Method for process parameter configuration in a converting machine and related converting machine

Abstract

The present invention relates to a method for changing operating parameters in a converting machine. The converting machine comprises an inlet section having a loader module and a feeder, a processing section, and a delivery section, and wherein the converting machine further comprises an optical detection system, the converting machine being configured to convey sheet elements in a direction of transportation, the method comprises the steps of implementing the set of changed configuration parameters to a disabled upstream section, and operating the delivery section of the converting machine while the upstream section of the converting machine is disabled.

Description

[0001] METHOD FOR PROCESS PARAMETER CONFIGURATION IN A CONVERTING MACHINE AND RELATED CONVERTING MACHINE

[0002] Field of the invention

[0003] The present invention relates to a converting machine for packaging elements, such as flat-packed and folded slotted boxes. In particular, the invention relates to a method for changing operating parameters in a converting machine and a related converting machine.

[0004] Background

[0005] Converting machines such as rotary die cutters and folder-gluers respectively produce packaging elements such as flat-packed and folded slotted boxes. These machines comprise a plurality of different work modules which are configured to process sheets of cardboard or similar materials.

[0006] The same machine is used in the production of many different types of boxes, where the format, type of packaging material and printed features change.

[0007] This requires many changes to the configuration or operation parameters of the machine when the format, type of packaging material or printed features change. Such changes or adaptations may include changing printing plates and anilox cylinders in printing modules, replacing die-cutting tools in cutting modules or modifying the positions of the cutting- and creasing tools in slotter assembles. All these changes in configuration are time consuming for a machine operator and results in lost production time.

[0008] Summary

[0009] It is an object of the present invention to reduce the idle time of the converting machine when modifying the machine configuration to accommodate for changed characteristics of the packaging elements.

[0010] This object is solved by a method according to claim 1 and a converting machine according to claim 10. Other optional features and advantageous embodiments of the invention are detailed in the appended dependent claims. According to a first aspect of the present invention, there is provided a method for changing operating parameters in a converting machine. The converting machine comprises an inlet section having a loader and a feeder, a processing section, and a delivery section, the converting machine further comprises an optical detection system, the converting machine being configured to convey sheet elements in a direction of transportation. The method comprises the steps of:

[0011] • comparing a set of operating parameters for a first production batch to a following set of operating parameters for a second production batch, and determining a set of required configuration parameters which are to be changed,

[0012] • detecting with the optical detection system when an upstream portion which is located upstream of the delivery section of the converting machine is empty of sheet elements,

[0013] • disabling the upstream portion of the converting machine,

[0014] • implementing the set of required configuration parameters which are to be applied to the disabled upstream section, and

[0015] • operating the delivery section of the converting machine while the upstream section of the converting machine is disabled.

[0016] One aspect of the invention is based on the fact that an optical detection system can detect when the converting machine is partially empty of sheet elements, and thus let the converting machine enter into an “end of production mode”. In the « end of production mode », a downstream section of the converting machine is continuing its operation according to a first set of operating parameters, while the upstream section shuts down, becomes inoperable and enters into a configuration mode such that a required set of operating parameters can be modified and applied to the inlet section and the processing section of the converting machine in view of the next job to be carried out.

[0017] In such a way, the transition from a current job command to a next job command is automated and thus requires a reduced idle time for the converting machine. Hence, a sequential shut down and re-configuration of the machine is performed. The term “sheet elements” can be defined as sheets having a square or rectangular shape, as well as printed sheets and cut-to shape blanks. In the loader module and the feeder module, the sheet is in the form of a square or rectangular sheet.

[0018] In the processing section, the sheet is transformed into a cut-to-shaped blank. In the delivery section the sheet elements are in the form of packaging element such as folded slotted boxes or flat-packed boxes.

[0019] The term “operating parameters” can be defined as all parameters which may be subject to change in the converting machine. These parameters include in particular all parameters which may change between different production batches. The operating parameters include operating settings which are electronically implementable. These settings may include speeds, forces, and register settings.

[0020] The operating parameters may also include automated mechanical displacements. These displacements are automatically effectuated by actuators and motors. Such automated mechanical displacements include displacements of conveyors, tools, printing cylinders (to adjust printing clearances) etc.. These automated mechanical displacements may be automatically implemented by the main control system of the converting machine. The displacements effectuated by actuators and motors may also provide displacements of machine parts to render tools accessible for manual replacement.

[0021] Another type of operating parameters are manual machine part displacements and replacements. These operating parameters can be partially modified by the displacements effectuated by actuators and motors. However, some operating parameters manual may require a completely manual intervention. The control system of the converting machine is preferably configured to display the operating parameters which need a manual change on an operator interface.

[0022] The term “configuration” can be defined as the settings, the arrangement and position of different tools and machine parts. Some tools and machine parts may be displaced in the converting machine, while others are replaced. The term “configuration parameters” thus includes a plurality of settings, components and positions of components which are subject to be changed. When changing the configuration of the converting machine, at least some operating parameters are changed. The upstream section which is located upstream of the delivery section may be the inlet section or the processing section, or both the inlet section and the processing section.

[0023] A following second production batch comprises packaging elements that are different from the packaging elements in a first production batch. The difference may be in terms of printed motif, dimensions and / or materials. The definition of the term “production batch" is a number of packaging elements having the same characteristics and being produced in a continuous sequence. The control system of the converting machine determines a difference in operating parameters between the first and second production batches and determines the changes in the machine configuration which need to be effectuated.

[0024] Brief description of the drawings

[0025] The invention will now be described with reference to the appended drawings, in which like features are denoted with the same reference numbers and in which:

[0026] Figure 1 is a schematic view of a converting machine in the configuration of a flexo folder-gluer;

[0027] Figure 2 is a schematic perspective view of a converting machine in the configuration of a rotary die cutter;

[0028] Figure 3 is a schematic perspective view of an exemplary delivery module for the converting machines in figures 1 and 2;

[0029] Figures 4a to 4c are schematic views of a sheet substrate, a flat-packed box and a folded slotted box;

[0030] Figure 5 is a schematic perspective view of an inlet portion of a converting machine according to an embodiment of the present invention;

[0031] Figure 6 is a schematic perspective view of a loader module according to an embodiment of the present invention;

[0032] Figure 7 and 8 are detailed schematic views illustrating a loader discharge conveyor;

[0033] Figure 9 is a schematic perspective view of a die-cutting module; Figure 10 is a schematic perspective view of a slotter module;

[0034] Figure 11 is a schematic view of a die-cutter module and a stripping module in an operating state;

[0035] Figure 12 is a schematic view of a die-cutter module and a stripping module in an open state ready for changing tools;

[0036] Figure 13 is diagram of a control circuitry according to an embodiment of the present invention;

[0037] Figure 14 is a schematic perspective view of an anilox handling carriage and its trajectory in a converting machine;

[0038] Figure 15 is a schematic diagram of a method of detecting sequential emptying of a converting machine; and

[0039] Figure 16 is schematic diagram of a method of changing operating parameters a converting machine.

[0040] Detailed description

[0041] General description of a modules in the PRO and FFG machines

[0042] Referring to the figures and in particular to figures 1 and 2 which respectively illustrate a converting machine 1 in the form of a flexo-folder gluer and a rotary die cutter.

[0043] As illustrated in figure 1 , a flexo-folder gluer may comprise successively in a direction of transportation T: a loader 2 for automatically loading stacks S (see figure 5) of sheets 3 (see figures 4a, b or c for example), a feeder module 4, a printing module 6 comprising a plurality of flexographic printing units 8, a converting module 10 comprising a slotter module (see figure 10) with at least one slotter assembly, and a folding-gluing unit 12. The converting machine 1 comprises a main control system 20 configured to control the overall operation of the converting machine 1. A main operator interface 16 may also be provided in the proximity of the converting machine 1.

[0044] As illustrated in figures 4a to 4c, packaging elements 3’ produced from the sheets 3 may be shaped as folded and glued boxes 3’ (see fig. 4a), also referred to as “folding boxes”. Alternatively, the packaging elements 3’ may be configured as flat- packed boxes 3’ (see fig. 4b), which are cut to shape as printed sheet elements 3 which can be assembled by manual folding.

[0045] The converting machine 1 also comprises a delivery module 14, which may be in the form of banding module 14, or a palletizer module 14 as illustrated in figure 3. The delivery module 14 is configured to group the produced packaging elements 3’ into stacks or bundles.

[0046] As best seen in figure 3, the palletizer module 14 may comprise a rotating table 11 , a breaker 13, a layering device 15, a squaring table 17, a bundle inverter 19, and a pile stacker 21 . The palletizer module 14 may also comprise a pallet entry conveyor 25 and an exit conveyor 23. The exit conveyor 23 is thus the outlet for the stacks of packaging elements 3’ positioned on the pallets.

[0047] The rotating table 11 is rotating the stack of juxtaposed packaging elements 3’ to position severance lines in relation to pressing plates of the breaker 13. The breaker 13 is configured to break the severance lines to separate juxtaposed blanks 3’. The layering device 15 is configured to arrange the packaging elements 3’ in layers. The squaring table 17 is configured to straighten the packaging elements 3’. The bundle inverter 19 is configured to rotate 180° the stacks to distribute the arrangement of the packaging elements 3’ in the piles for better stability. The pile stacker creates a stack of finished packaging elements 3’.

[0048] As illustrated in figure 2, the rotary die-cutter converting machine 1 is similarly configured as the flexo-folder gluer 1 in the sense that it also comprises a loader 2, a feeder module 4, printing module 6 comprising a plurality of printing modules 8, and a delivery module 14. However, the rotary die-cutter 1 comprises a different converting module 10 in the form of a rotary die-cutting module 10 and may be deprived of a folding-gluing module.

[0049] Hence commonly, the converting machines 1 of figures 1 and 2 comprise a loader module 2. The converting machine 1 further comprises a drive system provided with rollers and conveyor belts configured to drive the sheet elements 3 forward in a direction of transportation T through the converting machine 1 .

[0050] The loader module 2 and the feeder module 4 may be referred to as an inlet section S1 of the converting machine 1. The printing module 6 and the converting module 10 can be referred to as a processing section S2 of the converting machine 1. In the processing section S2, different mechanical operations are performed on the sheets 3. These operations include in particular printing and cutting the sheets 3.

[0051] A delivery section S3 is located downstream of the processing section S2 in the direction of transportation T. The delivery section S3 is configured to condition a stream of packaging elements 3’ into stacks or bundles. The delivery section S3 includes a delivery module 14 such as a palletizer module. Such a module with included devices is described in the documents EP3931139 A1 and EP3445549 A1 , which are incorporated herein by reference.

[0052] As illustrated in figures 5, 7 and 8, the loader module 2 is positioned upstream of the feeder module 4 and is configured to load separate batches B of sheets 3 into the feeder module 4 of the converting machine 1 . The loader 2 comprises an inlet conveyor 32, a vertically movable loading surface 34, a batch separator 36, a transportation arm 38, and a gauge 40.

[0053] The inlet conveyor 32 is configured to receive a plurality of stacks S and transport them further downstream onto the vertically movable loading surface 34. The inlet conveyor 32 allows loading the stacks S into the loader 2 with for instance a forklift or a robot gripper.

[0054] The vertically movable loading surface 34 moves stepwise upwards in the vertical direction and such that the batch separator 36 can move horizontally to push off separate batches B from the top of the stack S and place them onto a discharge conveyor 39of the transportation arm 38. The discharge conveyor 39 is configured to convey sheets S in a shingled stream with the help of the gauge 40. Preferably, the discharge conveyor 39 comprises a plurality of belt conveyors 39’ which convey the shingled stream of sheets S onto a loading surface 42 of the feeder module 4.

[0055] As best seen in figures 7 and 8, a distal outlet end 44 of the discharge conveyor 39 is preferably positioned upstream of the rear end of the sheets 3 positioned on the feeder loading surface 42. In such a way, the full longitudinal length of the sheets 3 can enter into the feeder module 4 without touching the discharge conveyor 39. The transportation arm 38 further comprises a telescopic frame 45 to which the discharge conveyor 39 is mounted. The telescopic frame 45 allows changing the length of the discharge conveyor 39 to adapt to different longitudinal lengths of the sheets 3. The telescopic frame 45 may be rotatably attached to a chassis 46 of the loader 2 such that it can be raised in the vertical direction V.

[0056] The longitudinal length of the transportation arm 38 in the horizontal direction H may be automatically set based on the longitudinal length of the sheets 3. Additionally, or alternatively, the longitudinal length of the transportation arm 38 can be manually set from an operator interface 16.

[0057] As illustrated in figure 14, the converting machine 1 may further comprise an anilox handling carriage 120, such as the one described in the document EP3927551. The anilox handling carriage 120 is configured to move and transport anilox cylinders (not illustrated) between flexographic printing units 8, a storage station 122 in the printing units 8 and a main storage station 124 located under the feeder module 4.

[0058] As illustrated in figures 9 and 10, the converting module 10 may be a rotary diecutting module 10 or a slotter module 10. These modules may be equipped with actuators 60 which enable an automatic displacement of cutting tools or actuators 48 which enable machine components to be distanced away from each other.

[0059] As illustrated in figure 9, the rotary die-cutting module 10 comprises a tool-holder cylinder 21 and an anvil 22. The die-cutting module 10 cuts and scores the sheets 3 to define the shape and location of folds on the sheet elements 3. The tool holder cylinder 21 comprises a die 24 provided with cutting edges 26 and creasing edges 28. The die-cutting module 10 may be provided with an actuator 48 which displaces the anvil 22 or the tool holder cylinder 21 such as to increase a clearance between therebetween.

[0060] As illustrated in figures 11 and 12, a stripping module 49 may be located downstream of the die-cutting module 10. The stripping module 49 is configured to release and remove cut-away sheet material from the sheet elements 3.

[0061] The stripping module 49 may be provided with a displacement mechanism 52. In such a way, the stripping module 49 can be horizontally moved apart from the diecutting module 10 such as to create space for a machine operator to enter in a space between the stripping module 49 and the die-cutting module 10 and replace the dies. The stripping module 49 may further comprise a locking mechanism 55 such as to create a fixed connection to the die-cutting module 10 when the diecutting module 10 is in use.

[0062] As illustrated in figure 10, the slotter module 10 comprises a plurality of cooperating upper disc-shaped tools 54a and lower disc-shaped tools 54b which are configured to cooperate in the formation of cut lines and cease lines in the sheets 3. The discshaped tools 54a, 54b are mounted in tool holders 56 which are slidably mounted on a respective upper cylinder shaft and lower cylinder shafts 58a, 58b. A displacement mechanism 60 for the disc-shaped tools is configured to displace the upper and lower disc-shaped tools 54a, 54b along the shafts 58a, 58b such as to change the position of the cut lines and crease lines on the sheets 3.

[0063] As illustrated in figure 13, the converting machine 1 further comprises a control circuitry 70. The control circuitry 70 comprises a main control system 20 configured to control the overall operation of the converting machine 1.

[0064] The control circuitry 70 may further comprise a plurality of sub-systems such as a register control system 74, a security control system 76, a pre-feeding control system 78, a stacker control system 80 and a drive and operating control system 82.

[0065] The drive and operating control system 82 is configured to control actuators and motors, and is further configured to control sheet transportation drive elements such as vacuum transfer modules. The vacuum transfer modules 51 comprise transportation elements such as drive roller or conveyor belts and apply suction to the sheets. Such vacuum transfer modules are further described in document EP4225541 A1.

[0066] As illustrated in figures 1 , 2, 3 and 5, the security control system 76 may comprise a plurality of security zones Z1 , Z2 controlled by light curtains. The security zones Z1 , Z2 may be closed off by a combination of fences and light curtains. A first security zone Z1 may be located around the inlet section S1 , and second security zone Z2 at the delivery section S3. The light curtains prevent human access to the converting machine 1 during production and will sense a passage of an inadmissible object or a human into the security zone Z1 , Z2. When such an intrusion is detected, a warning signal and / or a shutdown of the converting machine 1 is generated. Hence, the light curtains may be configured to allow a selective passage, i.e. to allow the passage of an admissible object such as a stack of sheets.

[0067] As illustrated in figure 5, the first security zone Z1 may comprise a detection unit 86 having at least one muting sensor 87 arranged at the inlet to the feeder module 4. The muting sensor 87 may allow the passage of a stack S through the light curtain without issuing an intrusion control signal. The light curtain may be turned off when the entire converting machine 1 or the specific modules located within the security zones Z1 , Z2 are turned off. Alternatively, the light curtain may be enabled / in operation but is configured to allow the passage of a machine operator without generating an intrusion control signal when the entire converting machine 1 or the specific modules located within the security zones Z1 , Z2 are turned off . This provides an advantage of providing an easy access to the converting machine 1 when the light curtain is turned off or allows a passage.

[0068] The register control system 74 is configured to detect the actual position of each sheet 3, determine the amount of the register displacements and provide a displacement correction to each sheet 3. Such a register control system 74 is described in the documents WO23025730 and EP4225541.

[0069] The register control system 74 comprises a feed sensor 90 (see figure 1) located between the feeder module 4 and the first printing module 8. Transfer sensors 92 (see figures 1 and 13) are positioned upstream of each printing unit 8 and upstream of the converting unit 10 . The feed sensor 90 and the transfer sensors 92 detect the time of passage of the front edge 3a of each sheet 3 and a register control unit 94 calculates if the sheet 3 arrives too early or too late to each printing unit 8 or converting unit 10 in relation to its predefined register position.

[0070] The loader 2 is connected to the pre-feeding control system 78. The pre-feeding control system 78 comprises a prefeed sensing system 96, a loader control unit 98, a counter 99 and a memory 100.

[0071] The prefeed sensing system 96 may comprise a passage sensor 102 configured to detect the passage of a stack S on the inlet conveyor 32 to the vertical loading surface 34.

[0072] The passage sensor 102 may be an occultation sensor comprising a light transmitter and receiver placed on opposite sides of the inlet conveyor 32. When the stack S passes, a light signal is broken, and the counter 99 determines the number of stacks S which have passed the passage sensor 102. The passage sensor 102 may be a dedicated transfer sensor or part of the security control system 76, such as a light curtain sensor.

[0073] Preferably, a stack height sensor 104 may be arranged upstream of the vertically movable loading surface 34. The stack height sensor 104 is configured to detect the height of the stack S. The stack height together with the vertical position of the vertical loading surface 34 can be used for the loader control unit 98 to determine when a last batch B from each respective stack S is discharged from the vertical loading surface 34.

[0074] The prefeed sensing system 96 may further comprise a transfer sensor 105 located on the feeder arm 38. The transfer sensor 105 is configured to detect the passage of the sheets 3 and provide a detection signal when the loader discharge conveyor 39 is empty of sheets 3.

[0075] Each time the type of packaging elements 3’ to be produced changes, a change of several operating parameters is needed. These operating parameters comprise the transportation speed, the feeder discharge timing, the type and position of cutting tools, types of anilox cylinders and printing plates, and the longitudinal position of the loader discharge conveyor 39.

[0076] The main control system 20 may be configured to receive operating parameters for several future production batches and store the operating parameters in a production log memory 108. A plurality of pre-programmed operating parameters for a plurality of different jobs can thus be stored in the memory of the main control system 20, or at a remote server location.

[0077] The main control system 20 is further configured to compare a set of first operating parameters of a first production batch to second set of operating parameters of a following production batch. The main control system 20 is also configured to determine the operating parameters which need to be changed and to which amount. The required change in operating parameters may be indicated on the operator interface 16. The operator interface 16 may be a remote interface located in a cloud network, and / or the machine interface 16 on the machine. Adjustments which require manual intervention from the operator are preferably displayed on the machine interface 16.

[0078] The operating parameters can be entered into the machine control system 20 from the operator interface 16 or from a remote computing location. The remote computing location may be at the premises of the converting machine operator, or at a remote site. For instance, the operating parameters may be transferred to the control circuitry of the converting machine from an enterprise resource system (ERP) at the remote site.

[0079] Each production batch may be associated with a number of sheet stacks S. The sheets 3 in the stacks S may be partially or entirely pre-printed, or be deprived from printed features, and may have a specific paper quality which is different from a following production batch.

[0080] According to the present disclosure, the main control system 20 further comprises an end of production control system 75. The end of production control system 75 is configured to detect an approaching end of a production batch. The approaching end of a production batch occurs when an upstream portion S1 , S2 of the converting machine 1 is empty.

[0081] The upstream portion of the converting machine 1 may be the inlet section S1 or the processing section S2. Hence the approaching end of a production batch occurs when any of the loader module 2, the feeder module 4, the converting unit 10 or the stacker module 18 is empty.

[0082] The end of production control system comprises a sensing system 110, a memory 112 and a control unit 114.

[0083] The sensing system 110 comprises a plurality of sensors 90, 92 distributed along the direction of transportation T. The control unit 114 is configured to receive control signals from the sensing system 112 and determine an approaching end of a current production batch. In an embodiment, the sensing system 110 comprises a plurality of dedicated sensors 90, 92, only used for detecting the approaching end of a production batch. The dedicated sensors 90, 92 may be optical sensors configured to detect the passage of the sheet elements 3. However, in another embodiment, the end of production control system 75 is configured to receive control signals from the pre-feeding control system 78 and the register control system 74. Optionally, the end of production control system 75 may also receive control signals from the security system 76. The control unit 114 of the end of production control system 75 is configured to receive detection signals from respective control units 94, 98 in the pre-feeding control system 78 and the register control system 74 and determine an approaching end of production state of a current work batch.

[0084] The present end of production system 75 preferably detects a sequential emptying of the converting machine 1. That is to detect which modules still contain sheet elements 3 and which ones are empty of sheet elements 3. In such a way, the sequential emptying of the converting machine 1 is detected in a plurality of sequential steps Stepl to Step6.

[0085] Preferably, and as illustrated in figure 15, the approaching end of a production batch can be initially sensed in a first step Stepl as the converting machine 1 detects the passage the last stack on the inlet conveyor 32 of the loader 2 with the passage sensor 102 (see figure 5). To determine that the last stack S has passed, the pre-feeding control system 78 receives the total initial number of stacks N to process and counts the number of stacks S delivered to the loader 2 with the passage sensor 102. The total initial number of stacks N may be provided in the production log memory 108.

[0086] Alternatively, the machine operator may enter the initial number of stacks N into the main control system 20. This can be entered into the user interface 16 of the converting machine 1. The end of production control system 75 may further receive information comprising the number of packaging elements 3’ to be produced. Optionally the number of sheets 3 in each stack S is provided to the end of production control system 75.

[0087] The end of production control system 75 may be configured to continuously track the number of remaining stacks S for the batch in production (i.e. for the current production job).

[0088] In an alternative embodiment, the number of produced packaging elements 3’ may also be continuously counted to determine the end of a production batch. However, this may be less accurate than tracking the number of stacks S available to the loader 2, as sheets may be discarded from the stack S before being placed in the feeder 4, and sheets 3 may also be discarded in-line in the converting machine due to paper-jams etc.

[0089] In a sequential manner, a second detection step Step2 is performed as a last batch of sheets B is discharged from the vertical loading surface of the loader module 2. This also means that the vertical loading surface 34 is in its upper position.

[0090] In a third detection step Step3, the transfer sensor 105 detects the passage of a last sheet 3 on the discharge conveyor 39 and provides a detection signal that indicates that the loader module 2 is empty.

[0091] After the loader module 2 is empty of sheets 3, the register control system 74 may detect in a fourth step Step4 that the feeder module 4 is empty. However, if the converting machine 1 does not comprise a loader 2, a first indication of an approaching end of production may be that the feeder module 4 is empty. This also means that the full inlet section S1 is empty.

[0092] The feeder module 4 is determined to be empty of sheets 3 as the register control system 74 detects the passage of the last sheet 3 from the feeder module 4 with a feed sensor 90. This can be done by detecting a time lapse issued from the last detection by the feed sensor 90. The time threshold may be between 1 and 10 seconds. The feed sensor 90 can be a separate sensor for the end of production system 75 or a feed sensor belonging to the register control system 74.

[0093] In a following third step Step5, the passage of the last sheet element 3 in the processing S2 section is detected with a transfer sensor 92 located downstream of the processing section S2. The passage of the last sheet element 3 can be determined from a time lapse from a last detected sheet element 3 with the transfer sensor 92. If the time lapse is larger than a time threshold, the control unit 114 determines that the processing section S2 of the converting machine 1 is empty. In another embodiment, the register control system 74 is configured to determine when the last sheet 3 is discharged from the feeder module 4 has passed the processing section S2. This can be done as the memory 91 of the register control system 74 tracks the position of each sheet 3 with the feed sensor 90 and transfer sensors 92. The register control system 74 can be configured to determine the exact location of each sheet 3. Hence, the register control system 74 is configured to determine when a module in the processing section S2 of the converting machine 1 is empty of sheet elements 3.

[0094] Sixth trigger- stacker module is empty

[0095] Additionally, a detection signal may be provided from a transfer sensor 92 located downstream of a stacker module 18. The detection signal may indicate that the stacker module 18 is empty. This corresponds to a sixth detection step Step6.

[0096] Preferably, the end of production control system 75 may be configured to detect the sequential emptying of the converting machine 1 in a steps Stepl to Step6 in a conditional order. Hence, to detect the second step Step2, the first step Stepl must have occurred.

[0097] The end of production control system 75 is configured to automatically and stepwise change at least some of the machine operating parameters. Additionally, the end of production control system 75 may be configured to facilitate manual intervention from an operator by automatically rendering components requiring a manual change accessible for the operator.

[0098] As illustrated in figure 16, by using the end of production control system 75, a method for changing operating parameters may comprise the steps of:

[0099] In a first step StepA, comparing a set of operating parameters from a first production batch with a set of operating parameters for a second production batch, and determining a set of required configuration parameters which are to be changed. The first production batch preferably occurs earlier in time than the second production batch. Optionally, it may also be determined a sequence according to which the operating parameters have to be changed. This sequence may be stored in the memory of the converting machine 1.

[0100] In a second step StepB, detecting with the optical detection system when an upstream portion of the converting machine 1 is empty of sheet elements. The upstream portion is the inlet section S1 or the processing section S2 of the converting machine 1 which is an upstream portion of the converting machine 1.

[0101] In a third step StepC, disabling the upstream portion of the converting machine. The term “disabling” can include a complete shut-down of the upstream portion of the converting machine 1 . However, it is also possible to enter the upstream portion into an idle mode. In this mode, the upstream portion of the converting machine 1 is in standby. In the standby mode, the parts of the control circuitry 70 dedicated to the upstream portion of the converting machine 1 is operable to retain process parameter information. In the standby mode, machine components which are in motion during a production run (such as vacuum transfers, motors for printing units and the security zones) are inoperable / stationary.

[0102] In a fourth step StepE, implementing the set of required configuration parameters which are to be implemented for the disabled upstream portion, while operating the delivery section S3 of the converting machine 1.

[0103] The control unit 114 may indicate on the user interface 16 the operating parameters which need manual adjustment as the upstream portion becomes empty of sheet elements 3. It may also be indicated on the user interface 16 the parameter adjustments and the associated sequence on the user interface.

[0104] Preferably, some configuration parameters are automatically set. These parameters may include settings such as transportation speed, the longitudinal position of the distal outlet portion 44 of loader discharge conveyor 39, the vacuum suction force in vacuum transfer units 51. The settings may further include modifying the feeder module settings in terms of positions of side guides, top gauge, vacuum suction force, and axis configurations of the printing cylinders to accommodate for skewing printing error, centerings, blank length and production speed. The printing gap between printing plate and counter cylinder may also be automatically modified.

[0105] The updated operating settings may also be pre-programmed such that they are automatically activated once the main control system 20 detects a change of work batch.

[0106] The loader conveyor arm 38 may be retracted from the feeder module 4. In the illustrated embodiment of figures 6 and 7, the horizontal length of the loader conveyor arm 38 can be changed such that the distal end 44 of the loader conveyor arm 38 is moved horizontally away from the feeder module 4. Additionally, or alternatively, the loader conveyor arm 38 can be lifted and rotated upwards. In such a way, the feeder module 4 and the loader 2 are spaced apart and changes to the feeder module 4 and loader 2 can be effectuated. The required configuration parameters of the loader 2 are preferably implemented before the feeder.

[0107] A cleaning program of the anilox cylinders is initiated when the printing module 6 is turned off. The anilox cleaning system 113 is configured to determine required displacements of anilox cylinders with the handling carriage. This may already be calculated as soon as the operating settings of the different production batches are entered into the production log memory 108. The characteristics of the anilox rolls may be stored in a memory 116.

[0108] In a first cleaning step, the printing units 8 automatically launch a cleaning procedure of the anilox cylinders within the respective printing units 8. Additionally, in a second step, the cleaning program may include a deeper cleaning procedure with ultrasonic cleaning devices in a separate cleaning station 125 (see figure 14). The separate cleaning station may be located at the inlet of the converting machine 1.

[0109] The anilox cylinders may be automatically released after the processing section S2 is turned off. The control unit 115 of the anilox cleaning system 113 determines which anilox cylinder to be used for the subsequent job. If the particular anilox cylinder is not used in the subsequent production batch, then the anilox handling carriage 120 is configured to remove the anilox cylinder from the flexographic printing assembly and displace the anilox roll to a storage station 122 within the printing unit 8 or the storage station 124.

[0110] Some operating parameters such as changing printing plates and removing and replacing die-cutter dies need manual interaction from a machine operator. These changes to the machine configuration are more time consuming but according to the present disclosure, these operations can be semi-automatically performed to reduce the required intervention time from the operator.

[0111] The control unit 114 of the end of production control system 75 may indicate on the user interface 16 the parameters which need manual adjustment. The parameter adjustments and the associated sequence may also be indicated on the user interface 16.

[0112] The first security zone Z1 arranged around the inlet section S1 may be disabled when the feeder module 4 is empty. When the inlet section S1 is disabled, the security control system 76 shuts off the security light curtain of the first processing section S1 of the converting machine 1 , while maintaining the second security zone Z2 of the security system activated for the delivery section S3 of the converting machine 1.

[0113] Changing the dies in the die-cutting module 10 may require a manual extraction of the dies. In the converting machine 1 , the die-cutting module 10 is placed next to the stripping module 49.

[0114] To facilitate operator access to the die-cutting module 10, the stripping module 49 is connected to a displacement mechanism 52 configured to displace the stripping module 49 in the horizonal direction away from the die-cutting module 10.

[0115] As illustrated in figures 10 and 11 , a vacuum transfer unit 51 is located between the stripper module 49 and the stacker module 18. To displace the stripping module 49, an actuator 53 is configured to rotate the vacuum transfer unit 51 upwardly, such as to create space for displacing the stripping module 49 further downstream in the direction of transportation T. In such a way, the stripping module 49 may be displaced underneath the vacuum transfer unit 51. The displacement of the stripping module 49 and the rotation of the vacuum transfer unit 51 is effectuated when the end of production control system 75 determines that the stacker module 18 is empty.

[0116] Hence, when the stacker module 18 is empty, the method may further comprise the step of rotating the vacuum transfer unit 51 and horizontally displacing the stripping module 49.

[0117] The disc-shaped tools tool-holder cylinder 21 in the die-cutting module 10 may be displaced with the displacement mechanism 48 allowing the tool-holder cylinder 21 to be distanced away from the counter cylinder 22.

[0118] If a slotter module 10 is used, the disc-shaped tools 54a, 54b may be displaced with the displacement mechanism 60 for the disc-shaped tools, when the processing section S2 is empty.

[0119] When the processing section S2 is empty, the drive and operating control system 82 may turn off transportation elements, such as belts and rollers and vacuum generators in the inlet section and processing section S2. The converting machine 1 may be automatically restarted. The main control system 20 is configured to detect when all automatic operating parameters have been implemented and when the manual interventions have been performed. The manual interventions can be determined as completed when the modules housing the element subject to the manual intervention have been opened and closed. For instance, the operator may close a housing or move a machine part in the converting machine 1 . This may trigger a signal to the main control system 20 which indicates that the manual intervention has been completed.

Claims

CLAIMS1 . A method for changing operating parameters in a converting machine, the converting machine comprising an inlet section having a loader module and a feeder, a processing section, and a delivery section, and wherein the converting machine further comprises an optical detection system, the converting machine being configured to convey sheet elements in a direction of transportation, the method comprises the steps of:• comparing a set of actual operating parameters for a first production batch to a following set of operating parameters for a second production batch, and determining a set of required configuration parameters which are to be changed,• detecting with the optical detection system when an upstream section which is located upstream of the delivery section of the converting machine is empty of sheet elements,• disabling the upstream section of the converting machine,• implementing the set of changed configuration parameters to the disabled upstream section, and• operating the delivery section of the converting machine while the upstream section of the converting machine is disabled.

2. The method according to claim 1 , further comprising the steps of:• detecting when the delivery section is empty, and• implementing a new set of configuration parameters to the delivery section.

3. The method according to claim 1 or 2, wherein the inlet section is disabled and re-calibrated before the processing section.

4. The method according to any one of the preceding claims, wherein the inlet section comprises a plurality of detectors and wherein the loader module is determined to be empty when a last package of sheets is loaded into the feeder module.

5. The method according to any one of the preceding claims, wherein the feeder is determined to be empty after a control signal is issued when the loader is empty of sheet elements and when a feed sensor detects the passage of a last of sheet element downstream of the feeder.

6. The method according to claim 4 or 5, wherein new operating parameters of the loader module are implemented before new operating parameters of the feeder.

7. The method according to any one of the preceding claims, wherein cleaning of the anilox cylinders within a flexographic printing unit is initiated when the processing section is turned off.

8. The method according to the preceding claim, wherein an anilox handling carriage being configured to receive a sequence of anilox displacements between the printing arrangement, a storage station and a cleaning station and wherein a step of displacing anilox cylinders is initiated when the processing section is turned off.

9. The method according to the preceding claim, wherein the step of releasing the anilox cylinders from the printing units is initiated when the processing section is turned off.

10. A converting machine comprising an inlet section having a loader module and a feeder module, a processing section, and a delivery section, and wherein the converting machine is configured to convey sheet elements in a direction of transportation (T), and wherein the converting machine comprises an end of production control system, the end of production control system comprises: a memory containing operating parameters for a plurality of sequential work batches, a control unit, a sensing system comprising a pre-feeding sensing system, a feed sensor (90) and a plurality of transfer sensors (92) distributed alongthe direction of transportation (T), the control unit being configured to receive control signals from the sensing system and detect when an upstream section which is located upstream of the delivery section of the converting machine is empty of sheet elements, and wherein the control unit is configured to disable the upstream section of the converting machine when it is empty of sheet elements.11 . The converting machine according to claim 10, wherein the control unit is configured to compare a set of actual operating parameters for a first production batch to a following set of operating parameters for a second production batch, and determining a set of required configuration parameters which are to be changed.

12. The converting machine according to the preceding claim, wherein the pre-feed sensing system comprises a passage sensor configured to detect the number of stacks transported to the converting machine and a height sensor configured to determine the height of the stack and to detect when a last batch (B) of sheets is delivered to the feeder module.

13. The converting machine to the claim 10 or 11 , wherein the loader comprises an extendable transportation arm with a conveyor belt and wherein the transportation arm is horizontally displaced according to the longitudinal length of the sheets in the direction of transportation.

14. The converting machine according to any one of claims 10 to 13, wherein the inlet section comprises a passage sensor (102), and wherein the passage sensor (102) is configured to detect each passage of a stack to the loader and wherein the number of passages is stored in the memory of the end of production control system.

15. The converting machine according to any one of claims 10 to 14, wherein the memory further comprises a program which allows the end of production control system to determine an introduction sequence of the parameters to be changed.

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