Method and apparatus for testing the tightness of a sealed package

Abstract

The invention relates to a device and a method for testing the tightness of a sealed package (10), in particular a bag, wherein the package (10) is conveyed by means of a conveyor (12) into a test station (11) in which the tightness of the package (10) is tested. According to the invention, it is provided that the packing (10) in the test station (11) is subjected to a force by at least one compression element (19) movable against the packing (10), so that the packing (10) is deformed, and that the tightness of the packing (10) is determined during the subjection by the at least one compression element (19).

Description

[0001] The invention relates to a method for testing the tightness of a sealed package, in particular a bag, wherein the package is conveyed by means of a conveyor into a testing station in which the tightness of the package is tested, according to the preamble of claim 1.

[0002] Furthermore, the invention relates to a corresponding device according to the preamble of claim 16.

[0003] Methods and devices of this type are known in practice in numerous embodiments. These typically involve third-party systems that then need to be implemented in packaging machines for manufacturing the packages. However, this implementation is very time-consuming and expensive. Furthermore, it is problematic that methods and devices known from practice often require a consistent package orientation for testing. This restricts the formation of package groups to specific configurations or leads to a complex regrouping of packages for other configurations.

[0004] Based on this, the invention aims to further develop methods and devices of the type mentioned above, particularly with regard to easy integration into packaging machines and / or orientation-independent testing of the packages.

[0005] A method for solving this problem has the features of claim 1. Accordingly, it is provided that the packaging in the test station is subjected to a force by at least one compression element movable against the packaging, such that the packaging is deformed, and that the tightness of the packaging is determined during the subjection by the at least one compression element.

[0006] In this way, the packaging can be easily checked for tightness, in particular for the proper formation of the packaging's sealing seams.

[0007] Preferably, it can be provided that the position of the at least one compression element acting on the packing is recorded during the actuation in order to conclude the tightness of the packing, or that the force exerted by the at least one compression element on the packing is recorded during the actuation in order to conclude the tightness of the packing.

[0008] These solutions are based on the understanding that properly sealed or airtight packages exhibit characteristic compression behavior that can be used to determine their tightness. Typically, a package contains not only its contents but also a quantity of a gaseous medium, such as air. When a force is applied to the package, a properly sealed package will exhibit a specific behavior; it will generally compress to a certain degree. This can be measured by the position of the compression element(s) or by the force with which the package can be compressed. Air will escape from a leaking package during compression, allowing the package to be compressed more, and the compression element(s) can be moved further against the package than in a sealed package.Furthermore, it is also possible to measure whether the package can withstand a specific force that corresponds to the force a properly functioning package can withstand. A defective package will be able to withstand less force due to escaping air. This is true, of course, at least as long as there is still air in the package. Both the movement of the compression mechanism(s) and the applied force can be measured in order to compare the measured values ​​with typical values ​​for the type of package and thus test the package's airtightness.

[0009] In a preferred embodiment, it can be provided that the packing to be tested is subjected to a force from opposite sides by two compression elements.

[0010] To implement this solution, it can be provided that the conveyor has several traversing units that can be moved individually along the conveyor, in particular along a guide of the conveyor, wherein at least one of the compression elements is assigned to each traversing unit, such that the compression elements are moved by means of the respective traversing unit to actuate one or more packs.

[0011] One advantage of this solution lies particularly in the individually movable traversing units, which allow for flexible positioning of the compression elements. This makes it easy to adapt the leak tightness testing of the packings to different conditions.

[0012] Preferably, the tightness of the package is checked before the package is pushed off the conveyor towards a tray in a push-off station, preferably with the possibility of pushing several packages into the tray simultaneously, in particular by means of a pusher, the packages preferably forming a layer of packages in the tray.

[0013] One advantage of this solution is that the packages are inspected before being placed in the tray. This allows defective packages to be removed before packaging.

[0014] Furthermore, it can be provided that the packages are fed to the conveyor via a feed conveyor, wherein the weight of each package is detected by means of a sensor, in particular by means of a load cell, preferably during the transport of the package on the feed conveyor, and wherein the package is rejected if the detected weight deviates from predetermined limits before the respective package is subjected to the leak test.

[0015] One advantage of this solution is that packages with an incorrect weight can be rejected before the leak test.

[0016] Preferably, it can be provided that the packages are transported lying flat on the feed conveyor and transferred to the conveyor at a feed station, in particular placed on a compression element of the conveyor, and that the packages are then erected into an upright position during transport on the conveyor, in particular by transporting the packages along a correspondingly curved conveying section of the conveyor.

[0017] One advantage of this solution is that the packages are already in an upright position for later steps, without the need for additional organs to be provided for uprighting.

[0018] Furthermore, it may be provided that the erection of the packages, particularly in the area of ​​a deflection of the conveyor, is supported by an auxiliary drive, which is preferably temporarily coupled via an arm to an element of the conveyor, preferably a compression element thereof, on which a package rests, in order to support the erection.

[0019] One advantage of this solution is that the erection of the packages also works when the packages are somewhat heavier, so that the conveyor alone could not erect the packages or only with difficulty.

[0020] Furthermore, it is possible that the tightness test is carried out in the area of ​​a straight section of the conveyor or in the area of ​​a deflection of the conveyor, in particular immediately following the feed station.

[0021] One advantage of this solution is that the sealing test of the packings can be easily adapted to different conditions. Sealing the packing in the deflection area allows for a higher throughput, while sealing the packing in the straight section of the conveyor is easier to implement, depending on the packing shape.

[0022] Another special feature may be that several packs are arranged as a group between two adjacent compression devices and tested together or simultaneously for leak tightness.

[0023] It is therefore possible not only to test the leak tightness of a single package between two compression elements, but also to test several in a single test. This simplifies the process, as a separate space does not need to be provided for each product. Furthermore, there may be minimum distances imposed by the building structure that result in gaps between the compression elements that could exceed the bag size. In this case, it is possible to test several packages simultaneously. However, all packages tested in a single test will then be rejected, even if only one package is defective.

[0024] One advantage of this solution is that the throughput of the testing station can be increased and it becomes possible to test the tightness of packages that would otherwise be incompatible with the testing station.

[0025] Preferably, it can be provided that individual packages or a group of packages are tested for tightness between two adjacent compression devices and that the tested packages are positioned in the area of ​​the ejection station for later insertion into the tray, and that after a corresponding number of tightness tests, a number of packages corresponding to a position of the packages in the tray has been grouped together in the ejection station and fed into the tray.

[0026] One advantage of this solution is that the packages or groups of packages can be checked individually before being grouped together.

[0027] Furthermore, it may be provided that a number of packs corresponding to a layer of packs in the tray are tested together in a common single test step with regard to the tightness between more than two compression elements.

[0028] One advantage of this solution is that the number of test steps can be reduced, thus enabling higher throughput of the test station.

[0029] Another special feature may be that the packings for the leak test are positioned upright or lying down between adjacent compression elements, and that for positioning packings in a lying orientation, the compression elements adjacent to the packings are moved apart to initiate a tilting of the packings.

[0030] One advantage of this approach is that the orientation of the packages can be freely chosen. In particular, an orientation of the packages used for testing can be chosen that corresponds to their later arrangement within a layer or in the tray.

[0031] Furthermore, it may be provided that defective packages are fed along the conveyor to a reject station located downstream of the discharge station and sorted out.

[0032] One advantage of this solution is that leaking packages can be directed to the rejection station by not being pushed into the tray at the discharge station, thus eliminating the need for additional organs to separate the leaking packages.

[0033] Furthermore, it may be provided that trays filled with packages are conveyed along a transport path that initially runs downwards in the discharge station and then crosses this path below the conveyor.

[0034] One advantage of this solution is that it requires little space for transporting the filled trays.

[0035] A device for solving the aforementioned problem has the features of claim 16. Accordingly, it is provided that the test station is configured to apply a force to the packaging in the test station by means of at least one compression element movable against the packaging, such that the packaging is deformed, and to determine the tightness of the packaging during the application of the force by the at least one compression element.

[0036] Furthermore, it may be provided that the test station is equipped to record the position of the at least one compression element acting on the packaging during the actuation in order to conclude the tightness of the packaging, or that the test station is equipped to record the force exerted on the packaging by the at least one compression element during the actuation in order to conclude the tightness of the packaging.

[0037] One advantage of this solution is that the measured size can be adapted to different circumstances without the need for additional organs.

[0038] In a preferred embodiment, the test station may be configured to apply pressure to the package to be tested from opposite sides using two compression devices.

[0039] Furthermore, it may be provided that the conveyor has several traversing units that are individually movable along the conveyor, in particular along a guide of the conveyor, wherein at least one of the compression elements is assigned to each traversing unit, such that the compression elements can be moved by means of the respective traversing unit to actuate one or more packs.

[0040] One advantage of this solution is that the traversing units allow for flexible positioning of the compression elements. This makes it easy to adapt the tightness testing of the packings to different conditions.

[0041] One special feature may be that the compression elements extend transversely, especially perpendicularly, to the direction of travel of the moving units.

[0042] One advantage of this solution may be that it results in better handling of the packages, especially improved transport of the packages.

[0043] Another special feature may be that a feed conveyor is arranged upstream of the conveyor to feed the packages to the conveyor, wherein the feed conveyor is designed to transfer the packages to the conveyor running transversely to the feed conveyor, in particular to one of the compression elements, and that a stopper device arranged downstream of the conveyor when a package is fed in the conveying direction is provided to stop the packages coming from the feed conveyor.

[0044] One advantage of this solution is that the stopper device can be used to slow down the packages for subsequent transport by the compression organs.

[0045] Furthermore, it may be provided that the stopper device has a stopper plate for stopping the packages coming from the feed conveyor, wherein the stopper plate is pivotable about an axis that is directed transversely to the transport direction of the packages on the conveyor, or wherein the position of the stopper plate is linearly adjustable.

[0046] One advantage of this solution may be that the stopper plate can be moved in such a way as to avoid a collision with the compression organs.

[0047] Another special feature may be that a sensor for recording the weight of the respective package is assigned to the feed conveyor, in particular a load cell, and that a reject container is arranged downstream of the feed conveyor, into which the package is ejected if the recorded weight deviates from predetermined limits, before the respective package is subjected to the leak test.

[0048] One advantage of this solution is that the weight of the products can be checked individually, and products with a weight outside the specified limits can be rejected regardless of their tightness, thus avoiding unnecessary testing steps.

[0049] Furthermore, it may be provided that a push-off station is located downstream of the testing station for pushing tested packages from the conveyor towards a tray, and that a reject station for defective packages is located downstream of the push-off station.

[0050] One advantage of this solution is that leaking packages can be directed to the rejection station by not being pushed into the tray at the discharge station, thus eliminating the need for additional organs to separate the leaking packages.

[0051] A preferred embodiment of the invention is described below with reference to the drawing. This shows: Fig. 1 a schematic spatial representation of a first embodiment of a device for testing the tightness of a package, Fig. 2 a side view of the device according to Fig. 1 before the start of an exam, Fig. 3 a side view of the device according to Fig. 1 during the exam, Fig. 4 a side view of the device according to Fig. 1 when inspecting a subsequent pack in the same position, Fig. 5 a side view of the device according to Fig. 1 when forming a layer of horizontally arranged packages, Fig. 6 a side view of the device according to Fig. 1. when inspecting a faulty package, Fig. 7 a side view of the device according to Fig. 1. in the case of the rejection of defective packages, Fig. 8 a schematic representation of a second embodiment in a representation analogous to Fig. 1, Fig. 9 a side view of the device according to Fig. 8 corresponding to arrow IX, and Fig. 10. A further development of the first and second embodiments in a representation analogous to Fig. 1 or 8.

[0052] Fig. Figure 1 shows a schematic three-dimensional representation of a device for testing the leak tightness of a package 10. In the illustrated embodiment, the package 10 is a bag. The bag has sealed (longitudinal and transverse) seams, which can leak if not properly formed. A leak can also result from defects or damage to the packaging material of the bag. It is understood that other types of packages 10 can also be tested instead of a bag, so the term "pack" is used hereafter to represent all types of packaging.

[0053] The tightness of the package 10 is tested in a test station 11, which will be described below. The test takes place in the area of ​​a conveyor 12, along which the test station 11 is located.

[0054] After the packages 10 have been inspected at inspection station 11, they are transferred to a discharge station 13. At discharge station 13, the inspected packages 10 are transferred to a tray 14. A feed conveyor 15 is located upstream of conveyor 12 to feed the packages 10 to conveyor 12.

[0055] Defective packages 10 can be ejected from the device at two points, namely on the one hand in the area of ​​a reject station 16 downstream of the discharge station 13 and on the other hand via a first reject container 17 downstream of the feed conveyor 15.

[0056] In the present embodiment, the feed conveyor 15 is arranged transversely to the conveyor 12, which connects to the end of the feed conveyor 15. A load cell, acting as a sensor 27, is integrated into the feed conveyor 15 to determine the weight of the packages 10 transported on the feed conveyor 15. If the determined weight of the individual packages 10 deviates from predefined limits or lies outside a predefined tolerance, the packages 10 identified as defective can be rejected at the end of the feed conveyor 15 and placed in the reject container 17 located below.

[0057] The feed conveyor 15 can consist of one or more conveying sections. In this case, the last conveying section is designed to extend horizontally, with the packages 10 lying flat on it.

[0058] In this case, the conveyor 12 is an endless conveyor, which is set up to take over the packages 10 from the feed conveyor 15 and to transport the packages 10 to the testing station 11 and subsequently to the discharge station 13.

[0059] A special feature is that the conveyor 12 has several travel units 18. The travel units 18 can be moved individually along the conveyor 12 and are each coupled to a compression element 19.

[0060] In the present embodiment, the traversing units 18 are arranged laterally at an edge of the conveyor 12 and are movable along its circumference. The compression elements 19 are designed as plate-shaped elements that preferably extend across the entire width of the conveyor 12, transverse to its conveying direction. It is understood that this is merely a preferred embodiment and that alternative designs are conceivable. As the name suggests, the compression elements 19 serve to compress the packings 10 during the leak test by exerting a force on them. Furthermore, the compression elements 19 also serve to support the packings 10 on the conveyor 12.

[0061] Fig. Figure 1 shows that the packages 10 are transferred from the feed conveyor 15 to the conveyor 12 and, in the illustrated embodiment, are placed on a compression element 19. A stopper device 20 arranged downstream serves to ensure that the packages 10 do not shoot beyond the end of the compression element 19. Further details of the design and function of the stopper device 20 are described below.

[0062] The trays 14 are moved via a tray feeder 21 (not shown) into the discharge station 13 and held there ready to receive the packages 10. In this case, the trays 14 must be tilted or swivelled by 90° so that the open side of the trays 14 faces the conveyor 12 and the packages 10 on it.

[0063] Fig. 2 shows corresponding to Fig. 1. A package 10 rests on a compression element 19. Three further packages 10, after leak testing, are located in the discharge station 13 and are laterally supported by the compression elements 19. Since the traversing units 18 are individually movable, e.g., by a corresponding control system, the distances between the traversing units 18 and the compression elements 19 attached to them are not fixed but are controlled as needed. Due to the horizontal feeding of the packages 10 in the area of ​​the deflection of the conveyor 12, the packages 10 are erected during further transport in the area of ​​the deflection.

[0064] Fig. Figure 3 shows the three packages 10 after being pushed into the waiting tray 14. The number of packages 10 corresponds exactly to one layer of packages 10 in the tray 14. The transfer units 18, which had supported the packages 10 until then, are moved along the conveyor 12 to wait in the area of ​​the lower run of the conveyor 12 for the take-up of new packages 10.

[0065] Furthermore, it shows Fig. 3. The testing of a single package 10 in the testing station 11. The package 10 is positioned between two compression elements 19, which are pressed against the package 10 from both sides by means of the traversing units 18. If the package 10 has a defect, this leads to an air leak 26 from the package 10, as shown in Fig. 6 indicated.

[0066] In the present embodiment, the test station 11 is located in the area of ​​a straight section of the conveyor 12. It is understood that the test station 11 can also be arranged in other areas of the conveyor 12, for example in the area of ​​a deflection.

[0067] Since the tightness of the packing 10 cannot be measured directly, it can be inferred from the position of the traversing units 18 during the test. If air escapes from the packing 10 during the test, it can be compressed more than a properly functioning packing 10, which in this case allows the traversing units 18 to move closer together than with a properly functioning packing 10. Preferably, in this type of test, a predetermined force F is exerted on the packing 10 by means of the compression elements 19. The force F should be dimensioned such that a properly functioning packing 10 can withstand the pressure without damaging its contents.

[0068] Another solution for determining the tightness of the packing 10 is to measure the force F with which the compression elements 19 act on the packing 10. A properly functioning packing 10 will be able to withstand a certain force F, whereas a defective packing 10, due to escaping air, will be able to withstand less force F. This is true, of course, at least as long as there is still air in the packing 10. As soon as the air has been completely expelled from the packing 10 and the compression elements 19 press directly against the packing contents, the force F that can be applied will increase again. With the aid of suitable control, however, the measured force profile can be compared with corresponding target values, and a reliable distinction can be made between properly functioning and defective packings 10.

[0069] Fig. Figure 7 shows that a package 10 identified as defective is transported from the inspection station 11 through the discharge station 13 to the rejection station 16 and there is fed into a second rejection container 22 for defective packages 10.

[0070] Assuming that the [item] according to Fig. If the first three tested packs of 10 are found to be in order, the next step involves testing the next pack of 10. How Fig. As shown in Figure 4, the next package 10 is moved into the testing station 11 so that it is positioned next to the package 10 that has already been tested. Both packages 10 are then tested by applying external pressure. Alternatively, it is also conceivable that only the next package 10 is tested individually, namely by applying pressure with the two adjacent compression elements 19. Furthermore, it is conceivable that a number of packages 10 corresponding to the number of packages 10 in a single layer are tested together, i.e., simultaneously. For example, three packages 10 can each be individually positioned between a corresponding number of compression elements 19, and the entire group can be tested in a single test step by applying force to the outer compression elements 19.However, one disadvantage of this solution is that it is not possible to identify which of the 10 packages in the group has a defect, so if a defect is detected, all products in the group may have to be removed.

[0071] Fig. Figure 4 further shows that tray 14 is moved downwards by the height of one layer to receive the next layer of packages 10. Once tray 14 is filled as intended, it is removed and the next tray 14 is moved to the discharge station 13.

[0072] Another special feature concerns the stopper device 20. The stopper device 20 has a stopper plate 23, which can be pivoted by means of a drive 24. The stopper plate 23 serves to stop the packages 10. Accordingly, it is located in the conveying path of the packages 10, so that the packages 10 run against the stopper plate 23 and are stopped and aligned with respect to the conveyor 12. When the stopper plate 23, as in Fig. As shown in Figure 1, the stopper plate 23 is located at the end of the compression element 19 and can be moved along with the package 10 during the initial transport on the conveyor 12 to prevent the package 10 from falling off the compression element 19.

[0073] How Fig. 1 and Fig. As shown in Figure 2, guide elements 25 are provided further along the conveyor to prevent packages 10 from falling off the conveyor 12.

[0074] Depending on the dimensions of the packages 10, and in particular their length in the conveying direction on the feed conveyor 15, the stop plate 23 may be arranged not next to the compression element 19, but on top of it, so that the fed packages 10 are stopped approximately in the middle of the compression element 19. In this case, the stop plate 23 can be moved together with the compression element 19, which carries the packages 10, by means of the drive 24 to prevent a collision between the stop plate 23 and the compression element 19. Alternatively, the stop plate 23 could also be moved by means of a linear unit.

[0075] As described above, the packages 10 are transported upright in the upper section of the conveyor 12, inspected, and pushed into the tray 14. Naturally, the arrangement of the packages 10 in the tray 14 may vary layer by layer. To prevent the need for additional mechanisms to change the relative position of the packages 10, the following can be done as described in Fig. 5 also shows that by moving the compression organs 19 apart the products 10 can be tilted so that a layer of lying packages 10 can be formed, which is then pushed into the tray 14.

[0076] For this purpose, the trailing compression element 19 can be retracted in the opposite direction of its previous movement, so that the package 10 is no longer clamped and can fall into a horizontal position. Alternatively, the trailing compression element 19 can stop on the straight section of the path to the discharge station 13, while the leading compression element 19 continues to move, increasing the distance between the two compression elements 19 and thus bringing the package 10 into the desired horizontal position.

[0077] Of course, the packs of 10 can not only be pushed off lying down, but it is also conceivable that the packs of 10 can be tested for leaks while lying down.

[0078] Another option for testing the tightness of the packings 10 is to place several packings 10 between two adjacent compression elements 19 and test them for tightness. A disadvantage of this solution is, of course, that it is then not possible to identify which packing 10 or packings 10 in the group are defective, meaning the entire tested group of packings 10 must be rejected. Nevertheless, this method can be useful if the packings 10 have dimensions so small that the compression elements 19 cannot be moved close enough together to exert pressure on the packings 10. This can be the case, for example, if the moving units 18 cannot be moved together beyond a predetermined distance due to their design.

[0079] A second embodiment of the device is described in Fig. 8 and Fig. Figure 9 shows the second embodiment. The second embodiment differs from the first embodiment according to Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 is powered only by an auxiliary drive 28 and is otherwise identical. The foregoing statements also apply accordingly to the second embodiment.

[0080] After the feeder conveyor 15 has fed the packages 10 to the approximately horizontally oriented compression elements 19, it can be difficult, depending on the weight of the packages 10, to reliably and consistently set the compression elements 19, with the package 10 on them, in motion. Against this background, the second embodiment provides an auxiliary drive 28 to assist in starting the compression elements 19.

[0081] The auxiliary drive 28 is precisely synchronized with the movement profile of the compression elements 19 and assists them during startup. The auxiliary drive 28 is connected to an arm 29, which temporarily rests against a compression element 19 and assists it during startup. The movement of the arm 29 counteracts gravity, allowing the compression elements 19 to start up even under prolonged product load without overheating in the deflection area.

[0082] Fig. Figure 10 shows a preferred further development of the two embodiments with regard to the removal of the filled trays 14. The illustration corresponds to the Fig. 1 and Fig. 8, however, for the sake of clarity, parts of the devices have been hidden, namely in particular the feed conveyor 15, the two reject containers 17, 22 and individual details. In this way, it serves Fig.10 to illustrate the transport route 30 of the filled trays 14.

[0083] It has proven particularly advantageous and space-saving if the filled trays 14 are guided under the discharge station 13 or under the conveyor 12 before being closed (e.g., by applying a lid). As already mentioned, the tray 14 is moved downwards in the discharge station 13 after, for example, a layer of packages 10 has been fed in. This process is repeated until the tray 14 is filled. The tray 14 then continues its downward movement until it is conveyed away below the conveyor 12, preferably in a horizontal plane. Reference symbol list: 10 pack 11 Testing station 12 sponsors 13 Departure Station 14 Tray 15 feed conveyors 16 Committee Station 17 first reject container 18 traversing unit 19 Compression organ 20 stopper device 21 Tray feeder 22 second reject container 23 stopper plate 24 drive 25 Conducting organ 26 Air outlet 27 Sensor 28 Auxiliary drive 29 Arm 30 Transport route

Claims

[1] Method for testing the tightness of a sealed package (10), in particular a bag, wherein the package (10) is conveyed by means of a conveyor (12) into a test station (11) in which the tightness of the package (10) is tested, characterized by , that the packing (10) in the test station (11) is subjected to a force by at least one compression element (19) movable against the packing (10) such that the packing (10) is deformed, and that the tightness of the packing (10) is determined during the subjection by the at least one compression element (19). [2] Method according to claim 1, characterized by, that the position of the at least one compression element (19) acting on the packing (10) is recorded during the actuation in order to conclude the tightness of the packing (10) or that the force exerted by the at least one compression element (19) on the packing (10) is recorded during the actuation in order to conclude the tightness of the packing (10). [3] Method according to claim 1 or any of the other preceding claims, characterized by , that the package (10) to be tested is subjected to a force from opposite sides by two compression organs (19). [4] Method according to claim 1 or any of the other preceding claims, characterized by, that the conveyor (12) has several traversing units (18) which are individually movable along the conveyor (12), in particular along a guide of the conveyor (12), wherein at least one of the compression elements (19) is assigned to each of the traversing units (18), such that the compression elements (19) are moved by means of the respective traversing unit (18) to actuate one or more packs. [5] Method according to claim 1 or any of the other preceding claims, characterized by , that the tightness of the package (10) is checked before the package (10) is pushed off the conveyor (12) in a push-off station (13) in the direction of a tray (14), wherein it is preferably provided that several packages (10) are pushed into the tray (14) simultaneously, in particular by means of a pusher, wherein the packages (10) preferably form a layer of packages (10) in the tray (14). [6] Method according to claim 1 or any of the other preceding claims, characterized by , that the packages (10) are fed to the conveyor (12) via a feed conveyor (15), wherein the weight of each package (10) is detected by means of a sensor (27), in particular by means of a load cell, preferably during the transport of the package (10) on the feed conveyor (15), and wherein the package (10) is rejected if the detected weight deviates from predetermined limit values, before the respective package (10) is subjected to the leak test. [7] Method according to claim 1 or any of the other preceding claims, characterized by, that the packages (10) are transported lying flat on the feed conveyor (15) and transferred to the conveyor (12) in a feed station, in particular placed on a compression element (19) of the conveyor (12), and that the packages (10) are then erected into an upright position during transport on the conveyor (12), in particular by transporting the packages (10) along a correspondingly curved conveying section of the conveyor (12). [8] Method according to claim 1 or any of the other preceding claims, characterized by , that the erection of the packages (10), in particular in the area of ​​a deflection of the conveyor (12), is supported by an auxiliary drive (28), which is preferably temporarily coupled via an arm (29) to an element of the conveyor (12), preferably a compression element (19) thereof, on which a package (10) rests, in order to support the erection. [9] Method according to claim 1 or any of the other preceding claims, characterized by , that the tightness test is carried out in the area of ​​a straight section of the conveyor (12) or in the area of ​​a deflection of the conveyor (12), in particular immediately following the feed station. [10] Method according to claim 1 or any of the other preceding claims, characterized by , that several packs (10) are arranged as a group between two adjacent compression organs (19) and are tested together or simultaneously with regard to tightness. [11] Method according to claim 1 or any of the other preceding claims, characterized by, that individual packs (10) or a group of packs (10) are tested for tightness between two adjacent compression elements (19) and the tested packs (10) are positioned in the area of ​​the discharge station (13) for later insertion into the tray (14), and that after a corresponding number of tightness tests, a number of packs (10) corresponding to a position of the packs (10) in the tray (14) has been grouped together in the discharge station (13) and fed to the tray (14). [12] Method according to claim 1 or any of the other preceding claims 1 to 10, characterized by , that a number of packs (10) corresponding to a layer of packs (10) in the tray (14) are tested together in a common, single test step with regard to the tightness between more than two compression elements (19). [13] Method according to claim 1 or any of the other preceding claims, characterized by , that the packings (10) are positioned upright or lying down between adjacent compression elements (19) for the leak test, and that for positioning packings (10) in a lying orientation the compression elements (19) adjacent to the packings (10) are moved apart to initiate a tilting of the packings (10). [14] Method according to claim 1 or any of the other preceding claims, characterized by , that defective packages (10) are fed along the conveyor (12) to a reject station (16) located downstream of the discharge station (13) and are rejected. [15] Method according to claim 1 or any of the other preceding claims, characterized by, that trays (14) filled with packages (10) are conveyed along a transport path (30) which initially runs downwards in the discharge station (13) and then runs perpendicular to this below the conveyor (12). [16] Device for testing the tightness of a sealed package (10), in particular a bag, comprising a conveyor (12) for transporting the packages (10) and a test station (11) arranged in the area of ​​the conveyor (12) for testing the tightness of the package (10), in particular for carrying out the method according to one of the preceding claims 1 to 13, characterized by , that the test station (11) is equipped to apply a force to the packing (10) in the test station (11) by means of at least one compression element (19) movable against the packing (10) so that the packing (10) is deformed, and to determine the tightness of the packing (10) during the application of the force by the at least one compression element (19). [17] Device according to claim 16, characterized by , that the test station (11) is equipped to detect the position of the at least one compression element (19) acting on the packing (10) during the actuation in order to conclude from this the tightness of the packing (10), or that the test station (11) is equipped to detect the force exerted by the at least one compression element (19) on the packing (10) during the actuation in order to conclude from this the tightness of the packing (10). [18] Device according to claim 16 or 17, characterized by , that the test station (11) is set up to apply pressure to the package (10) to be tested in the test station (11) by means of two compression devices (19) from opposite sides. [19] Device according to claim 16 or any of the other preceding claims 17 to 18, characterized by, that the conveyor (12) has several traversing units (18) which are individually movable along the conveyor (12), in particular along a guide of the conveyor (12), wherein at least one of the compression elements (19) is assigned to each traversing unit (18), such that the compression elements (19) are movable by means of the respective traversing unit (18) for applying pressure to one or more packs (10). [20] Device according to claim 16 or any of the other preceding claims 17 to 19, characterized by , that the compression elements (19) extend transversely, in particular perpendicularly, to the direction of travel of the travel units (18). [21] Device according to claim 16 or any of the other preceding claims 17 to 20, characterized by, that a feed conveyor (15) is arranged upstream of the conveyor (12) for feeding the packages (10) to the conveyor (12), wherein the feed conveyor (15) is designed to transfer the packages (10) to the conveyor (12) running transversely to the feed conveyor (15), in particular to one of the compression elements (19), and that a stopper device (20) arranged downstream of the conveyor (12) when a package (10) is fed in the conveying direction on the feed conveyor (15) is provided to stop the packages (10) coming from the feed conveyor (15). [22] Device according to claim 16 or any of the other preceding claims 17 to 21, characterized by, that the stopper device (20) has a stopper plate (23) for stopping the packages (10) coming from the feed conveyor (15), wherein the stopper plate (23) is pivotable about an axis that is directed transversely to the transport direction of the packages (10) on the conveyor (12), or wherein the position of the stopper plate (23) is linearly adjustable. [23] Device according to claim 16 or any of the other preceding claims 17 to 22, characterized by , that a sensor (27) for detecting the weight of the respective package (10) is assigned to the feed conveyor (15), in particular a load cell, and that a reject container is arranged downstream of the feed conveyor, into which the package (10) can be rejected if the detected weight deviates from predetermined limits, before the respective package (10) is subjected to the leak test. [24] Device according to claim 16 or any of the other preceding claims 17 to 23, characterized by, that downstream of the testing station (11) a push-off station (13) is provided for pushing tested packages (10) from the conveyor (12) towards a tray (14) and that downstream of the push-off station (13) a reject station (16) is provided for defective packages (10). [25] Device according to claim 16 or any of the other preceding claims 17 to 24, characterized by , that an auxiliary application (28) is provided for erecting the packs (10), in particular in the area of ​​a deflection of the conveyor (12), which is preferably temporarily coupled via an arm (29) to an organ of the conveyor (12), preferably a compression organ (19) thereof, on which a pack (10) rests, in order to assist the erection. [26] Device according to claim 16 or any of the other preceding claims 17 to 25, characterized by, that trays (14) filled with packages (10) can be conveyed along a transport path (30) which initially runs downwards in the discharge station (13) and then runs perpendicular to this below the conveyor (12).

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