EP1245386B1 - Method and means for obtaining an ink distribution in the inking device of a printing press - Google Patents

Abstract

To distribute the inks to the color printing stage of a printing press, and especially a sheet-fed offset printing press, during the sheet feed phase the roller assembly (4) of the color printing unit is at least partially interrupted by a separation (5). As the color printing unit is empty, a defined volume of ink is fed to it while it is interrupted. The upper section of the roller assembly, towards the color box (1), is filled with an additional ink dosage. The printing is started when the roller interruption is broken.

Description

The invention relates to a method and a device for producing a color distribution in the inking unit of printing presses according to the preamble of the method or device claim.

[State of the art]

In sheetfed offset presses, the color to be printed becomes via a color box and interacting with an ink fountain roller Dosing in the color requirement corresponding Layer thickness applied to the ink fountain roller. Over a Lifting roller is taken off paint from the inking roller and over friction and other inking rollers and inking rollers applied to a printing plate. Through the inking rollers and the plurality of cleavage sites will be those in the upper part of the Farbwerkes color layer on a few microns thick Color layer split on the applicator rollers. By several Ink rollers is an independent of the subject and stencil-free Coloring of the printing form possible. By number of rollers as well as arrangement of the rollers can in this way also large format prints over the entire format width and Print length can be optimally colored.

Due to the number of rollers, there is one in the inking unit relatively large amount of paint. According to the subject conditions (Proportion of printing / nonprinting area) decreases the ink layer thickness from the upper part of the inking unit to the inking rollers down. For a "heavy" subject (high proportion printing area) is the ink layer thickness in the upper part of the inking unit larger, compared with the ink layer thicknesses in the same part of the inking unit with a "light" subject (small proportion of printing area).

For a change of order or at the end of the shift, the in Ink color removed and then the inking unit with the intended for the respective print job Color to be filled. Removing the ink of a previous print job can be arranged by in the inking unit Washing devices (washing blade plus spraying device) respectively. Possibly. additional manual intervention is necessary.

Due to the large surface of an inking unit and the Variety of cleavage sites (number of ink rollers) are after Filling the inking unit a variety of machine revolutions necessary, until a sujetabhängiges color profile - the so-called production profile - has set. To reduce of startup waste is the one before a new print job If possible, prefill inking unit so that a paint layer thickness gradient is generated, as it is during the printing is present.

DE 40 13 740 A1 describes an offset printing machine as well as a method for quickly reaching the steady-state condition, in which the application rollers permanently or temporarily during the pre-printing ink run or during a stopper interrupting the printing process are employed on the printing form. This will take the printing form Color up, so even during the stopper or during the Print interruption a color flow takes place.

From DE 33 38 143 C2 a method for generating a corresponding to the printed image ink layer thicknesses in the inking unit a printing press known in which the inking unit at parked inking rollers and running lift with paint is filled. First, this is done with a uniform over the format width reaching adjustment at Farbdosierelementen. With the start of printing then comes one to be executed Print job (the subject) corresponding adjustment of the Farbdosierelemente (the color profile) to use.

Moreover, it is known from DE 37 07 695 C2, which in an inking unit and from the previous print job originating color quantity by closing the Farbdosierelemente at parked inking rollers and continuing lifter reduce, i. to transport the paint back into the ink fountain. If the inking by this measure as far as possible was colorless, can then by opening the Farbdosierelemente the inking unit filled with a predetermined amount of ink become.

DE 44 36 953 C1 describes a method for generating a paint layer thickness distribution on inking rollers of a Inking unit of a printing press, in which at a job change by appropriate adjustment of the Farbdosierelemente the quantity of ink in the inking unit except for one Basic quantity is reduced. Starting from this basic color quantity Then the color dosing is on the profile of the new Set the print job and then the inking unit with this Setting a specified number of machine revolutions preloaded.

The above-described methods for prefilling a Inking unit with the aim of a color print thickness distribution close to the print run take into account on the paint rollers but not that a color coat thickness gradient, which prevails in the production state, only hard during a predetermined number of machine revolutions and parked Can achieve inking rollers / printing cylinders.

To just during short-term print interruptions the Color flow state (ink layer thickness gradient) even with continuous running Machine and parked inking rollers upright To obtain, have color works of sheetfed offset printing presses Devices for inking separation on. It can the compactor of the inking unit at one or more points be interrupted by associated actuating means, so that despite continuous ink rollers, the ink layer thickness gradient does not balance over the entire inking unit (all ink rollers) but only in the one formed by the shutdown Group of paint rollers. Such an inking shows, for example DE 36 40 295 A1, wherein here by the Separation split-off compactor, for example during the Printing operation can be washed.

OBJECT OF THE INVENTION

The object of the present invention is therefore a method and a device for carrying out the method according to the preamble of the method or device claim to expand so that a differentiated to the color flow conditions of the print job to be executed adapted pre-inking with appropriate color layer thickness structure is achieved.

This problem is solved by the characterizing features the method or device claim. further developments The invention will become apparent from the respective dependent claims.

[Examples]

According to the invention it is provided that during the Farbeinlaufvorganges the compactor of the inking unit at least once disconnected and then again - by switching off the compactor separation - is closed. For a colorless, i. previously emptied by washing inking can be provided that initially the Farbdosierelemente to a uniform Position are raised, the lifter is hired, i. Run a certain number of bars and then again is turned off to the entire inking unit with a predetermined To fill amount of paint. Then it would be at this Embodiment of the invention, the inking separation turned on are, i. the roller of the inking unit would the designated places by the associated actuating means to be interrupted. This is followed by the setting the color dosing on the for the future print job provided profile, i. it comes that in prepress or by template scanning determined zonal profile for Attitude. Before the ink separation is suspended The jack is turned on a few cylinder turns. To Canceling the inking separation then begins the printing process.

Further education can be provided that after switching on the Inking unit separation (compactor interrupted) of the lift is, i. depending on the area coverage of the In the future print job, the lifter will be a metered number Let the clocks go. Then the jack is turned off again. So you get the subject of the future print job adapted filling of the upper part of the inking unit. The number of lifter strokes and machine revolutions exactly matched to the subject of the future new print job, so can in the upper part of the inking already a the later production exactly adapted layer thickness gradient be achieved.

Was the inking unit not washed and should the new print job executed in this printing unit with the same color be, so the present invention provides that in the end the previous print job already the inking unit separation is turned on. Then the closing of the Ink metering elements. The lifter is a certain Number of bars run so that the upper part of the Ink unit emptied by the resulting color return. Then the Farbdosierelemente on the for the next print job provided profile set, for example to the default values according to prepress or Printing form scanning. Some cylinder revolutions before printing the jack is turned off. Before the start of printing then the inking separation is canceled, i. the broken one Compactor is closed again. Then the Printing operation by adjusting the inking rollers and Place the blanket cylinder against the printing block cylinder.

The present invention is applicable to an inking unit, which has at least one inking separation, i. of the Compactor of the inking unit is in at least one place associated adjusting means interruptible. Indicates the inking unit several, in color flow direction successively arranged separation points on, it can be by applying the invention a achieve even more differentiated color layer thickness graduation. It would then at fully parked inking separation the inking unit with an average amount of ink filled and then the first (lowest) inking unit separation switched on. Thereupon would then over further Hebertakte and corresponding Dosierelementeeinstellungen a color amount introduced into the inking unit above this inking unit separation. This newly added amount of color adds up the already existing ink layer thickness, so that the ink layer thickness in this section of the inking unit is now higher as comprising in the lower and in particular the applicator rollers Inking part. Then the next inking unit separation turned on and turn the color inking parts located above it filled with a given amount of ink, which is through a corresponding number of Hebertakten takes place. this will as long as continued, by switching all existing Inking separations are desired in the direction of color flow Grading of the ink layer thicknesses on the individual inking rollers or the individual sections of the ink train has set.

Regardless of whether the procedure according to the invention a previously washed or not washed, i. so already filled with color from the previous print job Apply method, a paint layer thickness distribution produced in the lower and in particular the applicator rollers comprehensive part of the inking unit one of the proportion of printing Area of future print job almost independent Layer thickness produced, whereas in the upper, the Farbdosierelementen facing parts of the inking unit a layer thickness is generated, which depends on the color requirement the printing form (subject - proportion of printing area) selected can be. Such a layer thickness gradient arises also during the continuous printing, so that the invention a very differentiated adaptation to the color flow situation of the Continued printing allows. Waste is thereby largely avoided.

Fig. 1 bis 6

ein Farbwerk mit Farbwerktrennung und auf den Farbwerkwalzen befindlichen Farbschichtdicken, und

Fig. 7

eine das erfindungsgemäße Verfahren ausführende Steuerung in Verbindung mit einem Farbwerk.

Furthermore, the explanation of embodiments of the invention with reference to the drawings. It shows:

Fig. 1 to 6

an inking unit with inking unit separation and located on the inking unit rollers ink layer thicknesses, and

Fig. 7

an executing the process according to the invention control in conjunction with an inking unit.

Fig. 7 shows an inking unit, in which of a color box. 1 Paint over a ink fountain roller 2, a squeegee roller 3 dem Upper part 4 of an inking unit is supplied. With the Ink fountain roller 2 act on the underside of the ink fountain. 1 attached dosing together, which by a controller 16 are actuated via associated adjusting means 11. The Release, or the blocking of the movement of the lifter 3 takes place on the part of the controller 16 via adjusting means 12.

About the rollers of the upper inking unit 4 passes the color over a total of two compactors to those with the printing forme cylinder 9 cooperating application rollers. In the direction of rotation of Printing form cylinder 9 is in the lower part 6 of the inking unit Dampening unit 7 assigned.

As indicated by the double arrows, the upper part 4 of the inking unit from the lower part 6 of the inking unit by a total of two Farbwalzentrennungen 5 separable. The inking unit separation 5 is assigned by associated actuating means 13 on the part of Control 16 can be actuated. In the example shown is the Upper part 4 of the inking unit over a total of two rollers connected to the lower part 6 of the inking unit, so that the Separating upper and lower inking units 4, 6 by two Inking units 5 in both sub-strands at the same height he follows.

The penultimate with the last applicator roller connecting Bridge roller is associated with a washing device 8, through which absorbs the paint on this roller and so the entire compactor of the upper and lower inking unit 4, 6 can be cleaned. Also the washing device 8 are on the part of the controller 16 via associated actuating means 14th actuated. Ultimately, 16 are on the part of the controller Adjusting means 15, the application rollers of the lower inking unit 6, the dampening unit 7 and the pressure cylinder 9, 10 switchable, i.e. the corresponding rollers / cylinders can be turned off.

FIG. 1 shows the color flow situation in the inking unit 1 - 6 during the pressure, i. the applicator rollers of the lower inking unit part 6 are employed on the printing form cylinder 9, the Printing cylinder 9, 10 are connected to pressure, the Inking unit 5 is switched off. As indicated point the upper inking rollers 2, 3, 4 a higher layer thickness on as the rollers of the lower inking unit 6. The layer thicknesses in the upper part 4 of the inking depend on the subject from, i. the proportion of printing area on the plate cylinder 9. In the lower part of the inking unit 6 there is a largely independent color layer thickness from the subject.

Starting from an empty, i. for example by the Washing device 8 cleaned inking 1 - 6 is this now pre-filled with parked inking rollers with paint become. For this purpose, the lifter 3 between ink fountain roller 2 and the first distributor roller of the upper inking unit 4 is switched on, the Farbdosierelemente of the ink fountain 1 take a predetermined defined position to the ink fountain roller 2 a (Fig. 2).

After a few machine revolutions, the in Figure 3 indicated situation, i. all rolls of the Inking units 1 - 6 have a certain ink layer thickness. The number of revolutions of the machine, the setting of the ink metering elements on the ink fountain 1 and the number of lifter strokes 3 is chosen (empirically or by model calculation), that the ink layer thickness assumes the desired value.

Starting from the situation according to FIG. 3, after reaching the desired ink layer thickness on all rolls of upper and lower inking unit 4, 6 the inking unit separation 5 switched, i. the compactor at the intended places under smelled. This situation is shown in FIG. 4.

By further running the lifter 3 and setting the Color dosing on color box 1 on intended values (In particular, the intended for the intended print job Profile), the upper inking unit part 4 is filled with color, so that there is a largely the subsequent production conditions corresponding color layer thickness sets. These Situation shows Figure 5.

Then, the upper part 4 of the inking unit by switching off the inking unit separation 5 with the lower part 6 of the inking unit connected, which is shown in Figure 6. After hiring the Ink application rollers of the lower part 6 of the inking unit to the Printing form cylinder 9 - the situation arises as in FIG 1 - the pressure can begin.

When converting from a completed order to a new job the inking unit 1 - 6 not washed or completely emptied, it is according to one embodiment of the Invention provided that after stopping the inking rollers from the plate cylinder 9 (Figure 1 → Figure 6) simultaneously also the inking unit separation 5 is switched. So now is through Closing the paint dosing in color box 1 and on Lift 3 the upper part 4 of the inking unit emptied, so that the ink layer thickness - as indicated in Figure 6 - in degraded upper inking unit 4 - as shown in Figure 5 - can be. Then, the filling of the upper part of the Ink unit 4 by setting a designated color profile at the color box 1 as well as operating the jack 3. After the in the upper inking unit 4 the ink rollers the intended layer thickness by switching the ink fountain 5 of the separation Color flow closed and the applicator rollers can (as in Figure 1 shown) are employed on the printing form cylinder 9.

[REFERENCE LIST]

1

paintbox

2

Ink fountain roller

3

lifter

4

Inking unit (upper part)

5

Inking separation

6

Inking unit (lower part)

7

dampening

8th

Washing device (inking unit 1 - 6)

9

Plate cylinder

10

Blanket cylinder

11

Adjusting agent (Farbdosierelemente color box 1)

12

Adjusting means (lifting roller 3)

13

Adjusting means (inking unit separation 5)

14

Adjusting agent (washing device 8)

15

Adjusting agent (inking rollers, dampening unit 7, printing forme cylinder 9, blanket cylinder 10)

16

control

Claims (6)

1. Process for generating a layer thickness distribution in the inking unit of a printing press, particularly an offset sheet printing press, in which, during a run-up process with the press running and with ink applicator rollers set off from the forme cylinder, ink is fed via ink metering elements cooperating with an ink fountain roller and a driven ductor roller into the inking unit, characterised in that during the run-up process, the roller train of the inking unit is interrupted at least intermittently by an inking unit separation.
2. Process according to Claim 1, characterised in that, with the empty inking unit, first a preset quantity of ink is fed into the inking unit, that the roller train is interrupted by means of the inking unit separation, that thereafter the upper part of the inking unit turned towards the ink fountain roller is filled with an additional quantity of ink, and that, after the connection of the roller train by means of the inking unit separation, the printing starts.
3. Process according to Claim 1, characterised in that in the case of an inking unit filled with ink from a preceding print order, the roller train is interrupted by the inking unit separation, that the upper portion of the inking unit after feeding away of the printing ink is filled with a preset quantity of ink corresponding to the print order to be carried out and that, after connecting the roller train by the inking unit separation, the print is started.
4. Process according to Claim 1, 2 or 3, characterised in that the quantity of ink introduced with the roller train interrupted by means of the inking unit separation is carried out with a preset adjustment of the ink metering elements for the print order to be carried out.
5. Process according to Claim 3, characterised in that the feeding away of printing ink takes place by closure of the metering elements with the ductor running.
6. Device for generating an ink layer thickness distribution in the inking unit of a printing press, particularly an offset printing press, with an ink fountain roller, with metering elements cooperating with the ink fountain roller, a ductor roller, a roller train which can be separated by means of an inking unit separation, with ink applicator rollers cooperating with the print forme cylinder and which can be set against and away from this as well as a control which, by means of adjusting means, is connected with the ink metering elements, the ductor, the inking unit separation, the applicator rollers as well as the printing unit cylinders, for carrying out the process according to Claim 1, characterised in that by means of the control (16) during ink running in, the inking unit separation (5) can be at least actuated intermittently.

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