DE102008006192A1 - Printing machine i.e. printer, operating method for examining and adjusting contact zone, involves measuring contact strips printed on print substrate, where measured values provide actual values of contact zone - Google Patents

Abstract

The method involves providing a printing unit (1) with a printing-ready inking system. An application roller (7), whose contact zone along a form cylinder (4) is to be examined, is stopped at the form cylinder for a given time interval. Contact strips are printed on a print substrate in the printing unit. The substrate is moved through a column formed between a transfer cylinder (5) and an impression cylinder (6). The contact strips printed on the substrate are measured, where the measured values provide actual values of the contact zone between the form cylinder and the application roller.

Description

The The invention relates to a method for operating a printing press.

A Printing machine has one Variety of printing units to a substrate with a desired Print image to print. A printing unit of a printing press has beside a forme cylinder, a transfer cylinder rolling on the forme cylinder and one on the transfer cylinder unwinding impression cylinder continues via an inking unit and optionally a Dampening unit, wherein the so-called inking rollers of the inking unit and optionally the so-called dampening roller of the dampening unit Roll on the forme cylinder to print ink and if necessary Dampening solution positioned on at least one on the forme cylinder Apply printing form. The so applied to the or each printing form Printing ink is using at least one on the transfer cylinder positioned transmission form transferred to the substrate, by one between the transfer cylinder and the impression cylinder formed pressure gap moves through becomes.

The ink transfer in a printing on the or each positioned on the form cylinder printing plate is decisive from the contact zone between the forme cylinder and the or each on the form cylinder rolling applicator roll, namely the or each inking roller and optionally the or each dampening roller, depending. The Contact zone is when commissioning a printing machine by the commissioning staff set. Due to different influences such. B. thermal deformation and / or chemically induced change and / or wear-related Diameter reduction can over it the life of a printing press to change the contact zones between the forme cylinder and the applicator rollers rolling on the forme cylinder come.

hereby can causes sensitive fluctuations in the ink-dampening solution balance which ultimately affect print quality and the printing process. It is therefore important, the contact zone between the forme cylinder and to check the rolling on the form cylinder applicator rollers and if necessary, to cease upon detection of impermissible deviations. So far, no methods are known which such a review and optionally adjustment of the contact zones between the forme cylinder and the rolling on the form cylinder applicator rollers for a Enable printers easily and reproducibly.

Of these, Based on the present invention, the problem is based to provide a novel method of operating a printing press. This problem is solved by the method according to claim 1. The inventive method comprises at least the following, preferably automated Steps: a) first a printing unit is provided with a ready-to-print inking unit, however, there is an ink-dampening solution balance of the printing unit so disturbed is that the or each on the form cylinder positioned printing form continuously Takes ink or leads; b) subsequently is at least one applicator roll whose contact zone are checked for form cylinder should, to the form cylinder for hired a predetermined period of time and turned off again; c) Subsequently, a substrate in the printing unit is characterized by at least printed on a contact strip that the substrate by a between a rolling on the forme cylinder transfer cylinder and a on the transfer cylinder rolling counter-pressure cylinder formed pressure gap or through one between the forme cylinder and a rolling on the forme cylinder Counter-pressure cylinder trained pressure gap is moved through; d) subsequently the or each printed on the substrate contact strip is measured, wherein measured values determined here are actual values over the or each to be measured Provide contact zone.

The this invention proposes a simple and automated method for measuring and checking a Contact zone between a forme cylinder of a printing unit and at least one on the form cylinder rolling applicator roller before. This is a quick, easy and reproducible recording of the actual state of contact zones in all printing units of a printing machine at the same time possible. After adjustment of actual values of the contact zones with setpoints about that In addition, an automated adjustment of the contact zones possible, wherein the risk of incorrect settings is minimal.

preferred Further developments of the invention will become apparent from the dependent claims and the following description. Embodiments of the invention without being limited to this to be closer to the drawing explained.

there shows:

1 : A schematic representation of a Duckwerks a printing machine to illustrate a preferred embodiment of the method according to the invention.

The invention relates to a method for operating a printing press, namely for checking and optionally setting a contact zone between a forme cylinder of a printing unit and at least one applicator roll rolling on the forme cylinder in the printing operation. The invention will be described below with reference to 1 described in detail, wherein 1 a schematic representation of a printing unit 1 shows which next to an inking unit 2 and a dampening unit 3 continue a form cylinder 4 , a transfer cylinder 5 and an impression cylinder 6 includes. In the printing of the 1 it is an offset printing unit of an offset sheetfed press.

The inking unit 2 includes a plurality of rollers, wherein on the forme cylinder 4 or on at least one on the forme cylinder 4 arranged printing form rolling inking rollers of the inking unit 2 with the reference number 7 Marked are.

In the embodiment of 1 includes the inking unit 2 four inking rollers 7 , The dampening unit 3 includes one on the forme cylinder 4 or on the or each positioned on the form cylinder printing form rolling dampening roller 8th ,

With the help of the inking unit 2 becomes printing ink and with the help of dampening 3 Dampening solution on the or each on the form cylinder 4 Placed printed form, wherein the transfer of ink and fountain solution on the or each on the forme cylinder 4 Positioned printing form significantly from the contact zones between the forme cylinder 4 and the inking rollers 7 as well as the dampening roller 8th is determined.

For checking contact zones between the forme cylinder 4 and at least one applicator roll 7 respectively. 8th first becomes a printing unit 1 with a printable inking unit 2 provided, but a printing ink fountain solution balance of the printing unit is disturbed such that the or each on the forme cylinder 4 Positioned printing form continuously accepts ink or leads. Such a printing unit can, for. B. be provided by an ongoing printing process is terminated by the supply of ink in the respective printing unit on the inking unit 2 and the supply of dampening solution through the dampening unit 3 stopped and the applicator rollers 7 . 8th from the form cylinder 4 be turned off, so that on the applicator rollers 7 . 8th with evaporated dampening solution printing ink but no dampening solution and / or on the or each on the forme cylinder 4 Positioned printing form is no longer dampening solution.

Subsequently, on such a printing ready printing unit 1 at least one applicator roll 7 respectively. 8th , whose contact zone to the forme cylinder 4 should be checked, to the form cylinder 4 for a predetermined period of time and then turned off again. By such hiring the or each applicator roll 7 respectively. 8th to the form cylinder 4 can be imaged a contact strip, for which purpose a substrate in the printing unit is thereby printed with at least one such contact strip, that the printing material through the tragungszylinder between the over 5 and the impression cylinder 6 trained pressure gap is moved through.

Before starting and stopping the or each applicator roller 7 respectively. 8th to the form cylinder 4 and prior to printing a substrate having at least one contact strip, the or each one on the form cylinder 4 positioned printing form to be washed or cleaned, in which case over the entire axial width of the forme cylinder 4 and thus the printing substrate corresponding contact strips can be printed on the substrate. Such washing or cleaning of the or each on the forme cylinder 4 Positioned printing form is purely optional. So even without appropriate cleaning or washing the or each on the forme cylinder 4 positioned printing form contact strips are printed on the substrate, depending on whether printed with the or each printing form solid surfaces or Rastertonflächen extend in sections or even completely over the axial width of the substrate.

In connection with the method according to the invention are therefore by the defined hiring and stopping the application rollers 7 and 8th transferred on the or each printing form generated contact strip on a substrate. The printed on the substrate contact strips are from the contact zone between the forme cylinder 4 and the applicator rollers 7 and 8th dependent. A printing material printed in this way with at least one contact strip is then metrologically evaluated by measuring the or each contact strip printed on the printing material, whereby measured values determined here are actual values over the or each contact zone to be measured between the form cylinder 4 and applicator roller 7 respectively. 8th deliver.

To A first development of the present invention is the substrate by means of a positioned outside the printing machine measuring device offline for printing the same with the or each contact strip measured, in which case a one-dimensional measuring system, preferably a two dimensional measuring system is used. The measuring principle the measuring device used can be farbdensitometrisch or based on other measuring principles.

According to an alternative, preferred development of the present invention, the measurement of the or each contact strip is done with Hil fe an integrated into the printing machine measuring device online for printing the substrate with the or each contact strip, which due to the known, printing unit specific distribution of the contact zones each printed on the substrate contact strip clearly a contact zone between the forme cylinder 4 and one of the applicator rollers 7 respectively. 8th can be assigned.

The Measuring the contact strip can be at least in one place the same, better on at least two steles of the same Detection of an inclination the contact strip, up to a quasi-continuous measurement the contact strip over the entire format width of the same to the contact strip shape to capture.

In the above measurement of the contact strips on the printed substrate actual values over the width and / or the inclination and / or the shape of the or each contact strip to be measured and thus corresponding actual values of the respective contact zone are obtained. Then, if the measured actual width of the contact strip as a whole is too large or too small, it can be concluded that a faulty Beistellung the corresponding applicator roll, then on both sides of a uniform Beistellungskorrektur is necessary. Then, if the measurement results in an inclination of a contact strip to be measured, a one-sided adjustment correction on one side of the respective applicator roll is required. By actual measurement values of the strip shape of the respective contact strip to be measured, swelling or shrinkage of the respective applicator roll can be determined 7 respectively. 8th be closed, in which case, when the strip shape corresponds to a so-called cigar shape, can be closed on a swelling, and wherein when the vermes send contact strip has a trumpet shape, a shrinkage of the respective applicator roller can be closed.

at the measurement of printed on the substrate contact strip obtained actual values are compared with corresponding nominal values, where according to an advantageous embodiment of the invention from this either Automatically by a printer to carry out suggestions for adjusting the respective contact zone or control signals for automatic adjustment the respective contact zone are generated.

Then, if automatically for to run a printer proposals be generated to adapt the respective contact zone these suggestions z. B. on a display of the printing press or at the control center of the same displayed so that a printer can execute these suggestions specifically.

The above visualization for a printer can be displayed on the printing unit or on the control console of the press or monitors or LEDs or the like. Farther can a Einstelldokumentierung the respective contact zones over a Logbook, a regular invitation to Control of the respective contact zones via the control room or even a fully automatic, over values stored in the control room were checked for the respective Contact zones take place.

at a production changeover of, for example, conventional printing on UV pressure can after a start and after a number × arc or a number × operating hours a control of the respective contact zones are triggered. As a result, process protection can be optimized for the purpose of increased print quality become.

Then, however, when control signals are generated for automatic adjustment of the respective contact zone, the control signals are automatically transmitted to at least one of the respective applicator roller associated adjustment, then automatically order the corresponding applicator roll 7 respectively. 8th adapt.

If after change the roll settings or Walzenbeistellungen the applicator roll for Adjustment of the contact zones a repeat measurement desired or is required, can subsequently the printing material are printed, in which case preferably the printing press independently a cylinder position for hiring the applicator rollers selects such that the cylinder positions from the previously selected cylinder positions sufficient deviates, so that it is avoided when transferring the contact strips on the transmission form and thus ultimately the printing material to an overlap the roll strip or contact strip comes.

As already stated above, a swelling and / or shrinkage of the application rollers can be recorded and displayed via the evaluation of the strip shape of the printed contact strips. This is particularly useful in machines with so-called alternating operation between conventional and radiation-curing paint systems. In this way, an estimate of the short-term, medium-term and long-term changes in the materials of the applicator rolls can be realized. For this purpose, only changes in the roll jobs must be detected and acknowledged with a final measurement, so that any change in width and / or inclination and / or shape of the contact strip the corresponding cause such. B. roll adjustment or swelling or shrinkage can be assigned. There may also be manual misadjustments of the applicator rollers or mechanical errors such as B. component failure, wear of attacks and / or guides or the like can be detected.

Especially in conjunction with an integrated in the sheet-fed press measuring device a fully automatic review and Adjustment of the contact zones between the forme cylinder and the applicator rollers realizable.

The inventive method can also be used for printing units without transfer cylinders, z. B. in flexographic printing, are used, in which case the nip between the forme cylinder and a rolling on the forme cylinder Counter-pressure cylinder formed and the applicator roll as an anilox roller is trained.

1

printing unit

2

inking

3

dampening

4

form cylinder

5

transfer cylinder

6

form cylinder

7

Inking roller

8th

Dampener roller

Claims (9)

Method for operating a printing machine, namely to check and optionally setting a contact zone between a forme cylinder a printing unit and at least one on the forme cylinder in the printing operation Rolling Aufwalwalze, namely at least one inking roller and / or dampening roller, with at least the following, preferably automated, steps: a) first a printing unit is provided with a ready-to-print inking unit, however, there is an ink-dampening solution balance of the printing unit so disturbed is that the or each on the form cylinder positioned printing form continuous printing ink takes or leads; b) subsequently is at least one applicator roll whose contact zone are checked for form cylinder should, to the form cylinder for hired a predetermined period of time and turned off again; c) Subsequently, a substrate in the printing unit is characterized by at least printed on a contact strip that the substrate by a between a rolling on the forme cylinder transfer cylinder and a on the transfer cylinder rolling counter-pressure cylinder formed pressure gap or through one between the forme cylinder and a rolling on the forme cylinder Counter-pressure cylinder trained pressure gap is moved through; d) subsequently becomes the or each printed on the substrate contact strip measured, whereby thereby determined measured values actual values over the or provide each contact zone to be measured. Method according to claim 1, characterized in that that in step a) an ongoing printing process is terminated by that in the respective printing unit, the supply of ink and fountain solution stopped and the or each applicator roller off the form cylinder so that it evaporates on the or each applicator roll Dampening solution printing ink is located. Method according to claim 2, characterized in that that after step a) and before step b) the or each on the forme cylinder positioned printing form is washed or cleaned. Method according to one of claims 1 to 3, characterized in step d), measuring the or each contact strip with the help of an outside the press positioned measuring device offline for printing of the printing material with the or each contact strip. Method according to one of claims 1 to 3, characterized in step d), measuring the or each contact strip with the help of a measuring device integrated in the printing machine online for printing the substrate with the or each contact strip he follows. Method according to one of claims 1 to 5, characterized that in step d) actual values over the width and / or the inclination and / or the shape of the or each contact strip to be measured and thus actual values of the or each contact zone are obtained. Method according to one of claims 1 to 6, characterized that in step d) obtained actual values with corresponding setpoints being compared either automatically from one Printer to be executed proposals for adaptation of the respective contact zone or control signals for automatic Adjustment of the respective contact zone are generated. Method according to claim 7, characterized in that that in this case to be carried out by a printer proposals for change the roller adjustment of at least one roller, in particular the respective Application roller, the inking unit and / or dampening automatically generated become. A method according to claim 7, characterized in that in this case control signals for automatically changing the roll adjustment of at least one roller, in particular the respective Auftragwal ze, the inking unit and / or dampening automatically generated and provided on the respective roller associated adjustment.