punching machine

Abstract

A punching machine (10) for processing material in sheet form, in particular for processing cardboard sheets (12), comprising a transport mechanism (20, 36) for transporting sheets (12) one after the other from a feed side of the machine (10) via at least one processing station (22, 26, 30) to an ejection side along a transport path (TP), wherein the machine (10) has a recording system (42) with at least one high-speed camera (44) assigned to the waste ejection station (26) for recording a plurality of images of a representative section of the waste ejection section below the transport path (TP), a memory for storing recorded images, and a processing system (67) for processing the stored images.

Description

[0001] The invention relates to a die-cutting machine for processing material in sheet form, in particular for processing cardboard sheets, with a transport mechanism for transporting sheets one after the other from a feed side of the machine via at least one processing station to an ejection side along a transport path.

[0002] Die-cutting presses play a crucial role in the printing and packaging industries, serving as essential equipment for die-cutting, creasing, embossing, and other processing operations on sheet-fed materials. These machines are designed to handle materials such as cardboard, cardstock, and various types of paper, transforming flat sheets into the complex shapes and designs required for packaging, promotional materials, and other applications. Operating a die-cutting press involves the sequential processing of sheets, which are transported at high speed through multiple stations. This transport is typically facilitated by gripper bars driven by chains. The gripper bars securely hold the leading edge of each sheet to guide it precisely through the die-cutting and creasing stations.

[0003] In high-speed production environments, ensuring the integrity and precise positioning of each sheet throughout the entire process is crucial. However, a common challenge is the tendency of the sheets to deform as they move through the machine.

[0004] Factors such as rapid acceleration and deceleration, as well as aerodynamic effects, can cause the sheets to bend or become wavy. This deformation affects the sheet's flatness and leads to misalignment when the sheet undergoes punching or creasing operations.

[0005] A deformation of the sheet can have two serious consequences: firstly, premature detachment of pre-cut blanks from the rest of the sheet, and secondly, misalignment of the subsequent sections of the sheet in relation to the punching tools or creasing knives.

[0006] Premature separation can occur if the leading edge of a pre-cut blank is caught by the airflow and subjected to such force that the connection between the pre-cut blank and the rest of the sheet (the so-called "holding points," which are narrow material bridges left behind during the pre-cutting process) breaks. The leading edge of the blanks is exposed to the airflow when the sheet bends and the leading edge is located at the tip of a flute. Should the blank separate from the rest of the sheet at a location other than the intended ejection or collection point, it can fall into the machine and cause blockages, bringing the press to a standstill. Such interruptions reduce productivity.

[0007] Misalignment occurs when a sheet is processed in a processing station while still in a wavy state. The wavy state can result from the sheet slowing down considerably upon reaching the processing station. Due to the wavy shape of the sheet, the contact points between the sheet and the die-cutting tools or creasing knives change. Generally, the overall length of a wavy sheet is less than the length of a flat sheet, causing sections at the trailing end of the sheet to be positioned closer to the leading end than expected. This leads to incomplete cuts or unintended pressure on certain areas.

[0008] Modern die-cutting machines use sensors strategically positioned along the sheet's path to continuously monitor its condition and the desired processing. If a problem occurs, such as a blank unintentionally detaching from the sheet, the machine stops.

[0009] One of these sensors is a line scanner, which is used to determine whether parts to be removed (hereinafter referred to as "waste") are actually being properly removed from the sheets in the waste ejection station.

[0010] Waste that needs to be removed from the sheet might, for example, consist of pieces within a blank that will later form a window in a box made from that blank. The waste is punched out of the blank in a die press, except for a few small holding points that ensure the waste does not unintentionally detach from the blank.

[0011] A waste ejection station consisting of two tools is provided for removing the cut pieces. The lower tool is shaped like the pieces to be ejected, and the upper tool has a series of pushers that push the waste through the lower tool. The cardboard sheet is inserted between the two tools. By moving the upper tool close to the lower tool, the waste is pushed downwards through the lower tool.

[0012] The line scanner is located on the downstream side of the waste discharge station and scans the sheet as it is transported from the waste discharge station to a paper sorting station. Details can be found in WO 2023 / 280629 A1.

[0013] By comparing a model of the sheet, downloaded from the cloud within a job order description, with the scan, the line scanner can verify whether all waste has been ejected. If not, it can trigger a machine stop.

[0014] It can happen that waste is separated from the sheet but not ejected properly. For example, it might remain on the upper part of the lower die. This is not detected by the scanner. However, this waste might be detected by the scanner along with the sheet a few machine cycles later, triggering a machine stop. Additionally, waste can be held by a single, unbroken detent and thus transported along with the sheet, but folded on the cardboard. Therefore, if the waste is not covering another waste area but is concealed by the cutting process, it may remain undetected by the scanner.

[0015] For machine operators, identifying and diagnosing the cause of sheet detachment is a significant challenge. The rapid movement of sheets through the printing press makes it virtually impossible to visually monitor each sheet in real time. Operators often have no choice but to determine the causes of blockages after they occur, which can lead to repeated downtime as they make adjustments through trial and error. Without a clear understanding of when and where the deformation occurs, it is difficult to implement effective countermeasures, thus prolonging the production process interruption.

[0016] The invention offers a solution to this problem by providing a system and a method by which operators can determine the cause of the machine stopping.

[0017] For this purpose, the invention provides a machine as described above, wherein the machine has a recording system with at least one high-speed camera assigned to record several images of a representative section of the waste discharge section below the transport track of the waste discharge station, a memory for storing recorded images and a processing system for processing the stored images.

[0018] After the machine stops, the operator can view the video in slow motion and select which machine cycle to view (i.e., the last cycle, the previous cycle, etc.).

[0019] This allows the identification of the specific waste causing the problem, even if the incomplete waste separation occurred several machine cycles prior. By being able to view the video of the N-last machine cycle, it can be quickly determined that the problem was caused by poorly ejected waste, and specifically, which of the many waste materials that need to be separated from the cut material.

[0020] The camera can also serve as a backup detector or even a replacement for the scanner, detecting waste that might be held by a single, unbroken clip and thus transported along with the sheet, but folded on the carton in such a way that it cannot be detected by the scanner. The recording system captures the ejection of waste from the sheets. This real-time data allows for immediate analysis and reveals patterns that may point to underlying problems. By accurately determining the precise stage at which a problem occurs, operators can quickly identify what adjustments need to be made to resolve it.

[0021] Furthermore, the system can be programmed to automatically adjust certain machine parameters in response to detected problems, thereby further improving the efficiency of corrective actions.

[0022] Another embodiment of the invention comprises a display to provide an operator with an image sequence that is representative of a problem that occurs. Providing the operator with an image sequence representative of the problem improves troubleshooting capabilities. By visualizing the problem as it occurs, operators can diagnose problems more effectively and take appropriate corrective action immediately.

[0023] The recording system can be designed to capture multiple images of a representative section of the sheets synchronously with the machine cycles, enabling the analysis or display of a selected image sequence for any sheet in relation to the machine cycle timeline. This reduces the time required by an operator to retrieve the relevant images and also decreases the required storage capacity for the images, as only relevant images are captured.

[0024] Preferably, the display is designed to show a sequence of images in relation to the timeline of the machine cycle, thereby reducing the time required by an operator to understand what caused the machine to stop.

[0025] In one embodiment, the at least one high-speed camera is arranged in the waste discharge station of the machine, for example at the downstream end of the waste discharge station, below the transport track and facing upwards. This high-speed camera enables the identification of potential problems in the ejection of waste from the blanks.

[0026] The high-speed camera can be positioned on a machine frame such that its field of view covers the entire lower waste discharge tool attached to the waste discharge station. The camera is preferably oriented upwards so that it can "see" every position on the lower waste discharge tool and thus every piece of waste being pushed downwards through openings in the lower tool.

[0027] In one embodiment, a blower is installed above the camera to blow away any debris that might fall onto the camera lens. The blower is preferably oriented to expel an airflow horizontally across the lens.

[0028] In one embodiment, the processing system includes an image evaluation unit for detecting movement in job-specific sections of the sheet, thereby reducing the required image processing, since only those parts of the images need to be analyzed where a waste piece is actually to be ejected.

[0029] Preferably, the machine is designed to To transport the sheet with the gripper bar from the feed side of the machine via at least one processing station to an ejection side, to record several images of at least one representative section of the arc using the recording system, where the recording with the recording system is synchronized with the machine cycle in order to track the position of the image in relation to the timeline of the cycle, to store the recorded images in a buffer of limited size in order to retain a record of the images in relation to the timeline of the cycle for only a limited number of cycles, In the event of a machine stoppage, the recording system should be stopped to preserve the multiple images that were stored in the buffer before the machine stopped. to display a sequence of images selected in relation to the timeline of the cycles.

[0030] By recording an image sequence that depicts a representative section of the sheets synchronously with the machine cycles, synchronization allows the operator to analyze the behavior of a selected subsequence of the processing. For example, the operator can choose to visualize the movement of the ejected waste pieces immediately after they are pushed down by the upper waste ejection tool. By synchronizing the recording with the machine cycle, the operator can select to visualize the waste ejection process of the next or previous sheet (or any other sheet) within a time window that begins when the upper waste ejection tool strikes the sheet and ends when the sheet moves again, for example, by approximately 10 cm, which is roughly the size of a typical waste piece.It is then sufficient to jump to the position of the recorded images that is separated in time by an integer multiple of the machine cycle. By synchronizing the recording with the machine cycle, some metadata can also be inserted into the recording, for example, by adding the time of contact between the upper and lower waste ejection tools or the start of the gripper bar's movement. The time can be a timestamp if the action takes almost no time, or a time interval indicating the start and end of the action.

[0031] Preferably, at least two different image sequences with the same relationship to the timeline of the cycles are displayed, so that an operator can very easily compare two sequences of the ejection of waste pieces from the lower waste ejection tool.

[0032] The recorded images can be stored in a ring buffer, thus eliminating the need for large storage capacities to hold large amounts of data. In practice, only a limited number of the most recent processing cycles are relevant for identifying a problem. A typical number of recent cycles stored in the ring buffer is ten sheets.

[0033] The recording system can be designed to start a recording cycle when the waste ejection tool encounters the sheet during the processing phase and to stop when the sheet has moved approximately the size of a waste piece, preferably after a movement of 10 cm, using a high frame rate of at least 50 frames per second. This reduces the amount of data to be stored and processed.

[0034] The processing system is preferably designed to perform motion detection in specific areas within a limited timeframe within the recording cycle, so that motion detection can take place in real time.

[0035] To reduce the amount of data to be processed, the processing system is preferably designed to perform motion detection in one area per waste item, with each area surrounding the waste opening but excluding the opening itself.

[0036] If two pieces of waste are located close to each other, confusion during motion detection due to overlapping analysis areas can be avoided by the processing system excluding the overlapping areas of two adjacent pieces of waste from motion detection.

[0037] Preferably, the processing system considers the waste as not ejected if no movement is detected in the relevant area.

[0038] The processing system is preferably designed to identify, within a given number of recent machine cycles, the cycle with the highest probability of incomplete waste ejection and to display the video of the identified cycle to the machine operator. This speeds up the detection of a specific problem because the processing system displays the recent videos to the operator not in (reverse) chronological order, but in order of the probability of a problem occurring, starting with the highest probability.

[0039] In one embodiment, the machine can have a line scanner on the downstream side of the waste discharge station, so that there are two complementary ways to detect incorrectly discharged waste.

[0040] An embodiment of the invention will now be described with reference to the accompanying drawings. These drawings show... Fig. 1 schematically a punching machine, Fig. 2 the speed of a sheet being advanced from a first to a second processing station, Fig. 3 a bow that is advanced at high speed using a gripper rod, Fig. 4 schematically a waste ejection station of the machine Fig. 1 in a front view, Fig. 5 schematically an upper waste ejection tool and a lower waste ejection tool before the start of waste ejection, Fig. 6 schematically the tools from Fig. 5 in a position where waste would be ejected from an arc (not shown) between them, Fig. 7. Schematically shown in a top view, a sheet to be processed with some waste pieces, Fig. 8 schematic areas around each waste piece of the sheet Fig. 7, in which the processing system performs motion detection, Fig. 9 the bow Fig. 7, where areas excluded from motion detection are marked, Fig. 10 an image taken by the high-speed camera immediately before the start of waste ejection in a machine cycle, Fig. 11 a picture that was later than the picture from Fig. 10 was recorded, with the waste already beginning to separate from the arch, and Fig. 12 a picture that was later than the picture from Fig. 11 was recorded, with the waste being separated from the sheet.

[0041] Fig. Figure 1 schematically shows a die-cutting machine 10, which is designed to transform sheets 12 (usually made of cardboard) into pre-cut flat boxes. These boxes are then folded and glued using another machine.

[0042] The process of producing the pre-cut flat boxes (hereinafter referred to as "cutouts 14") consists of cutting out shapes from flat cardboard sheets 10 in the die-cutting machine 10. The sheets pass through several stations, including an infeed station 16, where sheets 12 are individually removed from a stack; a feed station 18 with a feed table 19, on which sheets 12 are aligned and gripped by a gripper bar 20; a press station 22, where the sheets 12 are punched and scored by a punch press 24; a waste ejection station 26, where unwanted parts of the sheet 12 are removed with an ejection tool 28; a blanking station 30, where the pre-punched blanks 14 are removed and stacked with a blanking tool 32; and an ejection station 34, where the remaining parts of the sheet 12 are released by the gripper bar 20 and removed via a belt 40.

[0043] The transport of the sheets 12 through various processing stations is carried out by a chain drive system and a gripper bar mechanism. The chain drive consists of endless chains 36 that run the length of the machine 10 and ensure synchronized and precise movement of the gripper bars 20 attached to the chains. The gripper bars 20 securely hold the leading edge of each sheet 12.

[0044] On the feed table 19, the sheets 12 are aligned to ensure correct positioning and then gripped by the gripper bar 20. The gripper bar 20 firmly grasps the leading edge of the sheet 12 so that it can be transported precisely through the subsequent stations of the machine. The movement of the gripper bar 20 is synchronized with the action of the tools in the pressing station 22, the ejection station 26, and the blanking station 30.

[0045] The movement of the arcs 12 from one station to the next comprises several different phases (viewed in direction A, in which the arcs are transported along a transport track TP by the machine 10): acceleration a, constant high-speed travel t, deceleration d and standstill s (see Fig. 2) The entirety of these phases constitutes a complete machine cycle MC.

[0046] To achieve a high throughput of approximately three large arcs 12 per second, the time required to transfer an arc 12 from one station to the next should be as short as possible. Accordingly, a high transport speed must be achieved, which requires strong acceleration so that the arc 12 reaches this speed as quickly as possible, while also requiring strong deceleration so that the arc 12 can be transported at this high speed for as long as possible.

[0047] Two phases of the transport cycle of the arc 12 are critical: the high-speed phase and the strong deceleration phase.

[0048] Due to the high speed at which the sheets 12 travel through the machine, it is impossible for an operator to visually identify the cause of interruptions. The core idea is to use at least one high-speed camera 44 to monitor specific points where the sheets 12 move within the machine. The camera(s) 44 is / are strategically positioned in the ejection station 34 at the point where deviations of the sheet 12 from the expected travel path are critical. This will now be demonstrated using the Fig. 3 to 12 explained.

[0049] In Fig. Figure 3 shows a bow 12 being transported at high speed along a conveyor track by the gripper bar 20 immediately before the ejection station 34. Due to the high speed, the bow 12 is wavy.

[0050] In Fig. Figure 4 shows a schematic representation of the waste discharge station 26. It comprises an upper waste discharge tool 28A, a lower waste discharge tool 28B, a sensor 42 (usually a line scan camera) and a high-speed camera 44.

[0051] The waste discharge station 26 comprises two main components: the upper waste discharge tool 28A and the lower waste discharge tool 28B. The lower tool 28B is shaped according to the parts of the arc 12 that need to be discharged, while the upper tool 28A is equipped with a series of slides 29 designed to drive the waste through the lower tool 28S.

[0052] The system works by positioning the respective cardboard sheet 12 between the two tools. The upper tool 28A approaches the lower tool 28B, and the pushers 29 in the upper tool 28A exert downward pressure to push the waste parts through the openings (designated by reference numeral 50) in the lower tool 28B. This mechanism ensures that the unwanted materials are physically separated from the sheet.

[0053] In operation, the tool functions are part of an automated sequence in the machine cycle. The waste is first separated from the sheet by punching, except for small holding points that prevent premature detachment. When the sheet reaches the waste ejection station 26, the coordinated movement of both tools 28A and 28B ensures the precise removal of these waste sections. After the upper tool 28A has pushed the waste through the lower tool 28B, the remainder of the sheet continues along the processing path.

[0054] Scanner 42 is designed to monitor and ensure that waste components are correctly removed from sheets 12 during processing. The line scan camera is strategically positioned after the waste discharge station 26, where it scans the condition of the sheet 12 as it is transported out of the waste discharge station 12 and towards the blanking station 30.

[0055] By comparing a model of sheet 12, downloaded from the cloud within a job order description, with the scan captured by scanner 42, it can be verified whether all waste has been properly ejected. If not, scanner 12 can trigger a machine stop.

[0056] The high-speed camera 44 is mounted on a machine frame 46, preferably centrally and below the lower waste ejection tool 28B (see Fig. 4), so that the high-speed camera 44 can capture the entire underside of the lower tool 28B with its field of view.

[0057] The high-speed camera 44 records all phases of the machine cycle at a high frame rate (> 50 frames per second). Each film segment recorded in this way begins at the moment the upper waste ejection tool engages the sheet 12 (i.e., at the point in the machine cycle when the slides 29 begin to engage the waste parts, see Figure 1). Fig. 10) The recording of images can be stopped when the waste ejection is complete, which is usually the case when the two waste ejection tools 28A, 28B have been moved apart and the arc 12 has begun to move a few centimeters towards the next downstream station (see Fig. 12) Preferably, a blower 45 is mounted above the camera to prevent debris from falling onto the camera and obstructing the field of view.

[0058] The high-speed camera 44 is connected to a memory 62 for storing the recorded images of the grid.

[0059] Memory 62 is a ring buffer used to store recordings of a specific number of machine cycles. An example of this specific number is ten. In other words, ring buffer 62 allows the retrieval of images from the last ten machine cycles.

[0060] Additional elements of machine 10 are a control unit 64 and a display 66, which are located in Fig. 5 are shown schematically.

[0061] The control unit 64 includes an image processing system 67.

[0062] When the machine 10 is in operation, the high-speed camera 44 records images of the underside of the lower waste discharge tool 28B, with the aim of determining whether all waste pieces have been properly separated from the sheet and pushed downwards through the openings of the lower tool 28B. The images are stored in the ring buffer 62, from which they can be retrieved and displayed to an operator in slow motion.

[0063] To reduce the amount of data to be processed for this determination, the determination is based on motion detection. Motion detection is implemented by processing system 67, which analyzes specific areas of the sheet during machine cycles. The system is designed to detect movement around the waste openings during the waste ejection phase, which occurs synchronously with the machine cycle, in order to optimize data processing and storage. The areas considered by processing system 67 are marked with reference numeral 52.

[0064] The process begins with the high-speed camera capturing a high-frame-rate (at least 50 frames per second) image sequence during the critical part of the machine cycle when waste is ejected from the sheet. The processing system focuses on motion detection in specific areas around each waste opening on the sheet, excluding the opening itself, thus accurately determining whether the waste has been successfully ejected.

[0065] One of the specific strategies used is to avoid confusion when two pieces of waste are close together. This is achieved by configuring the processing system to separate overlapping areas (in Fig.(9, marked with reference 54) between adjacent pieces are excluded from the motion detection analysis. This feature ensures that the ejection of each waste piece is precisely monitored without interference from neighboring areas.

[0066] The system considers waste as not ejected if no movement is detected in the predefined area. Importantly, the processing system can quickly identify any recent machine cycle where incomplete waste ejection is likely to have occurred and display the corresponding video footage to the machine operator. This is prioritized by probability, thus accelerating the problem identification process by focusing on the cycles where issues were most likely to arise.

[0067] This approach enables real-time analysis and provides immediate feedback to operators, who can then take the necessary corrective actions to maintain efficiency and reduce machine downtime.

[0068] In general, the image processing system 67 within the controller 64 processes the recorded images so that they are made available to an operator. This processing can include adding a timestamp or a reference to the machine cycle, which allows browsing and / or comparing "identical" images from different machine cycles. The processing can also include extracting an image sequence for different machine cycles, all starting at the same reference point within a machine cycle.

[0069] There are additional countermeasures that the control unit 64 can either initiate automatically or propose to the operator for approval.

[0070] When addressing problems related to waste ejection, several steps can be taken to diagnose and resolve the issue. Once the problem is identified, operators can decide on corrective actions. This might involve adjusting machine parameters, such as the gripper bar speed, or changing the alignment or pressure of the upper and lower waste ejection tools. The system can be programmed to suggest specific adjustments based on the analysis, thus reducing trial and error. Countermeasures can be automatically triggered or suggested by the machine control system to prevent recurrence. For example, the transport speed can be reduced to minimize sheet deformation and improve alignment accuracy.The control system can also provide empirical adjustment recommendations based on previously recorded data and results. After implementing these adjustments, it is crucial to conduct test cycles to ensure the problem does not recur. Monitoring systems—cameras and scanners—continue to monitor machine operation, providing data to verify that waste ejection is functioning correctly and without issues. Over time, the system accumulates data that can be analyzed to identify patterns or recurring problems, leading to further refinements of machine settings or process improvements. This iterative learning approach ensures continuous improvement in the machine's reliability and efficiency.By following these steps, the invention and the associated systems provide a robust framework for the effective diagnosis and solution of waste ejection problems in stamping machines, resulting in minimized downtime and increased productivity.

[0071] These automatic adjustments not only improve the quality of the finished products but also increase the efficiency of the stamping process by reducing downtime due to machine jams. The system's ability to react to detected problems in real time enables continuous operation at optimal speeds while maintaining product integrity. Furthermore, by minimizing manual intervention, the system reduces operator workload and the risk of human error. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2023 / 280629 A1

[0012]

Claims

[1] Punching machine (10) for processing material in sheet form, in particular for processing cardboard sheets (12), with a transport mechanism (20, 36) for transporting sheets (12) successively from a feed side of the machine (10) via at least one processing station (22, 26, 30) to an ejection side along a transport track (TP), wherein the machine (10) has a recording system (42) with at least one high-speed camera (44) assigned to record several images of a representative section of the waste ejection section below the transport track (TP) of the waste ejection station (26), a memory for storing recorded images and a processing system (67) for processing the stored images. [2] Machine (10) according to claim 1, wherein the processing system (67) comprises a display (66) to provide an operator with a sequence of images that is representative of a problem that has occurred. [3] Machine (10) according to one of the preceding claims, wherein the recording system (42) is designed to record multiple images of a representative section of the sheets (12) synchronously with the machine cycles, so that the analysis or display of a selected image sequence for any sheets with respect to the timeline of the machine cycle is possible. [4] Machine according to any of the preceding claims, wherein the display (66) is designed to display an image sequence in relation to the timeline of the machine cycle. [5] Machine (10) according to one of the preceding claims, wherein the at least one high-speed camera (44) is arranged at the downstream end of the waste discharge station (26) of the machine (10). [6] Machine (10) according to claim 5, wherein the high-speed camera (44) is arranged on a machine frame such that its field of view covers an entire lower waste ejection tool attached to the waste ejection station (26). [7] Machine (10) according to one of the preceding claims, wherein the processing system (67) comprises an image evaluation unit for determining movement in job-specific recorded sections of the sheet (12). [8] Machine (10) according to any of the preceding claims, wherein the machine is designed to - to transport the sheet (12) with the gripper bar (20) from the feed side of the machine (10) via at least one processing station (22, 26, 30) to an ejection side, - to record several images of at least one representative section of sheet (12) using the recording system (42), - wherein the recording with the recording system (42) is synchronized with the machine cycle in order to track the position of the image in relation to the timeline of the cycle, - to store the recorded images in a buffer of limited size in order to retain a record of the images in relation to the timeline of the cycle for only a limited number of cycles, - to stop recording with the recording system (42) in the event of a machine stoppage, in order to retain the multiple images that were stored in the buffer before the machine stopped, - to display a sequence of images selected in relation to the timeline of the cycles. [9] Machine according to claim 8, wherein the image sequence is selected to show the ejection of waste from a sheet (12) in the field of view of the high-speed camera (44). [10] Machine according to claim 8 or 9, wherein at least two different image sequences with the same relationship to the timeline of the cycles are displayed. [11] Machine according to any one of claims 8 to 10, wherein the recording system (42) is designed to start a recording cycle when the waste ejection tool hits the sheet during the processing phase and to stop when the sheet (12) has moved by about the size of a waste piece, preferably when the sheet (12) has moved by 10 cm, using a high frame rate of at least 50 frames per second. [12] Machine according to any one of claims 8 to 11, wherein the processing system (67) is designed to perform motion detection in certain areas within a limited time frame within the recording cycle. [13] Machine according to claim 12, wherein the processing system (67) is designed to perform motion detection in an area for each waste piece, wherein each area surrounds the waste opening but excludes the opening. [14] Machine according to claim 13, wherein the processing system (67) is designed to exclude overlapping areas of two adjacent waste pieces from motion detection. [15] Machine according to any one of claims 12 to 14, wherein the processing system (67) considers the waste as not ejected if no movement is detected in the relevant area. [16] Machine according to any one of claims 12 to 15, wherein the processing system (67) is designed to identify, within a certain number of recent machine cycles, the cycle in which there is the greatest probability of incomplete waste ejection having occurred, and is designed to display the video of the identified cycle to the machine operator. [17] Machine according to one of the preceding claims, wherein a line scanner is located on the downstream side of the waste discharge station (26).

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