WO2021110795A1

WO2021110795A1 - Thermoforming packaging machine, method and packaging material

Info

Publication number: WO2021110795A1
Application number: PCT/EP2020/084373
Authority: WO
Inventors: Stefan Löffler; Harald GEHRKE
Original assignee: Multivac Sepp Haggenmüller Se & Co. Kg
Priority date: 2019-12-04
Filing date: 2020-12-03
Publication date: 2021-06-10
Also published as: DE102019218900A1; EP4069590A1

Abstract

The invention relates to a thermoforming packaging machine (1) for creating packaging materials (12) from a first film (8) and a second film (10), wherein the first and the second film (8, 10) are each conveyed, preferably in a clocked manner, through the thermoforming machine (1) along a conveying path (R1, R2). The thermoforming packaging machine (1) comprises a sealing station (3) which is configured to seal the second film (10) to the first film (8) in a sealing region (31), a film cutting station (22) which is designed to make at least two cuts (26) in the second film (10) on the conveying path (R2) upstream of the sealing station (3), and a presealing station (23) which is designed to seal a presealing region (27) of the second film (10) at least partially onto the first film (8) on the conveying path (R2) upstream of the sealing station (2), the cuts (26) being arranged in the presealing region (27).

Description

Thermoforming packaging machine, process and packaging

The invention relates to a deep-drawing packaging machine for producing packaging from a first and a second film, to a method for producing packaging from a first film and a second film, and to packaging produced by such a method.

From US 2019 177 016 A1 a package is known that can be produced from a first and a second film. In order to facilitate the opening of such packages, means for facilitating the initiation of tears are proposed, for example notches, tears, slits or weaknesses in the material. However, these are only inserted into both foils after the foils have been welded together. From WO 2015 075 420 A1 a package with an opening aid is known which is made from a single film.

In the case of some packaging, it can be advantageous if part of the packaging, for example a tray, can remain intact after opening. This is especially true if parts of the contents of the packaging can still be stored in it after opening. In contrast, in the case of the packaging described in the above-mentioned documents, all foils from which the respective packaging was made are torn, i.e. none of them remain intact.

Accordingly, it is an object of the invention to provide a packaging, and in particular a machine and a method for its production, which can be easily opened without all of the components of the packaging being torn open in the process.

This object is achieved by a thermoforming packaging machine according to claim 1, by a method according to claim 7 and by a packaging according to claim 14.

The invention provides a thermoforming packaging machine for producing packaging from a first film and a second film, the first and second films being conveyed through the thermoforming packaging machine, preferably in cycles, each along a conveying path. The thermoforming packaging machine comprises a sealing station which is configured to seal the second film to the first film in a sealing area and a film cutting station which is set up to make at least two incisions in the second film on the conveying path in front of the sealing station. The thermoforming packaging machine furthermore comprises a presealing station which is set up to provide a presealing area at least partially to seal the second film on the conveying path in front of the sealing station to the first film, the incisions being arranged in the presealing area.

By making the cuts on the conveying path in front of the sealing station, it can be ensured that only the second film is cut. Incisions made inadvertently into the first film can thereby be avoided, which can reduce the risk of the first film tearing when the second film is torn open. The second film can be guided on the second conveying path by a chain conveyor. This can lead the second film into the presealing station and preferably end there. Alternatively, the chain conveyor can guide the second film into the sealing station, preferably through the presealing station.

So far, incisions made in a film before the sealing process have been avoided because they can lead to problems if the atmosphere prevailing in the packaging is to be changed during sealing, in particular by creating a vacuum or by filling with an exchange gas. In such processes, gas-tight sealed chambers are created by placing the respective foils on components of a sealing tool. This can be made more difficult by cuts made in the film before the sealing process. The pre-sealing station or the sealing of the second film carried out by it in a pre-sealing area, in which the incisions are also arranged, can avoid the problems mentioned, whereby the cutting of the second film on the conveying path before the sealing station can only be made possible.

For example, the sealing station, in which the packaging can also be evacuated and / or gas exchanged, can be configured in such a way that when the second film is applied to a sealing tool or to a part of the same, an area surrounding the incisions opposite the remaining space is sealed between the first and second films. For this purpose, a device can be provided in particular on a partial tool, preferably an upper tool, of the sealing station, which interacts with the presealing when the second film is applied, so that an area surrounding the incisions is sealed against the remaining space between the first and second film. This device can be heat insulated. This can prevent any undesired additional sealing from taking place.

An area on the second film in which the incisions are arranged can be regarded as the pre-sealing area. Furthermore, an area can be regarded as a pre-sealing area in which seals or sealing seams are arranged which are produced by the pre-sealing station be generated. Such seals or sealing seams produced by the presealing station can extend over the entire presealing area or only over parts of it. In particular, those parts of the presealing area in which the incisions are arranged can remain free of seals. It is also conceivable that seals produced by the pre-sealing station overlap with partial sections of the incisions.

It is advantageous if the presealing station is set up to seal an at least partially U-shaped partial area of the presealing area of the second film to the first film. Such a shape of the presealing area has proven to be particularly favorable in order to enable evacuation or filling of the packaging with replacement gas when the second film has been cut.

The incisions can be slits, for example, which preferably have a length between 10 mm and 30 mm. This can create a flap that can be easily gripped without the need for an unnecessarily large amount of film.

It is advantageous if the sealing area and the presealing area together form a closed curve. Such a closed curve can in particular run around a depression formed in the first film. As a result, the interior of the packaging can be enclosed in a gas-tight manner with respect to the surroundings of the packaging.

It can be provided that the sealing area and the presealing area partially overlap. On the one hand, this ensures that the contents of the packaging are actually shielded from the environment in a gas-tight manner. On the other hand, it can be provided that a sealing seam between the first and the second film can withstand higher tear forces at the overlapping points than sealing seams in non-overlapping areas. As a result, the course of the tear or the tears when the packaging is torn can be influenced in a targeted manner. The sealing area and the presealing area can be regarded as partially overlapping if at least one of the areas does not completely overlap with the other, i.e. H. if only a part of the sealing area overlaps with a part of the presealing area, if a part of the presealing area overlaps with the complete sealing area and / or if a part of the sealing area overlaps with the complete presealing area.

The sealing area can be a non-closed curve. In this way, an area in which there is no seal (but possibly a pre-seal) can be provided in a targeted manner, in which the first film can be detached from the second film more easily. This allows a place and / or a direction of tearing can be controlled in a targeted manner. Additionally or alternatively, the pre-sealing area can be a non-closed curve.

The thermoforming packaging machine can furthermore have a labeling station which can be configured to apply a label to the second film. The labeling station can be arranged on the conveying path of the second film before or after the film cutting station. The label can preferably be applied between the incisions. Such a label can improve both the stability and, in particular through suitable printing, the visibility of a tab delimited by the incisions.

In addition to the thermoforming packaging machine described above, a method is also provided for, preferably cyclically, producing packaging from a first film and a second film by means of a thermoforming packaging machine, the second film being sealed to the first film. The method comprises making two incisions in the second film by a film cutting station, at least partially sealing a presealing area of the second film to the first film by a presealing station, wherein the incisions are arranged in the presealing area, and sealing the second film to the first film in a sealing area by a sealing station after the incisions have been made and the second film has been sealed to the first film in the presealing area.

As already mentioned, by making the incisions before the foils are sealed together in the sealing station, it can be ensured that only the second foil is incised. Incisions made inadvertently into the first film can thereby be avoided, which can reduce the risk of the first film tearing when the second film is torn open. The second film can be guided on the second conveying path by a chain conveyor. This can lead the second film into the presealing station and preferably end there. Alternatively, the chain conveyor can guide the second film into the sealing station, preferably through the presealing station.

The pre-sealing station or the sealing of the second film carried out by it in a pre-sealing area in which the incisions are also arranged can avoid the problems already explained above when producing packaging from films which have been incised prior to sealing. As a result, the cutting of the second film can only be made possible before sealing in the sealing station. In addition to the sealing in the sealing area, especially shortly before it, the packaging can be evacuated and / or gas exchanged in the sealing station Part of the same, a region surrounding the incisions is sealed against the remaining space between the first and the second film. For this purpose, a device can be provided in particular on a partial tool, preferably an upper tool, of the sealing station, which interacts with the presealing when the second film is applied, so that an area surrounding the incisions is sealed against the remaining space between the first and second film. This device can be heat insulated. This can prevent any undesired additional sealing from taking place.

An area on the second film in which the incisions are arranged can be regarded as the pre-sealing area. Furthermore, an area can be regarded as a presealing area in which seals or sealing seams (used synonymously in the following) are arranged, which are produced by the presealing station. Such seals or sealing seams produced by the presealing station can extend over the entire presealing area or only over parts of it. In particular, those parts of the presealing area in which the incisions are arranged can remain free of seals. It is also conceivable that seals produced by the pre-sealing station overlap with partial sections of the incisions.

It can be useful if the sealing area and the presealing area partially overlap. On the one hand, this ensures that the contents of the packaging are actually shielded from the environment in a gas-tight manner. On the other hand, it can be provided that a sealing seam between the first and the second film can withstand higher tear forces at the overlapping points than sealing seams in non-overlapping areas. As a result, the course of the tear or the tears when the packaging is torn can be influenced in a targeted manner.

The sealing area can be, for example, an unclosed curve. In this way, an area in which there is no seal (but possibly a pre-seal) can be targeted, be provided in which the first film can be more easily detached from the second film. As a result, a location and / or a direction of the tearing can be controlled in a targeted manner. As an alternative or in addition to this, the pre-sealing area can be a non-closed curve.

It is advantageous if the first film and / or the second film is or are monoaxially stretched. In particular, by a suitable monoaxial stretching direction of the second film, the tear behavior, z. B. the direction of the crack can be specifically influenced. A suitably selected stretching direction of the first film can also be advantageous, since undesired tearing in a certain direction, preferably a direction in which the first film is stressed when the second film is torn, can be made more difficult.

The first film and / or the second film can, for example, have a thickness between 20 and 300 μm, preferably between 30 and 150 μm, particularly preferably between 40 and 100 μm. The thickness of the first film and the thickness of the second film can be different.

The method can advantageously comprise forming a recess in the first film. For example, after the second film has been sealed to the first film, the depression can be arranged opposite the presealing area. This makes it easier to grasp a tab provided through the incisions. The depression can in particular be formed in the lower film in addition to a packaging trough which can be provided for receiving a product to be packaged.

It is advantageous if the method further comprises applying a label to the second film, preferably between the incisions. The label can be applied before or after the incisions are made in the second film. It can be particularly favorable if the method further comprises printing the label. Such a label can improve both the stability and, in particular through suitable printing, the visibility of a tab delimited by the incisions.

Furthermore, a package is disclosed which has been produced by a method of the type described above. It can be particularly advantageous if a pre-seal in the pre-sealed area has a lower tear force than a seal in the sealed area. As a result, the risk of the packaging tearing open in places not intended for this purpose can be reduced. The invention relates to a deep-drawing packaging machine, a method and packaging of the type described above. In the following, a preferred exemplary embodiment is explained in more detail with reference to drawings.

FIG. 1 shows a schematic side view of a thermoforming packaging machine.

FIG. 2 shows a schematic perspective view of a finished package which can be produced by a thermoforming packaging machine according to the invention and a method according to the invention.

FIG. 3A shows a schematic top view of the packaging from FIG. 2, a presealing area being identified.

FIG. 3B shows a schematic top view of the packaging from FIG. 2, a sealing area being identified.

FIG. 4 shows a schematic top view of the packaging from FIG. 2, both the sealing area and the presealing area being identified.

FIG. 1 shows a schematic view of a packaging machine 1. As in the present example, it can be a deep-drawing packaging machine. However, the packaging machine can also be a tray sealing machine (traysealer). The packaging machine 1 can have a forming station 2, a sealing station 3, a transverse cutting device 4 and a longitudinal cutting device 5, which can be arranged on a machine frame 6 in this order. On the input side, on the machine frame 6, there can be a feed roller 7, from which a first film 8, in the present example a lower film 8, can be pulled off. The lower film can be conveyed through the packaging machine along a conveying path R1.

In the area of the sealing station 3, a material reservoir 9 can be provided, from which a second film 10, optionally already provided with a pre-print or primary print, can be pulled off, which can later serve as a cover or top film. The second film 10 can be conveyed through the packaging machine 1 along a conveying path R2. For example, the second film 10 can be conveyed by a chain conveyor (not shown) along the conveying path R2. A film cutting station 22 can be arranged along the conveying path R2 of the second film 10 (upper film). As in the present embodiment, can they can be arranged along the conveying path R2 in front of the sealing station 3. The film cutting station 22 can be set up to make at least two incisions (see FIG. 3A) in the upper film 10 on the conveying path R2 in front of the sealing station 3.

Furthermore, the packaging machine 1 can have a feed device 11 or a film drive 11. As in the illustrated embodiment, the film drive 11 shown schematically can be a motor which can drive transport chains or clamp chains that are arranged on both sides of the lower film 8 and grip it. Since the upper film 10 is sealed to the lower film 8 in the sealing station 3, the upper film 10 can also participate in the transport of the lower film 8, so that the film drive 11 can drive not only the lower film 8 but also the upper film 10. Correspondingly, the conveying path R1 of the lower film 8 and the conveying path R2 of the upper film 10 can unite. For each main work cycle of the packaging machine 1, both plastic films 8, 10 can be transported further along the conveying path R1, R2 by a predetermined feed length.

The packaging machine 1 can comprise a presealing station 23. It can be arranged on the conveying path R2 of the second film 10 and / or on the conveying path R1 of the first film 8 in front of the sealing station 3. The presealing station 23 can be set up to at least partially seal a presealing area (see FIG. 3A) of the second film 10 on the conveying path R2 in front of the sealing station 3 to the first film 8.

As in the illustrated embodiment, the forming station 2 can be designed as a deep-drawing station, in which packaging trays 14 can be formed in the lower film 8 by deep-drawing. The forming station 2 can be designed in such a way that a plurality of packaging trays 14 can be formed next to one another in the direction perpendicular to the production direction R, ie. H. several tracks of packaging trays 14. In addition, the forming station 2 can be configured in such a way that several trays in the production direction R in one work cycle

14 can be formed one behind the other, d. H. several rows of packaging trays.

On the conveying path R1 of the first film 8 behind the forming station 2, an insertion section

15, in which the packaging trays 14 formed in the lower film 8 can be filled with a product 16. The sealing station 3 can have a closable chamber 17 in which the atmosphere in the troughs 14 can be replaced prior to sealing, for example by gas purging with an exchange gas or with a gas mixture. Alternatively, the packaging trays 14 in the sealing station 3 can also simply be evacuated. The cross-cutting device 4 can be designed as a punch, which can cut through the lower film 8 and the cover film 10 in a direction transverse to the conveying path R1, R2 between adjacent packaging trays. The transverse cutting device 4 can operate in such a way that the film 8 is not severed over the entire width, but rather is not severed in at least one edge area. This can enable a controlled further transport through the feed device 11.

In the embodiment shown, the longitudinal cutting device 5 can be designed as a knife arrangement with which the lower film 8 and the cover film 10 can be severed between adjacent troughs 14 and at the lateral edge of the lower film 8, so that individual packagings 12 can ultimately be present behind the longitudinal cutting device 5 . On the output side, a discharge device 13, for example in the form of a conveyor belt, can be provided on the packaging machine 1, with which finished, separated packagings 12 can be transported away.

The packaging machine 1 can also have a machine control 18. It can be configured to control and monitor the processes running in the packaging machine 1. A display device 19 with operating elements 20 can be used for visualization or for influencing the process sequences in the packaging machine 1 for or by an operator.

The general mode of operation of the packaging machine 1 is briefly described below.

The lower film 8 can be pulled off the feed roller 7 and transported into the forming station 2 by the feed device or the film drive 11. In the forming station 2, packaging trays 14 can be formed in the film 8 by deep drawing. The troughs 14 can be transported together with the surrounding area of the film 8 in a main work cycle to the insertion section 15, in which they can be filled with product 16.

The filled troughs 14, together with the region of the film 8 surrounding them, can then be transported further into the sealing station 3 by the feed device 11 in a further main work cycle. After a sealing process on the film 8, the upper film 10 can be transported further with the advancing movement of the film 8. The upper film 10 can be pulled off the material storage device 9. By sealing the top film 10 onto the troughs 14, sealed packagings 12 can be created which are in the subsequent cutting devices 4 and 5 can be isolated and transported out of the packaging machine 1 by means of the discharge device 13.

FIG. 1 also shows a labeling station 21 which is integrated into the packaging machine 1 and can be arranged along the conveying path R2 of the upper film 10 in front of the sealing station 3. This labeling station 21 can be passed through by the upper film 10 and can be configured to print variable information or identifications, preferably in a precise spatial relationship to the pre-print, on the upper film 10 on this upper film. Alternatively or additionally, it can be set up to apply labels 24 (see FIG. 2) to the upper film 10 and preferably also to print them. The printing can take place before and / or after the labels 24 are applied. The labeling station 21 can be arranged on the conveying path R2 of the second film 10 in front of the film cutting station 22, as shown in the present exemplary embodiment. Alternatively, the labeling station 21 can be arranged on the conveying path R2 of the second film 10 after the film cutting station 22.

FIG. 2 is a schematic perspective view of a finished package 12. The second film 10 (upper film) can only be seen to a limited extent, since it is transparent in the present exemplary embodiment, as is often also the case in real applications. A filled product is not shown for the sake of clarity. As in the present exemplary embodiment, a label 24 can be applied to the upper film 10. A recess 25 can be formed in the lower film 8. The depression 25 can in particular be formed in the lower film 8 in addition to the depression 14.

In Figure 3A, the packaging 12 from Figure 2 is shown in a schematic plan view. Two incisions 26 can be provided in the upper film 10. These are shown in the sense of a good recognizability and can be narrower in reality. In particular, the incisions 26 can be simple slots. A presealing area 27, which can be provided on the upper film 10, is identified by a first dashed line. The presealing area 27 can be arranged on the second film 10 (upper film) in such a way that the incisions 26 are arranged completely in the presealing region 27.

The presealing station 23 can be set up to seal the upper film 10 to the lower film 8 in a partial region 28 of the presealing region 27. The sub-area 28 is identified in Figure 3A by a second dashed line. It can be arranged completely in the presealing area 27. The incisions 26 can extend at least partially outside of the sub-area 28. It is conceivable that the sub-area 28 is partially cut 26 overlaps. A presealing 29 or presealing seam 29 (can be used synonymously) can be produced in the sub-area 28 by the presealing station 23. This is shown in Figure 3A as a hatched area. The sub-area 28 and / or the pre-sealing seam 29 can be designed essentially U-shaped. Two parallel legs 30 of the U can extend parallel to the incisions 26.

FIG. 3B shows the packaging 12 from the same perspective as FIG. 3A. However, the pre-sealing area 27, the sub-area 28 and the pre-sealing seam 29 are not shown. A sealing area 31 can be seen, which can be arranged on the upper film 10. As shown in the exemplary embodiment, the incisions 26 can extend completely outside of the sealing area 31.

The sealing station 3 can be set up to seal the second film 10 (upper film) in the sealing area 31 to the first film 8 (lower film). A seal 32 or a sealed seam 32 (can be used synonymously) can be produced. This is shown in Figure 3B as a hatched area. The sealing area 31 can be arranged on the upper film 10 in such a way that it is arranged circumferentially around the trough 14 in the finished packaging 12. The sealing area 31 and / or the seal 32 can be a non-closed curve. The sealing area 31 can form a gap 34. The gap 34 can be provided between two end regions 33 of the sealing region 31. The incisions 26 can be oriented towards the gap 34.

FIG. 3B is primarily to be viewed as an auxiliary view for better understanding. While the configuration shown in FIG. 3B is actually present after the presealing station 23, the configuration from FIG. 3B will generally not occur in the normal production sequence. Rather, the configuration from FIG. 3A is added to the configuration shown in FIG. 4 in the course of processing in the sealing station 3.

FIG. 4 shows a view of the packaging 12 from the same perspective as in FIGS. 3A and 3B. However, FIG. 4 shows a state of the packaging 12 after the first and second films 8, 10 have been processed both by the presealing station 23 and by the sealing station 3. Consequently, both the preseal 29 and the seal 32 can be seen. As shown in the present exemplary embodiment, they can together form a closed curve. The preseal 29 and the seal 32 can, as shown, overlap in two overlapping areas 35. It should be clear that only one overlap area 35 or more than two overlap areas are also conceivable. However, it is particularly advantageous if two overlapping areas 35 are provided. These can preferably each be arranged next to the gap 34 of the sealing area 31. In the overlapping areas 35, the connection between the foils 8, 10 can be stronger than in the areas where only one seal 32 or only one pre-seal 29 is present. This makes it possible for the second film 10 to tear in the region of the gap 34. The location and the direction of a tear in the upper film 10 can therefore be influenced in a targeted manner.

In FIG. 4, the pre-sealing area 27, its sub-area 28 and the sealing area 31 are not shown again for the sake of better clarity. A person skilled in the art recognizes, however, that analogously to the overlap areas 35 between the preseal 29 and the seal 32, overlap areas between the preseal 27, in particular the partial area 28, and the seal area 32 can be provided.

Claims

Expectations

1. Thermoforming packaging machine (1) for producing packaging (12) from a first film (8) and a second film (10), the first and second films (8, 10), preferably intermittently, each along a conveying path (R1 , R2) are conveyed through the thermoforming packaging machine (1), the thermoforming packaging machine (1) comprising: a sealing station (3) which is configured to seal the second film (10) to the first film (8) in a sealing area (31) , a film cutting station (22) which is designed to make at least two incisions (26) in the second film (10) on the conveying path (R2) in front of the sealing station (3), and a presealing station (23) which is designed to do so to at least partially seal a presealing area (27) of the second film (10) on the conveying path (R2) in front of the sealing station (2) to the first film (8), the incisions (26) being arranged in the presealing area (27).

2. Thermoforming packaging machine according to claim 1, wherein the presealing station (23) is set up to seal an at least partially U-shaped portion (28) of the presealing region (27) of the second film (10) to the first film (8).

3. Thermoforming packaging machine according to claim 1 or 2, wherein the incisions (26) are slots (26) which preferably have a length between 10 mm and 30 mm.

4. Thermoforming packaging machine according to one of the preceding claims, wherein the sealing area (31) and the presealing area (27) together form a closed curve.

5. Thermoforming packaging machine according to one of the preceding claims, wherein the sealing area (31) and the presealing area (27) partially overlap.

6. Thermoforming packaging machine according to one of the preceding claims, wherein the thermoforming packaging machine (1) has a labeling station (21) which is configured to apply a label (24) to the second film (10), preferably between the incisions (26).

7. A method for, preferably in cycles, producing packaging (12) from a first film (8) and a second film (10) by a thermoforming packaging machine (1), the second film (10) being sealed to the first film (8) becomes, comprehensively, Making two incisions (26) in the second film (10) by means of a film cutting station

(22), at least partial sealing of a presealing area (27) of the second film (10) to the first film (8) by a presealing station (23), the incisions (26) being arranged in the presealing area (27),

Sealing the second film (10) to the first film (8) in a sealing area (31) by a sealing station (3) after the incisions (26) have been made and the second film (10) in the presealing area (27) to the first Foil (8) was sealed.

8. The method according to claim 7, wherein the sealing area (31) and the presealing area (27) together form a closed curve.

9. The method according to claim 7 or 8, wherein the sealing area (31) and the presealing area (27) partially overlap.

10. The method according to any one of claims 7 to 9, wherein the sealing area (31) is a non-closed curve.

11. The method according to any one of claims 7 to 10, wherein the first film (8) and / or the second film (10) is / are monoaxially stretched.

12. The method according to any one of claims 7 to 11, wherein the first film (8) and / or the second film (10) have a thickness between 20 and 300 μm, preferably between 30 and 150 μm, particularly preferably between 40-100 μm .

13. The method according to any one of claims 7 to 12, wherein the method further comprises applying a label (24) to the second film (10), preferably between the incisions (26)

14. Packaging (12) which has been produced by a method according to any one of claims 7 to 13.

15. Packaging according to claim 14, wherein a pre-seal (29) in the pre-sealing area (27) has a lower tear force than a seal (32) in the sealing area (31).