Method for operating web press

Abstract

The invention relates to a method for operating a web press for producing printed products. The web press comprises a web changing device and a plurality of printing units. A rapid web change from the first web to the second web takes place when the joining point is produced. The printing unit is arranged in coordination with the situation that the joint part passes through the web press. The printing units of the web press are each designed as double printing units for flexographic printing and are used to produce printed products. Each double-printing unit comprises a first printing sub-unit and a second printing sub-unit; the respective first or second sub-printing unit is activated or deactivated or switched from the first sub-printing unit to the second sub-printing unit of the respective dual-printing unit, or vice versa, depending on the situation of the joining point through the web press. According to the invention, the non-stop automatic operation of the flexographic printing machine during breadth replacement becomes possible. The device is used when a breadth processing rotary press for flexographic printing is operated, and the automation degree, the production rate and the printing quality are improved.

Description

Field of the Invention

[0001] The present invention relates to a method for operating a web-fed printing press.

[0002] The present invention belongs to the technical field of plate-making printing industry or graphic industry, especially the field of operation of flexographic printing presses, that is, rotary printing presses for flexographic printing on web printing materials. In particular, the present invention relates to the field of controlling or adjusting the machine or its drive and / or actuator to improve printing quality and productivity and / or avoid or reduce malfunctions. Background Art

[0003] JP2006321213A discloses an offset web-fed printing press including a web changer and a plurality of printing units. If a web roll is almost used up, it will be quickly replaced with a new web roll, and the web materials are basically the same, that is, the web materials still match the existing printing operation, or the two webs are connected to each other at the splice. During such a web change, due to the generation of the splice and the operation of the machine, registration changes may occur, so the registration settings of the printing units need to be adjusted. This adjustment seems to be coordinated with the process of the web-fed printing press passing through the splice. What is not disclosed here is: changing the printed image while changing the web; the two webs are very different (such as web thickness, web width or web material); or the impression cylinder or the offset cylinder is disengaged when performing registration adjustment. In addition, it seems to only involve length registration and does not involve lateral registration. Registration sensors are mentioned, but their measurement positions are not mentioned. A database can be accessed when performing registration adjustment.

[0004] For example, DE102017222700A1 or DE102021126115A1 discloses a web-fed flexographic printing press with a double printing unit.

[0005] During the continuous operation of a flexographic printing press (i.e., the "non-stop" operation with high productivity), web changes may occur, and there are significant differences between the two webs in at least one web parameter, especially in terms of web thickness. For example, this occurs when changing jobs. The operators in the printing workshop require that such a change should not interrupt production, should not reduce the printing quality, and should produce little or no waste. In addition, the operators in the printing workshop also require further improvement in the automation level of the printing press to save labor costs or be able to replace missing personnel. Summary of the Invention

[0006] Therefore, the task of the present invention is to improve the prior art, especially to enable the flexographic printing press to automatically operate without stopping when changing the web.

[0007] According to the present invention, the above task is solved by a method having the preferred technical solutions of the present invention.

[0008] Advantageous and thus preferred developments of the present invention result from the alternative technical solutions, the description and the drawings.

[0009] According to the present invention, there is provided a method for operating a web-fed printing press for producing printed products, the web-fed printing press including a web change device and a plurality of printing units, wherein in the case of generating a splice, a rapid format change from a first format to a second format is carried out, and wherein the setting of the printing units is coordinated with the passage of the splice through the web-fed printing press, characterized in that at least two printing units of the web-fed printing press are each constructed and configured as a dual printing unit for flexographic printing and for producing printed products, wherein each existing dual printing unit includes a first sub-printing unit and a second sub-printing unit; according to the passage of the splice through the web-fed printing press, the corresponding first sub-printing unit or second sub-printing unit is activated or deactivated; or a switch is made from the first sub-printing unit to the second sub-printing unit of the corresponding dual printing unit, and vice versa.

[0010] According to the present invention, there is also provided another (alternatively formulated) method for operating a web-fed printing press, wherein in the case of generating a splice, a rapid format change from a first format to a second format is carried out, characterized in that at least two impression cylinders of independent printing units are respectively off-pressed from the first format or respectively on-pressed onto the second format in coordination with the passage of the splice through the web-fed printing press.

[0011] Advantageous designs and effects of the present invention

[0012] Advantageously, the present invention enables a flexographic printing press to operate automatically without stopping (or without interruption) when changing formats.

[0013] Advantageously, the present invention is used in the operation of a web-fed rotary printing press for format processing in flexographic printing, improving its degree of automation, productivity and printing quality.

[0014] Advantageously, the present invention avoids production interruptions, thereby reducing production costs. Advantageously, the present invention reduces or avoids waste pages, thereby reducing production costs. Advantageously, the present invention improves the printing quality, for example, by rapidly and optimally setting the pressure (impression cylinder to counter cylinder), so that in flexographic printing, edge squeezing, misprinting or too low pressure can be particularly avoided. The present invention can reduce the number of personnel or reduce the number of trained personnel, thereby further reducing production costs.

[0015] The invention can in particular be used for so-called rapid or flying job changes, for example from a first printing job of a first product (first printed image, first format material, first format thickness) to a second printing job of a second product different from the first product (second printed image, second format material, second format thickness). Here, these products are preferably packages.

[0016] According to the invention, "switching from the first sub-printing unit to the second sub-printing unit of the respective double-printing unit in coordination with the passage of the joint through the web press". Since the joint passes through the double-printing units of the printing press successively in time, the switching is carried out for each double-printing unit one by one, i.e., not simultaneously on all printing units, but with a time offset corresponding to the movement time of the respective format from double-printing unit to double-printing unit. Therefore, preferably all double-printing units can be switched eventually.

[0017] The activation, deactivation or switching of the double-printing units is preferably carried out in time at the moment when the joint has passed through the printing nip between the impression cylinder and the counter-pressure cylinder and preferably successively, i.e., step by step from one printing unit to another and successively in time. In this way, waste sheets can be saved optimally. In the best case, the conversion is carried out as soon as the joint has passed through the printing nip. Therefore, the switching is carried out synchronously with the movement of the joint through the web press. The ideal situation is the following conversion, which is carried out very close in time to the passage of the joint through the double-printing unit, in particular through the printing nip formed therein. However, the time-varying location of the joint must be known, for which preferably the signal of the reel changer or a corresponding sensor is used, preferably a computer can also be used. Since the format conveying speed of an industrial web press is extremely fast, it is preferably to place the sensor at an appropriate spatial distance in front of the printing unit / in front of the printing nip, so as to be able to react to the switching process in time accordingly.

[0018] Similarly, a single printing unit (or multiple single printing units, preferably activated or deactivated successively) can also be activated or deactivated in coordination with the passage of the joint through the web press. For example, a single printing unit can be a varnishing unit with a varnishing cylinder; in this case, the single printing unit can remain in pressure during format change.

[0019] The invention can be extended to machines or devices for further processing, such as machines or devices for die-cutting, folding, gluing or palletizing. When changing the substrate, these machines or devices can be switched automatically: for example, the settings for die-cutting and / or folding can be adjusted according to the substrate.

[0020] Instead of flexographic printing, the invention can also be used for other printing processes, such as gravure printing.

[0021] Expansion solutions of the present invention

[0022] The preferred expansion solutions of the present invention (in short: expansion solutions) are described below. These expansion solutions can also be combined with each other if it is not technically impossible.

[0023] One expansion solution is characterized in that the second sub-printing unit or its corresponding flexographic printing cylinder - or in the reverse case the first sub-printing unit or its corresponding flexographic printing cylinder - can be brought into pressure contact with the second sheet at a speed adapted to the second sheet speed during switching. One expansion solution is characterized in that the second sub-printing unit or its corresponding flexographic printing cylinder - or in the reverse case the first sub-printing unit or its corresponding flexographic printing cylinder - can be brought into pressure contact with the second sheet at a pressure or feed rate adapted to the second sheet or its sheet parameters during switching. One expansion solution is characterized in that the pressure or feed rate can be set separately on both sides of the second sub-printing unit. For this purpose, the thickness of the sheet can be measured at multiple locations (in the transverse direction with respect to the sheet conveying direction). One expansion solution is characterized in that the anilox roll of the second sub-printing unit - or in the reverse case the anilox roll of the first sub-printing unit - can be brought into pressure contact with the flexographic printing cylinder at a pressure adapted to the second sheet or its sheet parameters during switching. One expansion solution is characterized in that the second sub-printing unit or its corresponding flexographic printing cylinder - or in the reverse case the first sub-printing unit or its corresponding flexographic printing cylinder - can be brought into pre-registration pressure contact with the second sheet at a pre-registration adapted to the second sheet or its sheet parameters during switching. One expansion solution is characterized in that the pre-registration can include longitudinal registration and lateral registration. The pressure contact (and the reverse pressure release) is preferably carried out using a servo motor.

[0024] One expansion solution is characterized in that the power of the dryer can be adapted to the second sheet or its sheet parameters during switching. The dryer can be a dryer on the sheet path between the double printing units and / or between the sub-printing units.

[0025] One expansion solution is characterized in that the printing task can be changed during switching. One expansion solution is characterized in that the printing image can be changed when changing the printing task.

[0026] A feature of an extended solution is that the flexographic impression cylinder of the first sub-printing unit - or, respectively, in the reverse case, the flexographic impression cylinder of the second sub-printing unit - can be successively de-pressed or re-pressed in coordination with the passage of the web-fed printing press through the joining section. A feature of an extended solution is that the flexographic impression cylinder of the first sub-printing unit - or, respectively, in the reverse case, the flexographic impression cylinder of the second sub-printing unit - can be de-pressed directly upstream of the joining section or re-pressed directly downstream of the joining section. A feature of an extended solution is that the flexographic impression cylinder of the second sub-printing unit can be re-pressed in coordination with the passage of the web-fed printing press through the joining section. A feature of an extended solution is that the flexographic impression cylinder of the second sub-printing unit can be re-pressed directly after the joining section. A feature of an extended solution is that the flexographic impression cylinder of the printing unit can be de-pressed directly upstream of the joining section and then re-pressed directly downstream of the joining section.

[0027] A feature of an extended solution is that the double printing units can each include one (or at least two) registration sensors, and the registration sensors change in terms of their respective measurement positions in coordination with the passage of the web-fed printing press through the joining section. A feature of an extended solution is that the registration sensors can move transversely to the web transport direction. A feature of an extended solution is that the double printing units can operate with a registration adjustment algorithm and at least one registration adjustment parameter respectively, and the registration adjustment algorithm and / or the registration adjustment parameter can change in coordination with the passage of the web-fed printing press through the joining section.

[0028] A feature of an extended solution is that the first web and the second web can be essentially different in terms of at least one web parameter. A feature of an extended solution is that the web parameter can be one of the following parameters: web thickness, web width, web material, web surface. For example, if the material is recycled and / or coated on one or both sides and / or calendered and / or stretched and / or extruded, the web surfaces are essentially different. The surface roughness or color of the two webs may also be different. The material / surface parameters of the material to be processed can be measured by reflection or infrared spectroscopy or by using ultrasonic waves or lasers. The measurement is preferably carried out upstream of the printing unit, particularly preferably not far upstream of the printing unit (less waste paper!). The measurement, especially the measurement of the web thickness, is preferably carried out continuously. The measurement of the web thickness is preferably carried out using an optical measurement system. Alternatively, the required parameters can be loaded from a database. Further alternatively, the required parameters can also be stored on the web (such as a QR code) or on the web reel (such as a QR code or an NFC chip) and then read out (preferably in a reel changer). A feature of an extended solution is that the web thickness can be determined by a sensor. A feature of an extended solution is that the web parameters can be stored and provided in a digital database.

[0029] One development is characterized in that the second web can be connected to the first web at a joining point.

[0030] An extension is characterized in that, during the passage of the joint through the web printing press, at least one first sub-printing unit can be set for a first printing task and contribute to the first printing task on a first web, and at least one second sub-printing unit can be set for a second printing task and contribute to the second printing task on a second web.

[0031] One development is characterized in that the web tension, in particular the feed web tension, can be adjusted before and / or after the double printing unit.

[0032] One development is characterized in that, in addition to the double printing units, at least one single printing unit can also be provided.

[0033] One development is characterized in that, when the web width changes, i.e., from a first width to a larger or smaller second width, at least one sensor or another component arranged at a first working distance relative to the first width can be moved to a safety distance relative to the second width and from there to a new working distance relative to the second width.

[0034] One development is characterized in that, instead of the flexographic printing unit, a gravure printing unit with a gravure cylinder can be used.

[0035] One development of the method according to the invention is characterized in that at least one double printing unit or at least one single printing unit can participate in the release and / or closing press.

[0036] The features and feature combinations disclosed in the above technical fields, the summary and the developments section as well as in the following exemplary embodiments (in any combination with one another) represent further advantageous developments of the invention.

[0037] Example 1: Specific Application

[0038] Package A ("six-pack") with a circumference of 567 mm is printed on the printing press. The corresponding product width W A Thickness is 300 microns and is available as a roll R A Located on the winding spindle W A On. Reel R B is placed in the free part of the non-stop unwinder, for example, the thickness of the roll is 250 microns. While the machine continues to produce package A, it is also preparing the printing job for package B ("mint tea") with a circumference of 678 mm. A On the winding spindle W A When the winding is unwound, operation A is completed. At the same time, the winding spindle W BReach the machine speed and "engage", i.e., the goods web B B is adhered to the running web B A onto it. Thus, the two goods webs have different thicknesses and possibly different elastic moduli. Once the new goods web B B enters the machine, certain machine parameters are adjusted, more precisely adjusted in the form of minimizing waste sheets. Next, the printing operation B (i.e., the corresponding impression cylinder) accelerates in the machine and is registered with each other, while continuing to produce the package A. Then, the printing impression of the printing operation B is carried out precisely at the position where the new goods web B B passes through the corresponding printing unit. The printing settings, such as the pressure / impression (on the web), are set so that it matches the new substrate with a changing thickness. This is first done at the front of the printing press, where the material has just entered and the printing operation B is carried out. At the rear of the printing press, the printing operation A is still in progress, and the printing settings here continue to use the value of 300 microns to avoid generating waste sheets there. The switching is carried out while the printing press continues to produce. Thus, two goods webs B A and B B with different characteristics exist simultaneously in the machine, and the printing press "manages" these two material webs and the two related printing operations A and B with different package sizes / package designs. Over time, the material change section (the engagement part) moves towards the end of the printing press. At a certain point in time, the replacement process is completed and only the printing operation B is produced, and only the goods web B B remains in the machine.

[0039] Example 2: Specific setting changes

[0040] The following presets and adjustments can be changed individually or in groups or all when the engagement part passes through:

[0041] The participating printing units, web thickness, web width, web material, web elastic modulus, web tension, the pressure / impression between the impression cylinder and the counter cylinder and / or the pressure / impression between the anilox roller and the impression cylinder, the printed image, the printing format, the pre-registration (registration preset), the position of the registration marks on the web (axial and circumferential), the measurement positions of the registration adjustment sensors (axial and circumferential), the dryer settings (temperature, fan speed, UV power), the ink pump speed. Description of the drawings

[0042] The figures show the preferred embodiments of the present invention and the expansion solutions. The corresponding features are provided with the same reference numerals in the figures. For clarity, some of the repeated reference numerals in the figures are omitted.

[0043] Figure 1 A cross-sectional schematic view of a web printing press when implementing a preferred embodiment of the method of the present invention is shown.

[0044] Figure 2 Schematic cross-sectional view of a reel changer showing a preferred embodiment for implementing the method of the present invention.

[0045] Figure 3 、 4 Figures 5 respectively show schematic cross-sectional views of a double printing unit showing a preferred embodiment for implementing the method of the present invention. Detailed implementation

[0046] Figure 1 Shows a web-fed printing press 1, especially for flexographic or gravure printing, for printing a substrate web 2, especially a paper web or a cardboard web, which is conveyed through the web-fed printing press 1 in a conveying direction 4 by a plurality of guide rollers 3. The control of the web-fed printing press 1 is preferably carried out by a computer 55.

[0047] The web-fed printing press 1 includes a reel changer 10 for rapid or in-flight reel change (see Figure 2 ), which includes two unwind stations 11 for unwinding a first reel 12 or a first web 13 and for unwinding a second reel 14 or a different second web 15. In addition, the reel changer 10 also includes a so-called splicing device 16 for connecting the first web 13 to the second web 15 through a common splice site 17 between the two webs 13 and 15. Alternatively, the web 13 or 15 wound and stored on the reel 12 or 13 already has one or more splice sites 17, that is, at least two different webs are wound on the reel and can be unwound. In addition, the reel changer 10 also includes a number of guide rollers 3, which determine the path of the web 2 or its conveying direction 4. Downstream of the reel changer 10, a pulling-in unit 18 is arranged, which is used to adjust the web tension and / or guide the web edge or the web center, for example, when two webs of different widths are stuck together.

[0048] The web-fed printing press 1 includes at least one printing unit 20 (see Figure 3 、 Figure 4 and Figure 5), but preferably includes a plurality of printing units 20 for producing multicolor printed matter. The printing unit 20 is designed as a double printing unit 20, i.e., it includes a first sub-printing unit 21 and a second sub-printing unit 22. The printing unit 20 is preferably designed for flexographic printing or gravure printing. The first sub-printing unit 21 includes a first impression cylinder 30, especially a flexographic printing or gravure impression cylinder, and preferably includes a first anilox roll 34 for printing a first printing image 31 onto the web 2; the second sub-printing unit 22 includes a second impression cylinder 32, especially a flexographic impression cylinder or a gravure impression cylinder, and preferably includes a second anilox roll 35 for printing a second printing image 33 onto the web 2. The double printing unit 20 is designed for rapid or in-flight job change, i.e., preferably the first sub-printing unit 21 prints the first printing image 31 or the second sub-printing unit 22 prints the second printing image 33, where (see Figure 3 and Figure 4 ) one of the two impression cylinders 30 or 32 is in nip with the central counter-pressure cylinder 36 and the other impression cylinder is out of nip with the central counter-pressure cylinder. Alternatively (see Figure 5 ), two counter-pressure cylinders 36 and 37 can also be provided. During rapid job change, a switch is to be made between the two sub-printing units 21 and 22, and for this purpose, each sub-printing unit 21 and 22 is equipped with a de-nip device 38. The non-printing sub-printing unit 21 or 22 can be configured for a new printing job during the production process, that is to say, it can be equipped with at least one new printing plate.

[0049] Figure 3 、 Figure 4 and Figure 5 respectively show the double printing unit 20, to which the web 2 is supplied in the conveying direction 4, and then the web 2 is further supplied in the conveying direction 4 to another unit. An upper structure is provided above the double printing unit 20, which upper structure has a number of guide rollers 3 for the web 2 and a dryer 53 for the printed web 2. As already described above, the double printing unit 20 includes a first sub-printing unit 21 and a second sub-printing unit 22.

[0050] At least upstream of the first double printing unit 20 of the web-fed printing press 1 (if necessary upstream of each double printing unit 20, see Figure 1)A sensor 40 is arranged. The sensor 40 can be, for example, a web thickness sensor 40 for determining the thickness of the incoming web 2 and / or for identifying the joining location 17; or, for example, a reflection sensor for identifying the tape. The web press 1 and / or the double printing unit 20 includes a computer 55 which is connected to the sensor 40 (preferably via a connection 56). The sensor 40 preferably continuously sends its measured values to the computer 55, which (after corresponding calculations) sends a control signal 57 (see Figure 1 ) to one or more double printing units 20. As can be seen from Figure 1 , the control signal 57 can preferably sequentially switch a plurality of double printing units 20 between two sub-printing units 21 and 22 in time. In this way, it can be ensured that the switching is coordinated with the passage of the joining location 17 through the web press 1 or its double printing units 20. When switching between the two sub-printing units 21 and 22, the pressure / impression of the impression cylinder 32 on its counter-pressure cylinder 36 or 37 and the pressure / impression on the web can preferably be preset. This preset can be selected according to the web thickness of the joining location 17 after the web 15; and vice versa. Similarly, when changing the web, the pressure / impression of the anilox roller 34 on the impression cylinder 30 can also be preset according to the passage of the joining location 17.

[0051] In addition, each double printing unit 20 preferably includes a registration sensor 41, and the registration sensor can be arranged immovably in terms of its measuring position 42; preferably, the registration sensor 41 can be moved transversely to the conveying direction of the web 2. Therefore, when changing the web, once the joining location has passed the registration sensor, the registration sensor 41 can change in terms of its measuring position 42 (preferably transversely to the running direction of the web, i.e., axially). The control signal 57 or a corresponding control signal can also be used for this switching process. Registration presetting can also be carried out when the joining location 17 passes and during synchronous switching.

[0052] Figure 5 It is also shown that intermediate dryers 54 can be arranged on the web path of the web 2 between the two counter-pressure cylinders 36 and 37. These intermediate dryers 54 and / or the dryer 53 of the web press 1 can also be controlled by the computer 55 when changing the web, so as to change the drying parameters from the first web 13 to the second web 15. This change is preferably carried out when the joining location 17 has passed the respective dryer.

[0053] In addition to the double printing units 20, Figure 1 the illustrated web press 1 can also optionally include at least one single printing unit 50, especially for flexographic printing or gravure printing. The single printing unit 50 is also impressionable and de-impressionable and can be controlled by the computer 55 in this regard.

[0054] In addition, the web press 1 further includes other units 51, which are preferably designed as a winder 51 for the printed web 2. In addition to or in place of the unit 51, the web press 1 may further include other units 52, which are preferably designed as further processing units 52, such as die-cutting units 52. When changing the web, the further processing unit 52 can also be controlled by the computer 55 in terms of the switching process.

[0055] The figure exemplarily shows the switching from the first web 13 to the second web 15. Obviously, it is also possible to switch from the second web 15 to the first web 13, and it is also possible to switch multiple times to the webs 13, 15 and other webs to be processed in sequence.

[0056] List of reference numerals

[0057] 1 Web press

[0058] 2 Web

[0059] 3 Guide roller

[0060] 4 Conveyor direction

[0061] 10 Reel changer

[0062] 11 Unwinder

[0063] 12 First reel

[0064] 13 First web

[0065] 14 Second reel

[0066] 15 Second web

[0067] 16 Joining device

[0068] 17 Joining part

[0069] 18 Pull-in device

[0070] 20 One or more printing units, especially a dual printing unit for flexographic printing

[0071] 21 First sub-printing unit, especially a flexographic printing unit

[0072] 22 Second sub-printing unit, especially a flexographic printing unit

[0073] 30 First impression cylinder, especially a flexographic impression cylinder

[0074] 31 First printed image

[0075] 32 Second impression cylinder, especially a flexographic impression cylinder

[0076] 33 Second printed image

[0077] 34 First anilox roll

[0078] 35 Second anilox roll

[0079] 36 (Central) impression cylinder

[0080] 37 Other impression cylinders

[0081] 38 Inking and / or impression device

[0082] 40 Sensors, in particular format thickness sensors or reflection sensors

[0083] 41 Registration sensor

[0084] 42 Measuring position

[0085] 50 One or more printing units, in particular single printing units for flexographic printing

[0086] 51 Other units, in particular winders

[0087] 52 Optional further processing units

[0088] 53 Dryer

[0089] 54 Intermediate dryer

[0090] 55 Computer

[0091] 56 One or more connections

[0092] 57 Control signals.

Claims

1. A method for operating a web-fed printing press to produce printed products, the web-fed printing press comprising a web-changing device (10) and a plurality of printing units (20, 50), wherein a rapid format change from a first format (13) to a second format (15) is carried out in the case of generating a splice (17), and settings are made on the printing units (20, 50) in coordination with the situation of the splice (17) passing through the web-fed printing press (1), characterized in that there are at least two printing units (20) of the web-fed printing press, which are each configured as a dual printing unit (20) for flexographic printing and operate to produce printed products, wherein each existing dual printing unit (20) comprises a first sub-printing unit (21) and a second sub-printing unit (22), and the corresponding first sub-printing unit (21) or second sub-printing unit (22) is activated or deactivated, or switched from the first sub-printing unit (21) to the second sub-printing unit (22) of the corresponding dual printing unit (20), or vice versa, in coordination with the situation of the splice (17) passing through the web-fed printing press (1).

2. The method according to claim 1, characterized in that the second sub-printing unit (22) or its corresponding flexographic impression cylinder (32) - or, in the reverse case, the first sub-printing unit (21) or its corresponding flexographic impression cylinder (30) - is brought into nip contact with the second format (15) at a speed adapted to the speed of the second format (15) during the switchover.

3. The method according to any one of the preceding claims, characterized in that the second sub-printing unit (22) or its corresponding flexographic impression cylinder (32) - or, in the reverse case, the first sub-printing unit (21) or its corresponding flexographic impression cylinder (30) - is brought into nip contact with the second format (15) with a pressure or feed adapted to the second format (15) or its format parameters during the switchover.

4. The method according to any one of the preceding claims, characterized in that the anilox roll (35) of the second sub-printing unit (22) - or, in the reverse case, the anilox roll (34) of the first sub-printing unit (21) - is brought into nip contact with the flexographic impression cylinder (32) with a pressure or feed adapted to the second format (15) or its format parameters during the switchover.

5. The method according to any one of the preceding claims, characterized in that the second sub-printing unit (22) or its corresponding flexographic impression cylinder (32) - or, in the reverse case, the first sub-printing unit (21) or its corresponding flexographic impression cylinder (30) - is brought into nip contact with the second format (15) with a pre-registration adapted to the second format (15) or its format parameters during the switchover.

6. The method according to any one of the preceding claims, characterized in that during the switchover, the power of the dryer (53) is adapted to the second format (15) or its format parameters.

7. The method according to any one of the preceding claims, characterized in that a printing task change is carried out during the switchover.

8. The method according to one of the preceding claims, characterized in that the flexographic impression cylinder (30) of the first sub-printing unit (21) - or, respectively, in the reverse case, the flexographic impression cylinder (32) of the second sub-printing unit (22) - is successively de-pressed or re-pressed in coordination with the case of the web-fed printing press (1) at the joining portion (17).

9. The method according to claim 8, characterized in that the flexographic impression cylinder (30) of the first sub-printing unit (21) - or, respectively, in the reverse case, the flexographic impression cylinder (32) of the second sub-printing unit (22) - is de-pressed directly before the joining portion (17) or re-pressed directly after the joining portion (17).

10. The method according to one of the preceding claims, characterized in that each of the double printing units (20) includes a registration sensor (41), and the registration sensor (41) varies in terms of its corresponding measurement position (42) in coordination with the case of the web-fed printing press (1) at the joining portion (17).

11. The method according to one of the preceding claims, characterized in that the first format (13) and the second format (15) are essentially different in at least one format parameter.

12. The method according to claim 11, characterized in that the format parameter is one of the following parameters: format thickness, format width, format material, format surface.

13. The method according to claim 11 or 12, characterized in that the format parameter is loaded from a database or from a memory on the format (2) or format reel (12, 14).

14. The method according to one of the preceding claims, characterized in that during the passage of the joining portion (17) through the web-fed printing press (1), at least one first sub-printing unit (21) is set up for a first printing task and contributes to the first printing task on the first format (13), and at least one second sub-printing unit (22) is set up for a second printing task and contributes to the second printing task on the second format (15).

15. The method according to one of the preceding claims, characterized in that when the format width changes, i.e., from a first width to a larger or smaller second width, at least one sensor (40, 41) or another component arranged at a working distance relative to the first width moves to a safe distance relative to the second width and from there to a new working distance relative to the second width.

16. The method according to one of the preceding claims, characterized in that a printing unit (20, 50) for gravure printing with gravure impression cylinders (30, 32) is used instead of the printing unit (20, 50) for flexographic printing.

17. A method for operating a web-fed printing press, in which a rapid format change from a first format (13) to a second format (15) is carried out in the case of generating a joining portion (17), characterized in that At least two impression cylinders (30, 32) of the independent printing units (20, 50) are respectively unimpressed from the first sheet (13) or respectively impressed onto the second sheet (15) in coordination with the case of the web press (1) at the engagement part (17).

18. The method according to claim 15, characterized in that at least one double printing unit (20) or at least one single printing unit (50) participates in the unimpressing or impressing.

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