Device and method for processing continuous cardboard web

Abstract

The invention relates to a device for processing continuous cardboard web (2) and for identifying folds (20, 21) therein, in particular leporello folds (20), as well as a method for same. The device comprises the following: a conveyor unit (3) designed for conveying continuous cardboard web (2) in a conveying direction x; at least one sensor (5) that is designed to at least partially detect a surface of the continuous cardboard web (2) while the continuous cardboard web is being conveyed and / or is stationary; and a controller that is designed to identify folds (20, 21) in the continuous cardboard web, in particular leporello folds (20), using data relating to the surface detected by the sensor (5); characterised in that the sensor (5) is also designed to detect the surface of the continuous cardboard web (2) in a linear manner or the controller is also designed to approximate the surface of the continuous cardboard web (2) in a linear manner using data detected by the sensor (5).

Description

[0001] P2022-0252-DE 248 342 p9 / t7 HOMAG Automation GmbH Homagstraße 1 09638 Lichtenberg Germany DEVICE AND METHOD FOR PROCESSING CONTINUOUS CARDBOARD Technical field The invention relates to a device and a method for processing continuous cardboard. State of the art In industry, for example, so-called continuous cardboard boxes are often used for packaging products. A continuous cardboard box is generally a box that is not infinitely long in the mathematical sense, but whose extension in one direction, which is usually the direction in which the continuous cardboard box is conveyed, is many times greater than in a direction transverse to this. Furthermore, the continuous cardboard box is folded in a zigzag fold and is often, but not exclusively, stored on a pallet. This zigzag fold of the carton is often also referred to as a Leporello fold, fanfold or Z-fold, although these terms are used synonymously.The fanfold creases, i.e. the creases created by the zigzag folding of the continuous carton, run perpendicular to the carton's length and divide it into sections of essentially equal length. Fanfolded continuous carton boxes offer the advantage of being particularly suitable for the automated production of cardboard boxes. For this purpose, the continuous carton is often automatically fed to a carton processing machine. The carton processing machine creates folds and cuts that correspond to the desired layout of the carton and cuts the continuous carton to length. A disadvantage of using continuous carton is its fanfold folding. Due to the fanfold folding of the continuous carton, it is divided into many, essentially equal-length sections without any folding. The maximum length of the sections is usually limited by the length of the pallet on which the continuous carton is stored.During the automated processing of these continuous cartons, it is common in practice that these fanfold creases are located in the outline of the cut-to-size cardboard in the area of ​​the glued flaps and inserted folds. This outline, also known as the cardboard construction, is the cutting of the cardboard in the plane, i.e. the shape of the unfolded box. If a fanfold crease is located in the area of ​​an glued flap of the cardboard, this often leads to the glued flap coming loose again after gluing. If a fanfold crease is located in the area of ​​a fold in the cardboard made by the cardboard processing machine, this often leads to the cut-to-size cardboard being folded not at the intended location, i.e. the inserted fold, but at a different location, i.e. the fanfold crease.This negatively impacts the dimensional accuracy of the packaging folded from the cardboard. WO 2018 / 136658 A1 therefore proposes a mechanism for detecting fanfold creases that uses two sensors that are offset from each other in the conveying direction of the continuous carton and each measure the distance between the sensor and the carton surface to detect the presence and position of fanfold creases. A fanfold crease is detected by each sensor individually detecting a change in the distance between the carton surface and the sensor, and by the time shift with which the two sensors each detect the change in distance corresponding to a conveying speed of the continuous carton. EP 3521 006 A1 also proposes a mechanism for detecting fanfold creases that uses sensors that measure the distance between the sensor and the carton surface to detect a fanfold crease.A fanfold crease is detected by a change in the distance between the carton surface and the sensor. However, the solutions known from the prior art have two main disadvantages: Firstly, relative movements of the continuous carton to the sensor, for example due to vibrations during conveying of the continuous carton or similar, can lead to measurement inaccuracies. In addition, fluctuations in the conveying speed can also lead to measurement inaccuracies. Secondly, due to the measuring principle, i.e. the distance measurement between the sensor and the carton surface, it is difficult or impossible to distinguish between fanfold creases and "other" creases, such as those which arise from the continuous carton being deflected over deflection rollers or through other feeding methods such as guide rails.The latter have a much smaller influence on the quality of the cardboard than the fanfold creases, which is why it is particularly desirable to be able to exclude areas with "other" creases from downstream processing measures after detection and thus ignore them. Description of the invention The object of the invention is to create a device and a method for processing continuous cardboard which is capable of reliably detecting creases, in particular fanfold creases, in a continuous cardboard and, in particular, of distinguishing between fanfold creases and creases which arise, for example, from the cardboard being deflected over deflection rollers. A device for processing continuous cardboard is defined in claim 1. A method for processing continuous cardboard is defined in claim 7. Subclaims relate to specific embodiments.The present invention provides a device for processing continuous cardboard and for detecting creases, in particular fanfold creases, contained therein. The device comprises a conveyor device configured to convey continuous cardboard in a conveying direction. The device further comprises at least one sensor configured to at least partially detect a surface of the continuous cardboard during conveying (during conveying and / or while the continuous cardboard is at a standstill). The device further comprises a controller configured to detect creases, in particular fanfold creases, present in the continuous cardboard using data about the surface acquired by the sensor.The sensor is further configured to linearly determine / capture the surface of the continuous cardboard box and / or the controller is further configured to linearly determine / approximate the surface of the continuous cardboard box using data captured by the sensor. The inventive design of the device makes it possible to detect creases present in continuous cardboard, for example during the production of cardboard boxes from continuous cardboard, particularly reliably and even when vibrations act on the continuous cardboard box. This allows the creases present in the continuous cardboard box to be taken into account, for example during the production of cardboard boxes. In the device described above, the sensor can be configured to linearly detect the surface of the continuous cardboard box. Alternatively or additionally, the controller can be configured to linearly approximate the surface of the continuous cardboard box using data captured by the sensor.In this case, “linear” does not necessarily mean linear in the mathematical sense. Rather, the surface of the continuous carton is detected or approximated along a direction and thus as a line rather than being detected as a point or an area. In the case of approximation, the line can be made up of several linear or non-linear line segments. Basically, detection during conveying means that at the moment of detection, the continuous carton is either being moved by the conveyor or is briefly stationary. Due to the inventive design of the device, the surface of the carton is detected or approximated linearly in a section at a specific time. Therefore, movement of the continuous carton is not necessary for the detection of creases, preferably fanfold creases.Detected creases can be taken into account, for example, during the production of cardboard boxes, in such a way that the control of a processing device specifies cuts and / or folds such that a crease is not positioned within an adhesive flap of the layout or is not positioned so close to a fold to be introduced that, during automated or manual folding of a cardboard box foldable from the layout, the cardboard would not be folded at the introduced fold, but rather at the accordion crease. Preferably, the distance between a fold to be introduced into the continuous cardboard box and a crease, such as a accordion crease, is at least 1 cm, preferably at least 2 cm, more preferably at least 5 cm.In a second preferred embodiment, the device is designed to carry out the linear detection of the surface by the sensor or the linear approximation of the surface by the controller at least not perpendicularly, preferably substantially parallel to the conveying direction. By means of this inventive embodiment of the device, a kink in the continuous carton is detected particularly reliably during the linear detection of the surface and / or during the linear approximation of the surface. The kinks to be detected in continuous cartons usually run substantially perpendicular to the conveying direction of the continuous carton. Thus, by aligning the line substantially parallel to the conveying direction, it is advantageous that, if a kink is present, the line both detects and approximates an area of ​​the surface.is approximated, in which the kink is located, as well as, at the same time, an area of ​​the surface in which the kink is not located. In the preferred embodiment of the device described above, the line is at least not aligned perpendicular to the conveying direction. The closer the alignment of the line approaches a parallel to the conveying direction, the more reliably a kink in the continuous carton can be detected. This applies both to the case in which the surface is detected linearly and to the case in which the surface is approximated linearly. In the case of linear approximation of the surface of the continuous carton by several point-detecting sensors, a scanning distance, i.e. a distance between two points on the surface detected by the sensors, is selected such that the length of the approximated line along the surface of the carton is greater than a width of the kink to be detected.The width of the creases to be detected depends on the thickness of the continuous cardboard to be processed (which is usually between 2 and 7 mm thick) and is typically about 3 to 8 mm, but can be in the range of about 0.5 mm to 3 mm for thinner materials such as cardboard or paper and in the range of 5 to 10 mm for thicker materials. The length of the linearly detected or approximated surface can, for example, be about 10 mm to 50 mm. Preferably, the length of the linearly detected or approximated surface is about 2.5 times the width of the creases to be detected. In a third preferred embodiment, the controller is further configured to measure a length of the surface of the continuous cardboard detected linearly by the sensor or to calculate a length of the surface of the continuous cardboard approximated linearly by the controller.The controller is also configured to detect creases, particularly fan-fold creases, in the continuous carton based on their length. This inventive design of the device allows creases in the continuous carton to be detected particularly reliably and with high accuracy. This is because if there is a crease in the continuous carton, the measured or calculated length of the surface of the continuous carton is greater than if there is no crease in the continuous carton. Furthermore, the measured or calculated length of the surface does not change, or only changes very slightly, even in the event of vibrations or relative movements of the continuous carton in the direction of the at least one sensor. Therefore, the detection of creases based on their length works particularly reliably even in the event of vibrations or relative movements of the continuous carton in the direction of the at least one sensor.In a fourth preferred embodiment, the controller is further configured to distinguish between fanfold creases and creases that are not fanfold creases when detecting creases. This inventive design of the device makes it possible to distinguish fanfold creases from other creases in the continuous carton and thus to react differently to fanfold creases in subsequent processing steps than to creases that are not fanfold creases. This is particularly advantageous because, for example, during the feeding and deflection of the continuous carton, creases can occur in the carton, which are less disruptive than fanfold creases during further processing of the continuous carton.In the preferred embodiment of the device described above, creases that are not fan-fold creases are, in particular, creases that arise when the continuous carton is guided over deflection rollers or rollers and is thereby intentionally or unintentionally bent. Such creases are generally less pronounced, i.e., generally less deep, than fan-fold creases that are caused by the folding of the continuous carton. In a fifth preferred embodiment, the sensor is a laser sensor that projects a laser line onto a section of the surface of the continuous carton. This inventive configuration of the device allows the operator to easily check the alignment of the linear detection area of ​​the surface, which should preferably be substantially parallel to the conveying direction.Such a check can be carried out, for example, when the device is first set up or when converting to different thicknesses of the continuous cardboard. It is advantageous if the laser operates in the wavelength range of visible light. In wavelength ranges outside of visible light, the linear detection area can be made visible, for example, by appropriate cameras. In a sixth preferred embodiment, the device further comprises a processing device configured to make cuts and / or folds in the continuous cardboard according to a cardboard layout specified by the controller. The controller is further configured, if a fanfold crease is detected, to take the position of the fanfold crease into account when specifying cuts and / or folds to the processing device.This inventive design of the device allows the position of a fanfold crease present in the continuous carton to be taken into account during carton production, and the position of the carton's outline to be inserted into the continuous carton can be adapted to the position of the fanfold crease. This outline, also referred to as the carton construction, represents the cut of the carton in the plane, i.e., the shape of the unfolded box.In a preferred embodiment, the control takes the position of the fanfold crease into account when specifying cuts and / or folds to the processing device in such a way that a fanfold crease is not positioned within an adhesive flap of the layout; or in such a way that a fanfold crease is positioned at least 1 cm, preferably at least 2 cm, more preferably at least 5 cm away from a fold to be introduced; or in such a way that a fanfold crease is positioned outside the layout of the cardboard box. This inventive design of the device can effectively prevent an fanfold crease from being located in an adhesive flap of a cardboard box produced from the continuous cardboard. This can prevent the adhesive flap from unintentionally becoming detached again after it has been glued due to the presence of a fanfold crease.Furthermore, the above embodiment according to the invention can prevent the cardboard produced from the continuous cardboard from being folded at a point where a fanfold crease is present, instead of being folded at a point where a fold introduced by the processing device is present. This can improve the dimensional accuracy of the cardboard or of a package folded from the cardboard. It can also prevent a fanfold crease from being present in the outline of a cardboard box at all. The section of the continuous cardboard containing the fanfold crease is severed by the processing device, and the outline is positioned on the continuous cardboard in such a way that there is no fanfold crease in the outline. This is particularly desirable when particularly high demands are placed on the surface quality of the cardboard.The present invention further provides a method for processing continuous cardboard and for detecting creases, in particular fanfold creases, contained therein. The method comprises the following steps: conveying a continuous cardboard along a conveying direction; detecting at least a portion of a surface of the continuous cardboard, preferably during conveying (during conveying and / or while the continuous cardboard is at a standstill), using at least one sensor; determining (detecting / approximating) a length of the surface of the continuous cardboard in a linear section of the surface of the continuous cardboard, preferably running parallel to the conveying direction; and detecting a crease, in particular a fanfold crease, based on the length of the linear section of the surface of the continuous cardboard. The method according to the invention makes it possible to detect creases present in a continuous cardboard particularly reliably.This is because if there is a kink in the continuous carton, the measured or calculated length of the surface in a linear section of the surface of the continuous carton is greater than if there is no kink in this linear section of the continuous carton. Furthermore, the measured or calculated length of the surface of the continuous carton in the linear section does not change, or only changes very slightly, even in the event of vibrations or relative movements of the continuous carton in the direction of at least one sensor. Therefore, the detection of kinks based on the length of the surface in the linear section works particularly reliably, even in the event of vibrations or relative movements of the continuous carton in the direction of at least one sensor. The alignment of the linear section essentially parallel to the conveying direction promotes the length of the surface in the linear section changing in the event of a kink.If both the kink and the linear section ran perpendicular to the conveying direction, in the worst case scenario the length of the surface in the linear section with a kink present in this section would not differ from the length of the surface in the linear section without a kink present. In a preferred embodiment of the method, the length of the surface in the linear section, preferably running parallel to the conveying direction, is determined by a laser sensor scanning the surface linearly. This inventive embodiment of the method allows the length of the surface in the linear section to be measured directly and thus determined particularly accurately. This allows even small changes in length to be detected and, in particular, a distinction to be made between kinks of varying severity.This makes it possible to distinguish, in particular, between fanfold creases and creases that are not fanfold creases. By using a laser sensor that scans the surface in a line pattern, a single sensor is sufficient to detect creases. If a laser sensor with a wavelength in the visible light range is used, the user can easily adjust and check the alignment of the laser line, essentially parallel to the conveying direction.In another preferred embodiment of the method, the length of the surface in the linear section, preferably running parallel to the conveying direction, is determined by detecting a part of the surface of the continuous carton by at least two, preferably at least three laser sensors that are arranged at a distance from one another in the extension direction of the linear section to be detected and that detect the surface of the continuous carton point-wise and at the same time; and by calculating the linear distance(s) between the points on the surface of the continuous carton detected by the sensors.This inventive embodiment of the method allows creases in the continuous carton to be detected particularly reliably even when no laser sensor that detects the surface in a line is used, but rather at least two more favorable laser sensors that detect the surface in a point-like manner. In this way, a more favorable embodiment can be provided and yet reliable detection of creases in the continuous carton can be ensured, even in the event of vibrations or relative movements of the continuous carton in the direction of the at least two sensors. Brief Description of the Drawings Further features and advantages of the device and the method will become apparent from the following description of embodiments with reference to the accompanying drawings. These drawings show: Fig.1 shows a perspective, schematic view of an embodiment of a device according to the disclosure for processing continuous cardboard and for detecting creases contained therein. Fig. 2 shows a perspective, schematic view of the continuous cardboard and the sensor for detecting creases in the continuous cardboard. Fig. 3A shows a schematic view transverse to the conveying direction of the continuous cardboard, on its cross-sectional area, of an embodiment of a sensor according to the disclosure for detecting creases in the continuous cardboard, which sensor detects a part of the surface of the continuous cardboard linearly parallel to the conveying direction, wherein the continuous cardboard has no creases. Fig.3B shows a schematic view transverse to the conveying direction of the continuous carton, across its cross-sectional area, of an embodiment of a sensor according to the disclosure for detecting creases in the continuous carton, which detects a portion of the surface of the continuous carton in a line parallel to the conveying direction, wherein the continuous carton has a crease that is not a fanfold crease, but rather one that arises, for example, from deflection of the continuous carton via deflection rollers. Fig. 3C shows a schematic view transverse to the conveying direction of the continuous carton, across its cross-sectional area, of an embodiment of a sensor according to the disclosure for detecting creases in the continuous carton, which detects a portion of the surface of the continuous carton in a line parallel to the conveying direction, wherein the continuous carton has a fanfold crease. Fig.4A shows a schematic view of the cross-sectional area of ​​the endless carton, transverse to the conveying direction of the endless carton, of another embodiment of three sensors according to the disclosure for detecting creases in the endless carton. These sensors detect part of the surface in a point-like manner, wherein the endless carton does not have a crease. Fig. 4B shows a schematic view of the cross-sectional area of ​​the endless carton, transverse to the conveying direction of the endless carton, of another embodiment of three sensors according to the disclosure for detecting creases in the endless carton. These sensors detect part of the surface in a point-like manner, wherein the endless carton has a crease that is not a fanfold crease, but rather one that arises, for example, from deflection of the endless carton over deflection rollers. Fig.4C shows a schematic view across the conveying direction of the continuous carton, across its cross-sectional area, of another embodiment of three sensors according to the disclosure for detecting creases in the continuous carton, which detect part of the surface in a point-like manner, wherein the continuous carton has a fanfold crease. Fig. 5 shows a schematic view across the conveying direction of the continuous carton, across its cross-sectional area, of another embodiment of three sensors according to the disclosure for detecting creases in the continuous carton, which detect part of the surface in a point-like manner, wherein the continuous carton has a fanfold crease and is displaced parallel to the detection direction of the sensors by vibrations. Fig. 6A shows a schematic plan view of a part of the continuous carton with an indicated outline of the carton, wherein in the left-hand outline, an accordion crease is undesirably located on an adhesive flap.6B is a schematic plan view of a portion of the continuous carton with an indicated outline of the carton, wherein in the left outline, a fanfold crease is located so close to an introduced fold that when folding a carton that can be folded from the outline, the carton would not be folded at the introduced fold but at the fanfold crease, and wherein in the right outline, a fanfold crease is located at a location that is not critical for folding. Description of Embodiments The same reference numerals listed in different figures designate identical, corresponding, or functionally similar elements. The method according to the invention can preferably be carried out using a device according to the invention. The device according to the invention can preferably carry out a method according to the invention.A preferred embodiment of the device for processing continuous cardboard 2 and for detecting creases contained therein is shown in Figure 1. Continuous cardboard 2 is to be understood in this case to mean materials such as cardboard, corrugated cardboard and cartons that are commonly used in the packaging industry. By appropriately parameterizing the control system, which will be discussed in more detail later, creases in thinner materials such as paper, foils or the like and creases in thicker materials can also be reliably detected. The device has a conveyor device 3 and preferably a processing device 4. The conveyor device 3 can convey the continuous cardboard 2 to a processing device 4 or through it.During conveyance, the continuous carton 2 can be guided over deflection rollers in order to adapt the device to the available space at the installation site and to ensure safe unfolding of the continuous carton 2 from the stack of zigzag-folded continuous carton 2. Figure 1 shows a deflection of the continuous carton 2, but the deflection roller has been omitted for clarity. Leporello creases 20 caused by the zigzag folding are present in the continuous carton 2. A sensor 5 is provided upstream of the processing device 4, which sensor detects a section A of the surface of the continuous carton 2. It is preferred that the sensor 5 detects section A of the surface in a linear manner. The various possible designs of the sensor 5 will be discussed in detail later. A controller detects, based on the data supplied by the sensor 5, whether a leporello crease 20 is present in the continuous carton 2.The processing device 4 downstream of the sensor 5 makes cuts and / or folds 62 in the continuous carton 2 in order to provide a floor plan of a cardboard box in the continuous carton 2 according to the specifications of a control system. This floor plan can then be removed from the continuous carton 2 as a cardboard box and folded and / or glued either manually or mechanically to form a package. Alternatively, the processing device 4 can also be designed such that it removes the parts of the continuous carton 2 that do not belong to the floor plan by cuts and feeds them to a waste disposal unit, so that the finished cardboard box can be removed from the processing device 4 or can be folded mechanically. Figure 2 shows a preferred embodiment of the sensor 5, which linearly detects a section A of the surface of the continuous carton 2. The conveying direction of the continuous carton 2 is indicated by an arrow.It can be seen that the area that is linearly detected or scanned by the sensor 5 is oriented essentially parallel to the conveying direction x and thus also essentially perpendicular to the fan-fold creases 20 present in the continuous carton 2. The principle of detecting a crease 20, 21 by this preferred embodiment of the device with a sensor 5 that linearly detects a section A (detection section) of the surface of the continuous carton 2 is illustrated in Figures 3A to 3C. Figures 3A to 3C each show the cross-section of an exemplary continuous carton 2 made of corrugated cardboard, which is conveyed from left to right and whose surface is partially linearly detected or scanned by a sensor 5. The sensor 5 projects a laser line 51 onto a portion of the surface of the continuous carton 2.Thus, not only a point P on the surface of the continuous carton 2 is detected at a time, but an entire linear section A is detected or scanned at a time. A controller integrated in the sensor 5 or implemented separately thus receives data about the surface of the continuous carton 2 in this entire linear detection section A at a single time. The controller can therefore measure or calculate a length L along the surface of the continuous carton 2 in the linear detection section A. Figure 3A shows a continuous carton 2 with a substantially smooth surface, i.e. without creases 20, 21. In comparison, Figure 3B shows a continuous carton 2 with a crease 21 that is not a fanfold crease 20. The curvature of the surface also increases the length L of the surface detected in the linear detection section A by the sensor 5 and measured by the controller.The length L therefore increases if a crease 20, 21 is present in the continuous carton 2. Figure 3C shows a continuous carton 2 with a fanfold crease 20. Since continuous cartons 2 are often manufactured and folded while still wet, the fanfold creases 20, which arise from the folding of the continuous carton 2, are particularly pronounced. Due to the correspondingly more pronounced curvature of the surface, the length L of the surface detected in the linear detection section A by the sensor 5 and measured by the control system also increases. The length L thus becomes a very reliable indicator of whether or not a crease 20, 21 is present in the continuous carton 2. Furthermore, the length L can also be used to determine whether it is a fanfold crease 20 or a crease 21 that is not a fanfold crease 20.For example, a length L of the surface with a kink 21 that is not a fanfold kink 20 can be 1% to 5% longer, preferably 1 to 2.5% longer, than a length L of the surface without a kink. A length L of the surface with a fanfold kink 20 can, for example, be more than 5%, preferably more than 2.5% longer, than the length of the surface without a kink. The classification of the surface into "no kink", "kink that is not a fanfold kink", and "fanfold kink" can therefore be carried out based on limit values ​​of the length L. By appropriately parameterizing limit values ​​of the length L, the detection and classification can also be adapted to materials of different thicknesses, such as paper, cardboard, or foils.The principle of detecting a crease 20, 21 by another preferred embodiment of the device with at least two, preferably at least three sensors that detect a section A of the surface of the continuous carton 2 in a point-like manner is shown in Figures 4A to 4C. Figures 4A to 4C each show the cross-section of an exemplary continuous carton 2 made of corrugated cardboard, which is conveyed from left to right and whose surface is partially detected or scanned in a point-like manner by two, preferably three sensors. Each of the sensors projects a laser spot P onto a part of the surface of the continuous carton 2. Thus, not only one point P on the surface of the continuous carton 2 is detected at a time, but at least two, preferably three points P1, P2, P3 distributed over a section A are detected or scanned at a time.A preferably separately implemented controller thus receives data about the distance d1, d2, d3 from two, preferably three points P1, P2, P3 on the surface of the continuous carton 2 to the respective sensors at a single point in time. Thus, the controller can, using the distance d. S between the respective sensors 5 a length L P1,2 , L P2,3 a straight line distance between two points P1, P2, P3 detected by the sensors 5 on the surface of the continuous carton 2 is calculated trigonometrically using the following formulas: The length L, which in the other preferred embodiment was measured directly by a linear sensor 5, can now be determined by the control system using two point-measuring sensors 5 by the linear distance L P1,2between the two detected points P1, P2. With the preferred use of three or more point-measuring sensors 5, the length L can be calculated by summing the straight-line distances L P1,2 , L P2,3 between the points P1, P2, P3 recorded on the surface of the continuous carton 2 can be approximated: ^^ ≈ ^^ ^^ = ^^ ^^1,2 + ^^ ^^2,3 +⋯+ ^^^^( ^^−1), ^^By means of this embodiment, a more cost-intensive, linear measuring sensor 5 can be dispensed with and the inventive principle for detecting creases in a continuous carton 2, as described above in connection with Figures 3A to 3C, can still be used. The inventive principle of detecting the presence of creases in a continuous carton 2 based on a length L, L PDetecting a surface of the continuous carton 2 in a linear section A offers several advantages over solutions known in the prior art: Figure 5 shows a case in which a continuous carton 2 is subjected to a vibration or a relative movement in the direction of the sensors. Although point-measuring sensors 5 are shown in Figure 5, the following advantages equally apply to a linear-measuring sensor 5. When the continuous carton 2 vibrates, the distances d1, d2, d3 between the surface of the continuous carton 2 and the sensors or the sensor 5 change. Thus, the distance d 1,1 at a time due to the vibration be greater or smaller than the distance d 1,2at a second time. This leads to measurement inaccuracies in devices whose detection is based on measuring a distance between the surface of the continuous carton 2 and the sensor 5. However, as can be clearly seen from Figure 5, a length L, L P a surface in a linear section A does not deform or deforms only slightly in the case of vibrations or relative movements in the direction of the sensor 5. It is irrelevant whether the length is measured approximately or directly. Thus, the detection of a kink 20, 21 in the endless carton 2, which is based on the measurement or calculation of a length L, L P of the surface in a linear section A, is significantly more robust against vibrations and relative movements than a detection based on measuring the distance of the surface of the continuous carton 2 to the sensor 5. This effect is further enhanced by the fact that the entire length L, L Pis recorded or approximated at a single point in time and thus neither the conveying movement of the continuous carton 2 nor vibrations or other relative movements can negatively influence the detection. In other words: Because several measuring points are recorded at the same time and a length is calculated or approximated from them, vibrations, relative movements or fluctuations in the conveying speed have no or at least a significantly smaller influence on the detection of creases in the continuous carton 2. Figures 6A and 6B show how a processing device 4 downstream of the at least one sensor 5 can use the information about the presence of a crease 20, 21. The figures represent a projection of floor plans 6 onto a continuous carton 2 with the fanfold crease 20.If the control system determines that a crease 20, 21, in particular a fanfold crease 20, is present in the continuous carton 2, the control system issues instructions to the processing device 4 such that, in a cardboard outline 6 introduced into the continuous carton 2 by the processing device 4, a fanfold crease 20 is neither located in the area of ​​an adhesive flap 61 (left in Figure 6A) nor in an area of ​​a fold 62 introduced by the processing device 4 (left in Figure 6B). The instruction can, for example, consist of shifting the cardboard outline 6 forwards or backwards in the longitudinal direction of the continuous carton 2 or of geometrically adjusting the cardboard outline. Furthermore, the processing device 4 can provide waste cuts to separate areas with fanfold creases 20 or to enable a shifting of the cardboard outline 6.It will be apparent to those skilled in the art that individual features described in different embodiments may also be implemented in a single embodiment, provided they are not structurally incompatible. Likewise, various features described in a single embodiment may also be provided in multiple embodiments individually or in any suitable subcombination.

[0002] List of reference symbols Continuous carton 2 Leporello fold 20 Other fold 21 Conveyor device 3 Processing device 4 Sensor 5 Laser line 51 Layout 6 Adhesive flap 61 Fold 62 Linear section A Distance between two sensors d S Distance between sensor and detected point d1, d2, d3Length of the surface L Approximate length of the surface L P Straight-line distance between two points L P1,2 , L P2,3 Detected point on the surface P1, P2, P3Conveying direction x

Claims

CLAIMS 1. A device for processing continuous cardboard (2) and for detecting creases (20, 21) contained therein, in particular fanfold creases (20), the device comprising: a conveyor device (3) configured to convey continuous cardboard (2) in a conveying direction (x); at least one sensor (5) configured to at least partially detect a surface of the continuous cardboard (2) during conveyance; and a controller configured to detect creases (20, 21) present in the continuous cardboard, in particular fanfold creases (20), using data about the surface acquired by the sensor (5); characterized in that the sensor (5) is further configured to at least partially detect the surface of the continuous cardboard (2) in a linear manner, or the controller is further configured to at least partially approximate the surface of the continuous cardboard (2) in a linear manner using data acquired by the sensor (5).Device according to claim 1, which is further configured to carry out the linear detection of the surface by the sensor (5) or the linear approximation of the surface by the controller at least not perpendicular to the conveying direction (x), preferably substantially parallel to the conveying direction (x).

3. Device according to claim 1 or 2, wherein the controller is further configured to measure a length (L) of the surface of the continuous carton linearly detected by the sensor or to determine a length (L). P ) to calculate the surface of the continuous cardboard (2) approximated linearly by the control system; and creases (20, 21) present in the endless carton (2), in particular Leporello creases (20), based on the measured or calculated length (L, L P).

4. The device according to claim 3, wherein the controller is further configured to distinguish, when detecting creases (20, 21), between fanfold creases (20) and creases (21) that are not fanfold creases.

5. The device according to one of the preceding claims, wherein the sensor (5) is a laser sensor and is configured to project a laser line (51) onto a portion (A) of the surface of the continuous carton in order to detect the surface.

6. Device according to one of the preceding claims, which further comprises a processing device (4) configured to introduce cuts and / or folds (62) into the continuous carton (2) according to a cardboard layout (6) specified by the controller, wherein the controller is further configured, in the event of detection of a fanfold crease (20), to take the position of the fanfold crease (20) into account when specifying cuts and / or folds (62) to the processing device (4).Device according to claim 6, wherein the control takes into account the position of the leporello fold (20) when specifying cuts and / or folds (62) to the processing device (4) such that a leporello fold (20) is not positioned within an adhesive flap (61) of the floor plan (6); or a leporello fold (20) is positioned at least 1 cm, preferably at least 2 cm, more preferably at least 5 cm away from a fold (62) to be introduced; or. a fanfold crease (20) is positioned outside the footprint (6) of the cardboard box.

8. A method for processing continuous cardboard (2) and for detecting creases (20, 21) contained therein, in particular fanfold creases (20), the method comprising the following steps: conveying a continuous cardboard box (2) along a conveying direction (x); detecting at least part of a surface of the continuous cardboard box (2) by means of at least one sensor (5); determining a length (L, L P) of the surface in a linear section (A) of the surface of the endless carton (2), preferably running parallel to the conveying direction; and detecting a kink (20, 21), in particular a Leporello kink (20), based on the length (L, L P ) of the surface of the continuous carton (2) in the linear section (A).

9. Method according to claim 8, wherein the length (L) of the surface of the continuous carton in the linear section (A), preferably running parallel to the conveying direction, is determined by the section (A) being linearly detected by a laser sensor (5).

10. Method according to claim 8, wherein the length (L P) of the surface of the continuous carton (2) in the linear section (A) extending preferably parallel to the conveying direction is determined by detecting a part of the surface of the continuous carton (2) by at least two, preferably at least three laser sensors (5) which are arranged in the direction of extension of the linear section (A) to be detected at a distance (d S ) are arranged relative to each other and detect the surface of the continuous cardboard (2) in a point-like manner and at the same time; and that the straight-line distance (L P12 , L P23 ) or the straight-line distances (L P12 , L P23 ) between the points (P1, P 2, P3) is or are calculated on the surface of the continuous cardboard (2).

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