ES2934104T3 - Method and device for setting up a circumferential register of a print job on a multicolor printing machine - Google Patents

Abstract

The invention describes a method for setting up a circumferential register for a print job on a multicolor printing press (100) having a first and at least one second plate cylinder (111, 121, 131), wherein the method comprises the steps: - a) inserting the plate cylinders in the printing units (110, 120, 130); b) positioning the plate cylinders in the circumferential direction based on a positioning mark (113, 123, 133) located on the plate cylinder; c) printing a printing mark (150) located on the first plate cylinder (111) seen in the direction of transport of a web (102); d) scanning the print mark on at least one second print unit (120, 130), into which at least one second plate cylinder (121, 131) is inserted, by means of a print mark sensor (125 , 135); e) fit at least a second iron cylinder (121, (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Method and device for setting up a circumferential register of a print job on a multicolor printing machine

The invention relates to a method for setting up a circumferential register of a print job on a printing machine and a rotary printing machine.

From DE 102009023963 A1 a printing machine for printing on a paper web is known, in which registration control in production is carried out with the aid of registration marks printed on the paper web and sensors designed as image readers. markings to achieve register printing between the individual printing units of the printing machine.

For print job handling on presses, especially multi-column presses such as in-line gravure, it is necessary to adjust the individual printing cylinders so that they are in register with each other on the production run. This means that the print cylinders of the individual print units must be in a fixed phase position relative to each other. This is the only way to ensure that printed images, which are made up of individual colors printed by one printing cylinder at a time, will look as desired.

Especially at the beginning of a print job, it takes some time to find the phase position. In most cases, this also consumes material for printing, so waste is produced. Also, finding the phase position often requires manual intervention.

Therefore, it is the task of the present invention to propose a method and a rotary printing machine that avoid or at least reduce some of the mentioned drawbacks.

According to the invention, this task is solved by all the features of claim 1. Possible embodiments of the invention are indicated in the dependent claims.

In accordance with the present invention, the method according to the invention for establishing a circumferential register of a print job on a multicolor printing machine having a first and at least a second printing cylinder is provided to comprise the following steps:

a) inserting the printing cylinders into the printing units

b) subsequent positioning of the printing cylinders in the circumferential direction with respect to the frame of the printing unit by means of a positioning mark located on the printing cylinder

c) back printing of a printing mark located on the first impression cylinder seen in the direction of transport of a web of material

d) post-scanning of the print mark on the at least one second print unit, into which the at least one second print cylinder is inserted, by means of a print mark sensor

e) e) Subsequent adjustment of the at least one second printing cylinder in the circumferential direction based on geometric data of the printing unit, which

includes the relative position of the print mark sensor to the frame of the printing unit, the circumference of the print cylinder, the angular position of the print cylinder and the position of the print counter cylinder, and the time when the print mark sensor scans the print mark, and the speed of the material web, such that a registration mark of at least one second impression the cylinder is in a capture range of the print mark sensor, being the at least one second printing unit in a non-printing arrangement.

To start a print job, the print cylinders supplied with the individual print images must first be inserted into the individual print units. In this case, the printing units also include printing rollers or printing cylinders through which the web of material passes. Subsequently, the printing cylinder and/or the printing roller are adjusted to each other so that they can change from a non-printing arrangement to a printing arrangement in which the printing roller contacts the web and thus transfers the ink. . Of course, the option of reverse adjustment (from printing to non-printing) is also offered.

In a method according to the invention, each impression cylinder comprises a positioning mark with which the impression cylinder can be or is positioned relative to the frame of the machine of which printing unit. The positioning mark has a fixed position with respect to a print image of the respective print cylinder, so that after positioning of the print cylinder, the print image also assumes a fixed position with respect to the machine frame. Preferably, the relative position of the positioning mark with respect to the print image is the same for all print cylinders of a print job. A positioning sensor is provided to detect the respective positioning mark. Preferably, after insertion and connection to a drive, the printing cylinder rotates at least until the positioning sensor detects the positioning mark. The advantage of this is that no print image has to be created to perform the step, ie waste is saved. If one were to rely on the positioning of the individual print images on the print unit side, the observer would realize that even with a known path length of the web of material between the print units, the print not true to record. The reason for this is that a belt can become shorter or longer due to various influences (temperature, elasticity, belt tension), especially during acceleration and deceleration phases. This influence is now offset, at least partially, by the process steps described below.

In a later step, a printing mark is printed on the first printing cylinder, viewed in the direction of conveying a web of material, on the web of material. This print mark is preferably a unique initial print mark that is different from other print marks and is only provided on or on the first print cylinder of a print job.

In a later stage, the web is conveyed through the other printing units, where a print mark sensor scans this print mark on each additional printing unit. The actual path of the web between the first printing cylinder and the respective print mark sensor can now be determined from the moment the print mark sensor detects the print mark and from the speed of the web. Since the print mark sensor is located at a known or at least easily determinable distance from the print cylinder, the actual path between the first print cylinder and the print cylinder in question, to which the respective print sensor is assigned, can be calculated. printing marks. The phase position of the print cylinder in question can be adjusted accordingly, so that both cylinders print the register print images on top of each other.

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

In accordance with the invention, the at least one second printing unit is in a non-printing arrangement.

In this case, the material to be printed is not printed, so no waste is produced. This means that even the direction of movement of the web of material can initially be reversed in order to be able to guide it backwards. Since the printing units are matched in phase with each other, the section of web that has already passed can be printed in this way. This means that not only is there no waste, but the section of the web that has already been used is immediately recycled. Especially in a serial rotogravure press, the printing counter cylinder often moves relative to the printing roller, so the distance between the printing counter cylinder and the printing cylinder is also included in the calculation of the effective travel of the press. band.

In another advantageous embodiment of the invention, provision is made for the positioning mark to be detected optically, magnetically and/or electrically. The position sensor is also designed accordingly, ie it can detect an optical contrast and/or a magnetic and/or electric field. The positioning mark can be arranged on the outer circumference of the impression cylinder or also on one of the end faces. In particular, a magnetically and/or electrically detectable positioning mark is insensitive to contamination, which can be caused by printing ink, for example. This embodiment of the invention naturally also includes corresponding sensors that can detect such positioning marks, ie an optical sensor, a magnetic sensor and/or an electrical sensor.

In another advantageous embodiment of the invention, provision is made for the positioning mark to comprise at least one of the following: bar code, QR code, magnet, electronic chip, engraving on the printing cylinder, body raised with respect to the impression cylinder surface. A barcode or QR code are optically detectable positioning marks that can be read with an optical scanner. A magnet can be a small body of magnetic material that can be inserted into a hole in the impression cylinder, for example. A simple magnetic sensor is enough to detect this magnet. Instead, an electronic chip can provide an electrical field that can be evaluated by an electronic sensor. In particular, you can An electronic chip, such as a magnet, can be installed to provide more information about the impression cylinder. Said chip can be, in particular, an RFID chip. A positioning mark can also include an engraving on the impression cylinder, which in turn can be detected by an optical sensor. It is also conceivable to have a body that rises with respect to the printing cylinder surface, which can be detected by an optical sensor or by a sensor that scans the cylinder surface. A scanning sensor can drift when it encounters the body. This deviation can be adequately detected.

Another preferred embodiment of the invention includes that the current state of the printing machine and/or the current state of the process and/or at least one error message is displayed by means of a display device. A display device is, for example, a monitor located in the area of the operating unit of the printing machine. However, the information can also be displayed on mobile devices that are in some way in contact with the printing press. In relation to the current state of the process, it is possible, for example, to show how much more the process according to the invention will need to complete.

In another embodiment, it is provided that in the event of an error message, it is indicated in which printing unit the error occurred and/or what type of error is present. In this way, it is possible, for example, to indicate to a machine operator whether the print mark on a printing unit has not been detected by a print mark sensor. This is because when the print mark should have been detected can be roughly determined based on the speed of the machine during the execution of the process. However, if the print mark has not been detected, this indicates an error. The same is true if a subsequent print mark sensor has already detected the print mark. An error message can mean, for example, that a print mark sensor is defective and/or incorrectly positioned in relation to the print cylinder. A list of the various causes that need to be checked can also be shown to the machine operator. This ensures that the print job is completed in its entirety and, above all, with the desired quality.

The procedure described above is particularly advantageous when printing a plastic web with the print job. A plastic band has a high elasticity, which can even depend on the temperature. This prevents printing from starting directly when the printing cylinders are positioned based on the positioning marks. Thus, the method according to the invention offers particular advantages in combination with a plastic web.

The aforementioned task is also solved by all the features of claim 8, namely by a multicolor printing machine for carrying out a process according to any of claims 1 to 7, having

- a first and at least a second printing cylinder

- a first and at least a second printing unit, into which the respective printing cylinder can be inserted,

- in which a printing mark can be printed on the web of material with the first printing cylinder viewed in the direction of transport of a web of material,

- a print mark sensor in the at least one second printing unit for scanning the print marks printed on the web of material,

- a positioning sensor in each printing unit for detecting a positioning mark of a printing cylinder, the positioning mark being located on the outer circumference or on one of the end faces of the printing cylinder,

- an evaluation and control device with which the data from the print mark sensor and/or position sensors can be received and with which the drives of the print cylinders can be controlled to adjust the circumferential positions of the print cylinders printing, wherein the at least one second printing unit may be held in a non-printing arrangement.

In this way, the same advantages are achieved as already described in connection with the process according to the invention.

Further advantages, features and details of the invention will emerge from the following description, in which various exemplary embodiments are explained in detail with reference to the figures.

The individual figures show:

Fig. 1 Schematic representation of a printing machine after inserting the printing cylinders. Fig. 2 Schematic representation of a printing machine after positioning of the printing cylinders by means of positioning marks

Fig. 3 Schematic representation of a printing machine after having kept the printing cylinders in register in the circumferential direction.

The Figures show schematic representations of a printing machine for carrying out the method according to the invention. The printing machine 100 is shown in FIG. 1. It first comprises an unwinding device 101, with which a web of material 102 is made available. It is fed to the individual printing units 110, 120, 130 via of several rollers 103, which can be, for example, transport rollers, deflecting rollers, spreading rollers or even entire roller units, such as those used in drying devices. The printing unit 110 is the first printing unit seen in the conveying direction T of the web of material, which has special features that will be discussed later. Three printing units can be seen, but a printing machine according to the invention can of course comprise any number of printing units. However, it is also possible that not all available print units are used in a process according to the invention, because not all print jobs require the inks available on a printing machine.

Each printing unit comprises a printing cylinder 111, 121, 131 and a counter printing cylinder 112, 122, 132. The web of material 102 is guided over the counter printing cylinders to be printed here by the printing cylinders. In the shown embodiment, the printing units are intaglio printing units of a series intaglio printing machine. In such a machine, the printing cylinders generally remain stationary in the frame of the printing unit, which is not shown, during the processing of a print job, while the counter printing cylinders are movable with respect to the cylinders. printing, often in a vertical direction, in order to bring the web of material into or out of contact with the printing cylinders.

After printing, the web of material is typically fed to a rewinder 141, where it is rewound onto reels for easy transport.

In Figure 1, it is shown that the printing cylinders have already been inserted into the respective printing units. Now the positioning of the printing cylinders is carried out by means of positioning marks 113, 123, 133, which can be detected by positioning sensors 114, 124, 134, which are preferably stationary arranged in the printing unit. respective. In Figure 1, it is shown that the positioning marks have already been detected in the printing units 110 and 120 (the positioning mark and the positioning sensor are directly in front of each other), while this is not yet the case. of the printing unit 130. Once this is done for all the printing cylinders, the angular positions of the individual printing cylinders with respect to the respective frames of the printing unit are set. However, it is also possible to specify the positions of the positioning marks relative to a zero line of the printing cylinder and to take this specification into account when applying the printing image to the printing cylinder. Instead of detecting the position mark using position sensors, these values can also be determined by manual measurement and then made available to an evaluation and control device. The zero line of an impression cylinder is a variable that has a predetermined or fixed relationship to the machine frame and with respect to which the angular position of the impression cylinder with respect to the machine frame can be indicated.

In Figure 2, it can be seen that all printing cylinders are now aligned with respect to the frame of the respective printing unit. Furthermore, the counter printing cylinder 112 of the first printing unit 110 is lowered so that the web 102 comes into contact with the printing cylinder. Furthermore, it can be seen that the printing cylinder 111 bears a printing mark 115, which is designed as a depression in gravure printing, for example. This print mark 115 has already been applied to the material web as a print mark imprint 150. During transport of the material web 102, the print mark 150 passes through all print units and thus Therefore, it passes through the print mark sensors 115, 125, 135, which preferably continuously scan the web of material and send a signal to a not shown evaluation and control device when the print mark 150 is detected. the conveying speed of the web of material and from the time when the print mark impression passes the respective print mark sensor, the effective path that the web of material has covered since the time of printing of the web can be calculated. print mark printing and/or from the time of detection of the print mark printing by the print mark sensor of one of the above printing units until the time of detection. n by the print mark sensor of the printing unit under consideration. Since the print mark sensors also have defined positions relative to the frame of the respective printing unit, the evaluation and control unit now, taking into account the geometrical data of the printing unit, in particular the circumference of the printing cylinder printing, including the installation position of the printing cylinder, the position of the counter printing cylinder at the time of printing the printing cylinder (in particular, if it is not placed on the printing cylinder) and the angular position of the printing cylinder, you can 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, in which case printing with accurate registration is possible.

This situation is illustrated in Figure 3, where all print units are now in print position and the print job can be processed. The print mark sensors 115, 125 and 135 now function in a known way as registration sensors, which scan registration marks that are not displayed but are printed together with the print job and sent to the evaluation and control unit. , which sends control signals to the printing cylinders in case of deviations. This is a well-known record control system.

Reference signs that have been explained from one figure are generally not shown in the other respective figures for the sake of clarity. However, the same reference signs are assigned to the same characteristics.

Claims (8)

1. Procedure for configuring a circumferential register of a printing job in a multicolor printing machine (100) with a first and at least a second printing cylinder, wherein the procedure comprises the following steps: a) inserting the printing cylinders (111, 121, 131) into the printing units (110, 120, 130) b) rear positioning of the printing cylinders in the circumferential direction with respect to the frame of the printing unit by means of a positioning mark (113, 123, 133) located on the printing cylinder c) rear printing of a printing mark ( 115) located on the first impression cylinder (111) seen in the direction of transport of a web of material (102) d) post-scanning of the print mark on the at least one second print unit, into which the at least one second print cylinder (121, 131) is inserted, by means of a print mark sensor (125, 135) e) subsequent adjustment of the at least one second printing cylinder (121, 131) in the circumferential direction on the basis of the geometric data of the printing unit, comprising the relative position of the printing mark sensor with respect to the printing frame. the print unit, the circumference of the print cylinder, the angular position of the print cylinder and the position of the counter print cylinder (122, 132), and the time the print mark sensor scans the print mark ( 115), as well as the speed of the web of material, so that a registration mark of at least one second impression cylinder (121, 131) is within a capture range of the impression mark sensor, wherein at least one second printing unit is in a non-printing arrangement. 2. Procedure according to the preceding claim, characterized because step b) is carried out with the aid of a positioning sensor with which the positioning mark is scanned. Method according to one of the preceding claims, characterized because the positioning mark is detected optically, magnetically and/or electrically. Method according to one of the preceding claims, characterized because the positioning brand comprises at least one of the following components: - Barcode - QR code - magnet - electronic chip - engraving on the impression cylinder - body elevated with respect to the surface of the impression cylinder. Method according to one of the preceding claims, characterized because the current state of the printing machine and/or the current state of the process and/or at least one error message is displayed by means of a display device. 6. Procedure according to the preceding claim, characterized because, in the event of an error message, it is indicated in which printing unit the error occurred and/or what type of error there is. Method according to the preceding claim, characterized in that a plastic web is printed with the print job. Multicolor printing machine for carrying out a method according to one of Claims 1 to 7, with - a first and at least a second printing cylinder (111, 121, 131), - a first and at least one second printing unit (110, 120, 130) into which the respective printing cylinder can be inserted, - wherein a printing mark (115) can be printed on the web of material with the first printing cylinder (111) viewed in the direction of conveying a web of material (102) - a print mark sensor (125, 135) in the at least one second printing unit (120, 130) for scanning the print marks printed on the web of material (102) - a positioning sensor (114, 124, 134) in each printing unit for scanning a positioning mark (113, 123, 133) of a printing cylinder, wherein the positioning mark is located on the outer circumference or on one of the end faces of the printing cylinder, - an evaluation and control device with which data can be received from the print mark sensor (115, 125, 135) and/or from the positioning sensors (114, 124, 134) and with which the impression cylinder drives for adjusting the circumferential positions of the impression cylinders, wherein the at least one second printing unit (120, 130) can be held in a non-printing arrangement.