Flow-wrapping machine with dosing device

Description

[0001] The invention relates to a flow-wrapping machine with a dosing device, such as is used for packaging filling goods. The flow-wrapping machine is equipped with a longitudinal sealing device for forming a film tube. This film tube is then transversely sealed in the flow-wrapping machine by means of two transverse sealing jaws that move relative to one another and weld the film tube transversely, so that flow-wrapping bags can be produced continuously or intermittently. Before the flow-wrapping bags are closed, they are filled with the filling material by means of a filling device. After the flow-wrapping bags are transversely sealed, the individual flow-wrapping bags are separated from one another by means of a separating device.

[0002] A tubular bag machine of this type is known, for example, from EP 0 469 105.

[0003] In conventional flow-wrapping machines, a dosing device is arranged upstream of the filling device. In the dosing device, a portion of the filling material is separated at a time to fill the flow-wrapping bag with the specified quantity, for example, a specified fill weight, a specified fill volume, or a specified fill number. In conventional flow-wrapping machines, the dosing device operates synchronously with the flow-wrapping machine, so that the filling device can add the required amount of filling material to the flow-wrapping bag at exactly the right time. This synchronous operation between the dosing device and the flow-wrapping machine is increasingly leading to problems.

[0004] A primary disadvantage of synchronous operation between the dosing device and the flow-wrapping machine is that even the smallest process disturbance during dosing in the dosing device leads to a downtime or an idle cycle in the flow-wrapping machine. Especially in high-performance flow-wrapping machines with an output of more than 200 flow-wrapping bags per minute, ensuring synchronization between the flow-wrapping machine and the dosing device is very difficult. A further disadvantage of synchronous operation between the flow-wrapping machine and the dosing device is that, according to the prior art, the dosing device must be positioned above the filling device.Since the dosing device requires an ever larger installation space to maintain the necessary dosing performance, this results in an ever higher room height, which is required for the installation of the flow-wrapping machine with the dosing device arranged above it.

[0005] A generic tubular bag machine with a dosing device is known from CN 107 215 507 A. The dosing device has the disadvantage that the filling quantity of the product cannot be specified.

[0006] Based on this prior art, it is therefore the object of the present invention to propose a new tubular bag machine which avoids the disadvantages of the prior art and is able to compensate for process deviations between the dosing process and the tubular bag filling process.

[0007] Advantageous embodiments of the invention are the subject of the subclaims.

[0008] The flow-wrapping machine is based on the basic idea that a transfer device with several transfer containers is provided between the filling device and the dosing device. In other words, this means that the required filling quantity of the filling material is no longer dosed directly by dispensing the filling material from the dosing device into the filling device of the flow-wrapping machine. Instead, the transfer device comprises an input station in which the specified filling quantities for each filling of the individual flow-wrapping bags are transferred from the dosing device into a transfer container. The transfer containers are then transported along a transfer line to a discharge station. At the discharge station, the transfer container is emptied and the filling material from the transfer container is transferred to the filling device of the flow-wrapping machine.The transfer container then travels along a return transfer route back to the input station and can be refilled there from the dosing device.

[0009] As a result, the transfer device decouples the dosing process from the flow-wrapping filling process, so that the dosing device and the flow-wrapping machine no longer necessarily have to be operated synchronously. This decoupling, in particular, ensures that malfunctions in one of the two processes do not directly cause a disruption to the other. Furthermore, the transfer device makes it possible to make the dosing device spatially independent of its location on the flow-wrapping machine, so that locating the dosing device above the filling device of the flow-wrapping machine is not mandatory.

[0010] With regard to decoupling the dosing process from the tubular bag filling process, the invention provides for the transfer device to be controlled by a dedicated transfer control system. This transfer control system can control the transfer process in the input station independently of the transfer process in the output station, thus ensuring true decoupling between the two processes.

[0011] This is made possible by compensating for minor process disturbances. The transfer control system can adjust the conveying speed of the transfer containers along the transfer line and / or along the return transfer line. Such speed variations can easily compensate for minor delays in the dosing area, ensuring the timely delivery of the pre-dosed quantity of product to the discharge station, even in the event of minor process disturbances.

[0012] In particular, this also allows for a reduction in the product drop height and increased process performance. Product protection for fragile products is also enhanced. Transfer containers with a non-constant diameter can be used to increase the emptying speed. By decoupling the dosing and bag filling processes, the filling process can be accelerated through optimized speed controls and improved opening procedures.

[0013] The type of flow-wrapping machine combined with the transfer device is fundamentally optional. Placing the transfer device between the dosing device and the flow-wrapping machine offers particularly significant advantages in cases where a vertical flow-wrapping machine is used.

[0014] The design of the filling device is, in principle, arbitrary. According to a preferred embodiment, the filling device is designed like a format tube, with the film tube guided along the outside of the format tube. Through the internal cross-section of the format tube, the filling material can then be poured into the still-open tubular bag from above under the influence of gravity.

[0015] There are different variants for the respective dosing device to be used. In principle, any gravimetric or volumetric dosing device, or any dosing device using a counting method, can be used. Depending on the method of dosing, the dosing device can be a scale, a screw conveyor, a counter, or a volumetric dosing device.

[0016] It is particularly advantageous if the transfer control can change the conveying speed of individual transfer containers independently of the conveying speed of the other transfer containers.

[0017] To compensate for major process disruptions and associated process deviations between the dosing process and the tubular bag filling process, the transfer device can be equipped with at least one buffer. At least one filled or unfilled transfer container can be temporarily stored in this buffer. If a minor process disruption occurs, for example, preventing a transfer container from being filled on time, the temporarily stored transfer container can be removed and inserted into the transfer line or the return transfer line. It can be particularly advantageous to provide a buffer before each delivery station.

[0018] In its basic form, a dosing device is connected to a flow-wrapping machine by means of the transfer device. According to a preferred variant, however, the transfer device comprises at least two input stations, at each of which filling material can be transferred from a dosing device to the transfer containers. In this way, it is particularly possible for the necessary dosing capacity to be distributed across several dosing devices, so that, for example, a high-performance flow-wrapping machine can be supplied with the pre-dosed filling quantities from two or more dosing devices. The individual dosing devices can then each have a correspondingly lower dosing capacity, so that, in particular, high-performance dosing devices do not need to be used for dosing on high-performance flow-wrapping machines.

[0019] Dosing the contents using multiple dosing devices and transferring them to at least two different input stations into the transfer containers is particularly advantageous when the tubular bags are to be filled with a mixed product, such as a nut mixture. To create this mixed product, different contents can be filled into the transfer containers at the various input stations, ensuring that the individual transfer containers contain the desired mixture of contents upon reaching the delivery station. The individual dosing of the components that make up the mixture also increases the dosing accuracy of the proportions of the components in the mixture.

[0020] Alternatively or in addition to the use of multiple input stations, the transfer system can also include multiple output stations. At each output station, the filling material or mixed material can then be transferred from the transfer containers to the filling device of different flow-wrapping machines. Using appropriate transfer systems, complex transfer systems can be created in which a large number of possibly different dosing devices are linked to a large number of different flow-wrapping machines, enabling an optimized capacity balance between dosing and filling capacities.

[0021] Various embodiments of the invention are shown schematically in the drawings and are explained below by way of example.

[0022] They show: Fig. 1 a tubular bag machine with upstream dosing device and intermediate transfer device in side view; Fig. 2 the transfer facility according to Fig. 1 in top view; Fig. 3 a second embodiment of a transfer device in a view from above; Fig. 4 a third embodiment of a transfer device in top view.

[0023] Fig. 1 shows a flow-wrapping machine 01 for producing flow-wrapping bags 02. During the production of the flow-wrapping bags 02, a packaging film 03 is first formed into a tube around a format tube serving as a filling device 04 and sealed lengthwise. The film tube 05 thus formed is sealed crosswise using cross-sealing jaws 06 and thus closed at the top and bottom ends. During the filling process in the flow-wrapping machine 01, the flow-wrapping bag 02, which is still unsealed at the top end, is filled with a filling material via the filling device 04. The filling material falls from above through the inner cross-section of the format tube into the still-open flow-wrapping bag.

[0024] Upstream of the tubular bag machine 01 is a dosing device 07, which in the illustrated embodiment is designed as a dosing screw 08 with a corresponding drive. By appropriately driving the dosing screw 08, a predetermined filling volume of the filling material can be metered out of a filling material hopper 09.

[0025] A transfer device 10 is arranged between the flow-wrapping machine 01 and the dosing device 07. The transfer device 10 comprises an input station 11 and a discharge station 12. In the input station 11, transfer containers 13 from the dosing device 07 can be filled with the pre-dosed amount of filling material. The transfer containers 13 are then transported along a transfer path 14 to the discharge station 12. In the discharge station 12, the transfer containers 13 are emptied so that the pre-dosed amount of filling material falls from above into the opened flow-wrapping bags through the filling device 04. The filling of the transfer containers 13 in the input station 11 takes place independently of the emptying of the transfer containers 13 in the discharge station, so that synchronization between the dosing process in the dosing device 07 and the flow-wrapping filling process in the flow-wrapping machine 01 is no longer required.By varying the conveying speed of the transfer containers 13 along the transfer path 14, synchronicity deviations between the two processes can be easily compensated.

[0026] Fig. 2 shows the transfer device 10 with the input station 11 and the output station 12 in a schematic view from above. As can be seen from Fig. 2 As can be seen, after being emptied at the discharge station 12, the transfer containers 13 are transported along a return transfer path 15 back to the input station 11 so that they can be refilled there with a pre-measured amount of the filling material. In order to compensate for even larger synchronization shifts between the filling of the transfer containers in the input station 11 and the emptying of the transfer containers 13 in the discharge station 12, the transfer path 14 also contains a buffer 16 in which several transfer containers 13 can be temporarily stored. Switch elements 17 are used for filling or removing the transfer containers 13 in the buffer 16.

[0027] Fig. 3 shows an alternative embodiment 18 of a transfer device. The basic structure of the transfer device 18 corresponds to the structure of the transfer device 10, wherein the transfer device 18 comprises an additional input station 19. At the additional input station 19, the transfer containers 13 can in turn be filled with pre-metered quantities of a filling material using a further dosing device. It is conceivable that different transfer containers are filled with filling material in the input stations 11 and 19 in order to increase the required dosing capacity by using two dosing devices. Alternatively, the transfer containers 13 in the input stations 11 and 19 can also each be filled with different filling materials, so that each transfer container contains a pre-metered mixture of filling materials after leaving the input station 19.

[0028] Fig. 4shows a third embodiment 20 of a transfer device. The transfer device 20 differs from the transfer device 18 by the additional use of a further delivery station 21. As a result, by means of the transfer device 20, the transfer containers 13 can be filled with filling material in the input stations 11 and 19 using different dosing devices, and the filling materials from the transfer containers 13 can then be delivered to two different flow-wrapping machines at the delivery stations 12 and 21. If the transfer devices comprise further input stations or delivery stations, complex transfer systems formed from a plurality of dosing devices and a plurality of flow-wrapping machines can be realized.

Claims

1. A tubular bag machine (01) having a longitudinal sealing element for forming a film tube (05), having two transverse sealing jaws (06), which are moveable against each other and which thereby transversely seal the film tube (05), for forming sealed tubular bags (02), having a mechanism which has a drive and which moves the transverse sealing jaws (06), having a filling device (04) for filling the unsealed tubular bags (02) with a filling material, having a separating element for separating individual filled tubular bags (02), a dosing device (07) being disposed upstream of the filling device (04), said dosing device allowing for the dosing of a prespecified filling quantity of the filling material to be filled into a tubular bag (02), a transfer element (10, 18, 20) having several transfer containers (13) being provided between the filling device (04) of the tubular bag machine (01) and the dosing device (07), and the transfer containers (13) being transportable to a dispensing station (12, 21) along a transfer line (14), and the filling material being transferable from the transport containers (13) into the filling device (04) in the dispensing station (12, 21), and the transfer containers (13) being transportable back to the input station (11, 19) along a return transfer line (15) characterized in that the prespecified filling quantity of the filling material is transferable from the dosing device (07) to the transfer containers (13) in an input station (11, 19), the transfer element (10, 18, 20) being controlled by a transfer control system, and in that the transfer control system (10, 18, 20) is able to change the conveying speed of the transfer containers (13) along the transfer line (14) and / or along the return transfer line (15), the transfer control system being able to control the transfer process in the input station (11, 19) irrespective of the transfer process in the dispensing station (12, 21).

2. The tubular bag machine according to claim 1, characterized in that the tubular bag machine (01) is a vertical tubular bag machine.

3. The tubular bag machine according to claim 1 or 2, characterized in that the filling device (04) is realized in the manner of a forming tube, the film tube (05) being guided on the outer surface of the forming tube.

4. The tubular bag machine according to any one of claims 1 to 3, characterized in that the dosing device (07) comprises at least a weighing scale or at least a screw conveyor (08) or at least a meter or at least a volume dosing element for measuring the filling material.

5. The tubular bag machine according to any one of claims 1 to 4, characterized in that the transfer control system changes the conveying speed of individual transfer containers (13) irrespective of the conveying speed of the other transfer containers (13).

6. The tubular bag machine according to any one of claims 1 to 5, characterized in that the transfer element (10, 18, 20) comprises at least one buffer (16), which temporarily stores at least one filled or unfilled transfer container (13).

7. The tubular bag machine according to any one of claims 1 to 6, characterized in that the transfer element (18, 20) comprises at least two input stations (11, 19), at each of which filling material from a dosing device (07) is transferable to the transfer containers (13).

8. The tubular bag machine according to claim 7, characterized in that for forming a mixed filling, at the different input stations (11, 19), different filling materials are transferable to one transfer container (13) each.

9. The tubular bag machine according to any one of claims 1 to 8, characterized in that the transfer element (20) comprises at least two dispensing stations (12, 21), at each of which filling material from the transfer containers (13) is transferable to filling devices (04) of different tubular bag machines (01).