Filling device and method for filling bags, each with an unsealed upper end

DE502019014120D1Active Publication Date: 2025-12-11WINDMOELLER & HOELSCHER GMBH
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Patent Information

Application Number
DE502019014120
Authority / Receiving Office
DE · DE
Patent Type
Patents
Current Assignee / Owner
Priority Date
2018-04-25
Filing Date
2019-02-05
Publication Date
2025-12-11
Estimated Expiration
2039-02-05

AI Technical Summary

Technical Problem

Existing filling devices for bags with unsealed upper ends face reliability issues in opening the bags due to strong adhesion between layers, leading to reduced output and performance in form-fill-seal machines.

Method used

A filling device with a layer movement device that uses suction devices and holding devices to move bag layers relative to each other, assisted by fluid flow and ionized fluid, to reduce adhesion and ensure reliable opening.

Benefits of technology

The device achieves reliable opening of bags with reduced mechanical effort, enhancing the efficiency and reliability of the form-fill-seal process by minimizing layer adhesion and ensuring effective filling.

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Description

[0001] The invention relates to a filling device for filling bags, each with an unsealed upper end, according to the preamble of claim 1, a method according to the preamble of claim 16, and a form-fill-seal device according to the preamble of claim 18.

[0002] With filling devices of this type, bags whose upper ends are unsealed and which are usually transported hanging are filled from the top. The bags are double-layered, with the two layers of material defining an interior space that provides volume for the contents. The two layers can be joined by simple side edges or by side folds. The bag is sealed at the bottom. This may be achieved by a weld seam encompassing both layers and, if applicable, the side folds.

[0003] In a known filling device, as described in EP 1 201 539 A1, an opening station is arranged within a filling station, eliminating the need for transport between the two. Within the opening station, an opening element engages each layer. Both opening elements then move away from each other, taking their respective layers with them, thus making the interior of the bag accessible to the filling station and, consequently, to the contents. However, it is possible for the two material layers to adhere so strongly that opening the bag fails. In such cases, one of the opening elements detaches from its layer during its movement, rendering the bag impossible to fill. The reliability of the opening process is therefore unsatisfactory. As a result, the machine's output, i.e., the number of bags filled per unit of time, is reduced.

[0004] EP 1 201 545 A1 shows a station for fully opening bags. However, this complete opening leads to a reduction in the performance of the entire FFS machine in which this station is installed.

[0005] DE 36 39 494 A1 discloses an opening station which, as is usual, is arranged within the filling station. The disadvantages already described also become apparent with this machine.

[0006] EP 0 293 615 A2 shows a filling device with which bags are pre-opened in an opening station before they reach the filling station. This pre-opening serves to separate the outer edges of the side gussets so that they can be gripped by grippers. The setup with four grippers is very complex.

[0007] DE 1 511 755 A1 describes a filling device in which the bags are pre-opened in a pre-opening station so that transport grippers can reach inside the bag to hold the bag walls. These transport grippers then convey the bag to the filling station. This procedure also slows down the entire FFS process.

[0008] German patent DE 78 24 437 U1 discloses a pre-opening station in which suction cups open the bag wide. However, opening the bag too wide can cause the suction cups to detach from the bag walls, so that the bag ultimately slips off and can no longer be transported to the filling station.

[0009] The object of the present invention is therefore to propose a filling device and a method in which the opening of the bags before filling is carried out with a higher reliability.

[0010] According to the invention, this problem is solved by all the features of claim 1. Possible embodiments of the invention are specified in the dependent claims.

[0011] According to the present invention, the filling device comprises at least one layer movement device for moving at least one layer of the bag relative to at least one second layer, with which the layers of the bag can be acted upon, wherein the layer movement device is arranged upstream of the filling station. A transport device for transporting a bag to the filling station may also be provided, wherein the bags can be transported successively from the layer movement device to the filling station by means of the transport device.

[0012] According to the invention, it is further provided that the layer movement device comprises at least one suction device which engages on the outside of a layer of the bag and that at least one holding device is provided with which the bag can be held in the layer movement device, wherein the holding device engages the bag below the suction device, wherein the contact surface of the holding device extends to the bag in a transverse direction, wherein the holding device extends over more than 50% of the bag width, wherein the holding device comprises two holding beams (42), one of which can be applied to each outer wall of the bag (18).

[0013] The movement of the two layers of the bag relative to each other reduces the adhesion between them. It is sufficient for the layers to be moved relative to each other in the area between the side gussets, provided side gussets are present. It is also sufficient if the layer movement device can be applied at the upper end of the bag, where "upper end" refers to a maximum of 10% of the bag's length along its longitudinal axis, measured downwards from the top edge.

[0014] If a bag prepared in this way is transported to the filling station and processed there, the opening of the bag occurs with significantly higher reliability compared to state-of-the-art filling equipment.

[0015] In a preferred embodiment of the invention, the retaining beams are provided that they remain stationary within the filling device before and / or during the action of the layer movement device, or are movable within the filling device in the direction of the bag's longitudinal axis with a stroke of at most 15 mm, preferably at most 10 mm. Thus, it is preferably not provided that the retaining elements move relative to each other. This eliminates any mechanical effort. Typically, the distance between the outer edges of a bag held by retaining elements is slightly less than the nominal bag width, so that the layers can move relative to each other solely due to the play. Alternatively, the retaining elements can be provided to move in the direction of the bag's longitudinal axis to increase the play.However, it is provided that the movement of the holding means in the direction of the bag's longitudinal axis is smaller than the movement of holding means which hold the bag for the purpose of opening, for example within the filling station, whereby these holding means are also movable in the filling station in the direction of the bag's longitudinal axis.

[0016] In a further advantageous embodiment, the layer movement device comprises at least one fluid nozzle with which a flow of fluid can be directed onto the upper end of the bag. This fluid flow makes it possible, for example, to introduce the fluid between the two layers of the bag in the region of the upper edge, thereby reducing the existing adhesive forces. The fluid flow causes the upper edge of the bag to move, with the two layers at the upper end moving slightly away from each other. This often creates a small opening through which the fluid flow can enter the interior and further separate the two layers.

[0017] Preferably, the fluid is a gas, in particular air, wherein the gas is preferably under overpressure. The overpressure is preferably between 4 and 8 bar. At this pressure, the effect according to the invention is particularly evident. In this case, a fluid nozzle can be referred to as an air nozzle. A filling device is often already connected to a compressed air system in a factory, so that the invention can be implemented cost-effectively. The air pressure of such a compressed air system is generally 6 bar, so that the overpressure according to the invention is available without further effort.

[0018] It is advantageous if at least one fluid nozzle is positioned and / or oriented such that the fluid flow includes a directional component in the direction of the bag's longitudinal axis. In the case where the bag is suspended (i.e., subject only to the influence of gravity), this directional component thus runs vertically downwards. Preferably, the fluid nozzle is also oriented such that at least a portion of the fluid flow strikes the upper edge of the bag precisely. In this case, the described effect leads particularly reliably to a relative movement of the layers. A fluid nozzle can be provided that generates a planar fluid flow, whose width is therefore greater than its thickness. In this case, it is preferred if the fluid nozzle, and thus also the fluid flow, is arranged parallel to, and especially in the plane of, the bag. Nevertheless, the fluid nozzle is preferably arranged at an angle to the bag's axis.Details can be found in the figure description. Advantageously, however, it can also be designed to direct at least one component of the fluid flow in a direction orthogonal to the plane defined by the bag. In other words, the fluid flow exerts external pressure on one of the two layers. This also causes the second layer to move, with both layers shifting relative to each other.

[0019] In an advantageous embodiment of the invention, at least one electrode is provided with which the fluid flow can be subjected to an electrical voltage. The applied electrical voltage, which is sufficiently high, causes atoms or molecules of the fluid to release electrons and thereby acquire an electrical charge. In other words, the fluid flow is ionized. An ionized fluid flow can at least partially compensate for an electrical charge between the layers and consequently reduce electrostatic attraction forces. As a result, opening a bag can be even more reliable.

[0020] In a further embodiment, the electrode is located downstream of the fluid flow from the fluid nozzle and is preferably arranged on or directly attached to it. This allows the fluid nozzle and the electrode to form a compact unit that requires minimal installation space.

[0021] It is further advantageous to provide a valve that allows the fluid flow from a pressure source to be passed through and / or interrupted. In this case, a fluid surge can be generated. This surge can cause the upper end or edge of the bag to move suddenly and forcefully, which helps to separate the two layers and thus reduces the adhesion between them. The duration of the fluid flow should preferably be kept short, preferably less than 1 second, and particularly less than 500 milliseconds (msec). The advantage of such a short fluid flow is that only a defined quantity of fluid is introduced into the bag. An excessively large quantity of fluid could potentially cause problems during the subsequent filling process.

[0022] It is further advantageous if a transport device is provided for moving the bag from the layer handling unit to the filling station, and in particular if the inside of the bag remains free of tools during transport. This eliminates the need for a tool that engages with the inside of the bag to keep it open during transport. Specifically, the at least two layers of the bag essentially lie on top of each other during transport. This ensures that the layers of the bag lie on top of each other again, so that as little fluid as possible remains inside the bag and no ambient air enters the interior. Since the adhesion between the two layers is already reduced by the brief movement of the layers relative to each other, reopening before filling is reliably possible.

[0023] According to the invention, the layer movement device further comprises at least one suction device which engages the outer surface of a layer of the bag. In particular, two suction devices may be provided. With such a suction device, it is possible to pull the layers of the bag apart and thus facilitate the introduction of a fluid flow to reduce adhesion between the two layers. At least parts of the suction device are preferably movable away from the original plane of the bag. For this purpose, at least one lever on which the suction device is arranged may be used. However, it may also be advantageous for the component or components on which the suction device is arranged to remain stationary relative to each other, at least during the movement of the layers. This minimizes the mechanical effort that might be required to move the layers of the bag.

[0024] Preferably, the suction device is positioned so that it touches or even overlaps the upper edge of the bag. In other words, the suction device should be positioned as close as possible to the upper edge of the bag to ensure optimal interaction between the suction device and the optional fluid flow. Specifically, the suction device is positioned horizontally within the plane of the bag in an area where the fluid flow meets the upper edge of the bag.

[0025] It is particularly preferred if at least one suction device is provided on each side of the bag, so that both layers can be actively moved away from each other. Preferably, the suction devices are offset from each other in the plane of the bag, particularly in the horizontal direction of this plane. This prevents the bag from being detached from one of the two suction devices if both suction devices do not apply the same negative pressure.

[0026] At least one suction device can advantageously be designed as a bellows suction device. A bellows suction device is a suction device characterized by one or more folds. When this suction device is attached to an object, in this case a bag, it can no longer draw in ambient air if a negative pressure is applied to the suction device. Consequently, the bellows suction device automatically shortens its length, as the negative pressure causes the internal volume to also experience a reduction in pressure. This reduction in pressure is compensated for by the reduction in the internal volume, in particular by a shortening of the length. However, a shortening of the length leads to the layers of the bag separating from each other. The range of movement of a bellows suction device can be small, in particular less than 20 mm, especially less than 10 mm, which is nevertheless sufficient to move the layers relative to each other and thus to further reduce the adhesive forces.Preferably, a bellows suction cup is made of an elastomeric material so that, after the vacuum is released, i.e., after disconnection from a vacuum source, it expands again similarly to a compression spring and returns to its original shape. Thus, a bellows suction cup is a cost-effective and easy-to-use means of further developing the present invention. It is also advantageous that at least parts of the bellows suction cup remain stationary in the layer movement device, at least during the period in which the movement of the two layers of the bag relative to each other is possible.

[0027] According to the invention, at least one holding device is provided with which the bag is held in the layer handling device. This can be an additional holding device or identical to the holding means already mentioned above. Preferably, the holding device comprises a lever arrangement, thus enabling an opening and closing movement. With a holding device, the bag is held in a fixed position within the layer handling device, ensuring, for example, that the fluid flow is directed precisely at the upper end of the bag. A holding device can also be advantageous so that a feeding transport device can release the bag within the layer handling device before the transport device of the filling station grasps the bag.

[0028] In particular, the holding device can engage the bag a few centimeters, a maximum of 10 cm, preferably a maximum of 5 cm, and especially a maximum of 2 cm below the upper edge of the bag, particularly directly below the suction device. Since the holding device keeps the two layers of the bag pressed together, this prevents excessive fluid from entering the interior of the bag, which in turn facilitates subsequent filling. However, the holding device should also engage at least 5 mm below the upper edge of the bag in a vertical direction to allow for relative movement of the layers.

[0029] It is advantageous if at least one holding device is beam-shaped. The contact surface of the holding device can extend horizontally in the plane of the bag. This direction can also be referred to as the transverse direction. The holding device extends over a large portion of the bag's width, with "large portion" being defined as more than 50%. However, to reliably allow the bag to be opened despite this large extension, the holding device may include a break and / or a recess. Preferably, this is arranged essentially vertically below the suction device and / or below the point where the fluid flow meets the upper end of the bag.

[0030] In a further advantageous embodiment of the invention, a device for cooling a bottom weld seam is provided in the layer movement unit. In other words, it is advantageous to provide a combined layer movement and bottom weld cooling station. While the layers of the upper end of the bag are moved relative to each other by the devices according to the invention, the lower end remains free. It is therefore advantageous to use the time required to move the layers at the upper end of the bag for a further processing step. Preferably, this is the cooling of the bottom weld seam of the bag. Preferably, the cooling device comprises at least one cooling jaw, which is preferably pivotably arranged in the machine frame to bear against at least one of the two layers of the bag. The cooling jaw can extend across the width of the bag.Furthermore, it is advantageous if the cooling jaw is permeated by or supplied with another fluid, preferably a liquid. Alternatively or additionally, the cooling device can include nozzles with which a gas, which is particularly cooled, is applied to the lower weld seam of the bag.

[0031] The above-mentioned problem is also solved by a method according to claim 16.The method of filling bags, each with an unsealed upper end and at least two superimposed layers, in which filling takes place in a filling station, is according to the invention, wherein at least one layer movement device acts on at least one layer of the bag in order to move this layer relative to the at least one second layer, wherein the layer movement device is arranged upstream of the filling station, characterized in that at least one suction device of the layer movement device engages on the outside of one layer of the bag and at least one holding device holds the bag in the layer movement device, wherein the holding device engages the bag below the suction device, wherein the contact surface of the holding device extends to the bag in the transverse direction, and wherein the holding device extends over more than 50% of the bag width.wherein the holding device comprises two holding beams (42), one of which is placed against each outer wall of the bag (18).

[0032] The method according to the invention achieves the same advantages as those already described above in connection with the filling device according to the invention.

[0033] The aforementioned problem is further solved by a form-fill-seal device according to claim 18, which A bag-forming device with which hose sections can be successively separated from a hose material, the lower ends of which can each be provided with a bottom in order to form open-topped bags; a filling device for successively filling a product into the bags; a closing device with which the upper openings of the bags can be closed; holding devices with which the bags can be held within at least one of the aforementioned devices; transport devices with which the bags can be moved individually between the individual aforementioned devices. comprises and is characterized according to the invention in that the filling device is designed as described above.

[0034] With such a form-fill-seal device, the same advantages can be achieved as those already described in connection with a filling device according to the invention. In the form-fill-seal device according to the invention, the bags are produced, filled, and sealed in separate units, which are often also referred to as stations, whereby they are never unguided due to the transport and holding devices within the form-fill-seal device.

[0035] Further advantages, features, and details of the invention will become apparent from the following description, in which various exemplary embodiments are explained in detail with reference to the figures. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination thereof. Within the scope of the entire disclosure, features and details described in connection with the method according to the invention naturally also apply in connection with the filling device and / or form-fill-seal device according to the invention, and vice versa, so that the disclosure always refers, or can refer, to the individual aspects of the invention. The individual figures show: Fig. 1 Side view of an FFS machine comprising the filling device according to the invention. Fig. 2 Detail view of a filling device according to the invention. Fig. 3 View III - III of the Figure 2 Fig. 4 View IV - IV of the Figure 3

[0036] The Figure 1 Figure 1 shows a form-fill-seal machine 1, often called an FFS machine for short, which is suitable for forming, filling, and sealing bags and in which the filling device according to the invention can preferably be provided. This device 1 comprises a support arm 2 on which a roll 3 of tubular film 4 rests. The tubular film 4 preferably has Figure 1The side folds (not shown) are present. The transport rollers 5, some of which may be driven, ensure a generally continuous unwinding of the tubular film 4. The lever 9, which carries a deflecting roller 6 and is often referred to collectively as a dancer unit, is actuated by a piston-cylinder unit 10. Together with the transport rollers 7, 8 and the feed roller pair 15, they ensure, in a manner known per se, that the tubular film 4 is intermittently advanced along its transport path. The transport roller 8a is part of a register device 29, which allows the length of the transport path of the tubular film 4 to be adjusted to the format of the resulting bags 27. For this purpose, the transport roller 8a is slidably arranged relative to the device 1. A manually or electrically operated spindle drive, known per se, is available for this displacement.

[0037] The feed roller pair 15 pushes the tubular film 4 through the welding jaws 33 of a transverse welding station 13 and through a transverse cutting station 16. The tools of the transverse welding station 13 and the transverse cutting station 16 can be moved towards and away from the tubular film 4 in planes orthogonal to its feed direction, for example, by a parallelogram arrangement 14, in a manner not described in detail below. After the grippers 17 have grasped the tubular film 4, a tubular section 18 is cut from the tubular film 4 above the grippers 17 in the transverse cutting station 16. Simultaneously, a transverse weld is applied above the cut edge of the tubular film 4 in the transverse welding station 13, forming the base of the tubular section 18 to be formed in the next work cycle of the device 1. Accordingly, bottom seams are produced in the transverse welding station 13.In general, the production of the head or bottom seams can be carried out not only by transverse welding, although preferably, but other joining methods, such as gluing, are also conceivable.

[0038] The grippers 17 transport the hose section 18 to a transfer point, where further grippers 19 grasp the hose section 18 and transport it to a filling station 20.

[0039] This transfer point is the layer movement device 30 of the filling device according to the invention. This layer movement device 30 can optionally interact with a bottom cooling device 31. Further details, structure and function of the layer movement device are shown below in conjunction with further figures.

[0040] In the filling station, the hose section 18 is transferred to stationary grippers 21 and opened by suction cups 22, allowing the product, which is conveyed through the filling device 23, to enter the hose section 18. The lower end of the hose section 18 rests on a conveyor belt 24, preventing excessive stress along its longitudinal edges during the filling process. Additional grippers 25 transport the filled hose section to the top or bottom seam welding station 26, where the hose section 18 is sealed with a top or bottom weld, forming a finished bag 27. Alternatively, the hose section 18 can be sealed at the top using a different joining method. The finished bag 27 is then conveyed out of the device 1 by the conveyor belt 24. The bag 27 is typically much taller (in the y-direction) than it is wide (in the x-direction).

[0041] The Figure 2Figure 18 now shows in more detail some important features of the filling device according to the invention. A finished bag, produced, for example, by the cross-cutting station 16 and the cross-welding station 13, can be seen on the far right. This bag 18 can be provided to the filling device 40 by means of the grippers 17. The bag 18 first enters the layer handling device 30. Here, a holding device 41 is provided, which secures or holds the bag 18. According to the invention, the holding device 41 is embodied by two holding beams 42, one of which rests against each outer wall of the bag. A lever mechanism connected to the machine frame can be provided for this purpose, enabling an opening and closing movement. As soon as the bag 18 is held by the holding device 41, the grippers 17 can release the bag and pivot back to pick up the next bag 18.

[0042] In the layer movement device 30, at least one fluid nozzle 43 is preferably arranged, which is preferably attached to a frame-mounted beam 44. A fluid is supplied to this fluid nozzle 43, which can be pressurized via a fluid line 45, in the direction of arrow 46. The fluid, preferably air, comes into direct contact with the upper edge 47 of the bag 18, allowing its two layers to separate. Consequently, one layer of the bag is moved relative to a second layer. In particular, the bag 18 is at least partially opened, which in the Figure 2as also shown. To further induce the relative movement of the layers of the bag 18, suction cups 48 are provided as an alternative or additional measure to the fluid nozzle. These suction cups are arranged above, i.e., opposite to the direction z, of the holding device and can also be applied to an outer wall of the bag from the outside. For this purpose, each suction cup 48 is arranged on a support 49, which can be fixed to the frame or movable relative to the machine frame, for example, by means of a lever mechanism, which is not shown. Alternatively, the suction cups 48 can be arranged on retaining jaws 42 of the holding device 41, so that the suction cups are already in contact with the outer sides of the bag when the retaining jaws have been closed. Since it may be intended that the suction cups 48 only perform a small lifting movement, they can be designed as bellows suction cups or as corrugated bellows suction cups, as shown in the Figure 2as also shown. The operating principle is as follows: After the suction cup 48 is in contact with the outer wall of the bag 18, a vacuum is applied to the bag via the vacuum line 50. As soon as the outer layer has pressed against the suction cup 48, so that no air is drawn between these two elements, the continuing vacuum causes the suction cup to contract, thus moving the outer wall or the layer in question. It is important that the supports remain stationary during this process, i.e., they do not move to open the bag. Since this process occurs with both layers of the bag, the two layers are separated from each other in this way. If fluid continues to be introduced through the fluid nozzle 43 during this time, a relative movement of the bag layers occurs not only in the area of ​​the suction cups, but also in the area between the suction cups 48 and the holding element 41.

[0043] Furthermore, as in the Figure 2 It is advantageous to provide a device 51 for ionizing the fluid flow. For this purpose, two electrodes are provided, arranged on either side of the fluid flow, and an electrical voltage is applied between them. In this way, the fluid flow can be ionized, thus reducing electrical charges on the layers of the bag. This results in the layers being more easily separated from one another. The electrodes can be fixed to a frame, but are preferably directly connected to the fluid nozzle 43.

[0044] After the bag 18 has been opened in the layer movement device 30, the fluid flow can be interrupted. For this purpose, a valve 52 is provided in the fluid line 45, which allows the fluid flow to be interrupted. The negative pressure acting on the suction cups 49 is also interrupted or reduced. After the grippers 19 have grasped the bag 18, the holding device 41 can be released from the bag 18. The bag 18 can now be transported by the grippers 19 to the filling station 20, so that conventional suction cups 22, which are arranged on carriers 61 movable by means of levers 60, can open the bag 18. Since the layers of the bag 18 have already been partially separated from each other or moved relative to each other in the layer movement device, the opening of the bag for the purpose of filling is significantly more reliable.In the prior art, however, it can be observed that the suction cups 22 lose contact with the bag during the opening process or are unable to separate the two layers from each other, so that in the end the bag is not opened.

[0045] After opening the bag 18, it and / or the filling funnel 62 of the filling device 23 can be moved so that the filling funnel 62 protrudes into the interior of the bag 63. The bag can then be filled.

[0046] The Figure 3 View III - III now shows the Figure 2This figure shows two fluid nozzles 43, both arranged on the beam 44, forming an angle with respect to direction z. The position of the fluid nozzles can be symbolized by the arrows S. This direction can also be referred to as the main flow direction, although it is intended that the fluid flow fans out by means of the fluid nozzles, which is represented by a plurality of arrows 46. The two fluid nozzles are offset outwards with respect to the imaginary center line 64 of the bag 18, i.e., in the direction of the vertical edges of the bag. This makes it possible to increase the area of ​​influence of the fluid flow and even to intensify it with respect to the area of ​​the center line 64. For the sake of clarity, the Figure 3 The devices 51 for ionizing the fluid flow are not shown. However, it should be emphasized that preferably each fluid nozzle 43 is assigned at least one such device 51.

[0047] The figure shows the retaining beams 42 of the holding device 41. It is shown as an example that the retaining beams 42 do not have to be a single piece, but can be interrupted to allow the bag material in the middle area to open. In a further development, it can be provided that the retaining beams are movable in or against the direction y, so that the bag material can be given even more room to move.

[0048] The suction cups 48, of which only one is visible, may also be displaced relative to the center line 64, which can be determined from the Figure 4 This will be explained in more detail later. It can also be seen that the suction cups 48 are positioned near or touching the upper edge of the bag 66. Overlap is also possible. This means that the suction cup can extend partially beyond the upper edge of the bag.

[0049] The Figure 4 View IV - IV from the Figure 3This view shows another embodiment in which the bag comprises 18 side pleats 65. It can also be seen again that the suction cups 48 can be displaced relative to the center line towards the side edges. This prevents the suction cups from drawing against each other, as this would prevent the bag from opening.

[0050] Furthermore, in the Figure 4 It can be seen that the fluid nozzles 43 can be rotated about their own longitudinal axis in the direction R relative to the plane defined by the bag 18. This ensures that the fluid flow reaches the edge of the bag 66 in any case, even if the fluid nozzle 43 does not point exactly into the plane defined by the bag 18.

[0051] Finally, based on the Figure 4 Another variant is shown in which the retaining bars 42 are not interrupted, as can be seen from the Figure 3It has not been explained, but merely has recesses 67 which also allow the bag material to move. In this illustration, the retaining bars 42 are shown as open, which, however, need not be the case. This is only for the sake of clarity.

[0052] Finally, it should be emphasized that the directions and directional relationships given, such as "above" or "above", always refer to the normal directions with respect to gravity. Reference symbol list 1 Form-Fill-Seal machine, FFS machine 2 support arm 3 wrap 4 film 5 Transport roller 6 deflection roller 7 Transport roller 8 8a Transport roller 9 lever 10 Piston-cylinder unit 11 12 13 Cross-welding station 14 Parallelogram arrangement 15 Feed roller pair 16 Cross-cutting station 17 Grabber 18 hose section 19 Grabber 20 Filling station 21 Stationary gripper 22 Mammal 23 Filling equipment 24 25 26 27 bag 28 29 30 Positioning device 31 32 33 Sweat jaw 34 35 36 37 38 39 40 41 Holding device 42 Stop bar 43 Fluid nozzle 44 beam 45 Fluid line 46 Diverting of the fluid flow using fluid nozzles 47 48 Mammal 49 Mammal 50 51 Device for ionizing the fluid flow 52 valve 53 54 55 56 57 58 59 60 lever 61 carrier 62 Funnel 63 Inside of the bag 64 Imaginary center line 65 side pleats 66 Upper edge of the bag 67 recess R Directional information y Directional information S Symbolic representation of the fluid nozzle positions

Claims

1. Filling apparatus for filling bags (18), each having an unsealed upper end and at least two layers lying on top of each other, with a filling station (20) for filling the bags (18), wherein the filling apparatus comprises at least one layer moving apparatus (30) for moving the at least one layer of the bag (18) relative to the at least one second layer, with which the layers of the bag (18) can be acted upon, wherein the layer moving apparatus (30) is arranged upstream of the filling station (20), in that the layer moving apparatus (30) comprises at least one suction apparatus (22, 48, 49) which engages with the outside of a layer of the bag (18), and in that at least one holding apparatus (41) is provided, with which the bag (18) can be held in the layer moving apparatus (30), wherein the holding apparatus engages with the bag (18) below the suction apparatus (22), wherein the contact surface of the holding apparatus (41) on the bag (18) extends in transverse direction, wherein the holding apparatus (41) extends over more than 50% of the bag width, characterized in that the holding apparatus (41) comprises two holding bars (42), each of which can be placed against an outer wall of the bag (18).

2. Filling apparatus according to claim 1, characterized in that the holding bars (42) remain stationary inside the filling apparatus before and / or during the action of the layer moving apparatus (30) or can be moved inside the filling apparatus by a stroke of at most 15 mm, preferably at most 10 mm.

3. Filling apparatus according to claim 1 or 2, characterized in that the layer moving apparatus comprises at least one fluid nozzle (43) by which a stream of fluid can be applied to the upper end of the bag (47).

4. Filling apparatus according to any one of the preceding claims, characterized in that the fluid is a gas, in particular air, which is preferably under overpressure.

5. Filling apparatus according to any one of the preceding claims, characterized in that the fluid nozzle (43) is aligned such that the fluid stream (46) comprises at least one directional component in the direction of the longitudinal axis of the bag.

6. Filling apparatus according to any one of the preceding claims, characterized in that at least one electrode (51) is provided, by which the fluid stream (46) can be subjected to electric voltage.

7. Filling apparatus according to the preceding claim, characterized in that the electrode (51) is arranged downstream of the fluid stream (46) after the outlet of the fluid nozzle (43).

8. Filling apparatus according to any one of the preceding claims, characterized in that at least one valve (52) is provided, which the fluid stream (46) from an overpressure source can pass through and / or be interrupted in order to be able to generate a fluid surge.

9. Filling apparatus according to any one of the preceding claims, characterized in that a transport apparatus is provided for transporting the bag (18) from the layer moving apparatus (30) to the filling station (20), wherein during the transport of the bag (18) to the filling station (20), the interior of the bag (18) is tool-free.

10. Filling apparatus according to any one of the preceding claims, characterized in that the suction apparatus (22, 48, 49) touches the upper edge of the bag (47) or overlaps the upper edge of the bag (47).

11. Filling apparatus according to any one of the preceding claims, characterized in that at least one suction apparatus (22, 48, 49) is provided on each side of the bag (18), which are preferably offset from each other in the plane of the bag (18).

12. Filling apparatus according to any one of the preceding claims, characterized in that the suction apparatus (22, 48, 49) is a bellows suction apparatus.

13. Filling apparatus according to any one of the preceding claims, characterized in that the suction apparatus (22, 48, 49) is arranged on at least one support element (61), wherein the support element (61) remains stationary inside the filling apparatus at least during the action of the layer moving apparatus (30).

14. Filling apparatus according to any one of the preceding claims, characterized in that the holding bars (42) comprise an interruption, in particular in the region of a suction apparatus, and / or at least one recess.

15. Filling apparatus according to any one of the preceding claims, characterized in that a cooling apparatus (31) for cooling the bottom seam of the bag is additionally provided in the layer moving apparatus (30).

16. Method for filling bags (18) each having an unsealed upper end and at least two layers lying on top of each other, wherein the filling takes place in a filling station (20), wherein at least one layer moving apparatus (30) acts on at least one layer of the bag (18) in order to move this layer relative to the at least one second layer, wherein the layer moving apparatus (30) is arranged upstream of the filling station (20), characterized in, that at least one suction apparatus (22, 48, 49) of the layer moving apparatus (30) engages externally on a layer of the bag (18) and that at least one holding apparatus (41) holds the bag (18) in the layer moving apparatus (30), wherein the holding apparatus (41) engages on the bag (18) below the suction apparatus (22, 48, 49), wherein the contact surface of the holding apparatus (41) extends on the bag (18) in transverse direction, wherein the holding apparatus (41) extends over more than 50% of the bag width, wherein the holding apparatus (41) comprises two holding bars (42), one of which is applied to each outer wall of the bag (18) respectively.

17. Method according to claim 16, characterized in that the distance between the two side edges of the bag (18) is kept constant or reduced by a maximum of 15 mm, preferably by a maximum of 10 mm, before and / or during the action of the layer moving apparatus (30).

18. Form-fill-seal apparatus (1) comprising - a bag forming apparatus by which pieces of tubing (18) can be separated one after the other from a tubular material (4), the lower ends of which can be provided with a bottom in each case to form bags that open at the top, - a filling apparatus for successively filling a product into the bags, - a sealing apparatus (26) by which the upper openings of the bags can be sealed, - holding apparatuses (41) by which the bags (27) can be held inside at least one of the aforementioned apparatuses, - transport apparatuses (24) by which the bags (27) can be transported individually between the individual aforementioned apparatuses, characterized in that the filling apparatus is configured according to any one of claims 1 to 15.