EP3552979B1 - Preparation of multilayer packages - Google Patents

Description

The invention relates to a packaging machine, in particular for food products, with several workstations arranged one behind the other along a transport direction for the production of multi-layer packs from a lower film, an upper film and at least one intermediate film, the lower film with the central film being a lower product layer and the upper film with the or a further central film encloses an upper product layer of a respective pack, the films each having a product area and laterally adjacent to the product area edge areas running parallel to the transport direction.

The invention also relates to a method for producing such multi-layer packs.

The invention also relates to uses of certain films in such a packaging machine and / or in such a method.

The invention also relates to a multi-layer pack which is produced or can be produced by such a packaging machine and / or which is obtained or obtainable by such a method.

The production of multi-layer packs, for example for packaging food products, is known in principle. In multi-layer packs, at least two products lie on top of one another, with two product layers lying directly on top of one another being separated from one another by a central film. The middle foils are also sometimes called intermediate foils or - just like the top one Foil of the pack - referred to as top foils. In the present disclosure, all of the films located between the lowest film (the lower film) and the uppermost film (the upper film) are each referred to as the middle film.

In such packs, film webs are used, each of which has a web width to which the packaging machine must be adapted. The edge areas of the foils are used to connect the foils to one another by sealing. In addition, the edge areas of the foils can be provided with perforations through which the product layers are accessible in order to evacuate the product layers and to fill them with a protective gas. Such a gas exchange is often preferred in practice, but in principle not mandatory. In some applications it is sufficient to simply evacuate the product layers before the final sealing. If gas exchange is desired, evacuation and gassing can take place one after the other, for example through the same perforations. Usually, however, different holes are used for evacuation and gassing. In general, it is therefore preferred in practice - especially for hygienic reasons - to carry out evacuation and gassing on different flow paths.For example, it is possible to simultaneously gass the product layers via one perforated edge area and evacuate them via the opposite edge area. Active evacuation can also be dispensed with if protective gas is introduced through one perforated edge area and exits through the opposite perforated edge area, that is to say the product layer in question is flushed with the protective gas, so to speak.

In practice, both the application of vacuum and / or gas and the final closing of the product layers usually take place in a single work station, which is referred to as the sealing station, since the closing of the product layers and thus the final closing of the multi-layer pack is carried out by sealing. This end seal surrounding the product areas, which is in the In practice, also referred to as a sealing seam, lies within the perforations of the edge areas, since the perforated sections of the edge areas are then separated - usually in a work station connected to the sealing station. Before or after this, the packs are usually provided with a label in practice.

In a typical packaging machine of the type in question here, the products forming the lower product layer are placed on the product area of the lower film that is fed to the machine on the input side. The central film is fed downstream of the product depositing point, thereby enclosing the lower product layer. In practice, the central film is often fixed to the lower film in order to ensure a correct relative position between the central film and the lower film during further transport in the packaging machine. This fixing is usually done by what is known as sealing, in which the middle film and the lower film are attached to one another by forming sealing points. Such a seal does not yet represent a gas-tight end seal, but rather serves - as mentioned - only to fix the two films to one another.

The products forming the upper product layer are then placed on the middle film, specifically at those points where the first product layer was previously placed. Further product layers and middle films can then be applied in order to produce multi-layer packs with more than two product layers lying one above the other.

Typically, such packaging machines are operated cyclically. In each cycle, the film webs are moved by one working length in the transport direction, the working length corresponding to the length measured in the transport direction of at least one pack. In practice, this working length, also referred to as the preferred or format length, is usually n times the length of a pack, possibly plus scrap between two immediately consecutive packs, where n is the number of packs following one another in the transport direction in a respective format.

After the single top product layer or the last of several top product layers have been applied, the top film is fed in so that the top or top product layer is also enclosed. The at least three film webs with the enclosed product layers then reach the sealing station already mentioned, in which the product layers are subjected to vacuum and / or gas through the perforations in the edge areas of the films and are finally sealed.

Depending on the respective working principle of the packaging machine, corresponding work stations are required for the individual work steps, which must be arranged one behind the other in the transport direction. Even when the pack to be produced has only two product layers and thus only a single central film, the necessary work steps can lead to a relatively complex structure of the packaging machine and, in particular, to a comparatively long machine length. This increases the costs and requires a comparatively large amount of space for the operator of the packaging machine.

It should also be taken into account here that at least the lower film often has to be reshaped in order to form shell-like lower packaging parts. To do this, the lower film must pass through a so-called deep-drawing station on the packaging machine. In some applications it is desirable to reshape the central film as well. This further increases the complexity and length of the processing machine. The effort increases even further if the packaging machine must also be able to perforate the or each central film in order to ensure the necessary access to a relevant product layer for evacuation and / or gassing.

With one off DE 10 2005 048 491 B4 known packaging machine, each central film is narrower than the lower film and than the upper film, so that the perforations of the lower film are not overlapped by the central film. This means that it is not necessary to punch holes in the middle foils. However, with such a concept it is difficult or impossible to fix the middle foils to a respective underlying foil. A comparatively simple sealing, as mentioned above, is not possible, since the middle foils each do not have a sufficiently wide edge area for this. In addition, all product layers must be evacuated and / or gassed via the perforations formed in the lower film. In many cases, advantageous individual treatment of the product layers during evacuation and / or gassing, in each case with direct access to the relevant product layer, is then not possible.

With an in DE 10 2011 010 601 B4 the packaging machine described, the evacuation and / or gassing takes place again exclusively via perforations in the lower film, with the edge regions of the middle films overlapping the edge regions and thus the perforations in the lower film. Here, a relatively large amount of effort is made to obtain direct access to the individual product layers. In particular, the middle foils are also perforated here, with the resulting openings each having to be provided with a seal in order to ensure a gas-tight passage through the respective foils involved.

Even with the off EP 2 788 259 B1 known packaging machine, the evacuation and / or gassing takes place through openings formed in the lower film. The process of sealing the individual product layers is divided into two individual sealing stations in order to be able to reshape the middle film. The central film must be provided with perforations if the product layer enclosed by the central film and the upper film is to be evacuated and / or gassed.

The object of the invention is to create a possibility of producing multi-layer packs as simply as possible, with the packaging machine used for this purpose in particular having the simplest possible structure and in particular the shortest possible machine length.

This object is achieved in each case by the features of the independent claims.

In the packaging machine according to the invention, a work station is a sealing station which is designed to apply vacuum and / or gas to the product layers through perforations in the edge areas of the upper film and the lower film and then to close them by sealing the films, the sealing station being a comprises the upper evacuation and / or gassing tool aligned with the perforation of the upper film and a lower evacuation and / or gassing tool aligned with the perforation of the lower film, a further work station being a sealing station located upstream of the sealing station, which is designed to attach the central film to seal the lower film to a seal located in the edge areas, and wherein the lower evacuation and / or gassing tool of the sealing station and a sealing tool of the sealing station serving to produce the seal on a common, parallel to the transport direction ve running working line.

The fact that the lower evacuation and / or gassing tool and the sealing tool are on a working line means that the packaging machine is designed to produce a seal during operation on overlapping edge areas of foils transported in the transport direction and to interact with a perforation, the sealing and the perforation in the same transverse position, ie on a common, parallel to the transport direction running line or within a strip running parallel to the transport direction, the width of which is not greater than the width of the edge areas.

This embodiment of the packaging machine according to the invention does not rule out a common or independent adjustability of the tools transversely to the transport direction, even for other applications.

In the method according to the invention, vacuum and / or gas are applied to the product layers through perforations in the edge areas of the upper film and the lower film and then closed by sealing the films, the application of vacuum and / or gas taking place, while the unperforated edge region of the The middle film and the perforated edge areas of the lower film and the upper film overlap one another, and the lower product layer is acted upon by the perforation of the lower film and the upper product layer is acted upon through the perforation of the upper film.

According to the invention, it was recognized that the edge area of the middle film can overlap the edge areas of the lower film and the upper film and does not need to be perforated if the sealing station of the packaging machine is designed to pass the upper product layer through the upper film and the lower product layer through the lower film to apply. A work station for perforating the central film can therefore be saved. The packaging machine can therefore be shortened by at least one working length and thus cycle length. A further simplification of the packaging machine results from the fact that no seals have to be formed on the perforations of the lower film and the upper film, since the perforation of the lower film only has to provide access to the lower product layer and the perforation of the upper film only has to provide access to the upper product layer.

The ability of the sealing station according to the invention to act on the superimposed foils both from below and from above for evacuation and / or gassing increases the expenditure for the construction and operation of the sealing station and the packaging machine overall, however, only apparently. This is because the lower tool and the upper tool can each be constructed and operated more simply than with a sealing station, which has to be able to act on several product layers lying one above the other from a single side. In addition, the sealing station according to the invention does not have to have any complex additional measures such as devices for producing hole seals, which are required when direct access to the individual product layers is required from a single side.

The overlapping of the edge areas of the lower film and the upper film by the unperforated edge regions of the central film also has the further advantage that the central film is simply fixed to the lower film by sealing, thus ensuring correct alignment of the central film and the lower film relative to one another. This makes it possible to use the edge area of the lower film both for evacuating and / or gassing the lower product layer and for sealing the middle film to the lower film.

The edge areas only need to be as wide as is necessary either for the perforation or the sealing if, according to the packaging machine according to the invention, the lower evacuation and / or gassing tool of the sealing station and the sealing tool of the sealing station are aligned with each other transversely to the transport direction, ie lie on a common working line running parallel to the transport direction. It has been recognized that the perforation of the lower film and the seal can be formed in such a way that neither the evacuation and / or gassing process, nor the production of the seal or the fixing function of the seal are impaired.

This also means that the middle film does not have to be wider or narrower than the lower film. Rather, the invention results in the advantage that not only the middle film and the lower film, but all film webs at least can have essentially the same web width. This considerably simplifies the procurement and storage of the individual films for the operator of the packaging machine.

The invention consequently also relates to the use of a non-perforated film as a central film in a packaging machine of the type disclosed herein and / or in a method of the type disclosed herein.

Furthermore, the invention also relates to the use of at least three films of at least essentially the same web width as the lower film, upper film and middle film in a packaging machine of the type disclosed herein and / or in a method of the type disclosed herein.

In general, "at least essentially the same web width" also includes slight deviations, e.g. due to unavoidable manufacturing tolerances, which in practice can be up to 2mm and sometimes up to 5mm, with a nominal web width of typically several 100mm.

Advantageous embodiments of both the packaging machine according to the invention and the production method according to the invention are also specified in the dependent claims, the following description and the figures.

It is preferably provided that, based on a respective pack, the lower evacuation and / or gassing tool and the sealing tool in Do not overlap the transport directions. Both tools can consequently be made comparatively short, namely shorter than a package length. This enables a further reduction in the length of the packaging machine.

However, such an arrangement of the tools is not mandatory. The tools can also be arranged relative to one another in the transport direction in such a way that, with respect to a respective pack, a sealing area and a perforation area overlap in the transport direction. The sealing area and the perforation area can each extend over the entire length of the pack or at least over a substantial part of the length of the pack. So that the perforation and the seal do not affect one another, it can be provided, for example, that a gas passage of the perforation and a sealing point of the seal alternate in the transport direction. As a result, at least essentially the entire length of the pack and thus the entire edge regions of the lower film and the middle film, which can also be made comparatively narrow, can be used both for the perforation and for the sealing.

The packaging machine can preferably be operated cyclically, the foils being movable in the transport direction by a working length corresponding to at least one pack length in a respective cycle.

If the entire length of the pack is not to be used both for applying a vacuum and / or gas and for sealing, then it can be provided that, based on a respective pack, the lower and / or upper evacuation and / or gas injection tool on the one hand and the Sealing tools on the other hand each have a length in the transport direction, the sum of which is smaller than the working length. In practice, the functions of the sealing station, namely evacuation and / or gassing on the one hand and the final closing by sealing on the other hand, are often in a single joint Tool unites, ie one does not speak of different tools in this case. In this case, this exemplary embodiment is to be understood as meaning that an evacuation and / or gassing area is provided on the common tool which does not extend over the entire working length of the tool.

Furthermore, it can be provided according to the invention that the upper evacuation and / or gassing tool also lies on the common working line. The construction of the sealing station can hereby be further simplified.

According to a further exemplary embodiment, it is provided that the upper evacuation and / or gassing tool and the sealing tool overlap one another in the transport direction, with reference to a respective pack. The separation of the lower package layer and the upper package layer with regard to the application of vacuum and / or gas consequently makes it possible to select the position of the upper evacuation and / or gas injection tool with regard to the sealing tool for sealing the middle film to the lower film in the transport direction. Because the sealing between the middle film and the lower film on the one hand and the perforation of the upper film on the other hand do not influence each other.

According to a preferred embodiment, it is provided that the lower evacuation and / or gassing tool on the one hand and the evacuation and / or gassing tool on the other hand do not overlap in the transport direction. Such an arrangement of the tools offset in the transport direction can be advantageous for certain applications and / or with regard to a simpler construction and / or operation of the sealing station and thus the packaging machine.

A middle film that overlaps the edge areas of the lower film and the upper film is particularly advantageous when the product layers are not in shaped depressions should or must lie, but when it is sufficient or desired to pack the products between two unformed film webs. Therefore, according to a preferred embodiment, it can be provided that the packaging machine does not have a deep-drawing or forming station for producing deformations in one or more of the foils. The packaging machine can be further simplified and shortened as a result.

In the method according to the invention, it can be provided that the lower product layer and the upper product layer are simultaneously subjected to vacuum and / or gas.

The application of vacuum and / or gas on the one hand and the closing on the other hand preferably takes place in a sealing station forming one of the work stations.

Preferably, after the lower film and the central film have been fed in, the edge region of the central film is sealed to the edge region of the lower film. A fixing of the lower film and the middle film to one another can in principle also take place in a different manner.

Furthermore, it is preferably provided that the sealing takes place along a working line running parallel to the transport direction, on which at least the perforation of the lower film, preferably also the perforation of the upper film, lies.

It can be provided that in a respective pack the sealing takes place in a sealing area which does not overlap with a perforation area of the lower film in the transport direction.

According to a further embodiment, the lower film and the upper film are not simultaneously and / or on different ones, in particular in the transport direction spaced apart locations of the packaging machine. The construction of the packaging machine can hereby be designed more flexibly.

The lower film and / or the upper film are preferably perforated during feeding. As a result, it is not necessary to arrange a work station performing the punching within the machine frame of the packaging machine. Rather, it is possible to arrange a tool for perforating the respective film outside the machine frame and in particular in the feed path of the film. A space that is to be made available anyway for feeding the respective film can thus be used at the same time for perforating the film.

The perforation of the lower film and the perforation of the upper film do not necessarily have to be integrated into the operation of the packaging machine. Rather, according to the invention, it is also possible to use a pre-perforated lower film and / or a pre-perforated upper film, i.e. films which are already perforated during their production and are used by the operator of the packaging machine in the already perforated state.

It can be provided that the lower film and the upper film are perforated or correspondingly pre-perforated films are used in such a way that the perforations of the lower film and the upper film do not overlap in the transport direction in a respective pack.

Furthermore, it is preferably provided that the perforations each have one or more gas passages, each of which was created either by removing material or by cutting, slitting or perforating the material without removing material, preferably additionally by exposing one or more material sections.

Particularly when the perforations are produced during the operation of the packaging machine, the formation of the gas passages without removing material has the advantage that no disruptive material snippets arise.

It is preferably provided that the lower film, the upper film and the central film each have the same web width.

As already mentioned above with reference to a preferred exemplary embodiment of the packaging machine, it can be provided according to the invention that a deep-drawing or shaping process for the production of reshapes cannot be carried out on any of the foils.

Furthermore, it is preferably provided that the application of vacuum and / or gas and the sealing take place on both sides of the product area, in particular simultaneously and / or in the same way.

The packaging machine can be constructed and / or operated symmetrically with respect to a central axis of the foils running parallel to the transport direction and thus the machine.

Fig. 1

schematisch ein mögliches Ausführungsbeispiel einer erfindungsgemäßen Verpackungsmaschine in einer Seitenansicht, und

Fig. 2

den Aufbau einer erfindungsgemäßen Mehrlagenpackung aus drei Folien, die jeweils mit noch nicht abgetrennten Randbereichen und der besseren Übersichtlichkeit halber mit Abstand voneinander dargestellt sind.

The invention is described below by way of example with reference to the drawing. Show it:

Fig. 1

schematically a possible embodiment of a packaging machine according to the invention in a side view, and

Fig. 2

the structure of a multi-layer pack according to the invention from three films, each with not yet separated Edge areas and for the sake of clarity are shown at a distance from one another.

In the Fig. 1 The packaging machine shown comprises an elongated machine frame 35 which extends in a transport direction T in which the foils 11, 13, 15 used for the desired production of multi-layer packs are moved. The foils 11, 13, 15 are each in the form of a foil web which is fed from a supply roll 11a, 13a, 15a.

For the lower film 11, a circulating endless transport chain (not shown) is provided in a basically known manner on both sides of the machine frame 35, which is guided on the machine frame 35 in a respective chain guide and holds the lower film 11 at an edge area. The lower film 11 is clamped in this way between the two transport chains spaced apart transversely to the transport direction T.

If no pre-perforated lower film 11 is used, the feeding of the lower film 11 is followed by a work station 21 in which the edge areas of the lower film 11 are each provided with a perforation 31 ( Fig. 2 ). The perforations 31 each include a plurality of gas passages 32, oval in this exemplary embodiment, which are formed in a front region of the respective film edge region 29, as seen in the transport direction T. The gas passages 32 can each be an opening produced by removing material, for example by punching. Alternatively, the passages 32 can each be formed without removing material, for example by cutting and then opening out a respective flap-like material section.

Furthermore, it is possible to reshape the lower film 11 at the work station 21, in particular by means of a deep-drawing process, if the The packs to be produced should each have a shell-shaped lower part.

As also mentioned in the introductory part, the work station 21 can be saved and the length of the packaging machine can be reduced if a pre-perforated lower film 11 is used and, in addition, reshaping of the lower film is not required.

Then, at a first product support station 23, indicated only by an arrow, the individual product areas 17 ( Fig. 2 ) a product to be packaged (not shown) is placed on the lower film 11. The product can, for example, be a portion of one or more product slices separated from a food product, for example sausage, ham or cheese, by means of a high-performance slicer.

Subsequently, the transport path in which the lower film 11 is transported is fed from above a middle film 13, which has at least essentially the same web width B ( Fig. 2 ) as the lower film 11. The edge regions 19 of the central film 13 each have the same width as the corresponding edge region 19 of the lower film 11. The edge regions 19 of the central film 13 are unperforated, so that the perforations 31 of the lower film 11 each come from the corresponding edge region 19 of the Central film 13 are covered when the central film 13 lies on the lower film 11.

The area between two superimposed product areas 17 of the lower film 11 and the upper film 13 contains the previously placed product and is also referred to as the product layer in the present disclosure. If - as shown - the lower film does not have any depressions produced by forming, these product layers are not chambers or compartments with a receiving volume determined by the forming, but rather only around areas between the lower film 11 and the upper film 13 in which a product is located. The lateral, front and rear boundaries of the product layers are each defined by a circumferential end seal 37, which will be discussed in more detail below.

After the central film 13 has been fed in, it is fixed to the lower film 11. This takes place by sealing in a sealing station 25, in which a rear region of each edge region 19 of the central film 13, seen in the transport direction T, is sealed to a corresponding region of the lower film 11.

The sealing and the final sealing are each carried out in a basically known manner by means of sealing tools heated to sufficiently high temperatures, which locally melt the foils involved and consequently fuse them together. In practice, each film is often a composite of a plurality of individual film layers connected to one another, one on top of the other, which have different functions and therefore have different properties and / or can consist of different materials. In a sealing process, each of these individual layers is not necessarily melted, but rather only one outer film layer, for example.

The seals 33 formed by means of a sealing tool 43 of the sealing station 25 overlap the perforations 31, i.e., based on a respective pack, a lower evacuation and / or gassing tool 41, which is explained in more detail below, is on the one hand a lower evacuation and / or gas supply tool 41 of a sealing station 29 explained in more detail below and the sealing tool 43 of the sealing station 25, on the other hand, arranged offset from one another in the transport direction T and each shorter than a pack length L ( Fig. 2 ). In the exemplary embodiment shown, the length of each of these tools 43, 41 is only about half the length of a pack L. Consequently, the sealing station 25 only needs to be about half the length of a pack length L.

For the central film 13, the packaging machine does not require any additional means of transport and, in particular, no transport chains, as are provided for the lower film 11, since the sealing of the central film 13 to the lower film 11 explained above, both for reliable transport of the central film 13 and for always correct transport Alignment of the central film 13 relative to the lower film 11 ensures.

Downstream of the sealing station 25, a second product support station 27, again indicated only by an arrow, is provided, at which a product to be packaged is placed on each of the individual product areas 17 of the central film 13.

Together with the subsequently fed top film 15, the middle film 13 thus forms an upper product layer between the two product areas 17, which contains the previously placed upper product.

If no pre-perforated upper film 15 is used, then according to Fig. 1 A work station 28 is arranged in the feed path of the upper film 15, in which a perforation 31 is made in each of the edge areas 19 of the upper film 15 ( Fig. 2 ). The perforations 31 of the upper film 15 can be identical in size, shape and position to the perforations 31 of the lower film 11. But this is not mandatory.

As Fig. 2 shows, the perforations 31 of the upper film 15 - in contrast to the lower film 11 - are each formed in a rear region of the respective edge region 19, as seen in the transport direction T. The perforations 31 of the upper film 15 are consequently, viewed in the transport direction T, arranged offset with respect to the perforations 31 of the lower film 11, the perforations 31 of the upper film 15 being located do not overlap with the perforations 31 of the lower film 11. The perforations 31 of the upper film 15 overlap with the seals 33 of the central film 13.

The transport of the upper film 15 - just like the transport of the central film 13 - is ultimately carried out by the transported lower film 11, since all three films are connected to one another by sealing downstream.

After the top film 15 has been fed in, all three films 11, 13 and 15, namely the bottom film 11, the middle film 13 sealed to the bottom film 11 and the top film 15 that was last fed, are fed together to the sealing station 29 that follows in the transport direction T. The three foils 11, 13 and 15 are aligned relative to one another in such a way as Fig. 2 shows in an exploded view for the sake of clarity.

In particular, all perforations 31 and seals 33 of the left edge areas 19, seen in transport direction T, and all perforations 31 and seals 33 of right edge areas 19, seen in transport direction T, are each located on a common working line W running parallel to transport direction T. . In Fig. 2 the left working line W is indicated in all three foils 11, 13 and 15 by a dashed line, while the right working line W is indicated by a dash-dotted line.

In the sealing station 29, for each pack P, the lower product layer between the middle film 13 and the lower film 17 and the upper product layer between the middle film 13 and the upper film 15 are simultaneously subjected to a gas exchange by first evacuating the product layers and then applying a protective gas. Such a treatment of product layers of a multi-layer pack is known in principle.

In the sealing station 29 according to the invention, the tools 41, 45 for evacuating and gassing the product layers are aligned with the respective gas outlets 32 of the lower film 11 and the upper film 15 in terms of their position transverse to the transport direction T and in relation to a respective pack P in the transport direction T. These tools 41, 45 can each be nozzles which are each aligned with one of the gas passages 32.

Furthermore, the sealing station 29 comprises a sealing tool, not shown, which is designed in a basically known manner to connect all three foils 11, 13 and 15 to one another by forming an end seal 37 that runs around the product areas 17 of the foils and thereby the lower product layer and the to close the upper product layer in a gastight manner. The lateral areas of the end seal 37 lie within the edge areas 19 of the foils 11, 13, 15. The sections of the edge areas 19 lying outside the end seal 37 are separated downstream of the sealing station 29, optionally before or after the packs P are labeled. As a result, the seals 33 and the perforations 31 are no longer present on the final packs, as they will be commercially available for example later.

As already mentioned in the introductory part, the packaging machine according to the invention works in cycles. In each work cycle, the foils 11, 13 and 15 are moved together by one working length in the transport direction T, the working length of the packaging machine corresponding to the format length already mentioned at the beginning, i.e. at least one pack length L.

The packaging machine can produce the packs P in one or more lanes. The upper film 11, the central film 13 and the upper film 15 can each be formed by a separate film web for each of the tracks running parallel next to one another in the transport direction T. Alternatively, all tracks can have a common lower film 11, a common central film 13 and also a have common upper film 15. In the latter case, the tools of the individual work stations are designed in such a way that between two adjacent tracks the edge regions 19 according to FIG Fig. 2 corresponding areas can be provided with the perforations 31 or seals 33.

In order to produce multi-layer packs with more than two product layers, several, each unperforated middle foils can be fed in one after the other. This consequently results in at least one product layer that is delimited neither by the lower film 11 nor by the upper film 15, but rather by two unperforated central films. There is no direct access for applying vacuum and / or gas as with the other product layers for this product layer or product layers. On the one hand, however, depending on the particular circumstances, a certain gas exchange can also take place from the side between the foils lying on top of one another. On the other hand, this product layer can optionally be used for products for which a gas exchange is not absolutely necessary and generally dispensable, for example for small packaging of additives such as mustard or dry spices (e.g. salt and pepper), for napkins, cutlery and / or toothpicks or for product information, advertising flyers, raffle tickets, etc.

List of reference symbols

11

Lower film

11a

Supply roll

13

Middle foil

13a

Supply roll

15th

Upper film

15a

Supply roll

17th

Product area

19th

Edge area

21st

Punching station

23

Product support station

25th

Sealing station

27

Product support station

28

Punching station

29

Sealing station

31

Perforation

32

Gas passage

33

Sealing

34

Sealing point

35

Machine frame

37

End seal, sealed seam

41

lower evacuation and / or gassing tool

43

Sealing tool

45

upper evacuation and / or gassing tool

P

pack

T

Transport direction

W.

Working line

L.

Package length

B.

Web width

Claims (15)

1. A packaging machine, in particular for food products, preferably for carrying out a method in accordance with any one of the claims 9 to 21,
   having a plurality of working stations arranged behind one another along a transport direction (T) for producing multilayer packs (P) from a bottom film (11), a top film (15) and at least one middle film (13) disposed therebetween, wherein the bottom film (11) encloses a bottom product layer with the middle film (13) and the top film (15) encloses a top product layer of a respective pack (P) with the or a further middle film (13);
   wherein the films each have a product region (17) and marginal regions (19) extending laterally next to the product region (17) in parallel with the transport direction (T);
   wherein one working station is a sealing station (29) which is configured to apply vacuum and/or gas to the product layers through perforations (31) present in the marginal regions (19) of the top film (15) and of the bottom film (11) and then to close said product layers by sealing the films, wherein the sealing station (29) comprises an upper evacuation and/or gassing tool (45) aligned with the perforation (31) of the top film (15) and a lower evacuation and/or gassing tool (41) aligned with the perforation (31) of the bottom film (11);
   wherein a further working station is an affixing sealing station (25) which is disposed upstream of the sealing station (29) and which is configured to seal the middle film (13) to the bottom film (11) in an affixing manner at an affixing sealing (33) disposed in the marginal regions (19); and
   wherein the lower evacuation and/or gassing tool (41) of the sealing station (29) and an affixing sealing tool (43) of the affixing sealing station (25) serving for the making of the affixing sealing (33) are disposed on a common working line (W) extending in parallel with the transport direction (T).
2. A packaging machine in accordance with claim 1,
   wherein, with respect to a respective pack (P), the lower evacuation and/or gassing tool (41) and the affixing sealing tool (43) do not overlap one another in the transport direction (T).
3. A packaging machine in accordance with claim 1 or claim 2,
   wherein the packaging machine can be operated cyclically, with, in a respective cycle, the films being movable in the transport direction (T) by a working length corresponding to at least one pack length (L),
   in particular wherein, with respect to a respective pack (P), the lower and/or upper evacuation and/or gassing tool (41, 45), on the one hand, and the affixing sealing tool (43), on the other hand, each have a length in the transport direction (T) whose sum is less than the working length.
4. A packaging machine in accordance with any one of the preceding claims,
   wherein the upper evacuation and/or gassing tool (45) is also disposed on the common working line (W).
5. A packaging machine in accordance with any one of the preceding claims,
   wherein the lower evacuation and/or gassing tool (41) and the upper evacuation and/or gassing tool (45) do not overlap one another in the transport direction (T), and/or wherein, with respect to a respective pack (P), the upper evacuation and/or gassing tool (45) and the affixing sealing tool (43) overlap one another in the transport direction.
6. A method of manufacturing multilayer packs (P), which in particular include food products, from a bottom film (11), a top film (15) and at least one middle film (13) disposed therebetween, in particular by means of an apparatus in accordance with any one of the preceding claims, wherein the bottom film (11) encloses a bottom product layer with the middle film (13) and the top film (15) encloses a top product layer of a respective pack (P) with the or a further middle film (13), and wherein the films transported along a transport direction (T) each have a product region (17) and marginal regions (19) extending laterally next to the product region (17) in parallel with the transport direction (T);
   wherein, in the method, the product layers are acted on by vacuum and/or gas through perforations (31) present in the marginal regions (19) of the top film (15) and of the bottom film (11) and are then closed by sealing the films;
   wherein the application of vacuum and/or gas takes place while the unperforated marginal region (19) of the middle film (13) and the perforated marginal regions (19) of the bottom film (11) and of the top film (15) overlap one another; and
   wherein the bottom product layer is acted on through the perforation (31) of the bottom film (11) and the top product layer is acted on through the perforation (31) of the top film (15).
7. A packaging machine in accordance with claim 6,
   wherein the bottom product layer and the top product layer are simultaneously acted on by vacuum and/or gas, and/or wherein the application of vacuum and/or gas and the closing take place in a sealing station (29) forming one of the working stations.
8. A method in accordance with claim 6 or claim 7,
   wherein, after the supply of the bottom film (11) and of the middle film (13), the marginal region (19) of the middle film (13) is sealed in an affixing manner to the marginal region (19) of the bottom film (11), and/or wherein the affixing sealing takes place along a working line (W) which extends in parallel with the transport direction (T) and on which at least the perforation (31) of the bottom film (11), preferably also the perforation (31) of the top film (15), is disposed, and/or wherein, in a respective pack (P), the affixing sealing takes place in an affixing sealing region which does not overlap with a perforation region of the bottom film (11) in the transport direction (T).
9. A method in accordance with any one of the claims 6 to 8,
   wherein the bottom film (11) and the top film (15) are not perforated simultaneously and/or at different locations of the packaging machine that are in particular spaced apart from one another in the transport direction (T), and/or wherein the bottom film (11) and/or the top film (15) is/are perforated on the supply, or wherein a pre-perforated bottom film (11) and/or a pre-perforated top film (15) is/are used.
10. A method in accordance with any one of the claims 6 to 9,
    wherein the bottom film (11) and the top film (15) are perforated such that or correspondingly pre-perforated films are used such that, in a respective pack (P), the perforations (31) of the bottom film (11) and of the top film (13) do not overlap one another in the transport direction (T).
11. A method in accordance with any one of the claims 6 to 10,
    wherein the perforations (31) each have one or more gas passages (32) which, respectively, were either produced by material removal or were produced without material removal by cutting into, slitting or perforating the material, preferably additionally by erecting one or more material sections.
12. A method in accordance with any one of the claims 6 to 11,
    wherein the bottom film (11), the top film (15) and the middle film (13) each have at least substantially the same web width (B).
13. Use of an unperforated film as the middle film (13) in a packaging machine in accordance with any one of the claims 1 to 5 and/or in a method in accordance with any one of the claims 6 to 12.
14. Use of at least three films, having at least substantially the same web width, as the bottom film (11), as the top film (15) and as the middle film (13) in a packaging machine in accordance with any one of the claims 1 to 5 and/or in a method in accordance with any one of the claims 6 to 12.
15. A multilayer pack,
    which is producing or can be produced by a packaging machine in accordance with any one of the claims 1 to 5 and/or which is obtained or can be obtained by a method in accordance with any one of the claims 6 to 12,
    comprising a bottom film (11); a top film (15); and at least one middle film (13) disposed therebetween, wherein the bottom film (11) encloses a bottom product layer with the middle film (13) and the top film (15) encloses a top product layer with the or a further middle film (13).

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