EP2279132B1 - Microwave-compatible bag having a valve and method for the production thereof - Google Patents

Abstract

In a reclosable bag (20) a zipper (Z) is provided on the inner surfaces (50) of the plastic film and the two parts of the zipper (Z) are fixed on the opposite inner surfaces (50) of the bag (20), wherein the zipper (Z) is connected to the inner surface (50) of the plastic film in such a manner that between the welded regions (12, 14) between the zipper (Z) and the inner surface (50) of the plastic film, recesses (15, 13) are left free in the longitudinal direction of the zipper (Z) to form a seal-free longitudinal channel and in the transverse direction of the zipper (Z) to produce free air or steam passage openings at defined distances between the zipper (Z) and the inner surface (50), through which openings a passage of steam is possible, wherein ends of the openings facing the interior (60) of the bag (20) are larger than ends of the openings facing the exterior (70) of the bag (20).

Description

TECHNICAL FIELD

The invention relates to a resealable bag, which is suitable for cooking food and has a device for the escape of steam.

The invention further relates to a tool for producing a connection between a zipper and an inner surface of a plastic film, which is intended as a bag wall of a bag.

A method for making a connection between a part of a zipper and an inner surface of a plastic film, which is intended as a bag wall of a bag.

BACKGROUND

For example, packaging suitable for microwave heating is off US 2007/297 698A . EP 661 219 A . WO 03/051745 A . WO 04/13015 A or EP 1 714 908 A known.

In this case, the packaging valves of different types and shapes.

The reclosability of the packages is usually given by pressure-sensitive adhesive coatings in an edge region of the packaging. However, even with little contamination of the sealable coating, the packaging is no longer completely closed.

Furthermore, it is off EP 1 721 833 A1 a self-ventilating resealable bag in which one or more discontinuities are provided in a sealed seam between the inner surface of the plastic film of the bag and a part of the zipper. These discontinuities are described as a gap and allow hot air or vapor to escape from inside the bag through them.

Furthermore, from the JP 2000-72156 also discloses a bag having a device for the escape of vapor, said bag having in the direction transverse to the zipper permanent openings between the inner surface of the plastic film of the bag and a part of the zipper. These permanent openings are disclosed as channels of constant cross section or constant width.

Also from the US 2004/0069157 A1 For example, there is disclosed an apparatus for evacuating vapor associated with a bag, which apparatus in the present case is disclosed by pseudo-closed columns in a polymer layer of the film.

The solutions disclosed in the context of a zipper often prove problematic because the channels or gaps between the inner surface of the plastic film and a part of the zipper are often laid by moisture and the so-called glass plate effect reliably opening these gaps or Channels significantly affected. The reason for the well-known glass plate effect is essentially that two glass plates, between which moisture enters, can hardly be separated from each other, or only with extreme force. This effect is particularly pronounced in the steam cooking of foods in a e.g. resealable by a zipper - bag of importance, because the possibly by moisture "adhering" areas of the channels or columns no longer ensure a controlled escape of steam and may occur inadvertent opening of the zipper, so that the steam-guarding effect of the bag is lost.

The object of the invention was to provide a reliable resealable bag, which is particularly suitable for steaming of packaged food and has a valve for the escape of steam during cooking.

SUMMARY OF THE INVENTION

This object is achieved on the one hand by a resealable bag according to claim 1 and on the other hand by a tool according to claim 10 and by a method according to claim 12.

The subject of the invention is therefore a resealable bag which is suitable for cooking food and a device for the Evaporating steam, consisting of a flexible plastic film or a flexible plastic film composite having an outer and an inner surface, wherein on the inner surfaces of the plastic film, a zipper is provided and the two parts of the zipper are fixed to the opposite inner surfaces of the bag and the allowing reclosable access to the packaged contents, wherein the zipper is connected to the inner surface of the plastic film such that between welded areas between the zipper and the inner surface of the plastic film longitudinal recesses of the zipper to form a seal-free longitudinal channel and in the transverse direction of the zipper for the production of free air or vapor passage openings at defined distances between the zipper and the inner surface remain free, through which openings a vapor passage is possible, the dimension and the geometry the recesses are harmonized with the internal opening force of the zipper and the bag size in that the steam pressure during cooking does not exceed the force necessary to open the zipper and wherein the interior of the bag facing ends of the openings are larger than the outside of the bag facing the ends of the openings.

In addition, the subject of the invention is a tool for establishing a connection between a zipper and an inner surface of a plastic film, which is intended as a bag wall of a bag, wherein the tool has sealing zones, which formed for sealing a part of the zipper with the inner surface of the plastic film and wherein the sealing zones are interrupted by notches in the longitudinal direction of the zipper to form a seal-free longitudinal channel and in the transverse direction of the zipper for the production of free air or vapor passage openings at defined distances between the zipper and the inner surface, wherein the dimension and the Geometry of the notches with the internal opening force of the zipper and the bag size harmonized in that the steam pressure during cooking does not exceed the force necessary to open the zipper and wherein the interior of the bag facing the ends of the openings are larger than the exterior of the Bag facing the ends of the openings.

Furthermore, the subject of the invention is a method for making a connection between a part of a zipper and an inner surface of a plastic film, which is intended as a bag wall of a bag, which Method comprising the following method steps, namely positioning the part of the zipper on the inner surface of the plastic film and establishing a connection within mirror areas between the part of the zipper and the inner surface of the plastic film by means of the tool according to the invention.

The inventive measure is achieved in an advantageous manner that in the area of the zipper reliable opening of the device for the escape of steam is ensured. Due to the relatively large formation of the interior of the bag facing the ends of the openings in relation to the bag exterior facing the ends of the glass plate effect is significantly defused or completely avoided and the adjacent areas of the inner surface of the plastic film and the respective part of the zipper can Separate more easily than if channels or columns are provided with a constant width.

At the same time, it is ensured by the relatively small openings in the direction of the bag exterior that the pressure necessary for steam cooking in the interior of the bag is maintained. This in turn has a positive effect on the cooking or Dampfgareigenschaften the bag. In addition, through the combination of longitudinal recess and longitudinally distributed recesses in the transverse direction, a system of communicating channels is realized which ensures that the vapor pressure does not concentrate at individual locations and possibly open the zipper there by deformation of the bag. Rather, the system of channels, for example, allows steam to enter the system at one location and exit the system at different locations. This avoids local stress on the bag and consequently also on the zipper because the bag does not deform at individual points due to the increased gas pressure. For the steam, the system of channels realizes a kind of labyrinth, into which the steam can enter at different points or positions, spread out in it and finally exit at different points or positions.

In summary, the solution according to the invention has as an outstanding feature that the bag-internal vapor pressure is controlled by the passage geometry and the fixation of the zipper on the film inside of the bag using a tool for heat sealing takes place, which has only minor modifications in relation to the prior art and can be used on a machine (eg a conventional standing bag manufacturing machine), with which the manufacturing method according to the invention is carried out with known performance and in particular without further adaptations of this machine to the external tool geometry. This is in appreciable contrast to known solution, which often requires a reduction in performance and / or significant changes in terms of the process-relevant steps or in relation to the machine.

Further, particularly advantageous embodiments and modifications of the invention will become apparent from the dependent claims and the following description. The advantages mentioned in connection with the bag also apply to the object of the tool or to the manufacturing process. Furthermore, the tool or the manufacturing method according to the dependent claims can be further developed to the bag.

The bag according to the invention may be a stand-up pouch or sachet in a conventional, pasteurizable or heat-sterilizable design.

The walls or the bottom of the bag, for example, consist of a pasteurizable or heat sterilizable flexible plastic film or a flexible plastic composite.

The zipper is located on the inner surfaces of the front and back wall of the bag and fixed by sealing or welding. In this case, recesses are provided in the sealing seams or welding points under the recesses between the chords of the Zippers, so that an air or steam passage through these recesses is possible. At the edges of the zipper between the front and rear wall of the bag is fixed.

The zipper is preferably made of a heat-resistant material such as HDPE, polyethylene-polypropylene copolymers or polypropylene.

Such zippers are commercially available and have from the inside to the outside of the bag strong toothing properties, whereby an initial resistance is given when opening the zipper. This ensures that a high vapor pressure can be achieved in the package. The asymmetric toothing ensures that the zipper is easy to open from the outside.

Said glass plate effect can also be influenced by the choice of the mechanical parameters of the film / films. The tendency for a pronounced glass plate effect is namely increased in a soft film, whereas there is a tendency for a less pronounced glass plate effect in a stiffer film. This finding can also be used in the choice of the material of the zipper or the base of the zipper, which is heat-sealed with the sealing layer of the bag. For example, when polypropylene is used instead of polyethylene, a material is used which has a higher density and thus also forms a stiffer structure compared to a polyethylene structure. Thus, the openings of the labyrinth are easier to open. At the same time also results in a higher internal opening force of the zipper. Polypropylene also has a higher heat resistance. Finally, if a harmonization between the material of the bag film or at least the material of the sealing layer of the bag and the material of the zipper realized - so both materials realized by polypropylene, the bag can also be used for heat sterilization.

Above the zipper may be provided a device for easier opening of the bag, as can be realized for example by a perforation, in particular a laser perforation.

According to one aspect of the invention, the front and rear walls of the bag are made of a plastic film consisting of polypropylene, higher density polyethylene, or their copolymers or blends. The polymer films may also be filled polymer films, for example polymer films filled with calcium carbonate, TiO ₂ and the like.

As plastic composite, for example, composites of different plastic films come into question. According to another aspect of the invention, the front and back walls of the bag are made of a plastic composite film, wherein the outer layer of the composite is made of polyester such as oriented PET, amorphous PET, polyolefins such as polypropylene, Cast-PP, blown, stretched, biaxially stretched PP. Films or polycarbonate, cellophane, polyamide or their copolymers. It can also be coextruded or laminated Plastic composite films or composites are used with paper. The thickness of the outer layer is for example 8 - 200 □ m.

According to a further aspect of the invention, the inner layer consists of polyethylene, EVOH, EVA, (cast) polypropylene and / or its copolymers or terpolymers. The inner layer can also be formed by an extrusion coating of the outer film with one of said plastics. The thickness of the inner layer is preferably 30 - 100 □ m.

According to an embodiment of the invention, between the ends of the openings facing the interior of the bag and the ends of the openings facing the exterior of the bag, a boundary interrupted by the longitudinal channel exists and this boundary runs in a straight line.

According to another embodiment of the invention, between the ends of the openings facing the interior of the bag and the ends of the openings facing the exterior of the bag, a boundary interrupted by the longitudinal channel exists and this boundary runs curved. In this case, for example, a concave or convex shape can be used.

According to another aspect of the invention, in one embodiment, the recesses in the transverse direction of the zipper may exist at one inner surface at other positions than the transverse recesses of the zipper at the other inner surface. This can for example lead to a zig-zag staggered structure of recesses in the transverse direction.

According to another aspect of the invention, in another embodiment of the invention, the recesses in the transverse direction of the zipper may be formed only between the zipper and one of the two inner surfaces.

According to a preferred aspect of the invention, the openings are formed between the zipper and both on the one inner surface and the other inner surface.

BRIEF DESCRIPTION

The invention will be explained in more detail below with reference to the accompanying figures with reference to embodiments. Here are in the same components with identical reference numerals provided the different figures.

Fig. 1

auf schematische Weise einen Beutel gemäß dem Stand der Technik.

Fig. 2

auf analoge Weise wie die Fig. 1 einen Teil eines Werkzeugs gemäß dem Stand der Technik.

Fig. 3

auf schematische Weise einen Querschnitt durch einen Beutel gemäß einem Ausführungsbeispiel der Erfindung.

Fig. 4

ein Detail einer Siegelzone entlang einer in der Fig. 3 eingetragenen Schnittlinie A-A.

Fig. 5

auf analoge Weise wie die Fig. 3 den erfindungsgemäßen Beutel in einer Frontalansicht.

Fig. 6

auf schematische Weise ein Abschnitt eines zweiteiligen erfindungsgemäßen Werkzeug gemäß einem Ausführungsbeispiel der Erfindung.

Fig. 7

das Werkzeug gemäß der Fig. 6 in einer zusammengefügten Konfiguration.

Fig. 8 bis 10

verschiedene Ausbildungen von Querkerben für verschiedene Ausführungsbeispiele des erfindungsgemäßen Werkzeugs.

It shows:

Fig. 1

schematically a bag according to the prior art.

Fig. 2

in an analogous way like that Fig. 1 a part of a tool according to the prior art.

Fig. 3

schematically a cross-section through a bag according to an embodiment of the invention.

Fig. 4

a detail of a seal zone along one in the Fig. 3 registered section line AA.

Fig. 5

in an analogous way like that Fig. 3 the bag according to the invention in a front view.

Fig. 6

schematically a section of a two-part tool according to the invention according to an embodiment of the invention.

Fig. 7

the tool according to the Fig. 6 in an assembled configuration.

Fig. 8 to 10

Various embodiments of transverse notches for different embodiments of the tool according to the invention.

DESCRIPTION OF THE EMBODIMENTS

In Fig. 1 a bag is shown. Therein 1 means the wall of the bag, 2 the zipper, 3 the areas in which the zipper is welded to the inner surface of the bag fabric of the bag, 4 the recesses between the welded areas, 5 a perforation to open the bag, 6 the contents ,

The bag can be opened for use initially on the pre-perforated line 5. After opening the zipper 2 liquids, such as water, spices and the like can be filled by the consumer in the bag. Subsequently, the zipper 2 is closed and the bag is heated in a microwave oven. During this process, the filled liquid is heated, steam is generated and the dry product is cooked. As a product, for example, wet (moist) and / or dry foods come into question.

In the FIG. 2 is part of a tool for making the connection between the zipper and the inner surface of the bag fabric film in two perspectives shown having a recess in the longitudinal direction of the zipper 2 to form a seal-free longitudinal channel and in the transverse direction of the zipper 2 for the preparation of the free air or vapor passage openings.

In the Fig. 2 7 represent the recesses for the formation of the air or vapor passage openings in the transverse direction of the zipper 2, 8 the longitudinal recesses for the formation of a seal-free longitudinal channel and 9 the sealing zones for the connection between a part of the zipper and the inner surface of the plastic film of the bag ,

In the Fig. 3 is a bag according to the invention 20 - shown more precisely a cross section through such a bag 20 transverse to the longitudinal direction of the zipper Z. The bag 20 is a stand-up pouch which, when filled, stands upright by its bottom geometry without any further support. The bag 20 is bounded by a wall 21 and has a bag interior 23. At the top, the bag 20 has a top seal 25. Below the top seal 25 is a tear zone 26, with the help of the head seal 25 can be separated. After tearing away the head seal 25 along the tear zone 26, a head portion 24 of the bag is freely accessible. The zipper Z has a female part 28 and a male part 27. The male part 27 has a first base 29. The female part 28 has a second base 30. The first pedestal 29 is sealed to the inner surface (50) of the plastic film forming the wall 21 in first seal portions 31. The second pedestal 30 is sealed to said inner surface (50) in second seal areas 32. The two sealing areas 31 and 32 and the zipper Z are shown greatly enlarged. Through the second sealing areas 32 extends a cutting line - or area AA.

A section along this line or surface AA through the second sealing regions 32 is shown in FIG Fig. 4 shown. The second sealing regions 32 are bounded on the one hand by a first recess 15 in the longitudinal direction and by four second recesses 13 in the transverse direction. At the left or right end of the first recesses 15 in the longitudinal direction in each case a final third seal area 14 is visible. Steam 16, which flows from the interior of the bag 23 in the direction of the head region 24 through the channel system of the second sealing region 32, is also indicated schematically. It can also be seen clearly how the steam 16 is an optimal way through the Labyrinth of the channel system through, where not necessarily steam entering at a position / position in the labyrinth at the same position / position in the transverse direction of the zipper Z must exit again from the labyrinth, but can also leave the labyrinth via adjacent exit points. The relatively large inlet openings in the area of the interior of the bag 23 allow for the heating and the release of steam 16 easy opening of the interior 60 of the bag 20 facing ends of the labyrinth and thus a smooth flow of steam 16 into the labyrinth. At the same time, the relatively narrow or small outlet openings in the direction of the head region 24-that is, the ends of the labyrinth facing the exterior 70-allow the bag 20 to retain the steam pressure in the bag interior 23 which is necessary for cooking. The entering into the labyrinth steam 16 can spread optimally in the labyrinth and easily emerge from the labyrinth, so that the risk of vapor concentration at individual points - and thus a pressure concentration and concomitant deformation of the bag 20 at these points - reliably avoided and thus no unnecessary stress on the interlocked male and female parts 27 and 28 of the Zipper Z is exercised. As a result, an unwanted partial or large-scale opening of the zipper Z is reliably avoided.

In the Fig. 5 Furthermore, another embodiment of a bag 20 according to the invention is shown in frontal view of the front of the bag 20. The zipper Z is only roughly schematic and indicated by its limitations and shown substantially transparent to make the underlying labyrinth visible. Clearly visible is the first recess 15 in the longitudinal direction of the zipper Z, which extends substantially below the respective male part 27 and the female part 28 of the zipper Z, respectively. In the present case, a first base 29 protrudes from the plane of the drawing. Clearly visible in the present case, three second recesses 13 in the transverse direction of the zipper Z in the direction of the bag interior 23 (the interior 60 of the bag 20 facing ends of the labyrinth) have substantially larger inflow than in the direction of the head portion 24 (the exterior 70 facing Ends of the labyrinth) of the bag 20. The third sealing regions 14 bound the first recess 15 in the longitudinal direction of the bag 20 and at the same time also form the longitudinal sealing seams of the bag 20. The openings emerging from the head region 24 openings of the labyrinth Steam 16 is shown schematically. Needless to say, this vapor 16 can, of course, only escape from the bag 20 when the head of the bag 20 has been torn away along the tear zone 26, which in the present case was created by laser weakening the film of the bag 20.

In the Fig. 6 the tool 40 for establishing the connection between the base 29 of the part 27 and the base 30 of the part 28 of the zipper Z and the inner surface of the plastic film of the bag 20 is shown. This tool 40 has a first tool part 17 and a second tool part 18, which are designed substantially symmetrical to one another, and have mutually corresponding sealing zones 40A, with the aid of which in the Fig. 3 or 4 illustrated first seal areas 11 and the second seal areas 12 can be realized. Clearly visible is also located between the sealing zones 40A longitudinal recess or longitudinal recess 19A, by means of which the first recess 15 is realized in the longitudinal direction of the zipper Z. The two tool parts 17 and 18 are - as in the Fig. 7 shown assembled in use (see arrows P1 and P2) so that the sealing zones 40A are opposite and between them the plastic film or the respective male part 27 or the female part 28 positioned on the plastic film are located. By pressure and heat, the first base 29 and the second base 30 is finally connected to the inner surface of the plastic film, so that the first sealing region 31 and the second sealing region 32 with the structure of the recesses 15 and 13 arise. In the transverse direction of the longitudinal notch 19A, transverse notches 19B are formed which substantially form a truncated triangle truncated triangle structure or in other words a truncated cone cross-sectional structure and are provided for forming the second recesses 13 in the transverse direction of the zipper Z. The transverse notches 19B realized between the first base 29 and the second base 30 thus have a conical taper from the interior of the bag 23 to the head region 24, whereby a valve effect is formed which counteracts the escape of the steam 16.

The dimension and the geometries of the recesses are harmonized with the internal opening force of the Zipper Z and the bag size in that the steam pressure during cooking does not exceed the force required to open the Zipper Z.

For example, with a bag size of 200x140mm with a zipper with 12 / 25N / 50mm opening force, 3 triangular openings each with a width of 20/5 mm are placed on both the front and the back of the bag. The larger width information always refers to the product direction of the opening. Preferably, however, a zipper with an opening force of 7.5 / 18N / 50 mm can be used for relatively large openings. For relatively small openings, a zipper with an opening force of 12/27 N / 50 mm is preferred. With regard to the indication of the opening force of the zipper, it should be explained at this point that the notation is e.g. 12 / 25N / 50mm, it is necessary to apply force from the exterior of the bag to the zipper of 12N per 50mm to open it, whereas force from the inside of the bag to the zipper of 25N per 50mm is required to to open this.

It should be noted at this point, however, that the shape of the taper can not be rectilinear, but also follow a curve, as in the FIGS. 8 to 10 is shown. Stair-like structures with sharp edges can also be used.

It should also be noted that the first sealing area 31 and the second sealing area 32 need not be provided at identical locations. Rather, the second recesses 13 formed in the respective sealing region 31 or 32 in the transverse direction of the zipper Z may also exist at different locations with respect to the male part 27 and the female part 28, possibly contributing to better stress reduction in the area of the zipper Z , Likewise, it should be mentioned that only one of the sealing regions 31 or 32 can have said second recesses 13 in the transverse direction of the zipper Z.

It is finally pointed out once again that the bag described above in detail as well as the illustrated tool and the method are merely exemplary embodiments which can be modified by the person skilled in many different ways without departing from the scope of the invention. For the sake of completeness, it is also pointed out that the use of indefinite articles does not exclude "a" or "one", that the characteristics in question can also be present multiple times.

Claims (12)

1. A reclosable bag (20) which is suitable for cooking food and which has a device for the escape of steam, comprising a flexible plastic film or a flexible plastic film composite having an outer and an inner surface, wherein a zipper (Z) is provided on the inner surfaces (50) of the plastic film and the two parts of the zipper (Z) are fixed on the opposite inner surfaces (50) of the bag (20) and which allows reclosable access to the packaged goods, wherein the zipper (Z) is connected to the inner surface (50) of the plastic film in such a manner that between the welded regions (12, 14) between the zipper (Z) and the inner surface (50) of the plastic film, recesses (15, 13) are left free in the longitudinal direction of the zipper (Z) to form a seal-free longitudinal channel and in the transverse direction of the zipper (Z) to produce free air or steam passage openings at defined distances between the zipper (Z) and the inner surface (50), through which openings a passage of steam is possible, wherein the dimension and the geometry of the recesses is harmonised with the internal opening force of the zipper (Z) and the bag size insofar that the steam pressure during cooking does not exceed the force required to open the zipper (Z) and wherein ends of the openings facing the interior (60) of the bag (20) are larger than ends of the openings facing the exterior (70) of the bag (20).
2. The reclosable bag (20) according to claim 1, characterised in that the front and rear wall of the bag (20) consists of a plastic film consisting of polypropylene, higher-density polyethylene or copolymers or blends thereof.
3. The reclosable bag (20) according to claim 1, characterised in that the front and rear wall of the bag (20) consists of a plastic composite film, wherein the outer layer of the composite consists of polyester such as oriented PET, amorphous PET, polyolefins such as polypropylene, cast-PP, blown, stretched, biaxially stretched PP films or polycarbonate, cellophane, polyamide or copolymers thereof. The outer layer can, for example, consist simultaneously of several layers of the above polymers in combination with aluminium film.
4. The reclosable bag (20) according to claim 3, characterised in that the inner layer consists of polyethylene, EVA, polypropylene and/or copolymers or terpolymers thereof.
5. The reclosable bag (20) according to any one of claims 1 to 4, wherein a boundary (80) interrupted by the longitudinal channel exists between the ends of the openings facing the interior (60) of the bag (20) and the ends of the openings facing the exterior (70) of the bag (20) and this boundary runs rectilinearly.
6. The reclosable bag (20) according to any one of claims 1 to 4, wherein a boundary interrupted by the longitudinal channel exists between the ends of the openings facing the interior (60) of the bag (20) and the ends of the openings facing the exterior (70) of the bag and this boundary (80) runs in a curved manner.
7. The reclosable bag (20) according to any one of the preceding claims, wherein the recesses in the transverse direction of the zipper (Z) on one inner surface (50) exist at different positions from the recesses in the transverse direction of the zipper on the other inner surface (50).
8. The reclosable bag (20) according to any one of claims 1 to 6, wherein the recesses in the transverse direction of the zipper are only formed between the zipper (Z) and one of the two inner surfaces (50).
9. The reclosable bag (20) according to any one of claims 1 to 7, wherein the openings are formed between the zipper (Z) and both of the one inner surface (50) and the other inner surface (50).
10. A tool (40) for making a connection between a zipper (Z) and an inner surface of a plastic film which is intended as a bag wall of a bag (20), wherein the tool (40) has sealing zones (40A) which are configured to seal a part of the zipper (Z) with the inner surface (50) of the plastic film and wherein the sealing zones (40A) are interrupted by notches or recesses (19A, 19B) in the longitudinal direction of the zipper (Z) to form a seal-free longitudinal channel and in the transverse direction of the zipper (Z) to form free air or steam passage openings at defined distances between the zipper (Z) and the inner surface (50), wherein the dimension and the geometry of the notches or recesses (19A, 19B) is harmonised with the internal opening force of the zipper (Z) and the bag size insofar that the steam pressure during cooking does not exceed the force required to open the zipper (Z) and wherein ends of the openings facing the interior (60) of the bag (20) are larger than ends of the openings facing the exterior (70) of the bag (20).
11. The tool (40) according to claim 10, wherein the tool (40) has two mutually corresponding tool parts (17, 18) between which both a part of the zipper (Z) and the plastic film can be positioned, wherein under the action of pressure and temperature the connection within the sealing zones (40A) can be made between the zipper (Z) and the inner surface (50).
12. A method for making a connection between a part of a zipper (Z) and an inner surface (50) of a plastic film which is intended as a bag wall of a bag (20), which method comprises the following process steps, i.e. positioning the part of the zipper (Z) on the inner surface (50) of the plastic film and
    making a connection within the sealing regions (31, 32) between the part of the zipper (Z) and the inner surface (50) of the plastic film, with the aid of the tool (40) according to claim 10.

Images