DE102018209345A1 - A method of setting up a perimeter register of a print job in a multi-color press - Google Patents

Abstract

The invention describes a method for setting up a circumferential register of a print job in a multi-color printing press with a first and at least one second printing cylinder, the method comprising the steps:
a) inserting the printing cylinders in printing units, b) positioning the printing cylinders in the circumferential direction using a positioning mark on the printing cylinder, c) printing a printing mark located on the first printing cylinder seen in the direction of transport of a material web, d) scanning the printing mark in at least one second printing unit , in which the at least one second printing cylinder is inserted, by means of a printing mark sensor, e) adjusting the at least one second printing cylinder in the circumferential direction on the basis of geometric data of the printing unit and the time at which the print mark sensor scans the print mark, so that a register mark of the at least one second printing cylinder lies in a capture area of the print mark sensor.

Description

The invention relates to a method for setting up a peripheral register of a print job in a printing press and to a rotary printing press.

In order to process print jobs in rotary printing presses, in particular multi-stand presses, such as multi-turn printing presses, it is necessary to set the individual printing cylinders in such a way that they are in register with each other in the continuous printing. This means that the printing cylinders in the individual printing units must be in a fixed phase relation to each other. This is the only way to ensure that the printed images, which are composed of individual colors, which are each printed by a printing cylinder, also have the desired appearance.

In particular, at the beginning of a print job, it takes a certain amount of time to find the phase position mentioned. Most of the time, material to be printed is also consumed, so that waste occurs. In addition, finding the phase position often requires manual intervention.

The object of the present invention is therefore to propose a method and a rotary printing press which avoid or at least reduce at least some of the disadvantages mentioned.

According to the invention this object is achieved by all features of claim 1. In the dependent claims, possible embodiments of the invention are given.

1. a) Einsetzen der Druckzylinder in Druckwerke
2. b) Positionieren der Druckzylinder in Umfangsrichtung anhand einer an dem Druckzylinder befindlichen Positioniermarke
3. c) Drucken einer sich auf dem in Transportrichtung einer Materialbahn gesehen ersten Druckzylinder befindlichen Druckmarke
4. d) Abtasten der Druckmarke in zumindest einem zweiten Druckwerk, in welchem der mindestens eine zweite Druckzylinder eingesetzt ist, durch einen Druckmarkensensor
5. e) Einstellen des zumindest einen zweiten Druckzylinders in Umfangsrichtung anhand von geometrischen Daten des Druckwerks und dem Zeitpunkt, an dem der Druckmarkensensor die Druckmarke abtastet, so dass eine Registermarke des zumindest einen zweiten Druckzylinders in einem Fangbereich des Druckmarkensensors liegt.

According to the present invention, it is provided that the method according to the invention for establishing a circumferential register of a print job in a printing press with a first and at least one second printing cylinder comprises the following steps:

1. a) insertion of the printing cylinder in printing units
2. b) Positioning the impression cylinder in the circumferential direction by means of a located on the printing cylinder positioning mark
3. c) printing a located on the transport direction in the direction of a web of material located first printing cylinder located print mark
4. d) scanning the print mark in at least one second printing unit, in which the at least one second printing cylinder is inserted, by a print mark sensor
5. e) adjusting the at least one second printing cylinder in the circumferential direction on the basis of geometric data of the printing unit and the time at which the print mark sensor scans the print mark, so that a register mark of the at least one second printing cylinder is located in a capture range of the print mark sensor.

In order to start a print job, the printing cylinders provided with the individual print images must first be inserted into the individual printing units. The printing units also include counter-pressure rollers or cylinders over which the material web runs. Later, printing cylinder and / or counter-pressure roller are adjusted relative to one another, so that they can be brought from a non-printing arrangement into a printing arrangement in which the pressure roller contacts the material web and thus transfers printing ink. Of course, the reverse adjustment (from printing to non-printing) is provided.

In a method according to the invention, each printing cylinder comprises a positioning mark with which the printing cylinder can be or is positioned relative to the machine frame of the printing unit. The positioning mark has a fixed position relative to the one printing image of the respective printing cylinder, so that after the positioning of the printing cylinder, the printing image also assumes a fixed position relative to the machine frame. The position of the positioning mark relative to the print image is preferably the same for all printing cylinders of a print job. A positioning sensor is provided for recognizing the respective positioning mark. After insertion and connection to a drive, the printing cylinder is preferably rotated at least until the positioning sensor detects the positioning mark. It is advantageous that no print image has to be generated to carry out the step, i. that is, waste is saved. If one were to rely on the positioning of the individual print images on the printing unit side, the viewer would notice that even with a known path length of the material web between the printing units, the printing does not take place in register. The reason for this is that a material web can shorten or lengthen due to various influences (temperature, elasticity, web tension), especially in acceleration and deceleration phases. This influence is now at least partially compensated for by the method steps described below.

In a further step, the imprint of a print mark located on the first impression cylinder seen in the transport direction of a material web is now applied to the material web. This print mark is preferably a unique and different from other print marks initial print mark, which is provided only in or on the first printing cylinder of a print job.

In a following step, the web is now transported through the other printing units, wherein in each additional existing printing unit, a print mark sensor scans this print mark. From the time at which the print mark sensor detects the print mark, and from the web speed can now determine the effective web path between the first impression cylinder and the respective print mark sensor. Since the print mark sensor occupies a known or at least easily determinable distance to the printing cylinder, can be calculated back to the effective web path between the first printing cylinder and the pressure cylinder under consideration, to which the respective print mark sensor is assigned. Accordingly, the phase position of the printing cylinder under consideration can now be set, so that then both cylinders print the printed images on top of each other in register.

The time that is required to carry out the method according to the invention is essentially limited to the passage of the first print mark through all printing units.

It is particularly advantageous if the at least one second printing unit is in a non-printing arrangement. In this case, the printing material is not printed, so that no waste accumulates. Thus, even the direction of movement of the material web can first be reversed in order to be able to guide it backwards. Since, in accordance with the method according to the invention, the printing units are adjusted relative to one another in their phase position, the already traversed material web section can thus be printed. Thus, not only no waste is generated, but the already used material web section immediately recycled. In particular, in a series gravure printing machine, the counter-pressure cylinder is often moved relative to the pressure roller, so that the distance between the counter-pressure cylinder and the pressure cylinder is received to calculate the effective web path.

In a further advantageous embodiment of the invention, it is provided that the positioning mark is recognized optically, magnetically and / or electrically. Accordingly, the positioning sensor is configured, d. h., He can detect an optical contrast and / or a magnetic and / or electric field. The position mark can be arranged on the outer circumference of the printing cylinder or on one of the end faces. In particular, a magnetically and / or electrically recognizable positioning mark is insensitive to contamination, which can be caused for example by printing ink. Of course, this embodiment of the invention also includes corresponding sensors that can detect such position marks, ie an optical sensor, a magnetic sensor and / or an electrical sensor.

In a further advantageous embodiment of the invention, it is provided that the positioning mark comprises at least one of the following components: bar code, QR code, magnet, electronic chip, engraving in the printing cylinder, raised body with respect to the surface of the printing cylinder. A barcode or a QR code are optically detectable positioning marks that can be read out with an optical scanner. A magnet may be a small body of magnetic material, which may for example be inserted into a bore of the printing cylinder. For detection of this magnet then a simple magnetic sensor is sufficient. An electronic chip, in contrast, can provide an electric field, which can be evaluated by an electronic sensor. In particular, an electronic chip, as well as a magnet, may be configured to provide further information about the printing cylinder. Such a chip may in particular be an RFID chip. A positioning mark may also include an engraving in the printing cylinder, which in turn is recognizable by an optical sensor. Also conceivable is a body which is raised in relation to the surface of the printing cylinder and which can be identified either with an optical sensor or a sensor which scans the surface of the cylinder. A scanning sensor can be deflected when it hits the body. This deflection can be detected in a suitable manner.

The method according to the invention can be supplemented particularly advantageously if, in addition, a step f) is carried out in which the register of the individual impression cylinders is adjusted to one another and / or regulated. In this way, it is ensured in the course of the processing of the print job that no or only tolerable deviations from the register arise. The setting of the register is carried out using register marks, which are preferably printed during printing and whose positions are recognized in the print image using the print mark sensors. In case of deviations of these positions compared to positions of the print marks, a correction of the position of the respective printing cylinder in the circumferential direction and / or in the axial direction of the printing cylinder takes place. The register marks are arranged in all printing cylinders belonging to the print job in a fixed positional relationship to the positioning marks. In the first printing unit seen in the direction of transport of the material web, the register mark additionally has a defined or known positional relationship to the print mark. It should be emphasized that the print mark and the register mark of this first cylinder differ from each other in terms of position and / or appearance, so that a confusion is to be excluded. Thus, the print mark sensors can be automatically adjusted to the position on which the register marks on the material web are to be expected. With the position relationships can thus be started directly after the implementation of the method described above with the good production and also the monitoring or improvement of the register, without requiring further intervention.

A further, preferred embodiment of the invention includes that the current state of the printing press and / or the current state of the method and / or at least one error message is displayed by means of a display device. A display device is, for example, a monitor in the area of the operating unit of the printing press. However, the information can also be displayed on mobile devices that are in any way in data contact with the printing press. With regard to the current status of the method, it can be displayed, for example, how much the method according to the invention will still need to complete.

In a further embodiment, it is provided that, in the event of an error message, it is indicated in which printing unit the error occurred and / or which type of error is present. It is thus possible, for example, to indicate to a machine operator if the print mark has not been recognized by a print mark sensor in a printing unit. This is because, based on the machine speed prevailing when the method is carried out, the point in time at which the print mark would have to be recognized can be approximately determined. However, if the print mark has not been recognized, this indicates an error. The same applies if a subsequent print mark sensor has already recognized the print mark. An error message can mean, for example, that a print mark sensor has a defect and / or is positioned incorrectly in relation to the printing cylinder. The machine operator can also be shown a list of various causes to be checked. This ensures that the print job is also completed in full and, above all, in the desired quality.

The method described above can be used particularly advantageously if a plastic web is printed with the print job. A plastic sheet has a great elasticity, which may even be temperature dependent. This prevents the print cylinder from being positioned directly based on the positioning marks. Thus, the inventive method in combination with a plastic sheet offers particular advantages.

• - einem ersten und zumindest einem zweiten Druckzylinder,
• - einem ersten und zumindest einem zweiten Druckwerk, in welche der jeweilige Druckzylinder einsetzbar ist
• - einem Druckmarkensensor in dem zumindest einem zweiten Druckwerk zum Abtasten von auf einem Bedruckstoff aufgedruckten Druckmarken
• - einem Positioniersensor in jedem Druckwerk zum Abtasten einer Positioniermarke eines Druckzylinders
• - einer Auswerte- und Steuereinrichtung, mit welcher Daten des Druckmarkensensors und/oder der Positioniersensoren empfangbar und welcher Antriebe der Druckzylinder zum Einstellen der Umfangspositionen der Druckzylinder ansteuerbar sind.

The object mentioned at the beginning is also solved by a multi-color printing machine for carrying out a method according to one of claims 1 to 9

• a first and at least a second impression cylinder,
• - A first and at least a second printing unit, in which the respective pressure cylinder is used
• a print mark sensor in the at least one second printing unit for scanning printed marks printed on a printing material
• a positioning sensor in each printing unit for scanning a positioning mark of a printing cylinder
• - An evaluation and control device, with which data of the print mark sensor and / or the positioning sensors receivable and which drives the printing cylinder for setting the circumferential positions of the impression cylinder can be controlled.

Thus, the same advantages are achieved, which have already been described in connection with the method according to the invention.

• 1 Schematische Darstellung einer Druckmaschine nach dem Einsetzen der Druckzylinder
• 2 Schematische Darstellung einer Druckmaschine nach der Positionierung der Druckzylinder anhand von Positioniermarken
• 3 Schematische Darstellung einer Druckmaschine nach der registerhaltigen der Druckzylinder in Umfangsrichtung

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the figures, various embodiments are explained in detail. The features mentioned in the claims and in the description may each be essential to the invention individually or for any combination of mentioned features. Within the scope of the entire disclosure, features and details described in connection with the method according to the invention apply, of course also in connection with the printing press according to the invention and in each case vice versa, so that reciprocal reference is always made to the disclosure of the individual aspects of the invention can. The individual figures show:

• 1 Schematic representation of a printing machine after insertion of the printing cylinder
• 2 Schematic representation of a printing machine after the positioning of the printing cylinder by means of positioning marks
• 3 Schematic representation of a printing press after the register-containing pressure cylinder in the circumferential direction

The figures show schematic representations of a printing press for performing the inventive method. In the 1 is the printing press 100 to recognize. This initially includes an unwinding device 101 with which a material web 102 is made available. This is done over different rollers 103 which can be, for example, transport, deflection, spreader rolls or even entire roll units, such as those used in drying devices, the individual printing units 110 . 120 . 130 fed. The printing unit 110 is in the direction of transport T seen the web of material, the first printing unit that has special properties, which will be discussed below. Three printing units can be seen, but of course a printing machine according to the invention can comprise any number of printing units. However, it is also possible that not all existing printing units are used in a method according to the invention, because the colors available in a printing press are not necessary for every print job.

Each printing unit includes a printing cylinder 111 . 121 . 131 as well as an impression cylinder 112 . 122 . 132 , About the impression cylinder is the web 102 led to be printed by the printing cylinder here. In the exemplary embodiment shown, the printing units are gravure printing units of a series gravure printing machine. In such a machine, the printing cylinders in the processing of a print job usually remain stationary in the printing unit frame, not shown, while the impression cylinders are displaceable relative to the printing cylinders, often in the vertical direction to bring the web in contact or out of contact with the printing cylinders.

After printing, the material web is usually a winding device 141 fed in, in which it is wrapped again for easier transport.

In the 1 It can now be seen that the printing cylinders are already used in the respective printing units. Now, the positioning of the impression cylinder takes place by means of positioning marks 113 . 123 . 133 by positioning sensors 114 . 124 . 134 , which are preferably arranged stationary in the respective printing unit, can be detected. In the 1 is based on the printing works 110 and 120 shown that the positioning marks have already been recognized (positioning mark and positioning are directly opposite), whereas this for the printing unit 130 not yet the case. After this has been done for all printing cylinders, the angular positions of the individual printing cylinders are fixed relative to the respective printing unit racks.

In the 2 it can now be seen that all the printing cylinders are now aligned relative to the respective printing unit frame. Furthermore, the impression cylinder 112 of the first printing unit 110 lowered to the web of material 102 in contact with the impression cylinder. It can also be seen that the printing cylinder 111 a print mark 115 carries, which is designed as a depression, for example in gravure printing. This print mark 115 has already been used as a print mark 150 applied to the material web. When transporting the material web 102 runs through the print mark imprint 150 all printing units and thus runs on the print mark sensors 115 . 125 . 135 over, which preferably scan the material web continuously and upon recognition of the print mark impression 150 send a signal to an evaluation and control device, not shown. Based on the transport speed of the material web and the time at which the print mark imprint passes the respective print mark sensor, this calculates the effective path that the material web has either from the time the print mark imprint was printed and / or from the time the print mark imprint was recognized by the print mark sensor of one of the previous printing units at the time of detection by the print mark sensor in the printing unit under consideration. Since the print mark sensors also have defined positions relative to the respective printing unit frame, the evaluation and control unit can now take into account the geometric data of the printing group, which include the installation position of the printing cylinder, the position of the impression cylinder at the time the printing mark is recognized and the angular position of the printing cylinder comprise, now change the angular position of the printing cylinder by means of a control signal, so that the printing images of each cylinder correspond to those of the other cylinders, printing in register then being made possible.

This situation is caused by the 3 clearly, in the now all printing units are in printing position and the print job can be processed. The print mark sensors 115 . 125 and 135 Now work in a known manner as register sensors, which scan not shown, but printed register marks and the evaluation and control unit forward, which sends control signals to the impression cylinder in case of deviations. For a known register control is realized.

The reference numerals, which have been explained with reference to a figure, are usually not shown in the other figures, in order to preserve the clarity. However, the same reference numerals are assigned to the same features.

LIST OF REFERENCE NUMBERS

100

press

101

unwinding

102

web

103

roller

110

printing unit

111

pressure cylinder

112

Impression cylinder

113

positioning marks

114

positioning sensor

115

print mark

120

printing unit

121

pressure cylinder

122

Impression cylinder

123

positioning marks

124

positioning sensor

125

print mark

130

printing unit

131

pressure cylinder

132

Impression cylinder

133

positioning marks

134

positioning sensor

135

Print mark *

141

unwinding

150

Print mark imprint

T

transport direction

Claims (10)

Method for setting up a circumferential register of a print job in a multi-color printing press with a first and at least a second printing cylinder, the method comprising the following steps: a) Inserting the printing cylinders in printing units b) positioning the printing cylinder in the circumferential direction using a positioning mark located on the printing cylinder c) printing a printing mark located on the first printing cylinder as seen in the transport direction of a material web d) scanning the print mark in at least one second printing unit, in which the at least one second print cylinder is inserted, by a print mark sensor e) Setting the at least one second printing cylinder in the circumferential direction on the basis of geometric data of the printing unit and the point in time at which the printing mark sensor scans the printing mark, so that a register mark of the at least one second printing cylinder lies in a catch area of the print mark sensor. Procedure according to Claim 1 , characterized in that the at least one second printing unit is in a non-printing arrangement. Method according to one of the preceding claims, characterized in that the step b) is carried out by means of a positioning sensor with which the positioning mark is scanned. Method according to one of the preceding claims, characterized in that the positioning mark is recognized optically, magnetically and / or electrically. Method according to one of the preceding claims, characterized in that the positioning mark comprises at least one of the following components: • bar code • QR code • magnet • electronic chip • engraving in the printing cylinder • against the surface of the impression cylinder raised body. Method according to one of the preceding claims, characterized in that in addition a step f) is carried out, in which the register of the individual printing cylinders is adjusted to one another and / or regulated. Method according to one of the preceding claims, characterized in that the current state of the printing press and / or the current state of the method and / or at least one error message is displayed by means of a display device. Method according to the preceding claim, characterized in that in the case of an error message is displayed in which printing unit the error has occurred and / or what type of error is present. Method according to the preceding claim, characterized in that the printing job a plastic sheet is printed. Multi-color printing machine for carrying out a method according to one of Claims 1 to 9 With - a first and at least one second printing cylinder, - a first and at least a second printing unit, in which the respective printing cylinder is used - a print mark sensor in the at least one second printing unit for scanning printing marks printed on a printing material - a positioning sensor in each printing unit for scanning a Positioning mark of a printing cylinder - an evaluation and control device, with which data of the print mark sensor and / or the positioning sensors can be received and with which drives the pressure cylinder for setting the circumferential positions of the impression cylinder can be controlled.

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