arrangement according to Claim 13, characterised in that the control is linked with the working cylinders and the nozzles of the washing device (2).
17. Arrangement according to Claim 13, characterised in that the control at angular position C periodically sprays the washing roller or the washing cloth with washing agent or water.
18. Arrangement according to Claims 13 to 17, characterised in that during the washing cycle, the liquid wedge of washing agent, ink/varnish residues, water, contamination is deposited in a circular sector between angular positions A and B and during the drying cycle is removed from the cylinder cover surface by the washing device (2).
19. Arrangement according to Claim 13, characterised in that the control after the end of the washing and drying cycle increases the rotational speed of a cleaned cylinder (1, 6).

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