Device and method for quality control as well as packaging system equipped therewith

Abstract

A device and a method for quality control of packaging units (12) are disclosed, wherein the packaging units (12) are each formed by primary packagings (16) secondarily wrapped with shrink film (30). On a conveyor section (22, 52) extending through a shrink device (36), the primary packagings (16) wrapped with shrink film (30) are conveyed for heat treatment by the shrink device (36). An optical detection device (54) is arranged at the outlet of the shrinking device (36) for optosensory scanning of at least one outer surface of the packaging units (12) passing through the outlet. Image signals (60) supplied by the optical detection devices (54) to the respective packaging unit (12) are compared with predefined target signals. If a deviation of the detected image signals (60) from the target signals is detected, which is below a predefinable limit value, or if detected image signals (60) are within a target range, a heating device located in the shrinking device (36) or supplying the shrinking device (36) with an increased shrinking temperature is throttled at least to such an extent that a shrinking temperature prevailing within the shrinking device (36) is reduced by a defined value.

Description

[0001] The present invention relates to a device and a method for quality control of packaging units, each consisting of at least one primary packaging secondarily wrapped with shrink film. The invention also relates to a packaging system equipped with such a device for quality control of packaging units.

[0002] It is common practice to group items such as beverage containers into handy packaging units or bundles of four, six, or more containers for transport purposes, with the containers within these bundles being held together in various ways. The individual container, which might be a PET bottle or a mineral glass bottle, forms the primary packaging, securely containing the beverage or liquid.

[0003] Several of these primary packages can be grouped and held together using suitable secondary packaging. Cardboard boxes, into which the items or primary packages can be inserted, are one example of suitable secondary packaging. Shrink film wrapping is another type of secondary packaging.

[0004] Shrink films used as packaging material or secondary packaging are typically supplied as continuous material on rolls. Within a packaging machine, the shrink film is measured and separated according to the required dimensions for wrapping a group of items. After separation, the film sheets can be wrapped around the items or groups of items in a film wrapping module using a wrapping system. The characteristic property of the shrink film used, and essential for packaging purposes, is its ability to change shape and length under the influence of temperature. This property is utilized in the packaging process by transporting the shrink-wrapped item groups through a shrink tunnel, where they are exposed to elevated temperatures.

[0005] During their transport through the shrink tunnel, the shrink-wrapped product groups are exposed to a suitable shrinking agent, usually hot air blown onto the wrapped items. This hot air causes the shrink film to contract, typically both in the direction of travel and across it, so that it clings to the products and mechanically clamps them together. This process forms the finished shrink-wrapped packages, which can optionally be fitted with additional features such as carrying handles.

[0006] The shrinkage properties of the shrink films used are generally the same across their entire surface area, so that with uniform heat input and exposure, uniform shrinkage behavior can be expected. However, it is not solely the film properties that determine the shrinkage behavior, as the packaged items also influence the behavior of the film as it contracts under the influence of heat.

[0007] Particularly in the film packaging of beverage containers, the pre-grouped container assembly is arranged upright on a free end section of a shrink film within a wrapping module. The shrink film can then be folded around the container assembly in such a way that the first end section of the shrink film and a second end section overlap below the container bottoms. This loose arrangement of containers and shrink film is transported through the shrink tunnel to be exposed to hot air as evenly as possible, which in turn triggers the desired shrinking behavior of the shrink film, causing it to tighten around the containers.

[0008] In principle, it is possible to completely enclose the containers in shrink-wrap packaging, so that the primary packaging can be entirely covered by the secondary packaging formed by the film. However, such shrink-wrap packaging typically has so-called "side film eyes," meaning open areas on the sides where the packaged containers are not covered by the film. To create these side film eyes, the respective film section is significantly wider than the container assembly, but not so wide that folding over the protruding film sections would completely cover the containers. These protruding film sections are referred to as side film overhangs.Due to the shrinkage behavior of the shrink film, in particular the extent of the shrinkage of the shrink film transversely to its direction of travel and in the direction of travel, the lateral film overhang conforms to the containers of the assembly.

[0009] Provided the key influencing factors in the shrinkage processes described above can be controlled, it can be assumed that the film "eyes" will form uniformly round or oval contours. The size of the resulting film eyes depends on the width of the lateral film overhang. The shrink film shrinks in the shrink tunnel according to its shrinkage properties, whereby the end faces are smoothed at their edges. After leaving the shrink tunnel, the package is cooled with ambient air and, if necessary, by means of additional cooling devices, thereby further stabilizing it. Depending on the film properties, the overlapping film ends in the bottom area can be additionally welded if this proves advantageous.

[0010] The side film loops have proven advantageous, as they stabilize the container and generally result in a more secure lateral bond between the container assemblies. The shrinkage force following the actual shrinking process pulls the container together and / or constricts it. This ensures that no containers tip sideways out of the bundle and that the containers can be transported safely to the end user.

[0011] Numerous process parameters can influence the shrinkage result and, in unfavorable circumstances, lead to insufficient shrinkage and / or packaging quality. For example, if the shrink film used exhibits inadequate shrinkage rates in the longitudinal and / or transverse direction, these film batches cannot be processed well in the shrink tunnel. In particular, if the ratio between the longitudinal and transverse shrinkage behavior of a shrink film does not meet the specifications, this can cause significant problems in the shrinking process. This manifests itself as creases and adhesions at the film's edges or on the end faces of the container.

[0012] Other variable process parameters include the temperature level in the shrink tunnel, the dwell time of the container assemblies, and the hot air flows within the shrink tunnel. Since it generally proves to be a complex control task to weigh and appropriately consider all these variable process parameters in order to consistently produce defect-free containers, it can be advantageous to seek strategies that can deliver equally satisfactory manufacturing quality with less effort.

[0013] In view of the identified problems in the packaging process, particularly when using shrink film as a secondary packaging material, a primary objective of the invention can be considered to be to provide a significantly simplified strategy for considering at least one effective control parameter among the multitude of available and controllable parameters for a shrinking process. In this way, a desired packaging quality should be achievable and ensured with the least possible technical effort.

[0014] These objectives are achieved by a device and a method for quality control of packaging units, which include the features in the independent claims. Further advantageous embodiments are found in the respective dependent claims.

[0015] To achieve at least some of the aforementioned objectives, the invention proposes a device for quality control of at least partial sections of a packaging process, comprising the features of the independent claim. This device is intended to enable the monitoring and / or influencing of the quality of packaging units, each of which consists of at least one primary packaging secondarily wrapped with shrink film. The device comprises at least one conveying section extending through a shrinking device for transporting the shrink-wrapped primary packaging units and for their heat treatment within the shrinking device. An optical detection device for optosensory scanning of at least one outer surface of the packaging units passing through the outlet is assigned to the conveying section at the outlet of the shrinking device.

[0016] This optical detection device can optionally be arranged or positioned directly on the shrinking device, i.e., in particular at its outlet. However, the optical detection device can also be arranged or positioned at a short or long distance from the outlet of the shrinking device, which in this context is also referred to as an arrangement or positioning downstream of the shrinking device or as an arrangement or positioning located after the shrinking device.

[0017] When it is stated here and in the broader context of this description that the packaging units should be formed by at least one primary packaging secondarily wrapped with shrink film, this should not be understood restrictively as meaning that only those shrink-wrapped packages are meant in which individual packaged goods or primary packagings or several grouped primary packagings are wrapped with shrink film, creating overlapping areas, after which this preliminary stage of the packaging units to be produced undergoes heat treatment within the shrinking device in order to obtain the finished packaging units or shrink-wrapped packages.

[0018] The present invention is intended to relate equally to and be suitable for packaging units in which pre-assembled, in particular tubular, shrink film sections are pulled or slipped over the primary packaging or around the primary packaging groups, after which the pre-stages of the packaging units to be produced, formed in this way, undergo heat treatment within the shrinking device in order to obtain the finished packaging units or shrink film bundles.

[0019] These pre-cut, tubular film sections can be supplied, for example, from a continuous supply by tearing or cutting off suitable lengths. These packaging options are also known as shrink packaging, while the film sections themselves are often referred to as sleeves or sleeve labels.

[0020] The tube- or hose-like film sections are slipped or pushed over the primary packaging along its longitudinal direction, especially from above. Since this slipping or pushing usually occurs at high speed, it is often said that the sleeves are shot onto the primary packaging from above.

[0021] These sleeve labels are preferably made of shrinkable film material, so that the primary packagings equipped with them are firmly enclosed by the tube- or hose-like film section after heat treatment, which preferably extends only over the outer surface of the primary packaging or over a outer surface section of the primary packaging, but not over an upper neck section and over a lower bottom area.

[0022] Since the primary packaging can typically be containers or bottles, especially beverage containers, the sleeve label, after its heat treatment, forms a label that completely encloses and covers the outer surface of the bottle or container, whereby the label can be optionally shorter or longer as required and thus cover a shorter or longer section of the outer surface in relation to the longitudinal center axis of the bottle or container.

[0023] After the grouped or individual primary packaging is wrapped or after sleeve labels are applied, these shrink-wrapped packages undergo heat treatment using a shrinking device. This shrinking device is followed by a quality control device, which in this case consists of at least one optical detection unit.

[0024] Especially with such packaging variants, i.e., with the described sleeves or sleeve labels, it can be useful to add defined amounts of water or moisture to the hot air or hot gas used as the shrinking medium in the shrinking device, so that the resulting steam facilitates shrinking and can have a beneficial influence on the shrinking behavior.

[0025] Therefore, whenever hot gas or hot air is mentioned in this description, it generally refers to the fluid used for heat transfer in the shrinking device. This fluid, hot air, or hot gas can optionally contain water and thus vapor, or include vapor, which can be advantageous in certain shrinking processes and / or with certain film types. Alternatively, this vapor can also be added as needed when the shrink medium is directed as a fluid flow onto the packaging units to be treated within the shrinking device.

[0026] The image signals supplied by the optical detection devices for each packaging unit are compared with predefined target signals in a computer and evaluation unit. If the computer and evaluation unit detects a deviation of the detected image signals from the target signals, preferably at least one heating element of the shrink-wrapping device is influenced and / or its heating behavior is modified. If it is determined that the deviation of the actual signals from the target signals is only slight and lies within a certain interval or below a predefined limit, the heating element located in the shrink-wrapping device or supplying the shrink-wrapping device with an increased shrink temperature is throttled at least to such an extent that the shrink-wrapping temperature prevailing within the shrink-wrapping device decreases by a defined value.Preferably, these target-actual comparisons are repeated at predetermined time or processing intervals, resulting in an iterative reduction of the heating power in the shrink tunnel.

[0027] Since this is an optical inspection, the limit values ​​can generally also be considered as tolerance ranges or as boundaries of target ranges, so that it can be considered characteristic of the device according to the invention to detect and determine the quality of a first packaging unit or the qualities of several first packaging units at the exit or after the exit of the shrink device in the manner described by means of the optical detection device in order to reduce the shrink temperature of the shrink device or the shrink temperature within the shrink device by a first value if the quality or if the optically detectable quality parameters are within the specified target range.

[0028] Furthermore, it may preferably be provided to also detect and determine the quality of a second packaging unit or the qualities of several second or further packaging units at or after the output of the shrinking device in the manner described, using the optical detection device, in order to lower the shrinking temperature of the shrinking device or the shrinking temperature within the shrinking device a second time, by a second value, provided that the quality or the optically detectable quality parameters of the second or further packaging unit(s) are within the specified target range.

[0029] These target ranges, determined or established in the first and second steps, do not necessarily have to be the same. For example, it may be advantageous to define a slightly narrower target range for the second or subsequent packaging units to determine their quality. This would mean that the second value by which the temperature in the shrinking device is reduced in the second step could be smaller than the first value by which the temperature was reduced in the preceding first step. However, it may also be advantageous to use the same or nearly the same values ​​for the first and second steps.

[0030] However, if subsequent measurements exceed the specified interval, or if a deviation of the recorded image signals from the target signals is detected that is above or corresponds to a predefined limit, then preferably no further reduction of the heating device or the shrinking temperature occurs. Preferably, in such a case, an increase in heating power is specified instead of a reduction.

[0031] This can mean, in particular, that if the quality of the optically scanned packaging units is found to be outside a specified target range, the temperature in the shrinking device is not lowered, but raised by a defined value.

[0032] The underlying logic enables a particularly simple control system that requires no manual intervention to continuously approximate the desired packaging quality as closely as possible during the production of shrink-wrapped packages. Furthermore, the control logic underlying the invention allows for energy-efficient operation of the shrinking device used in the packaging process, as its heating power can be reduced until the desired packaging quality is just barely achieved. As soon as this quality falls below the target, an immediate control intervention can restore the previously achieved packaging quality.

[0033] The optosensory detection of at least one surface or side surface of the foil-wrapped packaging units or containers can be carried out in particular by means of at least one optical detection device, i.e. in particular by means of at least one camera that detects and optically scans at least one side surface or top surface of the packaging unit in question.

[0034] If two cameras are to be used, they can be positioned on both sides along a transport route in order to capture the opposite side surfaces of the packaging unit.

[0035] The optical detection device, which includes at least one camera or both cameras, can be used to scan and evaluate, in particular, the foil eyes arranged on both sides of the foil-wrapped packaging units using image processing technology.

[0036] Since trials have shown that the quality of the film eyes on packaging can be used as an indicator of process quality during the packaging and heat treatment of shrink-wrap packaging, optical detection devices or cameras can be used to identify whether deviations from a target state are found in the contours and / or dimensions of the film eyes. A suitable image processing system can then be used to determine whether a deviation from a target state is quantitative or qualitative.

[0037] In this way, the logic underlying the invention can repeatedly lower the shrinkage temperature in smaller steps until the deviations in shape, form, and / or size of the film eyes reach such a degree that they can be considered a loss of quality or a defect. Such deviations in shape, form, and / or size of a certain magnitude in the film eyes can be considered as exceeding the aforementioned interval or a predetermined limit, which prevents a further reduction in the shrinkage temperature and instead triggers a renewed increase in the shrinkage temperature.

[0038] This aims to achieve a clean and satisfactory shrinkage quality with the lowest possible energy consumption for operating the shrink tunnel. Furthermore, it should reduce, where possible, the need to exclude packaging units from further handling and / or packaging if their packaging quality is deemed insufficient. Since such packaging units are generally rejected or diverted, it is advantageous to minimize the proportion of rejected packaging. The device according to the invention attempts to counteract this through suitable measures, such as changing the temperatures in the shrink tunnel, before the detected deviations reach a level that necessitates the rejection of the affected packaging units.

[0039] Since the subjective factor of quality assessment of packaging units by means of an inspection or visual check of the shrinkage results is to be avoided as far as possible in the present invention, the present invention proposes the use of objectifiable criteria, which are essentially based on an optical inspection of the finished packaging units, which can not only detect and evaluate several optically detectable properties, but can also take into account different manufacturing parameters that can have an influence on the optical properties detectable by means of suitable sensors.

[0040] For this purpose, the finished packaging units can be inspected with an optical detection device, which detection device is formed in particular by at least one camera. When inspecting the foil eyes of the packaging units formed by shrink wraps, two cameras can in particular be provided, arranged on both longitudinal sides of a transport section, so that each individual shrink wrap transported on this transport section passes an optical axis that runs horizontally and transversely to the transport direction above a support plane of the transport section between the two opposing cameras of the optical detection device.

[0041] When an optical axis is mentioned here, it essentially refers to a center point of the detection areas of the two cameras, which each capture the left and right side surfaces of the shrink wraps or packaging units and process the captured image data by means of an image evaluation system that is expediently connected downstream of the optical detection device. This system can then obtain information regarding a shrinkage result and / or shrinkage quality and generate control signals in order to influence and change at least one shrinkage parameter when controlling the shrinking device.

[0042] As mentioned above, the shape, size, and / or dimensional accuracy of the film "eyes," which can be visually assessed in the manner described, represent a particularly suitable quality indicator. These film eyes typically form on both sides of shrink-wrapped packages because the shrink film used as packaging material is folded around the packages in the wrapping module in such a way that initially both sides oriented parallel to the transport direction remain free of film. Since the film webs are usually wider than the width of the package being wrapped, an excess of film remains on both sides. This excess is either partially folded around the sides or is formed there during the shrinking process as the film shrinks.

[0043] Since the actual shrinkage processes occurring during the hot air treatment of the shrink-wrapped product groups within the shrink tunnel are directly related to the desired shrinkage quality, a uniformly oval or round film eye of consistent shape, size, and / or dimensional accuracy can serve as a useful indicator of optimal shrinkage. Conversely, an irregularly shaped, too small, or too large film eye detected by the optical sensor can indicate insufficient shrinkage quality.

[0044] Further indicators of suboptimal shrinkage quality can be used and recorded by means of the optical detection device, e.g. the position of certain markings, cut marks, etc. on the enclosing shrink films.

[0045] Since numerous factors influence the shrinkage result, it may be useful to additionally rely on the principles of machine learning and / or artificial intelligence, as this allows measurement data and experience from previous control cycles to gradually increase knowledge about details and global relationships in the described control interventions.

[0046] Implementing the described control logics can yield numerous advantages, such as increased plant efficiency and reduced rejects due to quality defects. Maintenance costs can also be reduced. Timely notification of malfunctions can prevent unnecessary scrap caused by continuing production with unfavorable machine settings.

[0047] By gathering information from all relevant process steps and understanding all overarching relationships, corrective action can be taken on various parameters to continuously optimize the quality of the formation, sealing, and all packaging steps. Only when a reject cannot be prevented are the affected defective packaging units removed or a machine stoppage initiated. Even in these cases, the operator of the system is notified whenever possible to enable or facilitate targeted manual intervention.

[0048] However, the statements made above should not be understood as restrictive with regard to possible control interventions, nor as meaning that only the foil eyes should be detected by optosensory means and that the image data obtained should be examined with regard to shape, size and / or form deviations of the foil eyes from specified target states in order to obtain control data for temperature changes in the shrink tunnel.

[0049] Optosensory detection can also be performed, for example, using at least one camera that captures and optically scans the top side of the packaging unit in question. Such optosensory detection can employ transmitted light imaging. The resulting image data can be analyzed, in particular, to determine whether there are any deviations in shape, size, and / or form in the packaging units detected in this way. This allows for the identification of packaging units that are not in proper condition, such as those where individual primary packages are crooked within the packaging structure or have even fallen over.

[0050] While such quality defects cannot be prevented or even influenced by changes in the shrinkage temperature, other intervention options are conceivable if such deviations from the target state occur frequently. With such a high frequency of defects, it is likely that certain handling errors are occurring during the grouping of the primary packaging or during its conveying. Errors may also occur in the film wrapping module, leading to defects in the arrangement and assembly of the primary packaging.

[0051] If, during a visual inspection of the packaging units, the focus is not on the film opening but on other types of shape deviations, then sensor scanning of the top surfaces of the respective packaging units or shrink wraps can be particularly useful. As mentioned, these shape deviations can arise from various disturbances during the assembly of the product groups and / or in connection with their wrapping with the prepared sections of shrink film. For example, if...If a bottle within a group of products has fallen over, and this defective group of products is then wrapped in shrink film and subjected to the usual heat treatment in the shrink-wrapping machine, a shrink-wrapped package is created. While this package contains the intended number of primary packaging or bottles, and all the primary packaging or bottles within it may still be mechanically held together, such a shrink-wrapped package must be considered defective. Such a shrink-wrapped package should under no circumstances be further processed or palletized.

[0052] Another type of shape deviation can occur, for example, due to a misaligned and irregular rectangular arrangement of several bottles with cylindrical or non-cylindrical outer surfaces. If a single bottle or primary packaging is missing within the product group, or if several bottles or primary packaging are missing, this also leads to defective shrink wraps, unless such a defect is detected before film wrapping and / or heat treatment and used to reject or discard the affected product group.

[0053] Another deviation in shape can occur, for example, due to a single bottle or primary packaging standing at an angle within the product group, or due to several bottles or primary packaging units standing at an angle within the product group. This, too, can result in a defective shrink wrap.

[0054] All described shape deviations can be detected by appropriate arrangement of the optical detection devices used and a corresponding image analysis, so that corresponding control signals can be generated for further control interventions. However, in the case considered here, these further control interventions are not sensibly directed at an adjusted and modified temperature setting of the shrinking device, since the shape deviations described above cannot be influenced by changed temperature settings in the shrink tunnel.

[0055] The control interventions derived from the control signals are sensibly aimed at rejecting the affected packaging units so that they are not processed further and potentially palletized undetected. However, in cases of a cluster of similar errors that occur repeatedly, control interventions in the area of ​​a grouping unit and / or horizontal conveying units located upstream of the shrink-wrapping device may be advisable in order to reduce such clusters of errors.

[0056] A measuring arrangement used for this purpose can be configured for either single-lane or multi-lane transport of packaging units. Above the existing transport lanes for packaging units, optical detection devices, preferably consisting of cameras with downstream image processing, can be positioned at appropriate intervals relative to the top of the transported goods or packaging units.

[0057] Optionally, trigger light barriers can also be provided, whose beam path runs above the support surface and perpendicular to the transport direction. The beam path of the trigger light barriers is located at a suitable height to ensure reliable interruption by each packaging unit passing through the beam path. Such a trigger light barrier, in conjunction with image evaluation, can ensure that only image data that can be reliably assigned to a single packaging unit is evaluated.

[0058] Such trigger light barriers can prove particularly important in multi-lane transport operations to prevent false triggers caused by misaligned transported goods.

[0059] To obtain better and higher-contrast image data with transparent or semi-transparent shrink films, which are typically used as packaging material, a light source can be positioned below the transport track. This light source can be located below the camera and below the support surface of the transport section. It can be a point light source. However, to ensure universal coverage of the entire width of the transport section, even in multi-lane operation, the light source can also be a light bar or similar device that shines from below across the entire width of the transport section, through the packaging units being transported above it, and towards the cameras.The light bar can preferably be flush and seamlessly integrated with the upper support surface of the transport section, whereby the support surface may be interrupted in the area where the light bar is inserted.

[0060] The monitoring steps described above can be repeated iteratively multiple times and used to further lower the temperature in the shrinking device, as long as the quality of the packaging units passing through the shrinking device, as determined by the optical detection device, remains within predefined tolerance ranges or target ranges. As soon as this is no longer the case for one or more packaging units, the temperature in the shrinking device is preferably increased, and the affected packaging units, whose quality is deemed insufficient, can preferably be removed from the further handling, transport, and / or treatment or packaging process.

[0061] The necessary increase in temperature within the shrinking device can also be carried out in several steps while simultaneously monitoring the achieved shrinkage quality, so that, for example, if a quality is detected that lies outside the target range, a further temperature increase can be initiated, while any detected quality of a packaging unit or of several packaging units that lies within the target range can lead to a temperature reduction.

[0062] Preferably, it may be useful to repeat these described quality specifications and temperature adjustments for the packaging units subsequently transported through the shrink device and subjected to heat treatment there, whereby the values ​​of the temperature increase or the temperature decrease can be chosen to be smaller in each case.

[0063] For example, the first temperature reduction value can be chosen to be equal to or greater than the second temperature reduction value. Alternatively, the third value can be smaller in magnitude than the second temperature reduction value, while the fourth value can again be smaller in magnitude than the third temperature reduction value. The same applies to fifth and subsequent temperature reduction values. Similarly, these values, which may be necessary for a temperature increase, can gradually decrease in magnitude over successive measurement cycles.

[0064] When discussing absolute values ​​for temperature decreases or increases, a temperature decrease of, for example, 10°C might be appropriate for the first measurement, while subsequent values ​​should gradually decrease. For instance, the temperature in the shrinking device could be reduced by approximately 10°C in successive measurement cycles, then by less than 8°C, then by less than 5°C, and so on. Since these processes can be repeated repeatedly, the temperature decrease in later measurement cycles could be less than 1°C and possibly even fractions of a degree (e.g., 0.1°C or 0.2°C).

[0065] In general, it can also be advantageous to use smaller values ​​for temperature increases when the quality of packaging units falls outside a target range than for previous temperature reductions. Similarly, it can be beneficial to choose smaller values ​​for subsequent temperature reductions following a temperature increase than for those previous temperature increases.

[0066] Since the probability of producing defective packaging units is higher, especially with greater temperature reductions at the beginning of the described search for a temperature and quality optimum, these defectively produced packaging units can preferably be rejected.

[0067] As a precaution, it should be noted at this point that the packaging processes mentioned can optionally be combined, which opens up the possibility of equipping individual primary packagings or containers with the sleeve labels in the same production mode, as well as subsequently grouping these primary packagings with shrunk-on sleeve labels into several in the manner described and wrapping them with a flat section of shrink film and feeding them to the described film wrapping module for this purpose.

[0068] In such a case, a sensible configuration might, for example, provide that the modules required for equipping individual primary packaging or containers are located upstream of the film wrapping module. This means that the module for supplying and applying the sleeve labels is followed by the first shrink tunnel, in which the sleeves or sleeve labels applied to the primary packaging or containers are shrunk around them so that they are stretched tightly around their outer surfaces.

[0069] This first shrink tunnel can optionally be followed by the optical detection device described above, i.e., located downstream of the shrink tunnel in the transport direction. This device can be used for quality control and monitoring of the primary packaging or containers equipped with the sleeve labels. However, a configuration is also conceivable in which, downstream of the first shrink tunnel in the transport direction, a grouping station, an area for providing the appropriately cut shrink film sections, and the wrapping module are located. This is necessarily followed by another shrink tunnel, to which the optical detection device can be attached in the transport direction.

[0070] Unless this optical detection device alone is to be used for quality control, optionally separate optical detection devices can be installed downstream of both the first and the second shrink tunnel, thus enabling separate optical quality monitoring of both the first labeling process with the sleeve labels and the second packaging process with the shrink film sections wrapped around the primary packaging or containers or their groupings.

[0071] It should be expressly stated here that the device according to the invention is preferably controlled in its functions or partial functions by means of an electronic control system. Such an electronic control system can in particular be implemented or designed as a so-called PLC control system, i.e., as a programmable logic controller, whereby it is generally assumed that such an electronic control system or PLC forms an integral part of the device according to the invention.

[0072] To achieve at least some of the above-mentioned objectives, the invention further proposes, in addition to the previously described device, a method for quality control of at least partial sections of a packaging process, which is to be achieved by quality control of packaging units, each of which is formed by at least one primary packaging secondarily wrapped by means of shrink film.

[0073] In the method according to the invention, packaging units that have previously passed through a shrink-wrapping device as semi-finished products are monitored. In this shrink-wrapping device, the shrink film with which the primary packaging is at least partially and / or regionally encased is subjected to heat treatment, ultimately forming the finished packaging units. At or after the outlet of the shrink-wrapping device, an optosensor is provided to detect at least one outer surface of the packaging units passing through the outlet, and the optosensor-detected image signals of the respective packaging unit are compared with predefined target signals. If a detected deviation of the detected image signals from the target signals falls below a predefined limit value, the shrink temperature prevailing within the shrink-wrapping device is reduced by a defined value.

[0074] The method according to the invention can be characterized in particular as follows, whereby at least the following steps can be carried out: In a first step, the quality of at least one packaging unit can be determined at or after the exit of the shrinking device. If the quality of the first packaging unit(s) is within a target range, the temperature of the shrinking device is reduced by a first value.

[0075] The quality of further packaging units, or at least one further or second packaging unit, is then preferably determined at or after the outlet of the shrinking device, i.e., which further or second packaging unit(s) were transported through the shrinking device after the temperature of the device was lowered. If the quality of the at least one further or second packaging unit is within a target range, the temperature of the shrinking device is lowered a second time by a second value.

[0076] In subsequent steps, the quality of a third packaging unit, or the quality of several third packaging units, can be determined after the temperature of the shrinking device has been lowered a second time. If the quality of the third packaging unit(s) is / are outside a target range, the temperature of the shrinking device is preferably raised by a third value.

[0077] Alternatively, the procedure may provide that, in a further step, the affected third packaging unit, whose quality has been found to be outside a target range, is removed from the further transport, handling and / or processing process.

[0078] Furthermore, in another embodiment, the method can provide that – possibly after carrying out at least some of the steps described above – the quality of a fourth packaging unit or units is determined in a further step. This fourth packaging unit(s) must be transported through the shrinking device after its temperature has been increased. If it is determined that the quality of the fourth packaging unit is outside a target range, the temperature of the shrinking device can be increased a fourth time. However, if it is determined that the quality of the fourth packaging unit(s) is within a target range, the temperature of the shrinking device can preferably be decreased a fifth time.

[0079] The process can also be designed or configured in such a way that repeated quality determinations for subsequent packaging units can be answered with increasingly smaller values ​​of temperature adjustments when raising or lowering the temperature of the shrink device.

[0080] The third value of the temperature change or decrease in the shrinking device can preferably be smaller in magnitude than the second value of the temperature decrease in the shrinking device. Furthermore, the fourth value of the temperature change or decrease in the shrinking device can preferably be smaller in magnitude than the third value of the temperature change in the shrinking device. In addition, the fifth value of the temperature change or decrease in the shrinking device can preferably again be smaller in magnitude than the third value of the temperature change in the shrinking device and / or than the fourth value of the temperature change in the shrinking device.

[0081] The monitoring steps performed in the method according to the invention can be repeated iteratively several times and used to further lower the temperature in the shrinking device, as long as the quality of the packaging units passing through the shrinking device, as determined by the optical detection device, remains within predetermined tolerance ranges or target ranges. As soon as this is no longer the case for one or more packaging units, the temperature in the shrinking device is preferably increased, whereby the affected packaging units, whose quality is deemed insufficient, can preferably be removed from the further handling, transport, and / or treatment or packaging process.

[0082] The necessary increase in temperature within the shrinking device can also be carried out in several steps while simultaneously monitoring the achieved shrinkage quality, so that, for example, if a quality is detected that lies outside the target range, a further temperature increase can be initiated, while any detected quality of a packaging unit or of several packaging units that lies within the target range can lead to a temperature reduction.

[0083] Preferably, it may be useful to repeat these described quality specifications and temperature adjustments for the packaging units subsequently transported through the shrink device and subjected to heat treatment there, whereby the values ​​of the temperature increase or the temperature decrease can be chosen to be smaller in each case.

[0084] When discussing absolute values ​​for temperature decreases or increases, a temperature decrease of, for example, 10°C might be appropriate for the first measurement, while subsequent values ​​should gradually decrease. For instance, the temperature in the shrinking device could be reduced by approximately 10°C in successive measurement cycles, then by less than 8°C, then by less than 5°C, and so on. Since these processes can be repeated repeatedly, the temperature decrease in later measurement cycles could be less than 1°C and possibly even fractions of a degree (e.g., 0.1°C or 0.2°C).

[0085] In general, it can also be advantageous to use smaller values ​​for temperature increases when the quality of packaging units falls outside a target range than for previous temperature reductions. Similarly, it can be beneficial to choose smaller values ​​for subsequent temperature reductions following a temperature increase than for those previous temperature increases.

[0086] Since the probability of producing defective packaging units is higher, especially with greater temperature reductions at the beginning of the described search for a temperature and quality optimum, these defectively produced packaging units can preferably be rejected.

[0087] Alternatively, the procedure can provide that, in the event of a detected deviation of the recorded image signals from the target signals that is above or corresponds to a predefinable limit value, the shrinkage temperature prevailing within the shrinking device is not lowered, but increased by the defined value of the previously carried out temperature reduction.

[0088] Instead of limit values, however, target ranges or tolerance ranges are preferably used, as this generally seems more sensible for the described optical monitoring methods and as it is also easier to coordinate and / or align with optosensor monitoring.

[0089] The underlying principle is to lower the shrink tunnel temperature when the shrinking result, i.e., the condition of the optosensor-monitored packaging units, is satisfactory or can be considered good. Thus, when the packaging units correspond to a defined target state, a (at least slight) temperature reduction occurs in the shrinking device, preferably in defined temperature increments. The temperature in the shrink tunnel should therefore be iteratively lowered as the captured image signals match the target signals until a deviation of the captured image signals from the target signals is detected. At this point, a renewed increase in the shrinking temperature should be initiated, with the overarching goal of finding an optimum temperature without having to configure it via parameter settings.

[0090] The deviation depicted by the image signals can be either a shape deviation and / or a size deviation and / or a shape deviation of a defined area of ​​the shrink film enclosing the primary packaging and / or of the entirety of primary packaging encased by the shrink film.

[0091] The deviation could, for example, be a deviation in shape, size and / or form of at least one surface section of the shrink film.

[0092] The side foil eyes of the shrink film wrappings of the packaging units are particularly suitable as an indicator of packaging quality, so that their deviation in shape, size and / or form can be used for a target-actual comparison.

[0093] Alternatively or additionally, a different type of deviation can also be considered and monitored. For example, the deviation under consideration could be a variation in shape, size, and / or design in the composition of the primary packaging, which might indicate irregularities in the composition and / or grouping of the primary packaging within the packaging units.

[0094] If a deviation of one kind or another is detected, i.e., in particular if a quality is detected outside or within a target range, a temperature adjustment can be initiated according to the system described above.

[0095] However, if a deviation is detected, intervention in the area of ​​preparation, feeding and / or cutting of the shrink films may also be useful, depending on the type of defect detected.

[0096] Furthermore, if a deviation is detected that is no longer tolerable, it may be useful to mark the packaging unit as defective and / or to remove it from further handling and / or packaging processes.

[0097] Regarding the process, it should be expressly emphasized here that the terms used, such as packaging, film packaging, shrink film wrapping, etc., refer equally to flat sections of shrink film, which are usually wrapped around several grouped primary packagings or containers using a wrapping module and then subjected to heat treatment, as well as to the sleeve labels described above, which are pushed, slipped, or shot along a longitudinal central axis over individual primary packagings or containers in order to be tightly stretched around the outer surface of the respective primary packaging or container by means of heat treatment.

[0098] As mentioned, these two packaging variants can also be combined, because containers or primary packaging that are equipped with sleeve labels on the outer surface in the manner described above can be grouped together and wrapped with flat shrink film sections in order to subsequently undergo further heat treatment.

[0099] Regarding further details, options, or modifications, the above statements concerning the device apply. Furthermore, it should generally be the case that some or all of the aforementioned variations or embodiments of the inventive method and / or the inventive device can optionally be combined with one another in order to at least partially achieve the above-formulated objective(s) and / or to achieve the desired effect of the invention.

[0100] It should be expressly mentioned here that all aspects and embodiments explained in connection with the inventive device for quality control of packaging units equally relate to or can constitute partial aspects of the inventive method. Therefore, whenever certain aspects, relationships, and / or effects are mentioned in the description or the definitions of the claims for the inventive device, this applies equally to the inventive method. Conversely, the same applies, meaning that all aspects and embodiments explained in connection with the inventive method for quality control of packaging units equally relate to or can constitute partial aspects of the inventive device.Therefore, if at any point in the description or in the claim definitions for the method according to the invention certain aspects and / or relationships and / or effects are mentioned, this applies equally to the device according to the invention.

[0101] Furthermore, the present invention comprises a packaging system for the production of packaging units, each consisting of at least one primary packaging secondarily wrapped with shrink film. This packaging system according to the invention includes at least one feeding device for the at least one primary packaging or for assemblies of several grouped primary packagings, and a module for providing appropriately cut sections of shrink film and for feeding them to the at least one primary packaging or for assembling several grouped primary packagings.

[0102] This module can, for example, provide pre-cut, flat sections of shrink film, which are then wrapped or folded around individual primary packaging units or groups of several primary packaging units. Alternatively, this module can also be a feeding and dispensing module for so-called sleeve labels, which are tubular or tube-like sections of film that are slid over the primary packaging along its length. Typically, these sleeve labels are slipped or slid over the primary packaging from above. Because this process usually occurs at high speed, it is often described as "shooting" the sleeves onto the primary packaging from above.

[0103] Furthermore, the packaging system according to the invention comprises an application module for applying and at least partially and / or selectively wrapping the at least one primary packaging or the group of articles with several primary packaging with the prepared shrink film. This application module ensures that the flat sections of the shrink film are applied to individual primary packaging or to the available groups of articles with several primary packaging. Depending on the embodiment of the packaging system, the application module can also be used to apply the aforementioned sleeve labels to the available individual primary packaging.

[0104] These sleeve labels are preferably made of shrinkable film material, so that the primary packagings equipped with them are firmly enclosed by the tube- or hose-like film section after heat treatment, which preferably extends only over the outer surface of the primary packaging or over a outer surface section of the primary packaging, but not over an upper neck section and over a lower bottom area.

[0105] Since the primary packaging can typically be containers or bottles, especially beverage containers, the sleeve label, after its heat treatment, forms a label that completely encloses and covers the outer surface of the bottle or container, whereby the label can be optionally shorter or longer as required and thus cover a shorter or longer section of the outer surface in relation to the longitudinal center axis of the bottle or container.

[0106] Furthermore, the packaging system according to the invention comprises a shrinking device located downstream of the application module in a transport direction for the heat treatment of the article groups or primary packagings at least partially and / or partially covered with the shrink film or for the heat treatment of the individual primary packagings covered with the shrinkable sleeve labels.

[0107] Finally, in the packaging system according to the invention, a device for quality monitoring is provided downstream of the shrinking device in the transport direction, as already defined above in various embodiments or variants.

[0108] Depending on the selected configuration of the packaging system according to the invention, it may, for example, be provided that the module for supplying appropriately cut sections of shrink film provides and feeds these to a wrapping module, wherein the packaging system is further equipped with a wrapping module for applying and at least partially and / or partially wrapping the at least one primary packaging or the group of articles with several primary packagings with the prepared shrink film. This wrapping module serves to apply and wrap the at least one primary packaging or the group of articles with several primary packagings with the prepared shrink film.

[0109] In contrast, such a wrapping module is not suitable for processing sleeve labels, but rather for handling flat film sections that are cut to the appropriate length, for example, from a continuous supply of shrink film. While such sleeve labels can also be advantageously peeled from a continuous supply of tubular material and provided at the appropriate length, the storage and provision are naturally different than with flat film. Furthermore, the application of these sleeve labels is normally carried out from above the primary packaging or containers to be labeled, as they are slipped or pulled over the primary packaging or containers from above along the longitudinal center axis.

[0110] In contrast, the provision of flat film sections usually takes place from below, so that the containers or primary packaging are each pushed onto a shorter area of ​​these films, so that the film sections can then be wrapped around the primary packaging or around the assemblies with several grouped primary packaging using the wrapping module.

[0111] The packaging system further comprises a shrink device downstream of the wrapping module in a transport direction for the heat treatment of the article groups or primary packagings wrapped with shrink film or the individual primary packagings equipped with sleeve labels, as well as a device downstream of the shrink device in the transport direction for quality control, as defined above.

[0112] Such a packaging system, as defined here, may also be particularly suitable for carrying out a process according to one of the above-described design variants.

[0113] Finally, it should be noted that the modules mentioned can also be optionally installed in combination within the packaging system, which opens up the possibility of equipping individual primary packagings or containers with the sleeve labels in the same production mode and then grouping these primary packagings with shrunk-on sleeve labels into several groups in the manner described and wrapping them with a flat section of shrink film and feeding them to the described film wrapping module for this purpose.

[0114] In such a case, the system configuration can be such that the modules required for equipping individual primary packaging or containers are located upstream of the film wrapping module. This means that the module for supplying and applying the sleeve labels is followed by the first shrink tunnel, in which the sleeves or sleeve labels applied to the primary packaging or containers are shrunk around them so that they are stretched tightly around their outer surfaces.

[0115] This first shrink tunnel can optionally be followed by the optical detection device described above, i.e., located downstream of the shrink tunnel in the transport direction. This device can be used for quality control and monitoring of the primary packaging or containers equipped with the sleeve labels. However, a configuration is also conceivable in which, downstream of the first shrink tunnel in the transport direction, a grouping station, an area for providing the appropriately cut shrink film sections, and the wrapping module are located. This is necessarily followed by another shrink tunnel, to which the optical detection device can be attached in the transport direction.

[0116] Unless this optical detection device alone is to be used for quality control, optionally separate optical detection devices can be installed downstream of both the first and the second shrink tunnel, thus enabling separate optical quality monitoring of both the first labeling process with the sleeve labels and the second packaging process with the shrink film sections wrapped around the primary packaging or containers or their groupings.

[0117] Finally, it should be expressly defined at this point that the packaging system according to the invention is preferably controlled in its functions or partial functions by means of an electronic control system. Such an electronic control system can in particular be implemented or designed as a so-called PLC control system, i.e., as a programmable logic controller, whereby it should generally be the case that such an electronic control system or PLC forms an integral part of the packaging system.

[0118] The following exemplary embodiments of the invention and its advantages will be explained in more detail with reference to the accompanying figures. The relative sizes of the individual elements in the figures do not always correspond to the actual relative sizes, as some shapes are simplified and others are enlarged for better illustration. Fig. Figure 1 shows a schematic view of an embodiment of a packaging system according to the invention for the production of packaging units. Fig. Figure 2 shows a perspective detail view of a measuring arrangement of the packaging plant according to Fig. 1. Fig. Figure 3 shows schematic representations of various variants of undistorted and differently deformed foil eyes, which are located on side surfaces of the packaging system according to Fig. 1 manufactured packaging units are located. Fig. Figure 4A shows a schematic front view of an alternative variant of a measuring arrangement used in the packaging plant according to Fig. 1 is intended for scanning the top surfaces of the packaging units transported in single-lane operation. Fig. 4B a perspective view of the measuring setup according to Fig. 4A. Fig. Figure 5A shows a schematic front view of another alternative variant of the measuring arrangement, which is used in the packaging plant according to Fig. 1 is intended for scanning the top surfaces of packaging units transported in multi-lane operation. Fig. 5B a perspective view of the measurement setup according to Fig. 5A. Fig. Figure 6 shows a schematic and perspective view of an optional equipment with which the packaging system can be equipped according to Fig. It can be additionally equipped with 1.

[0119] For identical or similarly acting elements of the invention, the following figure description generally uses the same reference numerals. Furthermore, for the sake of clarity, in many cases only those reference numerals are used in the individual figures that are necessary for the description of the respective figure. The illustrated embodiments merely represent examples of how the device or method according to the invention may be configured and do not constitute an exhaustive limitation. Moreover, the features described below are not to be understood as closely related to other features of the respective embodiment, but may be provided for or used in a general context.

[0120] Based on the schematic view of the Fig. 1. First, a typical application variant of a device according to the invention for process and quality monitoring in the production of packaging units will be illustrated. Thus, the Fig. 1. A variant of a packaging system 10 for the production of packaging units 12. The components and modules typically present in such a packaging system 10, as well as their function and interaction in the production of the packaging units 12, are explained below.

[0121] The packaging system 10 shown comprises a grouping unit 14 (far left) in which primary packaging 16, such as bottles 18 or cans, etc., are grouped and assembled into product groups 20. These product groups 20, each consisting of a defined number of primary packaging 16 or bottles 18 arranged in a defined configuration relative to one another, are conveyed on a horizontal conveyor 22 or, as shown in Fig. 1 is shown, on several successive horizontal conveying devices 22 in a defined transport direction 24 (in Fig. (1 pointing from left to right) to subordinate modules.

[0122] In the illustrated embodiment of the packaging system 10, the article groups 20 formed from the primary packaging 16 or bottles 18 are conveyed by means of the horizontal conveyor 22 to a wrapping module 26 downstream of the grouping unit 14, in which the article groups 20 are each wrapped with a flat packaging material 28. Preferably, this is a thermoplastic packaging material 28 in the form of a shrink film 30.

[0123] In the wrapping module 26, a shrink film 30, unwound from a continuous film supply 32, is provided for packaging the grouped primary packaging 16. This film is cut to length and portioned by means of a film cutting station 34, so that appropriately cut shrink film sections 30 are formed and can be fed into the article groups 20 within the wrapping module 26, so that the article groups 20 can be wrapped with the sections of shrink film 30.

[0124] The article groups 20, thus wrapped with packaging material 28 in the form of suitable sections of shrink film 30, subsequently pass through a shrink device 36 downstream of the wrapping module 26 in the transport direction 24, wherein the article groups 20 are transported from the wrapping module 26 to the shrink device 36 and through it by means of further successive horizontal conveying devices 22 as shown.

[0125] Within the shrinking device 36, which is typically designed as a shrink tunnel 38, the article groups 20 wrapped in shrink film 30 are tempered and heated, usually by blowing hot air onto the article groups 20. This hot air serves as the heat energy carrier for the targeted tempering and shrinking of the shrink film 30. The heat treatment of the article groups 20, which are conveyed through the shrink tunnel 38 in the transport direction 24, i.e., their all-around exposure to hot air of a defined temperature, causes the packaging material 28 formed by the shrink film 30, with which the primary packaging 16 or bottles 18 of the article group 20 are wrapped and encased, to shrink to a defined extent, thereby mechanically contracting the article group 20 and forming the respective packaging unit 12.

[0126] These packaging units 12 formed in this way can in this case also be referred to as shrink wrap 40 or as shrink film wrap.

[0127] The shrink device 36 formed here by the shrink tunnel 38 has an interior 42 with a transport track 44 for the transport of at least one-lane article groups 20 wrapped with packaging material 28 in the transport direction 24 shown. Optionally, the transport track 44 can also be designed and configured for two-lane or multi-lane transport, which, however, is not possible due to the side view in Fig. 1 cannot be represented. If a two-lane or multi-lane transport of the article groups 20 through the shrink tunnel 38 is provided, the transport route 44 can comprise two or more conveying means arranged parallel to one another. In the case of single-lane transport, therefore, such a conveying means is provided with which the article groups 20 are transported through the shrink tunnel 38.

[0128] Furthermore, the shrinking device 36 has suitable means 46 for introducing and distributing the hot air into the interior 42 of the shrink tunnel 38, wherein these means 46 are normally formed by shaft walls with outlet openings, optionally by ceiling surfaces with such outlet openings and / or by a floor chamber with outlet openings. The purpose of these means 46 is, in each case, to supply the article groups 20 conveyed through the shrink tunnel 38 with tempered hot air in the most targeted and homogeneous way possible, in order to achieve the desired shrinkage result.

[0129] The side walls of the shaft, not shown in detail here, typically have outlet surfaces for the hot air directed towards the respective transport track, as do the ceiling surfaces, which may be equipped with further outlet openings, and / or the floor chamber, which may also be equipped with further outlet openings for the hot air. These are collectively referred to here as the devices 46 for introducing and distributing hot air. A floor chamber, preferably located below the transport track 44, is designed to direct the hot air with an upward flow component through the conveying means onto the underside of the article groups 20 wrapped with packaging material 28.

[0130] To prevent localized or widespread overheating of the conveying elements of the transport section 44, which could, for example, lead to the shrink film 30 sticking together, hardening, and thus damage to the product groups 20 wrapped in packaging material 28, an optional cooling device 48 can be provided in the interior 42 of the shrink tunnel 38. Alternatively, several such cooling devices 48 can be provided to cool the conveying elements of the transport section 44 as needed. This is particularly relevant for an endlessly circulating traction element such as a conveyor chain or conveyor belt, especially in the area of ​​the lower run of the traction element that retraces its path against the direction of transport 24 below a support level for the product groups 20.

[0131] Alternatively, the conveying speed of at least one conveying element of the transport section 44 can be regulated, which can be useful for influencing the temperature control duration to which the hot air-exposed article groups 20 are subjected in the interior 42 of the shrink tunnel 38. In connection with influencing the shrinking temperature, the flow rate and volume flow of blown-out hot air, as well as the control of the optional cooling device 48 or the multiple optional cooling devices 48, several control options arise that are in a complex interrelationship, so that the shrinking result of the packaging units 12 can be influenced in different ways by various intervention options, which are sensibly coordinated.

[0132] Furthermore, it can be provided that the shrink-wrapped packages 40, i.e., the packaging units 12 completed in the manner described, are supplied with additional cooling air after leaving the interior 42 of the shrinking device 36 or the shrink tunnel 38. This can be ensured, in particular, by suitable cooling fans 50 located near the outlet of the shrinking device 36. Such additional cooling of the shrink-wrapped packages 40 or packaging units 12 conveyed out of the shrink tunnel 38 allows them to be cooled and the surrounding shrink film 30 to be calmed and stabilized before further processing of the packaging units 12.

[0133] An additional advantage of using such a cooling fan 50 can be the supplementary cooling of the conveying equipment as well as the targeted cooling of non-conveyed packaging units 12, which can be advantageous, for example, in the event of a plant stoppage.

[0134] The finished packaging units 12 or shrink wraps 40 are fed via a further transport section 52 to subsequent packaging and / or processing stations, which are not shown here, e.g., a palletizing device or other handling and / or packaging stations. This further transport section 52, like the preceding transport sections, can also be formed by a suitable horizontal conveyor with a circumferential support surface for the packaging units 12 or shrink wraps 40 transported on it.

[0135] As previously indicated, the sequential process steps, both in terms of timing and conveying technology, result in a packaging product that adheres to certain specifications. Most of these specifications can be directly derived from the desired outcome: producing a large number of identical, flawless, and defect-free packaging units 12. However, it is advisable to allow certain tolerances for some of these specifications, such as the uniform shrinkage of the shrink film 30 across as many areas as possible. Intervention is possible as soon as several consecutively produced shrink-wrapped packages 40 exhibit noticeable deviations from a desired or intended target state during a visual inspection of the packaging units 12 transported on the next transport section 52 or located elsewhere. Such anomalies can be detected, for example, by...A person monitoring the shrinkage results should notice the issue by visually inspecting the shrink wraps 40, so that a manual plant stop can be triggered.

[0136] Since an unavoidable subjective factor can play a significant role in such an inspection or visual check of the shrinkage results, the present invention proposes the use of objectifiable criteria which, although essentially based on an optical inspection of the finished packaging units 12 or shrink wrappers 40, can not only detect and evaluate several optically detectable properties, but can also take into account different manufacturing parameters that may have an influence on the optical properties detectable by means of suitable sensors.

[0137] For this purpose, the in Fig. 1. Packaging system 10 shown in schematic representation is equipped with an optical detection device 54, which in the illustrated embodiment is formed by two cameras 56 arranged on both longitudinal sides of the transport path of the further transport section 52, so that each individual shrink-wrapped container 40 transported on this further transport section 52 passes an optical axis 58, which runs in a horizontal orientation and transverse to the transport direction 24 above a support plane of the transport section 52 between the two opposing cameras 56 of the optical detection device 54.

[0138] The optical axis 58 merely defines the center point of the detection areas of the two cameras 56, which each detect the left and right side surfaces of the shrink wraps 40 and process the captured image data 60 by means of an image evaluation 62 downstream of the optical detection device 54, which can obtain information regarding a shrinkage result and / or shrinkage quality and generate control signals 64 in order to influence and change at least one shrinkage parameter in the control of the shrinking device 36.

[0139] A suitable quality indicator that can be visually detected in the manner described can be, for example, the shape, size, and / or dimensional accuracy of a so-called film eye 66 on the respective shrink wrap 40. These film eyes 66 typically form on both side surfaces of the product groups 22 in shrink wrap packages because the shrink film 30 used as packaging material is wrapped around the product groups 22 in the wrapping module in such a way that initially both side surfaces oriented parallel to the transport direction 24 remain free of film. Since the film webs are usually wider than the width of a product group 22 to be wrapped with the shrink film 30, a film overhang remains on both sides, which is either partially folded around the side surfaces or formed there during the shrinking process and by the shrinking of the film.

[0140] Since the actual shrinkage processes occurring during the hot air treatment of the article groups 20 wrapped with the shrink film 30 within the shrink tunnel 38 are directly related to the desired shrinkage quality, a uniformly oval or round film eye 66 of constant shape, size, and / or dimensional accuracy can thus represent a usable indicator of an optimal shrinkage result. Conversely, an irregularly shaped, too small, or too large film eye 66 detected by the optical detection device 54 can indicate insufficient shrinkage quality.

[0141] Based on the following Fig. Sections 2 to 5B will examine these relationships and the meaningful consideration of further shrinkage parameters for the regulation of the shrinkage device 36 in more detail.

[0142] Thus, the perspective detail view of the Fig. 2 a partial section of the further transport section 52 downstream of the shrinking device 36 in the transport direction 24 (cf. Fig. 1) identify which is normally formed by a horizontal conveying device with an upper flat support surface 68, which moves in the transport direction 24 and thus also transports the packaging units 12 standing on the support surface 68, each formed by shrink wrap 40, without slippage in the same transport direction 24.

[0143] The single shrink-wrapped package 40 shown in the illustration can comprise several primary packagings 16, each formed by bottles 18, which can be grouped together as a product group 20, for example, in a rectangular arrangement (e.g., a 3x3 arrangement). The bottles 18, which in the illustrated embodiment each form the primary packagings 16, are in the Fig. 2 only schematically indicated, among other things by the bottle caps 70 visible on the top of the shrink container 40, which are covered by the shrink film 30 enclosing the bottles 18.

[0144] The Fig. Figure 2 also shows the film eye 66 on the left longitudinal side of the shrink wrap 40 with respect to the transport direction 24, which was formed in conjunction with the lateral film overhang 72 of the shrink film 30 enclosing the article group 20. Within an oval border 74 of this film eye 66, the bottles 18 located there are not covered with film. At the in Fig. On the two concealed opposite side surfaces of the shrink wrap 40, in the area of ​​the folded-over film overhang 72, there is a similar film eye 66, which is not visible here and which ideally has the same size and shape as the other film eye 66 under regular shrinkage conditions.

[0145] In order to better detect the shape and size deviations of the foil eye 66 from a defined and predefinable target state by optical means, it is useful to design the oval edge 74 of the foil eye 66 as shown by changing the color or contrast as a widened edge marking 76, i.e. as an edge strip of constant width, the inside of which defines the opening of the foil eye 66.

[0146] The already based on the Fig. 1 explained, in Fig. The optical detection device 54, which is even more clearly recognizable, serves, as already described above, to optically scan and detect the entire side surfaces of the packaging units 12 or shrink wraps 40 transported on the transport section 52. In particular, the optical detection device 54 serves to optically detect the film eyes 66 on both sides of the shrink wraps 40 in order to detect size and / or shape deviations of the film eyes 66 from a target state at an early stage and to be able to react to them by influencing the shrink parameters within the shrink device 36.

[0147] Further indicators for indicating suboptimal shrinkage quality can be used and recorded by means of the optical detection device 54, e.g. the position of certain markings, cut marks, etc. on the enclosing shrink films 30, which will be explained below using some examples.

[0148] The optical detection device 54 is designed according to the above description for Fig. 1 also in the in Fig. In the embodiment shown in Figure 2, the optical axis is formed by two cameras 56 which are arranged on both longitudinal sides of the transport path of the further transport section 52, so that each individual shrink wrap 40 transported on the support plane 68 of this further transport section 52 which moves in the transport direction 24 passes the optical axis 58, which runs in a horizontal orientation and transverse to the transport direction 24 above the support plane 68 of the transport section 52 between the two opposing cameras 56 of the optical detection device 54.

[0149] As explained above, the optical axis 58, located horizontally between the two cameras 56, merely defines the approximate center point of the detection areas of the two cameras 56, which each capture the left and right side surfaces of the shrink wrap 40 moving between them, so that the entire foil eye 66, including its oval edge 74 and the optional edge marking 76, can be captured on each side surface. The aperture cone of the camera optics must be selected such that this capture of the entire foil eye 66 is ensured.

[0150] The electronic image data 60 supplied by the two cameras 56 are processed by means of the downstream image evaluation 62, so that the control signals 64 for the control of the shrinking device 36 or the shrinking tunnel 38 (shown here only schematically and partially) can be generated from it.

[0151] According to the present invention, the image signals 60 are compared with predefinable target signals in the image evaluation unit 62 and / or in a downstream computer and evaluation unit 78. This essentially means that if the oval or circular edge 74 of the film eye 66 deviates from a target contour, a corresponding deviation of the image signals 60 is also detected. Based on this, a particularly simple measure, which also involves minimal computational and control effort, can be implemented to change the shrinking temperature set in the shrinking device 36, which prevails in the interior 42 of the shrink tunnel 38 and directly influences the shrinking processes.

[0152] The Fig. Figure 2 shows that the image evaluation unit 62 can be a component or integrated part of the downstream computer and evaluation unit 78, so that the control signals 64 do not have to be generated directly by the image evaluation unit 62, but can optionally be calculated and generated by the computer and evaluation unit 78. In practice, however, this distinction is not significant, since the processing of the image signals 60 and the calculation of the control signals 64 for the shrinking device 36 can be implemented with different hardware and / or software. In the present context, the functional relationships are of primary interest, rather than the specific hardware implementation and / or the programming of the respective control modules used.

[0153] The simplest implementation of the control principle described here can provide that, if a deviation of the detected image signals 60 from the specified target signals is detected and is below a predefinable limit, the shrinking temperature prevailing within the shrinking device 36 is reduced by a defined value. The underlying principle involves reducing the shrinking temperature when the result, i.e., the optically detected properties of the respective shrink container 40, is deemed acceptable. These preferably small temperature reductions can be repeated iteratively until the deviation of the contours of the film eye 66 and its surrounding edge 74 becomes too large and is no longer considered acceptable because it exceeds a predefinable limit.

[0154] At this point, a slight increase in the shrinking temperature can preferably be carried out, which is expected to result in the temperature falling below the previously exceeded limits. This is equivalent to classifying the optically monitored shrink wraps 40 as flawless, since the dimensional accuracy of the film eye 66 and the surrounding edge 74 can be assumed to be given when the limit is undercut in this way. Even when approaching the desired target state again in this way, several small temperature increases can be triggered in the shrinking device 36 if a single temperature increase does not prove to be effective.

[0155] The present control measures for influencing the temperature of the shrink device provide the user with a range of measures for verifying various requirements for quality control of the shrink-wrapped containers 40 produced and processed with the packaging system 10 according to the invention. Bilateral camera monitoring and camera inspection of the film eyes 66 makes it possible to check their size and contour, the different positions of reference points or reference surfaces, and to make size comparisons. In addition, predefined positions of cut marks can be monitored.

[0156] These optical monitoring systems can be extended to include three-dimensional image capture, possibly from several different directions, in order to detect and identify contour deviations of the monitored shrink-wrapped containers 40. In this context, multiple camera or scanner images can be combined, possibly using transmitted light techniques, to capture the external dimensions of the shrink-wrapped containers 40 and compare them with predefined target dimensions. This allows for the detection of whether all bottles 18 or primary packaging units 16 are present in the packaging unit 12. It also enables the detection of incorrect positioning of any of these bottles 18 or primary packaging units 16, for example, due to a bottle 18 lying down that has become part of the article group 20, which was subsequently wrapped in film and further processed.

[0157] Preferably, all recorded data such as product, performance, container, packaging formation, shrink parameters, ambient temperature, size of the film eyes, position of the cut mark, container temperature, laboratory measurements, etc., can be considered and combined to generate a logic that can contribute to achieving the goals of reducing energy consumption in the shrink tunnel 38 and reducing the rate of defective packaging units 12. The rate of rejected defective packaging units 12 should be as low as possible.

[0158] The logic in the computer and evaluation unit 78 can, in particular, follow the procedure described above and continuously or in stages reduce the shrink temperature until a noticeable deterioration, e.g., in the dimensional accuracy of the film eye 66, is observed. The temperature is then slightly increased again until a clean shrink quality can be achieved with the lowest possible energy consumption.

[0159] A related objective is to avoid or reduce the rejection of defective packaging units 12. Before the rejection limit is reached, attempts can be made to counteract this by changing one or more process parameters. One such measure could, for example, involve correcting the relative positions of the shrink film sections 30 to the product groups 20 being packaged, so that the film overhang 72 and thus also the film eyes 66 are the same size on both long sides.

[0160] Furthermore, the positions of the cutting mark can be corrected. In addition to changing the shrinking temperature, the blow-off nozzles in the shrink tunnel 38 can also be adjusted to influence the temperature applied to the shrink containers 40.

[0161] Since numerous factors influence the shrinkage result, it may be useful to additionally rely on the principles of machine learning and / or artificial intelligence, as this allows measurement data and experience from previous control cycles to gradually increase knowledge about details and global relationships in the described control interventions.

[0162] Implementing the described control logics can yield numerous advantages, such as increased plant efficiency and reduced rejects due to quality defects. Maintenance costs can also be reduced. Timely notification of malfunctions can prevent unnecessary scrap caused by continuing production with unfavorable machine settings.

[0163] The information gathered from all relevant process steps and the understanding of all overarching relationships allow for corrective intervention on various parameters, thereby continuously optimizing the quality of the formation, sealing, and all packaging steps. Only when a reject cannot be prevented or avoided are the affected defective packaging units (12) removed or a machine stop initiated. Even in these cases, the operator of the system is notified whenever possible to enable or facilitate targeted manual intervention.

[0164] As described above Fig. As explained in Section 2, the shape, size, and / or general dimensional accuracy of the film eyes 66, optically measured on both longitudinal sides of the shrink wrap 40, can be used as a quality indicator for the shrinking process and for the resulting optical quality of the packaging unit 12 formed by the shrink wrap 40. In this context, the primary focus is on the resulting control options for the shrinking device 36, while the optical quality of the film packaging of the packaging units 12 is an important secondary objective. However, according to the present invention, the optical quality of the film packaging of the packaging units 12 is intended to result from the optimized settings of the shrinking devices 36.

[0165] The Fig. Figure 3 shows, by way of example and without any claim to completeness, some examples of different shape, size and contour deviations that can occur during the optical measurement of the foil eye 66. All of the in Fig. The three foil eyes 66 shown describe an approximately horseshoe- or ring-shaped contour with an open ring at the bottom. The inner oval or circular edge 74 of the foil eye 66 can preferably be colored or highlighted by a contrasting element, which in this context is defined as an edge marking 76 and which can be achieved, for example, by appropriate printing on the shrink film sections 30. If the visual impression of such a colored or contrasting edge marking 76 is not desired in the finished packaging unit 12, the edge 74 or the edge marking 76 can also be applied to or incorporated into the film in a way that is not visible or at least not noticeable to the human eye, but which is fully recognizable to the optical detection device 54 used.

[0166] A target state of the foil eye 66 with an approximately circular contour can be indicated, for example, by the illustration in the upper left. The contours following in the upper row to the right show differently distorted foil eyes 66, i.e., a slightly smaller foil eye 66 (top row, second foil eye from the left), a significantly smaller foil eye 66 that is vertically compressed (top row, third foil eye from the left), and a significantly larger foil eye 66 that is horizontally stretched (top row, rightmost foil eye). The thickness of the edge marking 76 can also vary due to different shrinkage behavior, which, for example,This is the case with the smaller foil eye 66 in the top row (second from the right), so that the edge marking 76 may have a smaller width there than in the other examples of the deformed (second from the left and far right, each in the top row) or ideally shaped foil eyes 66 (far left, top row).

[0167] Furthermore, a target state of the foil eye 66 with a regularly oval contour can be characterized, for example, by the illustration at the bottom left. The contours following to the right in the bottom row show differently distorted foil eyes 66, i.e., a foil eye 66 slightly rotated about its axis (bottom row, second foil eye from the left), a significantly smaller foil eye 66 rotated about its axis to the left (bottom row, third foil eye from the left). The bottom row also shows a foil eye 66 on the far right that is distorted and compressed in several ways, which therefore appears irregular (bottom row, far right foil eye). The foil eyes 66 shown as examples in the bottom row of the Fig. 3. The strength of the edge marking 76 may vary due to different shrinkage behavior, which is the case, for example, with the smaller foil eye 66 in the bottom row (second from the right), so that the edge marking 76 may have a smaller width there than in the other examples of the deformed (second from the left and far right, bottom row) or ideally shaped foil eyes 66 (far left, bottom row).

[0168] In addition to the deformed foil eyes 66 shown as examples, numerous other deviations from an ideal shape are possible; the two left foil eyes 66 of the upper and lower rows serve as examples of a desirable ideal shape. Such deviations from the ideal shape can also consist, for example, of creases, sharper curves, folds of the edge marking 76, etc. Since it is not possible to record all such deviations here, the eight schematic representations of the Fig. 3 should be considered explicitly as a small excerpt from the vast number of variants.

[0169] For the sake of completeness, it should be noted again here that, due to the relationship between the actual shrinkage processes occurring in the film during the application of hot air to the article groups 20 wrapped with the shrink film 30 within the shrink tunnel 38 and the desired shrinkage quality, a uniformly oval or round film eye 66 of constant shape, size, and / or dimensional accuracy can be considered a useful indicator of an optimal shrinkage result. Conversely, an irregularly shaped film eye 66, too small or too large, detected by the optical detection device 54 (e.g., according to one of the illustrations of the Fig. 3, except for the two left examples for regularly shaped foil eyes) can be interpreted as an indication of insufficient shrinkage quality.

[0170] Based on the Fig. 4A, Fig. 4B, Fig. 5A and Fig. Section 5B will examine another aspect of the formation of packaging units 12 by combining primary packaging 16, wrapping it with shrink film 30, and subsequently heat-treating these packaging assemblies. While previously the focus was primarily on the outer wrapping of the shrink wraps 40 forming the packaging units 12 and their potential impairments, quality defects, and possible deviations from a target state—particularly noticeable in deformations and irregularities in the formation of the film eyes 66 of the shrink films 30 encasing the article groups 20—other types of deviations, disturbances, and / or quality defects in the formation of the packaging units 12 will be examined in more detail below.

[0171] These other types of deviations, malfunctions, and / or quality defects in the formation of the packaging units 12 can be any shape deviations of the shrink wraps 40 that can be detected optically by scanning at least one outer surface of the shrink wraps 40 in question. In the following, sensor arrangements will be considered in more detail that scan the shrink wraps 40 from their upper surface 80 during their transport on the support level 68 of the further transport section 52 downstream of the shrink tunnel 38, and that sensorially detect the corresponding optical appearance of the shrink wraps 40.

[0172] Thus, the schematic front view of the Fig. 4A as well as the perspective detail view of the Fig. 4B a partial section of the further transport section 52 downstream of the shrinking device 36 in the transport direction 24 (cf. Fig. 1) identify which is normally formed by a horizontal conveying device with the upper flat support surface 68, which moves in the transport direction 24 and thus also transports the packaging units 12 standing on the support surface 68, each formed by shrink wrap 40, without slippage in the same transport direction 24.

[0173] In the front view of the Fig. 4A can optionally point the transport direction 24 either perpendicularly out of the drawing plane or into it, which is irrelevant for describing the details recognizable in the illustration and their interaction. In the perspective view of the Fig. 4B indicates the transport direction 24 from left to right, as is also the case with the Fig. 1 as well as at the Fig. 2 is the case.

[0174] The depictions of Fig. 4A and Fig. The individual shrink-wrapped packages 40 shown in Figure 4B can comprise several primary packagings 16, each formed by bottles 18, which can be grouped together as a product group 20, for example, in a rectangular arrangement (e.g., a 3x3 or 4x4 arrangement) (see Figure 4B). Fig. 1 as well as the Fig. 2) In the present context, however, the focus is not on the foil eye 66, which is not shown in detail here, but on other types of shape deviations that can be detected by a sensor scan of the top surface 80 of the respective packaging unit 12 or the respective shrink wrap 40.

[0175] These deviations in shape can be caused by various disturbances during the assembly of the article groups 20 and / or in connection with their wrapping with the prepared sections of shrink film 30. For example, if a bottle 18 within article group 20 has fallen over and this defective article group 20 is wrapped with shrink film 30, and this defective semi-finished product is subjected to the usual heat treatment in the shrinking device 36, a shrink-wrapped container 40 is produced. While this container does contain the intended number of primary packagings 16 or bottles 18, and all the primary packagings 16 or bottles 18 within it may still be mechanically held together, such a shrink-wrapped container 40 must be considered defective. Such a shrink-wrapped container 40 should under no circumstances be further processed or palletized.

[0176] Another deviation in shape can occur, for example, due to a misaligned and irregular rectangular arrangement of several bottles 18 with cylindrical or non-cylindrical outer surfaces. If a single bottle 18 or a single primary packaging 16 is missing within the article group 20, or if several bottles 18 or primary packaging 16 are missing, this also leads to defective shrink-wrapped containers 40, unless such a defect is detected before film wrapping and / or heat treatment and used to reject or discard the affected article group 20.

[0177] Another deviation in shape can occur, for example, due to a tilted bottle 18 or primary packaging 16 within article group 20, or due to several tilted bottles 18 or primary packaging 16 within article group 20. This can also result in a defective shrink wrap 40.

[0178] All described shape deviations can be corrected by suitable arrangements of the optical detection devices 54 used and by a corresponding image evaluation 62 (see Fig. 1 and Fig. 2) detect, so that corresponding control signals 64 can be generated for further control interventions. However, in the case considered here, these further control interventions are not sensibly directed at an adapted and modified temperature setting of the shrink tunnel 38 of the shrink device 36, since the shape deviations described above cannot be influenced by changed temperature settings in the shrink tunnel 38.

[0179] The control interventions derived from the control signals 64 are sensibly aimed at rejecting the affected packaging units 12 so that they are not processed further and potentially palletized undetected. However, in the event of a cluster of similar errors that occur repeatedly, control interventions may be necessary in the area of ​​a grouping device 14 and / or the horizontal conveying devices 22 located upstream of the shrink-wrapping device 36 (see Figure 1). Fig. 1) be useful in order to reduce such identified error clusters.

[0180] The measuring arrangement used for this purpose for a single-lane transport of packaging units 12 on the transport section 52 is described in the Fig. 4A and Fig. 4B is shown schematically. Above a transport track 82, which runs approximately centrally along the longitudinal direction of the transport section 52 and along the transport direction 24, the optical detection device 54 is located at a suitable distance from the top 80 of the transported unit loads 12. As before, this is preferably a camera 56 with downstream image evaluation 62 (see Figure 4B). Fig. 1 and Fig. 2) can be formed.

[0181] However, in this case the optical axis 58 of the camera 56 points vertically downwards and sensibly meets approximately the middle of the top 80 of a packaging unit 12 located below the camera 56 or of a shrink container 40 located below the camera 56.

[0182] For a single-lane transport operation, the camera 56 is therefore located approximately above the transport lane 82. The camera 56 advantageously has a sufficiently widened detection area 84, which, for example, extends downwards in a conical shape around the optical axis 58, so that at least the entire top surface 80 of the packaging units 12 or shrink wraps 40 conveyed below the camera 56 can be detected and corresponding image data 60 can be generated. It should be noted that this detection area 84, which widens downwards towards the support surface 68, is only available in the Fig. 4A is schematically indicated, while the Fig. 4B is limited to the representation of the optical axis 58 running perpendicularly between the camera 56 and the top surface 80 of a shrink container 40.

[0183] The schematic front view of the Fig. Finally, section 4A reveals an optional, but technically useful, trigger light barrier 86, whose beam path 88 runs above the support surface 68 and perpendicular to the transport direction 24. The beam path 88 of the trigger light barrier 86 is located at a suitable height, ensuring reliable interruption by each shrink wrap 40 or packaging unit 12 passing through the beam path 88. In conjunction with the image evaluation 62, such a trigger light barrier 86 can ensure that only image data 60 is evaluated which can be reliably assigned to a single packaging unit 12 or a single shrink wrap 40.

[0184] Such trigger light barriers 86 can prove particularly important in multi-lane transport operations, as described in the Fig. 5A and Fig. 5B provides an example explanation. However, even in the single-lane operation described here, the trigger light barrier 86 offers the advantage of more reliable image evaluation, which is therefore not disturbed by patterns, spots or irregularities on the support surface 68.

[0185] To obtain better and higher-contrast image data 60 from the transparent or semi-transparent shrink films 30 typically used as packaging material, a light source 90 can be arranged below the transport track 82, sensibly located below the camera 56 and below the support surface 68 of the transport section 52. The light source 90 can be designed as a point light source, as shown by the Fig. 4A is suggested.

[0186] In order to be universally applicable even in a multi-lane operation (cf. Fig. 5A and Fig. 5B) to cover the entire width of the transport section 52, the light source 90 can, however, be positioned according to Fig. 4B may also be formed by a light bar 92, which shines from below across the entire width of the transport section 52, through the packaging units 12 or shrink wraps 40 transported above it, and towards the camera 56. The light bar 92 preferably terminates flush and seamlessly at its upper side with the upper support surface 68 of the transport section 52, the support surface 68 being interrupted in the area where the light bar 92 is inserted.

[0187] Furthermore, the schematic front view of the Fig. 5A as well as the perspective detail view of the Fig. 5B the same subsection of the further transport section 52 downstream of the shrinking device 36 in the transport direction 24 (cf. Fig. 1) as in the Fig. 4A and Fig. 4B can be identified. Again, the front view of the Fig. 5A the transport direction 24 can optionally point vertically out of the drawing plane or into it, which is irrelevant for describing the details recognizable in the illustration and their interaction. In the perspective view of the Fig. 45 indicates the transport direction 24 from left to right, as is also the case with the Fig. 1, Fig. 2 and Fig. 4B is the case.

[0188] The depictions of Fig. 5A and Fig. The two shrink-wrapped packages 40 shown in Figure 5B can each comprise several primary packagings 16, each formed by bottles 18, which can be grouped together as a product group 20, for example, in a rectangular arrangement (e.g., a 3x3 arrangement or a 4x4 arrangement) (see Figure 5B). Fig. 1 as well as the Fig. 2).

[0189] The above in connection with the explanation of the Fig. 4A and Fig. The shape deviations described in 4B within the transported shrink wraps 40 or packaging units 12 can be detected by suitable arrangements of the optical detection devices 54 used and a corresponding image evaluation 62 (see 4B). Fig. 1 and Fig. 2) recognize, so that corresponding control signals 64 can be generated for further control interventions.

[0190] These control interventions, derived from the control signals 64, are sensibly aimed at rejecting the affected packaging units 12 so that they are not processed further and potentially palletized unintentionally. Further useful control interventions can be implemented in the area of ​​a grouping device 14 and / or the horizontal conveying devices 22 located upstream of the shrink-wrapping device 36 (see Figure 1). Fig. 1) as explained above.

[0191] The measuring arrangement used for this purpose for a two-lane parallel transport of packaging units 12 on the transport section 52 is described in the Fig. 5A and Fig. 5B is shown schematically and exemplarily. Above two parallel transport tracks 94, each running off-center parallel to the longitudinal direction of the transport section 52 and parallel to the transport direction 24, optical detection devices 54 are located at a suitable distance from the top 80 of the transported unit loads 12. These devices are preferably cameras 56 with downstream image evaluation 62 (see Figure 5B). Fig. 1 and Fig. 2) can be formed.

[0192] Above each of the two transport lanes 82 is a camera 56, so that the optical detection device 54 in the case shown is formed by at least two cameras 56 arranged side by side. The optical axes 58 of the two cameras 56 each point vertically downwards and sensibly intersect approximately in the middle of the respective top surfaces 80 of the packaging units 12 located below the cameras 56 or of a shrink wrap 40 located below the respective camera 56.

[0193] Each of the two cameras 56 is thus located approximately above the respective transport lane 94 for a two-lane transport operation. The cameras 56 used for this purpose also have a sufficiently widened detection range 84, which extends downwards, for example, in a conical shape and concentrically around the respective optical axis 58, so that at least the entire top surfaces 80 of the packaging units 12 or shrink wraps 40 transported below the camera 56 can be detected and corresponding image data 60 can be generated.

[0194] It should be noted that these detection areas 84, which widen downwards towards the support level 68, are only available in the Fig. 5A are schematically indicated, while the Fig. 5B is limited to the representation of the optical axis 58 running vertically between the respective camera 56 and the top surface 80 of a shrink container 40.

[0195] The schematic front view of the Fig. 5A further allows for the detection of two optional, but technically useful, trigger light barriers 86, whose beam paths 88 each run above the support level 68 and perpendicular to the transport direction 24. For two-lane operation, it is not practical to use the same arrangement of the trigger light barrier 86 as for single-lane operation according to Fig. 4A and Fig. 4B makes perfect sense.

[0196] However, since the shrink wraps 40 in a two-lane operation according to Fig. 5A and Fig. Since the shrink wraps 40 (5B) do not necessarily have to be in the same conveying position with respect to the transport direction 24 at all times, but can generally have a more or less large offset from each other in the transport direction 24, a trigger light barrier 86, which, due to its horizontal beam path 88, cannot distinguish between a left or right shrink wrap 40 passing through the beam path 88, cannot generate meaningful trigger information for scanning the respective top surface 80 of one of the two shrink wraps 40 if, with offset shrink wraps 40 being transported, one of the two passes through the beam path 88. A clear assignment to one of the two shrink wraps 40, the left or the right, is not possible in such a case with the described technical features of the trigger light barrier 86 according to Fig. 4A not possible.

[0197] If this disadvantage is to be eliminated in a two- or multi-lane operation, for example, the following can be used for a two-lane operation: Fig. The arrangement of two trigger light barriers 86 shown in Figure 5A with intersecting or nearly intersecting beam paths 88 is useful. The two trigger light barriers 86 are arranged such that their non-horizontal beam paths 88 run approximately perpendicular to the transport direction 24, but in such a way that each of the two shrink wraps 40 transported in the laterally spaced and parallel transport tracks 94 passes through and intersects only exactly one of the two beam paths 88 of the two trigger light barriers 86, while the other beam path 88 is submerged.

[0198] To achieve this, the two beam paths 88 are located within a common vertical plane, which is oriented perpendicular to the generally horizontal support plane 68 of the further transport section 52 and also perpendicular to the transport direction 24. In the front view of the Fig. 5A, in which the transport direction 24 runs exactly perpendicular to the drawing plane, the described plane in which both beam paths 88 are located is thus exactly in the drawing plane or lies parallel to it.

[0199] A suitable inclination of the two beam paths to the horizontal can be, for example, between approximately 15° and up to 45° or slightly more, which may depend on the size and, in particular, the height of the transported packaging units 12 or shrink wraps 40, as well as on their lateral distances to one another, i.e., on the distances between the transport lanes 94. In any case, the inclination must be selected such that, for two-lane operation, a reliable triggering of a signal from one of the two trigger light barriers 86 occurs when one of the two beam paths 88 is interrupted, without the other beam path 88 of the other of the two trigger light barriers 86 being simultaneously traversed and interrupted by the same shrink wrap 40 or the same packaging unit 12.

[0200] In the illustrated embodiment of the Fig. 5A The inclination angle of the two beam paths 88 forms an angle of approximately 20° with the horizontal. However, this angle can be significantly larger in the case of transport tracks 94 that are closer together and / or packaging units 12 that are taller.

[0201] Thus, the two trigger light barriers 86 can also be used according to Fig. 5A in two-lane operation in connection with the respective image evaluation 62 of the two cameras 56 shown ensure that only such image data 60 are evaluated which can be assigned to a single packaging unit 12 or a single shrink wrap 40.

[0202] To obtain better and higher-contrast image data 60 for the transparent or semi-transparent shrink films 30 typically used as packaging material, light sources 90 can be arranged below the transport tracks 94, even in multi-lane operation. These light sources 90 are sensibly located below the respective camera 56 and below the support level 68 of the transport section 52. These light sources 90 can, for example, be designed as point light sources, as is the case with the Fig. 5A is suggested.

[0203] Especially in multi-lane operations ( Fig. 5A and Fig. 5B) to cover the entire width of the transport section 52, the light source 90 is preferably positioned according to Fig. 5B formed by the light bar 92, as already seen in Fig. As shown in Figure 4B and mentioned above, the light bar 92 shines from below across the entire width of the transport section 52, through the packaging units 12 or shrink wraps 40 transported above it, and towards the two cameras 56. The light bar 92 preferably terminates flush and seamlessly at its upper end with the upper support surface 68 of the transport section 52, the support surface 68 being interrupted in the area where the light bar 92 is inserted.

[0204] Finally, it should be noted at this point that the in the Fig. The configurations shown in 4A to 5B can also be installed cumulatively in order to use the transport section 52 equally for single-lane, double-lane or multi-lane transport of packaging units 12 or shrink wraps 40.

[0205] If the optical detection device 54 is formed, for example, by three cameras 56 arranged side by side and at approximately the same vertical distance to the support plane 68, then in a single-lane operation (cf. Fig. 4A and Fig. 4B) the middle of these cameras 56 is used to generate image data 60, while the two outer cameras 56 can remain inactive. For a two-lane operation (see Fig. 5A and Fig. 5B) In contrast, the two outer cameras 56 can be used, while the middle camera 56 can remain inactive.

[0206] The same applies to the trigger light barriers 86. If the transport section 52 is to be used equally for single-lane, double-lane or multi-lane transport of packaging units 12 or shrink wraps 40, then all three of the [missing information] should be [missing information]. Fig. 4A and Fig. The trigger light barriers 86 shown and described above in 5A must be present in this configuration, so that for single-lane operation the trigger light barrier 86 can be used in accordance with Fig. 4A is used with its horizontally running beam path 88, while the other trigger light barriers 86 with their obliquely running beam paths 88 (cf. Fig. 5A) remain deactivated. For two-lane operation (see below). Fig. 5A and Fig. 5B) on the other hand, the ones in Fig. 5A shows and describes above, the trigger light barriers 86 are activated and used to detect passing packaging units 12 or shrink wraps 40, while the other trigger light barrier 86 with its horizontal beam path 88 (see Figure 5A) is used to detect passing packaging units 12 or shrink wraps 40. Fig. 4A) can remain deactivated.

[0207] Even for a three-lane operation or for an operation with four or more parallel transport lanes, sensible variants can be found, such as a certain longitudinal offset of the respective cooperating pairs of cameras 56 and trigger light barriers 86, so that the beam paths 88 have sensible paths without false triggering by packaging units 12 that are transported on transport lanes that cannot each be assigned to the respective beam path 88.

[0208] The schematic and perspective view of the Fig. Figure 6 illustrates an optional equipment variant with which the packaging system 10 can be configured according to Fig. 1 may be additionally equipped. Considering the in Fig. The packaging system 10 shown in schematic side view 1 can be used in Fig. The modular machine equipment shown and described below is sensibly grouped with the grouping device 14 (in 6). Fig. 1 (far left) upstream.

[0209] As described below, the grouped primary packagings 16 or bottles 18 can be wrapped with shrink film 30 in the manner described above, subjected to heat treatment, and subsequently inspected using the optical detection device 54. Before entering the grouping station 14, however, it can also be provided that one, several, or even all of the primary packagings 16 entering the grouping station 14 are fitted with sleeve labels made of shrinkable film.

[0210] This illustrates Fig. 6 a support level 96 of a horizontal conveying device 22, which may optionally be the same horizontal conveying device 22 which according to Fig. 1. A conveying connection is established between the grouping device 14 and the impact module 26, which follows downstream in the transport direction 24. Optionally, the same horizontal conveying device 22 can also lead into the grouping device 14, which is why the same reference numeral is used for their designation in this context. However, the described horizontal conveying devices 22 can optionally also be separate, but aligned in the transport direction 24 and providing a continuous conveying connection.

[0211] On the support level 96 of the horizontal conveying device 22, individual primary packagings 16 are conveyed at regular intervals in the transport direction 24, wherein the primary packagings 16 can in particular be bottles 18 which may preferably be filled with a liquid or a beverage.

[0212] Above and spaced apart from the support level 96 is a module 98 for feeding and providing so-called sleeve labels 100, whereby the module 98 can specifically be designed as a so-called sleeve labeling machine 102.

[0213] Using this module 98, or this sleeve labeling machine 102, the primary packaging 16 or bottles 18 conveyed below can each be fitted with sleeve labels 100. These sleeve labels are tubular or tube-like sections of film that are slid over the primary packaging 16 or bottles 18 along its longitudinal axis. Typically, these sleeve labels 100 are slipped or pushed over the primary packaging 16 from above. Since this process usually occurs at high speed, it is often described as shooting the sleeves 100 onto the primary packaging 16 or bottles 18 from above.

[0214] The sleeve labels 102 are typically made of shrinkable film material, so that the primary packagings 16 equipped with them are firmly enclosed by the tube- or hose-like film section after heat treatment, which preferably extends only over the outer surface of the primary packaging 16 or over a outer surface section of the primary packaging 16, but not over an upper neck section and over a lower bottom area.

[0215] The sleeves 100 can be fed to the module 98 or the sleeve labeling machine 102, in particular as a continuous supply 104, which can be unwound from there in order to be divided into suitable length sections in the sleeve labeling machine 102, which are then applied from above as sleeves 100 or sleeve labels 100 to the primary packagings 16 or bottles 18 conveyed on the support level 96.

[0216] Ideally, the primary packaging 16 or bottles 18 are transported on the horizontal conveyor 22 in single-lane or single-track operation, although this does not preclude multi-lane or multi-track operation. In this case, the sleeve labeling machine 102 must be configured and equipped accordingly for multi-lane operation.

[0217] The schematic representation of the Fig. Figure 6 shows optional lateral guide rails 106 between which the primary packagings 16 or bottles 18 move in the transport direction 24. The primary packagings 16 or bottles 18 should be able to move freely between these lateral guide rails 106, with only slight and non-delaying contact at most. However, the guide rails 106 can advantageously serve as a lower stop, since the sleeves 100, which are pushed or closed over the primary packagings 16 or bottles 18, can preferably rest on the upper edges of the guide rails 106, thus preventing them from sliding uncontrollably downwards along the length of the outer surfaces of the respective primary packagings 16 or bottles 18.

[0218] The lateral guide rails 106, which can be adjusted in height as an option, thus serve as a height stop and ensure that a defined height level is specified, by which the sleeves 100 can each be moved downwards, so that all sleeves 100 are at the same height level.

[0219] Downstream of module 98 or sleeve labeling machine 102 in the transport direction 24, a sleeve shrink tunnel 108 is arranged, which serves for the heat treatment of the primary packaging 16 or bottles 18 equipped with the sleeve labels 100. The lateral guide rails 106 extend into this sleeve shrink tunnel 108 to prevent premature slippage of the sleeves 100 along the outer surface of the primary packaging 16 or bottles 18.

[0220] Since the primary packagings 16 can typically be containers or bottles 18, in particular beverage containers, the sleeve label 100, after its heat treatment by means of and within the sleeve shrink tunnel 108, forms a label that completely encloses and covers the outer surface of the bottle 18, the container or the primary packaging 16, wherein the label can be optionally shorter or longer as required and can thus cover a shorter or longer section of the outer surface with respect to the longitudinal center axis of the bottle 18, the container or the primary packaging 16.

[0221] Finally, even in the Fig. The additional equipment shown in Figure 6, in the form of the sleeve labeling machine 102 and the sleeve shrink tunnel 108, may include a quality control device located downstream of the sleeve shrink tunnel in the transport direction 24, as already defined above in various embodiments or variants. The optical detection device 54, schematically indicated here, can, for example, be formed by two cameras 56 arranged laterally on the transport path and above the level of the support surface 96, with downstream image evaluation, as already explained in detail above. In principle, the optical detection device 54 can be designed in any way, as shown, for example, in the Fig. 1 to 5B have already been explained.

[0222] Finally, it should be noted that the aforementioned modules 98, 102 and 108 can also optionally be used within the packaging plant 10 (see below). Fig. 1) can be installed in combination, which opens up the possibility of equipping individual primary packagings 16 or containers with the sleeve labels 100 in the same production mode, as well as subsequently grouping these primary packagings 16 with shrunk-on sleeve labels 100 into several in the manner described and wrapping them with a flat shrink film section 30 and feeding them to the described film wrapping module 26 for this purpose.

[0223] As mentioned above, in such a case the system configuration can be such that the modules 98, 102, 108, which are required for equipping individual primary packagings 16 with sleeves 100, are arranged upstream of the film wrapping module 26 and preferably also the grouping module 14. That is, the first shrink tunnel or sleeve shrink tunnel 108 follows the module 98 for providing and applying the sleeve labels 100, in which the sleeves 100 or sleeve labels 100 applied to the primary packagings 16 or bottles 18 are shrunk around the primary packagings 16 or bottles 18 so that they are stretched tightly around their outer surfaces.

[0224] This first shrink tunnel or sleeve shrink tunnel 108 can optionally be followed by the optical detection device 54 described above, i.e., located downstream of the sleeve shrink tunnel 108 in the transport direction 24. This device can be used for quality detection and control of the primary packaging 16 or bottles 18 equipped with the sleeve labels 100. Thus, in this configuration, the grouping station 14, an area for providing the appropriately cut shrink film sections 30, and the wrapping module 26 preferably follow the sleeve shrink tunnel 108 downstream in the transport direction 24. This is necessarily followed by another shrink tunnel 38, namely the shrink device 36 described above, to which the optical detection device 54 is located in the transport direction 24 as described above (see Figure 1). Fig. 1 to 5B) is subordinate.

[0225] Unless only this last-mentioned optical detection device 54 is to be used for the quality control of the packaging units 12, optionally separate optical detection devices 54 can be arranged downstream of both the first shrink tunnel or sleeve shrink tunnel 108 and the second shrink tunnel (the shrink tunnel 38 described above), thereby enabling separate optical quality monitoring of both the first labeling process with the sleeve labels 100 and the second packaging process with the shrink film sections 30 wrapped around the primary packaging 16 or their groupings.

[0226] The temperature adjustment procedure described above, which involves iteratively lowering the shrink tunnel temperature, should also apply equally to the shrink tunnel 38 or the shrink device 36 as well as to the sleeve shrink tunnel 108 and be equally applicable to both shrinking processes.

[0227] The invention has been described with reference to a preferred embodiment. However, it is conceivable to a person skilled in the art that modifications or alterations of the invention can be made without departing from the scope of protection of the following claims. Reference symbol list 10 Packaging system, packaging device 12 packaging units, containers 14 Grouping facility 16 Primary packaging 18 bottles 20 Article group, Article groups 22 Horizontal conveying device 24 Transport direction 26 Impact module 28 Packaging material, flat packaging material 30 shrink film 32 sheets of foil, continuous foil supply 34 film separation station 36 Shrink device 38 shrink tunnels 40 shrink wraps 42 Interior 44 Transport route 46 Distribution device, device for introducing and distributing hot air 48 Cooling unit 50 cooling fans 52 Transport section, further transport section 54 Optical detection device 56 Camera 58 Optical axis 60 image data, image signals 62 Image analysis 64 Control signal 66 foil eye 68th printing level 70 bottle caps 72 film overhang, lateral film overhang 74 edge, oval edge 76 Edge marking 78 Computer and evaluation unit 80 Top side (shrink wrap, packaging unit) 82 transport lane, central transport lane 84 Detection area 86 Light barrier, trigger light barrier 88 Beam path 90 light source 92 light bars 94 transport lanes, parallel transport lanes 96th printing level 98 Module for feeding and dispensing sleeve labels 100 sleeve labels, sleeves 102 Sleeve Labeling Machine 104 Endless Supply 106 side guide rails 108 Sleeve shrink tunnels

Claims

[1] Device for quality control of packaging units (12), each formed by at least one primary packaging (16) secondarily wrapped by means of shrink film (30, 100), which device comprises at least one conveying section (22, 52) extending through a shrink device (36) for transporting the primary packagings (16) wrapped with shrink film (30, 100) and for heat treatment within the shrink device (36), - wherein an optical detection device (54) for optosensory scanning of at least one outer side of the packaging units (12) passing through the output is assigned to the conveying section (52) at the output of the shrink device (36), - wherein image signals (60) supplied by the optical detection devices (54) to the respective packaging unit (12) are compared with predefinable target signals in a computer and evaluation unit (78), and - wherein, in the event of a deviation of the recorded image signals (60) from the target signals detected by the computer and evaluation unit (78) which is below a predefinable limit value and / or in the event of a detected deviation which is outside a target range, a heating device located in the shrink device (36) or supplying the shrink device (36) with an increased shrinking temperature can be throttled at least to such an extent that a shrinking temperature prevailing within the shrink device (36) can be reduced by a defined value. [2] Device according to claim 1, in which, in the event of a detected deviation of the detected image signals (60) from the target signals which is above a predefinable limit value or corresponds to the predefinable limit value, or in the case of detected image signals (60) which are within a target range, the heating device is not throttled, but the heating power is increased. [3] Device according to claim 1 or 2, in which at least one camera (56) is provided for optosensory detection, which can detect and optically scan at least one side surface of the packaging units (12) concerned. [4] Device according to claim 3, wherein two cameras (56) are positioned on both sides along a transport path, which are provided for capturing opposite side surfaces of the respective packaging units (12) and are equipped or configured accordingly. [5] Device according to claim 3 or 4, wherein the cameras are provided and equipped or configured to detect the foil eyes (66) located on both sides of the packaging units (12). [6] Device according to claim 3, in which at least one camera (56) is provided for optosensory detection, which can detect and optically scan a top side of the packaging unit concerned. [7] Device according to one of claims 3 to 6, in which the optosensory detection can be carried out using the transmitted light method. [8] Device according to one of claims 3 to 7, in which an image evaluation unit (62) is connected downstream of the at least one camera (56), which is provided and equipped or configured for evaluating the image data (60) supplied by the at least one camera (56) with regard to shape, size and / or form deviations of defined surface areas of the packaging units (12), in particular the foil eyes (66). [9] Method for quality control of packaging units (12), each formed by at least one primary packaging (16) secondarily wrapped by means of shrink film (30, 100), in which method the primary packagings (16) at least partially and / or partially wrapped with shrink film (30, 100) pass through a shrink device (36) for heat treatment of the shrink film (30, 100) and for forming the packaging units (12), comprising at least the following steps: a) Determining the quality of at least one first packaging unit (12) at or after the exit of the shrinking device (36), and b) if the quality of the first packaging unit (36) is within a target range, lowering the temperature of the shrink device (36) by a first value, and c) Determining the quality of at least one further or second packaging unit (12) at or after the outlet of the shrinking device (36), which further or second packaging unit (12) was transported through the shrinking device (36) after the temperature of the shrinking device (36) was lowered, and d) if the quality of at least one further or second packaging unit (12) is within a target range, lower the temperature of the shrinking device (36) a second time by a second value. [10] The method of claim 9, wherein, after carrying out steps a) to d), in a further step e) the quality of a third packaging unit (12) is determined, which was transported through the shrinking device (36) after the temperature had been lowered a second time, and f) if the quality of the third packaging unit (12) is outside a target range, increase the temperature of the shrinking device by a third value. [11] Method according to claim 10, wherein, following step f), in a further step g), the affected third packaging unit (12), whose quality has been determined to be outside a target range, is removed from the further transport, handling and / or processing process. [12] The method of claim 10 or 11, wherein, after carrying out at least steps a) to f), in a further step h) the quality of a fourth packaging unit (12) is determined, which was transported through the shrinking device (36) after the temperature of the shrinking device has been increased, and i) if the quality of the fourth packaging unit (12) is outside a target range, further increase the temperature of the shrink device (36) by a fourth value, or j) if the quality of the fourth packaging unit (12) is within a target range, further reduce the temperature of the shrinking device (36) by a fifth value. [13] Method according to any one of claims 9 to 12, wherein repeated quality determinations for subsequent packaging units (12) are answered with progressively smaller values ​​of the temperature adjustments when raising or lowering the temperature of the shrinking device (36). [14] Method according to any one of claims 9 to 13, wherein the third value of the temperature change or the reduction of the temperature of the shrinking device (36) is preferably smaller in magnitude than the second value of the reduction of the temperature of the shrinking device (36) and / or wherein the fourth value of the temperature change or the reduction of the temperature of the shrinking device (36) is preferably smaller in magnitude than the third value of the change of the temperature of the shrinking device (36) and / or wherein the fifth value of the temperature change or the reduction of the temperature of the shrinking device (36) is preferably smaller in magnitude than the third value of the change of the temperature of the shrinking device (36) and / or than the fourth value of the change of the temperature of the shrinking device (36). [15] Method according to one of claims 9 to 14, wherein an optosensory detection of at least one outer surface of the packaging units (12) passing through the output is provided at the output of the shrinking device (36), as well as a comparison of optosensory detected image signals (60) of the respective packaging unit (12) with predefinable target signals, and wherein, in the event of a detected deviation of the detected image signals (60) from the target signals and / or in the event of a detected deviation of the detected image signals (60) from a target range, a reduction of a shrinking temperature prevailing within the shrinking device (36) by a defined value takes place. [16] Method according to claim 15, wherein the shrinking temperature prevailing within the shrinking device (36) is not reduced when a deviation of the detected image signals (60) from the target signals is detected that lies outside a target range, but is increased by the defined value of the previously carried out temperature reduction or by a smaller value of the previously carried out temperature reduction. [17] Method according to claim 15 or 16, wherein the deviations depicted by the image signals (60) are a shape, size and / or form deviation of a defined area of ​​the shrink film (30, 100) enclosing the primary packaging (16) and / or of the totality of primary packaging (16) enclosed by the shrink film (30). [18] Method according to claim 17, wherein the deviation is a shape, size and / or form deviation of at least one surface section of the shrink film (30, 100). [19] Method according to claim 17 or 18, wherein the deviation is a shape, size and / or form deviation of at least one lateral foil eye (66) of the shrink film (30) enclosing the primary packaging (16) of the packaging units (12). [20] Method according to claim 17 or 18, wherein the deviation is a shape, size and / or form deviation in the assembly of the primary packagings (16) within the respective article group (20) and / or within the respective packaging unit. [21] Method according to one of claims 17 to 20, wherein, in the event of a detected deviation, an intervention is carried out in the area of ​​a preparation, a feeding and / or a cutting of the shrink films (30, 100). [22] Method according to any one of claims 17 to 20, wherein, in the event of a detected deviation, the affected packaging units (12) are each marked as defective and / or removed from a further handling and / or packaging process. [23] Packaging plant (10) for the production of packaging units (12), each of which is formed by at least one primary packaging (16) secondarily wrapped by means of shrink film (30), which packaging plant (10) comprises at least: - a feeding device for at least one primary packaging (16) or for assemblies of several grouped primary packagings (16), - a module for providing appropriately cut sections of shrink film (30, 100) and for feeding them to at least one primary packaging (16) or for assembling several grouped primary packagings (16), - an application module (26, 98) for applying and at least partially and / or area-wise wrapping of the at least one primary packaging (16) or the article group (20) with several primary packagings (16) with the prepared shrink film (30, 100), - a shrink device (36) downstream of the application module (26, 98) in a transport direction (24) for the heat treatment of the article groups (20) or primary packagings (16) at least partially and / or partially wrapped with the shrink film (30, 100), as well as - a device for quality control located downstream of the shrinking device (36) in the transport direction (24) according to one of claims 1 to 8. [24] Packaging system (10) according to claim 23, wherein the module for providing appropriately cut sections of shrink film (30) supplies and feeds these to a wrapping module (26), and wherein the packaging system (10) is further equipped with a wrapping module (26) for applying and at least partially and / or partially wrapping the at least one primary packaging (16) or the group of articles (20) with several primary packagings (16) with the prepared shrink film (30), wherein the shrinking device (36) for heat-treating the groups of articles (20) or primary packagings (16) at least partially and / or partially wrapped with the shrink film (30) is arranged downstream of the wrapping module (26) in the transport direction (24), and wherein the device for quality control of the shrinking device (36) is arranged downstream of the shrinking device (36) in the transport direction (24). [25] Packaging plant (10) according to claim 23 or 24, which is designed and equipped for carrying out a method according to one of claims 9 to 22.

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