EP3733528B1 - Sealing tool and method for sealing trays - Google Patents

Description

The invention relates to a sealing tool according to the preamble of claim 1 and to a method for evacuating and/or gassing and sealing packaging trays.

Tray sealing machines and corresponding sealing tools are e.g. B, from the DE 10 2012 005 891 A1 known. They usually include an upper tool and a lower tool. In order to be able to use them to evacuate and/or gas packaging trays before they are closed by sealing on a cover film, conventional sealing tools have channels that are configured for sucking off and/or introducing gas. Since the cover film, which is initially in the form of a web of film, is clamped between the upper tool and the lower tool in this process, existing sealing tools sometimes have branched channels that are in any case difficult to access, so that both the interior of the packaging to be sealed and the chamber surrounding it can be can be evacuated and/or gassed to the desired degree.

From the WO 2011 092 103 A1 a tool is also known which has a so-called clamping frame. This is set up to first clamp the cover film to the upper part of the tool. In the WO 2011 092 103 A1 channels are provided within this clamping frame, which serve to gas the packaging tray to be closed.

Such conventional tools have the disadvantage that they are complicated to manufacture because of the channels described. In tray sealing machines that process food in particular, there is also the fact that the channels make it difficult to clean the machine and the tool, which has to be carried out regularly. Both increase the costs of purchasing and operating the tool.

From the U.S. 2011 0 072 764 A1 a device for sealing containers is known, comprising a sealer. According to one exemplary embodiment, the latter has a gas plate which is arranged between a sealing module body and a carrier. The gas plate is machined from one side to add channels and can be fixed to the beam with this side. Other devices for packaging products are in EP 1 842 776 A2 as in WO 2018 193 382 A1 disclosed.

It is an object of the invention to specify an improved sealing tool and an improved method for evacuating and/or gassing and sealing packaging trays, which enables simplified manufacture and cleaning of the tool and thus causes lower costs.

This object is achieved according to the invention by a sealing tool having the features of claim 1 or by a method having the features of claim 7.

The invention provides a sealing tool for a tray sealing machine. The sealing tool includes an upper tool and a lower tool having a main body having a tray cavity for receiving at least a portion of a tray to be sealed, and a tray support, with a gas passage extending through the tray support. The sealing tool is characterized in that the tray carrier comprises a first plate with a first pressing surface and a second plate with a second pressing surface, and the first plate has a first indentation which extends from the first pressing surface, the first indentation having at least one Section of the gas channel forms when the first plate and the second plate are pressed together at the first and second pressing surface.

A protrusion is provided on the second pressing surface and is configured to extend into the recess when pressed. This can make it possible to influence the flow direction of the gas in the gas channel in a targeted manner, for example in order to give the gas flow a specific direction. It is conceivable that the recess forms a funnel-shaped end section of the gas channel together with the projection when it is pressed on. The projection can be made in one piece with the second plate.

By providing a first and a second plate, the tray support can be divided along a parting surface which can be of any shape. The parting surface can preferably be a plane to which the closing direction of the sealing tool, in particular the direction of movement in which the upper tool and the lower tool move toward one another, runs perpendicularly.

A depth of the depression, which can be defined perpendicularly to the first pressing surface, can in particular be smaller than the extension of the depression parallel to the first pressing surface. Said depth can preferably be smaller than a thickness of the first plate, wherein the thickness of the first plate can also be defined perpendicular to the pressing surface.

A section of the gas channel can be formed, for example, by the second pressing surface covering an opening surface of the depression, which can run parallel to the first pressing surface. The configuration described above can facilitate the manufacture and in particular the cleaning of the shell support since, after separating the first plate from the second plate, the section of the gas channel formed in part by the depression is more accessible.

It is advantageous if the main body and the second plate are connected to one another immovably relative to one another during operation of the sealing tool. In this way, both can be moved with one and the same drive, which reduces the drive and control effort. It is particularly favorable if the first plate is connected to the second plate during operation of the sealing tool, so that the first and second plates are arranged immovably with respect to one another. This can further reduce the drive and control effort.

Tool-free fastening devices can be provided for the connection of the second panel to the main body and/or the connection of the first panel to the second panel. In particular, tool-free fastening devices can be provided which hold the main body, the second plate and the first plate immovably with respect to one another during operation of the sealing tool. Tool-free fastening devices can significantly reduce assembly and disassembly work. Cleaning can also be simplified.

The end portion, which can also be designed in any shape other than a funnel shape, can be provided, for example, as an inlet or outlet for a gas. A section which opens directly into a sealing chamber of the sealing tool can be regarded as the end section of the gas channel. A funnel-shaped shape of the end section of the gas channel can enable a targeted collection and/or distribution of a gas flow. This can e.g. B. the flow rate of the gas can be influenced.

In a further variant, the second plate can have a second indentation which extends from the second pressing surface, the first and the second indentation together forming a section of the gas channel in the pressed state. This section can be an end section or another section of the gas channel. With regard to the definition of the term "indentation", the explanations given above with regard to the first indentation apply correspondingly to the second indentation.

The invention also relates to a method of evacuating and/or gassing and sealing packaging trays by a sealing tool including a lower tool having a main body and a tray support comprising a first panel and a second panel, and an upper tool. The method includes inserting a packaging tray into the second plate of the tray carrier, the second plate having a second pressing surface, closing the sealing tool by pressing the upper tool and the lower tool together, pressing the second plate of the tray carrier against the first plate so that the second pressing surface and a first pressing surface provided on the first plate abut each other, thereby forming at least a portion of a gas channel for evacuating and/or gassing the packaging tray, evacuating and/or gassing the packaging tray, and sealing the tray with a cover film. The pressing of the two plates and the associated formation of the gas channel can also enable the use of a shell carrier that is easier to manufacture and easier to clean due to the division into a first and a second plate.

The second plate is pressed against the first plate in such a way that a projection provided on the second pressing surface extends into the first depression in the pressed state.

In a further variant, the method can include clamping the cover film to the upper tool by the first plate before closing the sealing tool. As a result, the use of a separate clamping frame for clamping the cover film to the upper tool can be dispensed with, which means that the number of parts can remain constant compared to conventional sealing tools or methods with a one-piece tray carrier and clamping frame.

It is conceivable that the first plate is pressed against the second plate while the sealing tool is being closed. This can make it possible to carry out the pressing of the first plate to the second plate and the closing of the sealing die at the same time, thus saving time, which can increase the efficiency of the process or the tray sealing machine.

In a further variant, the first plate can be pressed onto the second plate before the sealing tool is closed. This can be particularly advantageous in embodiments in which the cover film is not to be clamped to the upper tool by the first plate. It is particularly conceivable here that, as already mentioned above, the first panel is connected to the second panel in such a way that during the Operation of the sealing tool are arranged immovably to each other. Furthermore, it is conceivable that, in addition, the main body of the lower tool is immovably connected to the first plate and the second plate during operation.

Figur 1

zeigt eine schematische Perspektivansicht einer Verpackungsmaschine.

Figur 2

zeigt eine schematische Perspektivansicht eines Siegelwerkzeugs in einem geöffneten Zustand.

Figur 3

zeigt eine schematische Perspektivansicht eines Siegelwerkzeugs in einem geschlossenen Zustand.

Figur 4

zeigt eine schematische Perspektivansicht eines Schalenträgers, der eine erste und eine zweite Platte umfasst, die im aneinandergedrückten Zustand zu sehen sind.

Figur 5

zeigt eine schematische Perspektivansicht der ersten Platte des Schalenträgers mit Blick auf die erste Andrückfläche.

Figur 6

zeigt eine schematische Perspektivansicht der zweiten Platte des Schalenträgers mit Blick auf die zweite Andrückfläche.

Figur 7

zeigt eine schematische Schnittansicht aus der in Figur 4 mit VII-VII angedeuteten Perspektive.

The invention relates to a sealing tool and a method of the type described above. An advantageous exemplary embodiment is explained in more detail below with reference to drawings.

figure 1

shows a schematic perspective view of a packaging machine.

figure 2

shows a schematic perspective view of a sealing tool in an open state.

figure 3

shows a schematic perspective view of a sealing tool in a closed state.

figure 4

Figure 12 shows a schematic perspective view of a tray carrier comprising a first and a second plate seen pressed together.

figure 5

shows a schematic perspective view of the first plate of the shell support looking at the first pressing surface.

figure 6

shows a schematic perspective view of the second plate of the shell support looking at the second pressing surface.

figure 7

shows a schematic sectional view from FIG figure 4 with VII-VII indicated perspective.

1 shows an example of a packaging machine 1. This is a tray sealing machine. The packaging machine 1 can have a feed belt 7 . Furthermore, it can have a closing station 9 . Shells 8 that are filled but are still unsealed at this point in time can be conveyed to the closing station 9 by the feed belt 7 . The trays 8 can be transferred to the closing station 9 with a gripper device 11 and closed there with a cover film 5 (foil) fed from above, for example by sealing on the cover film 5. For this purpose, the closing station 9 can include a sealing tool 10, which later will be described in more detail. The packaging finished in this way can be transferred from the closing station 9 to a discharge belt 15 via the gripper device 11 .

After the cover film 5 has been sealed on, areas of the cover film 5 corresponding to the packaging or composite packaging can be cut out of the web of cover film 5 in the closing station 9 . A residual film lattice of the cover film 5 remains, which is wound up with a device 3 for winding up the film 5 .

In figure 2 the sealing tool 10 can be seen in a perspective view. As in the exemplary embodiment shown, the sealing tool 10 can comprise an upper tool 12 and a lower tool 13 . These can be moved towards one another in a closing direction S in order to close the sealing tool 10 in this way. As shown in the figure, the die 13 may include a main body 14 . This can be mounted, for example, on a hoist (not shown), which can be configured to the lower tool 13 in the Closing direction S on the upper tool 12 to move. The lower tool 13 can also have a shell carrier 16 (see figure 4 ) exhibit. As can be seen in the figure, this can be provided on that side of the main body 14 which faces the upper tool 12 .

The tray support 16 may include a first panel 17 and a second panel 18 . Even though the first plate is 17 in figure 2 shown closer to the upper tool 12 than to the other components of the lower tool 13, it (the first plate 17) is to be regarded as part of the lower tool 13 because of its function. A tray recess 19 may be provided in the main body 14 and may be configured to receive at least a portion of the tray 8 to be sealed.

The first plate 17 can have a first pressing surface 20 (see figure 5 ) exhibit. The second plate 18 can have a second pressing surface 21 . The first plate 17 and the second plate 18 can be pressed against one another with the first pressing surface 20 and the second pressing surface 21, as a result of which the shell support 16 can be formed. This is explained below with reference to the Figures 4-6 be explained in more detail.

In figure 2 fastening devices 22 can be seen. As shown in the present exemplary embodiment, these can be configured to connect the second plate 18 to the main body 14 in such a way that the main body 14 and the second plate 18 are arranged immovably relative to one another during operation of the sealing tool 10 . Those skilled in the art will recognize that in embodiments other than the one shown, the fasteners 22 may be configured to also connect the first panel 17 to the main body 14 and the second panel 18 such that the first and second panels 17, 18 and the main body 14 are connected to one another in such a way that they are arranged immovably relative to one another during operation of the sealing tool 10 . In figure 3 the sealing tool 10 is shown in a closed state.

In figure 4 1, the tray carrier 16 is shown in perspective as a separate assembly containing the first panel 17 and the second panel 18. The shell carrier 16 can have shell openings 23 . These can, for example together with the shell depressions 19 in the main body of the die, form a lower part of a sealing chamber. Furthermore, the shell carrier 16 can have a carrying edge 24 . Such can preferably be provided around one of the shell openings 23 in each case. For inserting the shells 8 in the shell carrier 16 provided on the shell 8 flange on the Carrying edge 24 are placed. The support frame 24 can serve as a counter bearing for a sealing plate. As later with reference to figure 7 will be explained in more detail, the shell carrier 16 can have gassing and/or evacuation openings 25 (see figure 7 ) exhibit.

In figure 5 the first plate is shown in perspective. Compared to the representation in figure 4 the first plate 17 is rotated through 180° about an axis which runs parallel to the longer side of the shell carrier 16 . As a result, the first pressing surface 20 becomes visible. A first depression 26 which can be provided in the first plate 17 can also now be seen. In particular, it can extend from the first pressing surface 20, preferably in a direction perpendicular to the first pressing surface. In addition, a groove 27 can be provided in the first pressing surface, in which a seal can be placed.

Different types of first depressions 26 can be provided, which have different shapes. As in the present exemplary embodiment, a first evacuation recess 26a can be provided, for example. In addition, a first gassing depression 26b can be provided. As the name already indicates, the former can be used in the in figure 4 shown state of the shell carrier 16 form a section of an evacuation channel, while the latter in FIG figure 4 shown state of the shell carrier 16 can form a portion of a gassing channel.

In figure 6 the second plate 18 is shown. Opposite to figure 4 the missing first plate 17 gives a view of the second pressing surface 21 . As in figure 6 shown, a projection 28 can be provided on the second pressing surface 21 . This can be configured to be in the in figure 4 shown state of the shell carrier 16 in the first recess, in particular in the first gassing recess 26b to extend into it. Furthermore, a second depression 29 can be provided, which can extend from the second pressing surface 21 . It can also be seen that the second plate 18 can have evacuation holes 30 . These can be set up to figure 4 State shown to connect the first recess 26 with the lower part of the sealing chamber. In particular, it can be prevented that the shell 8 accommodated in the shell carrier 16 is undesirably deformed during evacuation.

In figure 7 FIG. 14 is a sectional view of the tray carrier 16 in FIG figure 4 shown condition. It can now be seen that the first depression 26 can form a section 31 of a gas channel 32 when the first plate 17 and the second plate 18 are pressed against one another on the first and second pressing surfaces 20, 21, respectively. As in the present exemplary embodiment, the section 31 can be an end section 31 of the gas channel 32 . Through the first depression

26, however, any section of the gas channel can also be formed. In particular, the end section 31 can be an inlet or an outlet through which gas can be introduced into or discharged from the gas channel 32 . Even if with reference to figure 7 the facts were illustrated using the first gassing depression 26b, a person skilled in the art will recognize that the explanations can also be transferred to the first evacuation depression 26a.

Claims (9)

1. Sealing tool (10) for a tray sealing machine (1), comprising:

   an upper tool (12),

   a lower tool (13) with a main body (14), which has a tray depression (19) for receiving at least a part of a tray (8) to be sealed, and with a tray carrier (16), wherein a gas channel (32) runs through said tray carrier (16),

   wherein said tray carrier (16) comprises a first plate (17) with a first pressing surface (20) and a second plate (18) with a second pressing surface (21) and said first plate (17) has a first depression (26) extending from said first pressing surface (20), wherein said first depression (26) forms at least a section (31) of said gas channel (32) when said first plate (17) and said second plate (18) are pressed against each other at said first and the second pressing surface (20, 21), respectively,

   characterized in that a protrusion (28) is provided on said second pressing surface (21) and, in the pressed-on state, said protrusion (28) is configured to extend into said first depression (26).
2. Sealing tool according to claim 1, wherein said main body (14) and said second plate (18) are connected to each other in an unmovable manner during the operation of said sealing tool (20).
3. Sealing tool according to one of the preceding claims, wherein said first plate (17) is connected to said second plate (18) during operation of said sealing tool (10), so that said first and said second plate (17, 18) are arranged unmovable relative to each other.
4. Sealing tool according to one of the preceding claims, wherein, in the pressed-on state, said first depression (26) together with said protrusion (28) forms a funnel-shaped end section (31) of said gas channel (32).
5. Sealing tool according to one of the preceding claims, wherein said second plate (18) comprises a second depression (29) extending from said second pressing surface (21), wherein, in the pressed-on state, said first and said second depression (26, 29) together form a section of said gas channel (32).
6. Method for evacuating and/or gas-flushing and sealing packaging trays (8) by a sealing tool (10), which contains a lower tool (13) with a main body (14) and a tray carrier (16), which comprises a first plate (17) and a second plate (18), as well as an upper tool (12), comprising:

   inserting a packaging tray (8) into said second plate (18) of said tray carrier (16), wherein said second plate (18) comprises a second pressing surface (21),

   closing said sealing tool (10) by pressing said upper tool (12) and said lower tool (13) against each other,

   pressing said second plate (18) of said tray carrier (16) against said first plate (17), so that said second pressing surface (21) and a first pressing surface (20) provided on said first plate (17) bear against each other, said first plate (17) having a first depression (26) extending from said first pressing surface (20), wherein said first depression (26) forms at least a section (31) of a gas channel (32) for evacuating and/or gas-flushing said packaging tray (8) when said first plate (17) and said second plate (18) are pressed against each other,

   evacuating and/or gas-flushing said packaging tray (8),

   sealing said tray (8) with a top film (5)

   characterized in that said second plate (18) is pressed against said first plate (17) in such a way that a protrusion (28) provided on the second pressing surface (21) extends into said first depression (26) in the pressed-on state.
7. Method according to claim 6, furthermore comprising clamping said top film (5) onto said upper tool (12) by said first plate (17) before closing said sealing tool (10).
8. Method according to claim 6 or 7, wherein pressing said first plate (17) against said second plate (18) occurs while the sealing tool (10) closes.
9. Method according to claim 6 or 7, wherein pressing said first plate (17) against said second plate (18) occurs before said sealing tool (10) is closed.

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