SEALING STATION WITH CENTRIFUGAL SEPARATOR

Description

[0001] The present invention relates to a sealing station for a packaging machine according to claim 1. Furthermore, the invention relates to a method for separating a particle-laden gas stream at a sealing tool of a packaging machine according to claim 13.

[0002] In practice, thermoforming packaging machines and tray sealing machines are used to produce sealed packages. Such machines can utilize a sealing station to seal the unsealed thermoformed trays or prefabricated tray parts fed to it with a top film. For this purpose, the sealing station has a lower and upper tool section, which can form a hermetically sealable chamber in which the atmosphere in the thermoformed trays or tray parts can be evacuated, for example, and / or replaced by gas purging with a replacement gas or a gas mixture before sealing with the top film released from a top film holder.

[0003] A sealing station with a tool lower part designed for atmosphere exchange is disclosed, for example, in EP 3 733 536 A1.

[0004] However, during an atmosphere exchange, especially when the air in the packaging is optionally extracted using a vacuum and replaced with a preset gas mixture, it can happen, especially when packaging products with loose components on the product surface, for example, products coated with breadcrumbs or herbs, that individual components are blown out of the packaging and consequently contaminate the extraction channels of the lower part of the tool. Contaminated extraction channels must be cleaned regularly and lead to significant machine downtime.

[0005] Tools designed exclusively for gas purging do not have the aforementioned extraction channels. However, loose product components, such as breading, herbs, etc., are then blown directly into the machine chamber, thus contaminating the machine area used for food packaging.

[0006] The object of the invention is to provide a sealing tool for a packaging machine that eliminates the disadvantages described above in connection with known tools. Furthermore, the object of the invention is to provide a corresponding method.

[0007] This object is achieved by means of a sealing tool according to claim 1 and further by means of a method according to claim 13. Advantageous developments of the invention are specified by the respective subclaims.

[0008] The invention relates to a sealing tool for a packaging machine, for example, a thermoforming packaging machine or a tray sealing machine. According to the invention, the sealing tool comprises a lower tool part with at least one centrifugal separator for separating a particle-laden gas stream.

[0009] The centrifugal separator provided on the lower part of the tool according to the invention ensures that any product particles, such as breading or herb particles, that may be stirred up during an atmosphere exchange can be essentially filtered out of the atmosphere, i.e., from the gas stream generated within the sealing tool. This prevents the particles released from the product from spreading within the sealing tool, i.e., outside its packaging. Consequently, the centrifugal separator can effectively counteract contamination of the sealing tool. In particular, it makes it possible to reduce the cleaning intervals required on the packaging machine due to particle deposition, which leads to less machine downtime.

[0010] It is advantageous if the centrifugal separator is designed as a tangential cyclone separator. This represents a simple, technical device that can be implemented cost-effectively on the lower part of the tool. Separating a potentially particle-laden gas stream into particles and pure gas is possible using a tangential cyclone separator in a confined space, making it ideal for a multifunctional lower part of the tool.

[0011] The centrifugal separator preferably has an inlet cylinder and an inlet that tapers towards the inlet cylinder. This allows a large volume of gas flow to be captured and directed to the centrifugal separator. The inlet, which tapers towards the inlet cylinder, also provides a jet effect, which can accelerate the particle-laden gas flow into the inlet cylinder, allowing the particles to be more effectively separated from the gas flow due to the increased centrifugal forces acting there.

[0012] An advantageous variant provides for the inlet to be assigned to a shell receptacle in the lower part of the tool. The centrifugal separator is then positioned with its inlet in close proximity to the product and open towards it, so that any particles stirred up can be easily captured due to the suction effect of the centrifugal separator.

[0013] The lower tool part preferably has at least one suction channel and / or at least one gas purging channel. The suction channel can be used to generate a vacuum within the sealing tool, i.e., within a chamber that can be closed thereon. It is conceivable for the suction channel and the centrifugal separator to be present as separate components or to be formed as an integral functional unit on the lower tool part. In a separate embodiment, the centrifugal separator could be positioned directly next to the suction channel, especially next to a suction opening formed thereon. As an integral functional unit, the centrifugal separator could be formed directly at the inlet of the suction channel.

[0014] In particular, it is advantageous to provide the centrifugal separator closer to the extraction channel than to the gas purge channel, in particular to a gas purge opening formed thereon. For example, the centrifugal separator and the extraction channel could be formed together on one side of the tool base, which is opposite to another side of the tool base, on which one or more gas purge openings are formed.

[0015] It would be conceivable for all extraction channels on the lower part of the tool used for atmosphere exchange to have a centrifugal separator at their inlets, i.e., at all extraction openings. This would allow the air mass extracted from the sealing tool to be completely cleaned.

[0016] According to an advantageous embodiment, the lower part of the tool for the centrifugal separator comprises a particle collection container. This container can hold the particles separated from the air or gas stream within the sealing tool by the centrifugal separator. This container can be easily emptied and cleaned in a short time. The particle collection container provides a central collection point for the particles, to which the particles can be fed in a controlled manner.

[0017] It is conceivable for the lower part of the tool to have a fill level indicator for the particle collection container. Preferably, the lower part of the tool includes a window, for example, a transparent wall, allowing an operator to view the interior of the particle collection container.

[0018] It would be possible for the lower tool section to have several centrifugal separators. These can be functionally connected to one another or driven individually, for example, by means of a dedicated valve device. In particular, the centrifugal separators can be arranged side by side along one side of the lower tool section, toward which the gas flow is directed during an atmosphere exchange. This has the effect that the potentially particle-laden gas flow enters the inlet area of ​​the centrifugal separator(s) in its flow direction, i.e., without being initially deflected, which promotes the removal of the particles contained therein.

[0019] Preferably, the centrifugal separator on the lower part of the tool is designed to separate a particle-laden gas stream blown through it and / or a particle-laden gas stream sucked through it. Thus, the centrifugal separator can be used during a gas purging process and / or during the evacuation of the sealing tool.

[0020] Preferably, the centrifugal separator is connectable to a pump that can be used on the lower part of the tool for atmosphere exchange. The centrifugal separator can be connected, for example, at least temporarily, for example during predetermined evacuation intervals, to the pump that can be used on the sealing tool for an evacuation process. It is conceivable that the centrifugal separator can be operated continuously during use of the sealing tool in order to continuously extract particles flying around its surroundings.

[0021] A preferred variant provides for the lower part of the tool to be assembled in a layered manner from several superimposed plates, with the centrifugal separator being integrated within at least two superimposed plates. Using such a sandwich construction, the centrifugal separator can be manufactured cost-effectively on the lower part of the tool.

[0022] Preferably, the centrifugal separator comprises a cylindrical insert mounted on the lower part of the tool with a conical separation section for the particle-laden gas stream. Such an insert body can be manufactured separately and cost-effectively and can then be easily installed as a component on the lower part of the tool.

[0023] The invention also relates to a packaging machine, which is in particular in the form of a thermoforming packaging machine or in the form of a tray sealing machine, wherein the packaging machine has at least one sealing tool with a centrifugal separator for separating a particle-laden gas stream.

[0024] The invention further relates to a method for separating a particle-laden gas stream at a sealing tool of a packaging machine, wherein the particle-laden gas stream is separated by means of a centrifugal separator provided on a lower part of the sealing tool. This prevents particles, such as breadcrumbs, herb flakes, or the like, that may be stirred up during an atmosphere exchange process carried out on the sealing tool from contaminating the sealing tool, in particular the suction channels provided thereon. The centrifugal separator thus promotes operation that meets the highest hygienic standards.

[0025] Preferably, the centrifugal separator is operated with a pump installed on the lower part of the tool for atmosphere exchange. For example, a pump used for an evacuation process on the sealing tool can be functionally connected to the centrifugal separator simultaneously, i.e., during the evacuation, and / or during a subsequent process, for example, during a gas purging process.

[0026] It is conceivable that the centrifugal separator is operated with a pressure vessel that can be inserted into the lower part of the tool for atmosphere exchange. Such a pressure vessel can, for example, flush a replacement gas into the sealing tool, especially into a pre-evacuated chamber therein. The gas flow thus generated within the sealing tool is at least partially blown through the centrifugal separator, so that any particles contained therein remain in the centrifugal separator.

[0027] The invention is explained in more detail using exemplary embodiments according to the following figures. In detail: Figure 1 is a perspective view of a thermoforming packaging machine, Figure 2 is a perspective view of a tray sealing machine, Figure 3 is a perspective view of a sealing tool according to the invention, Figure 4 is a plan view of the sealing tool according to the invention, and Figure 5 is an enlarged sectional view of two centrifugal separators formed side by side on the sealing tool.

[0028] Identical components are provided with the same reference numerals throughout the figures.

[0029] Figure 1shows a perspective view of an intermittently operating thermoforming packaging machine 1. This thermoforming packaging machine 1 has a forming station 2, a sealing station 3, a cross-cutting device 4, and a longitudinal cutting device 5, which are arranged in this order in a transport direction R on a machine frame 6. On the input side, a feed roller 7 is located on the machine frame 6, from which a bottom film 8 is drawn. Furthermore, the thermoforming packaging machine 1 has a transport chain 11, which grips the bottom film 8 and transports it further in the transport direction R per main work cycle, in particular transport chains or clamp chains 11 arranged on both sides.

[0030] In the illustrated embodiment, the forming station 2 is designed as a deep-drawing station, in which troughs are formed in the bottom film 8 by deep-drawing, for example, using compressed air and / or vacuum. The forming station 2 can be designed such that several troughs are formed next to one another in the direction perpendicular to the transport direction R. A filling line 12 is provided downstream of the forming station in the transport direction R, in which the troughs formed in the bottom film 8 are filled with products.

[0031] The sealing station 3 has a hermetically sealable chamber 3a in which the atmosphere in the troughs can be evacuated, for example, and / or replaced by gas purging with a replacement gas or with a gas mixture before sealing with the upper film 10 released from an upper film holder 9.

[0032] The cross-cutting device 4 can be designed as a punch that cuts the bottom film 8 and the top film 10 in a direction transverse to the transport direction R between adjacent troughs. The cross-cutting device 4 operates in such a way that the bottom film 8 is not cut across its entire width, but rather remains uncut at least in one edge area. This enables controlled further transport through the transport chain 11.

[0033] The longitudinal cutting device 5 can be designed as a knife arrangement with which the lower film 8 and the upper film 10 are severed between adjacent troughs and at the lateral edge of the lower film 8 in the transport direction R, so that individual packages are present behind the longitudinal cutting device 5.

[0034] The right and left transport chains 11 of the thermoforming packaging machine 1, which grip the bottom film 8 on both sides, are each guided in a chain guide 13. These chain guides 13 are each protected from the outside by a side panel 14 of the thermoforming packaging machine 1 and, if necessary, are attached to the side panel 14. The side panel 14 can be a sheet metal part.

[0035] The thermoforming packaging machine 1 also has a controller 19. Its task is to control and monitor the processes taking place in the thermoforming packaging machine 1. A display device 20a with control elements 20b serves to visualize or influence the process sequences in the thermoforming packaging machine 1 for or by an operator.

[0036] Figure 2shows a tray sealing machine 15, also known in technical circles as a "tray sealer." The tray sealing machine 15 comprises a feed belt 16, a sealing station 17, and a discharge belt 18, which are arranged in this order in the transport direction R on a machine frame 21. Furthermore, the tray sealing machine 15 has a gripper device 22 configured to transport trays S transported by the feed belt 16 into the sealing station 17 for a sealing process. The trays S transported into the sealing station 17 are sealed with a top film 23 and then transported by the gripper device 22 onto the discharge belt 18 for removal.

[0037] Figure 3shows a sealing tool 24 (here without the upper tool part). The sealing tool 24 comprises a lower tool part 25, which can be used on a packaging machine, in particular on the sealing station 3 of the thermoforming packaging machine 1 from Figure 1 or at the sealing station 17 of the tray sealing machine 15 Figure 2 .

[0038] The lower tool part 25 has a first and a second centrifugal separator 26a, 26b. However, only a single centrifugal separator 26a, 26b could equally well be formed on the lower tool part 25.

[0039] For an improved representation of the centrifugal separator 26a, the Figure 3 A corner area is cut free on the lower tool part 25. The first centrifugal separator 26a and the second centrifugal separator 26b can have a substantially identical structure. This will be explained in more detail below using the first centrifugal separator 26a as an example.

[0040] The centrifugal separator 26a is according to Figure 3 designed as a tangential cyclone separator 27. The lower tool part 25 has a first plate 28, a second plate 29, and a third plate 30. The plates 28, 29, 30 are assembled in a stacked manner, with the centrifugal separator 26a, like the centrifugal separator 26b, being integrated within the plates 28, 29, 30.

[0041] The centrifugal separator 26a has a particle collection container 31 formed in the first plate 28. The particle collection container 31 is manufactured as a milled recess in the first plate 28. Furthermore, the centrifugal separator 26a has an inlet cylinder 32 and an inlet 33 tapering toward the inlet cylinder 32. Both the inlet cylinder 32 and the inlet 33 are formed in the third plate 30. A suction pipe 34 is arranged within the inlet cylinder 32.

[0042] Figure 3 also shows that the centrifugal separator 26a provides a cylindrical insert 35 installed in the second plate 29, which has a conical separation section 36 for a particle-laden gas stream G. Furthermore, Figure 3 a pure gas stream G` which no longer contains any particles P and which leaves the centrifugal separator 26a via the suction pipe 34.

[0043] The inlet 33 of the centrifugal separator 26a is associated with a shell receptacle 37 of the lower tool part 25. The shell receptacle 37 is configured to receive a deep-drawn trough or a prefabricated shell S therein. Furthermore, Figure 3 that suction openings 38 are provided in the third plate 30 next to the two centrifugal separators 26a, 26b. A vacuum can be generated within the sealing tool 24 via the suction openings 38 when the latter is closed.

[0044] To evacuate the sealing tool 24, the latter could also be dispensed with using the suction openings 38. This means that the air mass extracted to create a vacuum within the sealing tool 24 flows completely through the two centrifugal separators 26a, 26b.

[0045] Furthermore, Figure 3 that gas purge openings 38' are formed on a side of the lower tool part 25 opposite the suction openings 38. Through these, a replacement gas can be blown into the sealing tool 24. The Figure 3 The suction openings 38 shown can be used for an evacuation process and the gas purging openings 38' for a gassing process on the sealing tool 24.

[0046] Figure 4 shows the tool base 25 in a top view. Figure 4shows that both centrifugal separators 26a, 26b are designed side by side as tangential cyclone separators 27, 27'. The inlet 33 of the first centrifugal separator 26a and an inlet 33' of the second centrifugal separator 26b open with increasing cross-section towards the shell receptacle 37. A gas stream G laden with particles P can thus be sucked out via the two inlets 33, 33', cleaned, i.e. separated, within the respective conical separation sections 36, 36', and can leave the respective centrifugal separator 26a, 26b as a particle-free gas stream G', optionally be blown back into the lower tool part 25 or leave this directly through the suction openings 38.

[0047] Figure 5shows the two centrifugal separators 26a, 26b in a sectional view. The two centrifugal separators 26a, 26b are connected via a common suction channel 39. The respective suction pipes 34, 34' are connected to the suction channel 39. Both centrifugal separators 26a, 26b are driven by a schematically illustrated pump 40, which can also be used primarily to carry out an evacuation process.

Claims

1. Sealing tool (24) for a packaging machine, characterized in that said sealing tool (24) comprises a tool lower part (25) with at least one centrifugal separator (26a, 26b) for separating a particle-laden gas flow (G).

2. Sealing tool according to claim 1, characterized in that said centrifugal separator (26a, 26b) is configured as a tangential cyclone separator (27, 27').

3. Sealing tool according to one of the preceding claims, characterized in that said centrifugal separator (26a, 26b) comprises an inlet cylinder (32, 32`) and an inlet (33, 33`) which tapers towards said inlet cylinder (32, 32').

4. Sealing tool according to claim 3, characterized in that said inlet (33, 33`) is associated with a tray receptacle (37) of said tool lower part (25).

5. Sealing tool according to one of the preceding claims, characterized in that said tool lower part (25) comprises at least one extraction duct (39) and / or at least one gas flushing duct.

6. Sealing tool according to one of the preceding claims, characterized in that said tool lower part (25) for said centrifugal separator (26a, 26b) comprises a particle collection container (31, 31`).

7. Sealing tool according to one of the preceding claims, characterized in that said tool lower part (25) comprises several centrifugal separators (26a, 26b)8. Sealing tool according to one of the preceding claims, characterized in that said centrifugal separator (26a, 26b) at said tool lower part (25) is configured to separate a particle-laden gas flow (G) blown through the former and / or to separate a particle-laden gas flow (G) sucked through the former.

9. Sealing tool according to one of the preceding claims, characterized in that said centrifugal separator (26a, 26b) can be connected to a pump (40) that can be employed at said tool lower part (25) for atmosphere exchange.

10. Sealing tool according to one of the preceding claims, characterized in that said tool lower part (25) is assembled from several plates (28, 29, 30) disposed one above the other in a stack-like manner, where said centrifugal separator (26a, 26b) is formed to be integrated within at least two plates (28, 29, 30) that are disposed one above the other.

11. Sealing tool according to one of the preceding claims, characterized in that said centrifugal separator (26a, 26b) comprises a cylindrical insert (35, 35') built into said tool lower part (25) and having a conical separation section (36, 36`) for said particle-laden gas flow (G).

12. Packaging machine, which is present in the form of a tray sealer (15) or in the form of a deep-drawing packaging machine (1), comprising at least one sealing tool (24) according to one of the preceding claims.

13. Method for separating a particle-laden gas flow (G) at a sealing tool (24) of a packaging machine, characterized in that said particle-laden gas flow (G) is separated by way of a centrifugal separator (26a, 26b) provided at a tool lower part (25) of said sealing tool (24).

14. Method according to claim 13, characterized in that said centrifugal separator (26a, 26b) is operated with a pump (40) that can be employed at said tool lower part (25) for atmosphere exchange.

15. Method according to claim 13 or 14, characterized in that said centrifugal separator (26a, 26b) is operated with a pressure vessel that can be employed at said tool lower part (25) for atmosphere exchange.