METHOD FOR OPERATING A FLATBED DIE CUTTER

Description

invention

[0001] The invention relates to a method having the features of the preamble of claim 1. Technical field of the invention

[0002] The invention lies in the technical field of the graphic industry and there in particular in the field of further processing of sheet or web-shaped printing materials, such as paper, cardboard, paperboard or film, following inline or offline printing by punching, in particular by flatbed punching. State of the art

[0003] It is well known that a web of substrate can be printed on a printing press and then further processed inline or offline in a flatbed die-cutter. The problem that can arise is that the printing press is stopped and then started up again when a job changes, and that during the stoppage what is known as web curling occurs: i.e. unwanted waves or other deformations or damage to the web, such as wavy web edges. Curling can be caused, for example, by changes in humidity and / or ambient temperature. Curling can lead to problems when processing the printing press. When restarting, register shifting can also occur, i.e. the register between the printed image and the die-cutting image can be disrupted.

[0004] It is also known to remove an unusable (e.g., "curled") section of the web as waste before further processing, i.e., before punching or the flatbed die cutter. The problem with this is that the web transport must be stopped again after starting up to feed the web start into the die cutter and adjust the register. Only then can production begin. Overall, this results in significant production downtime and a high amount of waste.

[0005] DE102012019992A1 discloses a flatbed die cutter in which an unusable and unprinted web section (located in front of a printed web section) is wound up before the flatbed die cutter and removed by cutting. To do this, the web is unwound and reconveyed before cutting, and then, after cutting, is fed forward again while maintaining the web tension. The newly created web beginning must be fed into the flatbed die cutter. Furthermore, the register must be adjusted.

[0006] EP2080600A1 discloses a generic printing machine, i.e. a printing machine having the features of the preamble of claim 1. Task

[0007] It is therefore an object of the present invention to provide an improvement over the prior art, which in particular enables products to be manufactured by punching a web, thereby reducing waste and downtime. In particular, it should be possible to quickly start up a flatbed die cutter at the start of production ("new order") and, in particular, to avoid having to stop a flatbed die cutter again due to curling during start-up. Inventive solution

[0008] This object is achieved according to the invention by a method according to claim 1.

[0009] Advantageous and therefore preferred developments of the invention emerge from the subclaims as well as from the description and the drawings.

[0010] A method according to the invention for operating a printing press with an integrated or inline flatbed die cutter and with a printing unit arranged upstream of the die cutter, wherein printing material is fed as a web to a die-cutting module of the flatbed die cutter, the web is guided through the die-cutting module, and a web section is separated from the web in or after the die-cutting module and removed as waste, is characterized in that the web section is cut off by means of a rotating or up-and-down moving cross cutter, which is different from a die-cutting knife of the die-cutting module, or in that the web section is only partially cut off and then torn off by means of a rotating or up-and-down moving cross cutter, which is different from a die-cutting knife of the die-cutting module, and in that the waste is mechanically either i) removed as a web and wound up on a winding roller or ii) removed as a sheet and deposited or shredded,that the punching module is activated and / or operated during or after the removal of the web section in register and at a precise speed to a print image of an imprint on the web generated by the printing unit, and that the feeding of the web to the flatbed punch and the passage of the web through the punching module is started at the beginning of a production run with the printing press, then continued without stopping during the removal of the web section and the punching in register and at a precise speed, and is only stopped at the end of the production run.

[0011] The invention advantageously enables products to be manufactured by punching a web, thereby reducing waste and downtime.

[0012] The invention also advantageously enables a flatbed die cutter to be quickly started up at the start of production ("new order").

[0013] The invention also advantageously prevents a flatbed die cutter from having to be stopped again when starting up due to curling, e.g. during color matching or proofing.

[0014] Furthermore, it is advantageously also possible to operate the so-called phasing of a flatbed die cutter automatically and in register: The (after a

[0015] The web (which is running again after a production change) can be severed, an unusable section of the web can be removed from the running web as waste (e.g., as a web section or sheet), and the running web can be processed in register, preferably by punching. This advantageous method can reduce machine downtime and significantly reduce the amount of waste. Further developments of the invention

[0016] A preferred development of the invention can be characterized in that the severed web section is moved, preferably pulled, from the punching module by means of a pair of rollers. Preferably, at least one of the rollers of the pair is driven, in particular driven intermittently and / or synchronously with the punching cycle.

[0017] A preferred development of the invention can be characterized in that the cross cutter is arranged before or after the pair of rollers.

[0018] A preferred development of the invention can be characterized in that the sheet is ejected from a transport path by means of a switch.

[0019] In the following (points 1 to 15) a preferred first concrete development of the method according to the invention for operating a flatbed punch using a winding roller is described in detail: 1. The die cutter can move into a maintenance position, if it has not already been moved. In the maintenance position, the gap between the upper and lower die plates of a die cutting module can be at its largest. 2. The desired die cutting format and, if applicable, the die-cutting-to-printing ratio can be specified, e.g., by operator input or by reading from a digital storage device, e.g., a cloud-based storage device. Alternatively, the die-cutting-to-printing ratio can be automatically recorded using a register sensor, a register camera, or a code reader. Alternatively, a barcode or area code, e.g., QR or Datamatrix, can be provided on the web, and the value can be read from it. Alternatively, the value can be automatically provided by a printing press spatially and / or productively located upstream of the flatbed die cutter. 3.The material web can, if not already threaded, be fed into an infeed area of ​​the punching module, e.g., into a roller arrangement in front of the punching module, and can contact both a feed roller and a feed roller (or several such rollers), and possibly counter rollers. 4. There is also the case (alternatively to 3) where the material web is already in the infeed area, and (only) the web section with existing curling is to be removed. 5. The material web can be moved through the punching module and attached to a winding roller. 6. A feed or web rewind can be activated (starting a "feed" mode). The value of a distance or distance between a punch register mark (on the printing substrate) and a cutting knife of the punching module can be specified, e.g., by operator input or by reading from a digital storage device, e.g., a cloud-based storage device.Alternatively, the distance can be automatically recorded using a register sensor, a register camera, or a code reader. Alternatively, a barcode or area code, e.g., QR or Datamatrix, can be provided on the web, and the value can be read from it. Alternatively, the value can be automatically provided by a printing press spatially and / or productively upstream of the flatbed die cutter. 7. Starting "Feed" mode can cause the winding roller to switch on or rotate and build up web tension. A (web) storage roller can be moved to an optimal position and then stopped or held in this position. A feed roller can be converted from discontinuous operation to continuous operation. Kicker rollers, which convey sheets from the die-cutting area during die-cutting operation, can move to the optimal position ("open") and then remain stationary.If a winding roller is arranged below a sheet transporter, a lower of the two kicker rollers can rotate continuously at web speed, and the upper of the two kicker rollers can be in an "open" position. 8. The die cutter (and, if applicable, the upstream printing press or, if applicable, an offline unwinder, preferably with a pulling station and tools) can be started, and the web can be moved continuously. The feed roller can feed the web into the die cutter, and the winding roller can feed the web through the die cutter and back out again. Movable deflection rollers / guide rollers can be moved into the web path, preferably by about 20 mm. 9. The position of the register mark can be observed or monitored. The register mark can either be pre-printed on the web or printed on the press. A preferred or optimal in-phase time can be calculated or specified.This phasing-in time is the time at which the punching module of the flatbed punch is activated and begins punching in register and at a precise speed. Punching occurs in register when the punching register is adjusted to the printing register. 10. The register-accurate phasing into punching operation can be triggered manually by the operator. Alternatively, it can be triggered depending on a preferably predefined and / or specified and / or calculated distance, e.g. the material web path from an unwinder (or another web feed to the punch) to the punch. Alternatively, it can be triggered by a continuously operating sensor system for detecting curling, with triggering preferably occurring when the curling falls below a preferably specified threshold. 11. At the moment the phasing-in starts, the web can be moved to a preferably calculated or specified, suitable register position.A feed roller activated for this purpose can then be stopped. If the path to the correct register position has already been exceeded, a corresponding portion of the length of a sheet or web section to be punched can be moved into the punching module and moved to the correct register position. The feed roller can then be stopped and a platen of the flatbed die cutter can move towards the web, preferably upwards. The tension in the web and / or the web tension on the winding roller is preferably maintained. The diecuts can then be cut using a die of the platen. The tension of the web with the winding roller, which can create a higher web tension at the moment of cutting, can tear the web off at the cutting points. To prevent a grid tear, a knife can optionally be placed in the die at the intersection point of the first diecut on the sides of the sheet.This ensures controlled cutting at a desired location. Alternatively, an additional separating knife can be used to cut the web at a desired location, e.g., approximately 2 mm behind the maximum feed position. 12. At the same time, the web can be continuously fed by means of the feed roller. A movable storage roller can store the fed web, i.e., a web section of preferably a predetermined length. The storage roller can be moved by a cam disk. 13. When the cutting platen moves away from the web again, preferably downwards, the winding roller can be operated with slight web tension and the feed roller can feed the web back into the die cutter. The die-cut sheet can be fed out of the die-cutting module by one or more kicker rollers. For this purpose, the lower kicker roller can switch back to "kick" mode (feed sheet).At the same time, the movable deflection rollers / guide rollers can move away from the web again, preferably by approximately 20 mm. 14. The winding roller can be automatically deactivated after a short, preferably predefined, time. 15. The flatbed die cutter can now run in normal operation and produce diecuts. The "feed" mode is ended.

[0020] In the following (points 1 to 15), a preferred second specific development of the method according to the invention for operating a flatbed die cutter using a waste paper delivery is described in detail, whereby some of the points remain unchanged compared to the aforementioned first specific development: 1. Unchanged. 2. Unchanged. 3. Unchanged. 4. Unchanged. 5. A web feed or web pull-in can be activated (start mode "Feed"). A waste diverter can be activated, i.e. it can be set to a mode and / or position in which it directs waste to the waste delivery. The material web can be moved through the punching module and moved a distance, e.g., approximately 0.5 meters, into the waste diverter, e.g., by pushing or pulling. The web can contact a roller, e.g., a pull roller and counter roller, in the waste delivery. 6. Unchanged. 7. Starting "Feed" mode can activate a cross cutter in the waste delivery and operate it synchronously with the web feed. A (web) storage roller can be moved to an optimal position and then stopped or held in this position.A feed roller can be converted from discontinuous operation to continuous operation. Kicker rollers can move to the optimal position ("open") and then stop if necessary. 8. The die cutter (and, if applicable, the upstream printing press) can be started, and the web can be moved continuously. The feed roller and, if applicable, the feed roller can convey the web into the die cutter and to the waste diverter. Preferably immediately after the diverter, the cross cutter can separate the web and deposit the severed section, preferably over a guide plate. Alternatively, the sheet can be moved to a shredder. 9. Unchanged. 10. Unchanged. 11. At the moment phasing starts, the web can be moved to a preferably calculated or specified, suitable register position. A feed roller activated for this purpose can then be stopped.If the path to the correct register position has already been exceeded, a corresponding portion of the length of a sheet or web section to be punched can be moved into the punching module and moved to the correct register position. The feed roller can then be stopped and a platen of the flatbed die cutter moves towards the web, preferably upwards. 12. A cutting die of the platen cuts the diecuts to be produced. One or more kicker rollers can feed the remaining web out of the die cutter. The waste diverter is deactivated, i.e., returned to a mode or position for production, as soon as the cut web has passed the diverter. At the same time, the web can be continuously fed by means of the feed roller. A movable storage roller can store the fed web, i.e., a web section of preferably a predetermined length. The movement of the storage roller can be controlled by a cam disk. 13.When the cutting platen moves away from the web again, preferably downwards, the feed roller can feed the web back into the die cutter and feed or push the sheet out of the die cutting module. The die-cut sheet can be fed out of the die cutting module by one or more kicker rollers. 14. The die-cut sheet can be deposited on a sheet transporter, e.g. one or more belts. The waste diverter remains in the mode or position for production. 15. The flatbed die cutter can now run in normal operation and produce diecuts. The movement of the cross cutter and, if applicable, the material transport to the waste delivery or shredder is stopped. The first sheet can be moved via the sheet transporter to a downstream stripping unit. The "feed" mode is ended.

[0021] In the following (points 1 to 15), a preferred third specific development of the method according to the invention for operating a flatbed die cutter using a waste paper delivery is described in detail, whereby some of the points remain unchanged compared to the aforementioned second specific development: 1. Unchanged. 2. Unchanged. 3. Unchanged. 4. Unchanged. 5. Unchanged. 6. Unchanged. 7. Starting the "Feed" mode can activate a cross cutter in the waste delivery and operate it synchronously with the web feed. A (web) storage roller can be moved to an optimal position and then stopped or held in this position. A feed roller can be converted from discontinuous operation to continuous operation. Kicker rollers can be moved, in particular rotated, in such a way that a severed sheet is fed into the waste diverter. 8. The die cutter (and, if applicable, the upstream printing press) can be started, and the web can be moved continuously. The feed roller and, if applicable, the feed roller can continuously feed the web into the die cutter. The cross cutter can separate the web, and the kicker rollers can feed the severed section to the waste diverter.From there, the sheet can be conveyed preferably over a guide plate and deposited. Alternatively, the sheet can be moved to a shredder. 9. Unchanged. 10. Unchanged. 11. Unchanged. 12. A cutting die of the platen cutter cuts the diecuts to be produced. One or more kicker rollers can convey the last sheet out of the die cutter. The waste diverter is deactivated, i.e. it is brought back to a mode or position for production, as soon as the last sheet has passed the diverter. The cross cutter can be switched off. At the same time, the web can be continuously conveyed by means of the feed roller. A movable storage roller can store the conveyed web, i.e. a web section of preferably a predetermined length. The movement of the storage roller can be controlled by a cam disk. 13. Unchanged. 14. Unchanged. 15. The flatbed die cutter can now run in normal operation and produce diecuts.The material transport to the waste delivery or shredder is stopped. The first sheet can be moved via the sheet transporter to a downstream stripping unit. "Feed" mode is ended.

[0022] Not all details of the aforementioned developments need to be implemented; only a single detail or any selection of the details of the respective development may be implemented. To execute the respective process, a control device may also be present, e.g., a digital computer, particularly for storing and processing individual or all of the data listed below.

[0023] The features of the invention, the developments of the invention and the exemplary embodiments of the invention also represent advantageous developments of the invention in any combination with one another. Further developments of the invention can also have the individual features or combinations of features disclosed in the above section "Technical field of the invention". Embodiments of the invention

[0024] The invention and its preferred developments are described in more detail below with reference to the drawings using preferred embodiments. Corresponding features are provided with the same reference numerals in the figures.

[0025] The figures show: Figure 1: Implementation of a first preferred embodiment; Figure 2: Implementation of a second preferred embodiment; and Figure 3: Implementation of a third preferred embodiment.

[0026] The figures each show a machine 1 performing various preferred embodiments of the method according to the invention. The punching process is described below, among other things. Alternatively, embossing or simultaneous punching and embossing can be performed.

[0027] The figures each show a machine 1 comprising a flatbed die cutter 1. The cutter is fed with a web of printing material 2, in particular made of paper, cardboard, paperboard, or film, preferably as a cardboard web. The web can be unwound from a supply roll (not shown). The supply roll can be accommodated in a roll unwinder (not shown).

[0028] The web is preferably printed on at least one side or bears at least one print register mark. Printing can be done with the same machine, i.e. the machine can comprise at least one printing unit upstream of the die-cutter. The machine can be a printing press with an integrated or inline flatbed die-cutter. The printing unit can be an offset printing unit, a gravure printing unit, a letterpress or flexographic printing unit, or a digital printing unit, in particular an inkjet printing unit. Several identical or different upstream printing units are also possible. Alternatively, printing can be done with a different machine, e.g. a separate printing press.

[0029] The web is fed via preferably several rollers 3 along a preferably winding transport path 4. At least the roller 3a and / or 20 can be a pull roller, i.e., it can be motor-driven. At least the roller 3b can cooperate with a counter-roller or adjusting roller. The counter-roller or adjusting roller can be segmented. At least the roller 3c can be a storage roller, i.e., it can be movably arranged and motor-driven. At least the roller 3a and / or 20 can be a steel roller,

[0030] The transport path can include a so-called curl sensor 5 and / or a register sensor 6. The curl sensor is used to detect so-called curling, i.e. unwanted waves or other deformations or damage to the web, such as wavy web edges. Curling can be caused, for example, by changes in humidity and / or ambient temperature. Curling can lead to problems when processing the printing substrate. The register sensor is used to detect the print register of an imprint on the web. The register sensor can be used to detect a barcode or an area code. The transport path can include a so-called decurler 21.

[0031] The figures each show a punching module 7 of the flatbed punch 1. The module can comprise an upper punching platen 8, e.g. with a punching tool or a punching die or punching plate, and a lower punching platen 9, e.g. with a counter tool or a creasing plate. At least one of the two plates can be arranged to be movable for punching, e.g. the lower platen can perform lifting and lowering movements. At least one of the two plates can preferably comprise a plurality of punching knives (not shown). At least one of the two plates can preferably comprise a separating knife 10. The separating knife is preferably used to separate a punched sheet 2a from the web 2. The separating knife can sever the web 2 across its full width. Alternatively, the separating knife can only partially sever the web, e.g. only in the web edge area.

[0032] The figures each show an upper so-called kicker roller 11 and a lower kicker roller 12. The kicker rollers preferably serve to grip a severed sheet 2a, preferably in its trailing third, and convey it out of the punching module 7. At least one of the kicker rollers preferably comprises a lip, e.g., a rubber lip. This lip can grip a sheet severed from the web.

[0033] The Figure 1 shows embodiments with preferably one or more deflection rollers 3d and with a preferably motor-driven winding roller 13. The web 2 is guided along a transport path 4b over the deflection rollers to the winding roller. The winding roller serves to wind up an interfering section 2b of the web 2.

[0034] The Figure 1 (and the one in the Figures 2 and 3The section 2b shown in Figure 2b may, for example, exhibit curling or be otherwise deformed, damaged, and / or printed beyond use. The section is preferably separated from the web by cross-cutting or partial cross-cutting and tearing. The separated section constitutes waste paper.

[0035] Figure 1 shows a first embodiment in which the machine 1 comprises a winding roller 13, which is arranged in front of the punching module 7. The web 2 is preferably guided to the winding roller via several deflection rollers 3d. Figure 1shows second and third embodiments (shown in dashed and dotted lines, respectively), in which the respective winding roller is arranged after the punching module 7. The web 2 is preferably guided to the winding roller via a deflection roller 3d. The rollers 3d are preferably movable. "Before" and "after" are to be understood spatially: in the first embodiment 1, the winding roller is arranged relative to the module 7 in its inlet-side region; in the second and third embodiments, in its outlet-side region. In the first and second embodiments, the respective winding roller is arranged "above"; in the third embodiment, "below." "Above" and "below" are also to be understood spatially: in the first and second embodiments, the respective winding roller is arranged above the plane 14 of the transport path of the printing substrate 2 through the module 7; in the third embodiment, below the plane of this path.Preferably, an embodiment with a short transport path 4b is used, e.g., the second or third embodiment. If a prior art machine is retrofitted, the first embodiment may be preferred if the winding roller is already present in the position "in front of the punching module and below the level." In all three embodiments, the web 2 is advantageously guided through the punching module 7 before being guided to the winding roller. This enables the advantageous severing of the web in the punching module, preferably with severing elements of the punching module, e.g., one or more punching knives or at least one severing knife.

[0036] In addition to the three embodiments, Figure 1how the web guide to the winding roller 13 is solved in the prior art: The web 2 is guided along the transport path 4a shown in dashed lines, i.e. disadvantageously in front of the punching module 7 or not through it, from the storage roller 3c to the winding roller.

[0037] The Figure 2shows two further embodiments (four and five) preferably with a waste diverter 15, preferably a guide plate 15a and preferably with a waste delivery 16. A severed web section or a sheet 2a is guided via the diverter to the delivery; the guide plate can support this. In addition to or as an alternative to the delivery, a shredder (not shown) can be provided for the waste. The web section or the sheet 2a can be separated from the web 2 by a cutting device 17, e.g. a rotating cross cutter 17. This can be arranged between the punching module 7 and the kicker rollers 11 and 12; alternatively (in dashed lines) between the kicker rollers and the delivery. The winding roller 13 is not required in this embodiment; however, it can still be present for another purpose.

[0038] The Figure 3shows two further embodiments (six and seven), also preferably with a waste diverter 15, preferably a guide plate 15a and preferably with a waste delivery 16. A severed web section or a sheet 2a is guided via the diverter to the delivery; the guide plate can support this. In addition to or as an alternative to the delivery, a shredder (not shown) can be provided for the waste. The web section or the sheet 2a can be separated from the web 2 by a cutting device 17, e.g. a rotating cross cutter 17. This can be arranged between the punching module 7 and the kicker rollers 11 and 12; alternatively (in dashed lines) between the kicker rollers and the delivery. The winding roller 13 is not required in this embodiment; however, it can still be present for another purpose. List of reference symbols

[0039] 1 Machine with or flatbed die cutter 2 Printing material or web 2a Sheet 2b Web section 2c Waste 3 Rollers 3a Feed roller 3b Roller with counter roller 3c Storage roller 3d Deflection rollers 4 Transport path (web feed) 4a Transport path 4b Transport path 4c Transport path (die-cut product) 5 Curl sensor 6 Register sensor 7 Die-cutting module 8 Upper die platen 9 Lower die platen 10 Separating knife 11 Upper kicker roller 12 Lower kicker roller 13 Winding roller 14 Level 15 Waste deflector 15a Guide plate 16 Waste delivery 17 Cutting device or cross cutter 18 Print image 19 Control device 20 Feed roller 21 Decurler

Claims

1. Method for operating a printing press with an integrated or inline-connected flatbed die-cutter and with a printing unit arranged upstream of the die-cutter, wherein printing material (2) is fed as a web (2) to a die-cutting module (7) of the flatbed die-cutter (1), said web (2) is passed through the die-cutting module (7) and a web section (2b) is separated from the web in or after the die-cutting module and removed as spoilage (2c), characterized in that the web section (2b) is cut off by a cross-cutter (17) - which is distinct from a die-cutting knife of the die-cutting module - said cross-cutter (17) being either rotary or reciprocating, or the web section (2b) is only partially cut a cross cutter - which is distinct from a die-cutting knife of the die-cutting module - and subsequently torn off; wherein the spoilage (2c) is mechanically removed either i) in web form (2c) and wound onto a winding roller (13), or ii) in sheet form (2c) and deposited or shredded; wherein the die-cutting module (7) is activated and / or operated during or after the removal of the web section (2b), in register and at a speed corresponding to a printed image (18) produced on the web (2) by the printing unit; and wherein feeding of the web (2) to the flatbed die-cutter (1) and guiding of the web through the die-cutting module (7) is initiated at the beginning of a production run of the printing press, continued without interruption during the removal of the web section and the register-accurate and speed-synchronized die-cutting, and only terminated at the end of the production run.

2. Method according to claim 1, characterized in that the separated web section (2b) is transported out of the die-cutting module (7) by means of a pair of rollers (11, 12).

3. Method according to claim 2, characterized in that the cross cutter (17) is arranged before or after the pair of rollers (11, 12).

4. Method according to one of the preceding claims, characterized in that the sheet (2c) is diverted from a transport path (4c) by means of a diverter (15).