CN107416352B

CN107416352B - Film package and method for packaging a product in a film package

Info

Publication number: CN107416352B
Application number: CN201710082291.7A
Authority: CN
Inventors: W·索伯
Original assignee: Mondi Consumer Packaging Technologies GmbH
Current assignee: Mondi Co ltd; Nitto Advanced Film Gronau GmbH
Priority date: 2016-02-16
Filing date: 2017-02-16
Publication date: 2020-07-28
Anticipated expiration: 2037-02-16
Also published as: US20170233157A1; JP2017145051A; EP3208211A1; EP3208211B1; DE102016102691A1; CN107416352A

Abstract

The invention relates to a film package (1) comprising a front side (2) extending in a longitudinal direction (l) and a transverse direction (q) and a back side (3) extending in the longitudinal direction (l) and the transverse direction (q). The front side (2) and the rear side (3) are connected to each other by a transverse sealing seam (6) extending in the transverse direction (q) and forming a closing edge (5) of the film package (1). According to the invention, at least two weakening lines (7) extending in the longitudinal direction (l) are provided on the front side (2) and the rear side (3), respectively, and extend in the longitudinal direction (l) over the entire front side (2) and the entire rear side (3). The invention further relates to a method for packaging products (14) in a film package (1), in particular according to the invention.

Description

Film package and method for packaging a product in a film package

Technical Field

The present invention relates to a film package comprising a front side extending in a longitudinal direction and a transverse direction and a back side extending in the longitudinal direction and the transverse direction. The front side and the rear side are connected to each other by a transverse sealing seam extending in the transverse direction. The transverse sealing seam simultaneously forms a closed edge of the film package in the sense that the transverse sealing seam isolates the package interior arranged between the front side and the rear side in the longitudinal direction with respect to the environment for accommodating the product. It is not harmful here that the front side and/or the rear side project in the longitudinal direction from the side of the transverse sealing seam facing away from the interior of the package. The subject of the invention is also a method for packaging products, in particular in a film package according to the invention.

Background

The same type of film package can be produced particularly simply in the so-called "form-fill" (FFS) method and filled simultaneously. Here, a film material is supplied for forming a front side extending in the longitudinal and transverse directions and a back side extending in the longitudinal and transverse directions, thereby forming a package inner space between the front side and the back side. The product is arranged in the package interior space between the front side and the back side, and the package interior space is subsequently closed at least by a transverse sealing seam connecting the front side and the back side and extending in the transverse direction.

This type of method is used on a large scale in automated packaging lines in order to provide any product with an easy-to-handle outer package made of film material. The method is also suitable for any product type. Such products, in particular in the form of rectangular parallelepipeds or rods, are particularly well suited for such packaging methods. However, bulk materials such as iron sand, powder and even liquids can also be processed in the FFS process, when the process is carried out vertically as a so-called vffs (vertical FormFill seal) process. The film package is first prefabricated in such a way that it is sealed off both laterally and on the underside, so that the bulk product can be poured in from above. The film package is then closed by a transverse sealing seam on the head side.

In order to be able to withstand the high mechanical requirements of transport and bag formation, film materials having high strength are preferably used for carrying out the FFS method. Preferably oriented or biaxially oriented polymer films such as OPET (oriented polyethylene terephthalate) or BOPP (biaxially oriented polypropylene) are used. Cellulose-based film layers are also particularly well suited for the application purposes.

However, these materials have the disadvantage that they have unpredictable crack characteristics. Although the material layer made of said material can be easily torn, the crack propagation then proceeds largely randomly. In multilayer film composites with other functional layers, for example sealing or cover layers, the crack behavior is also determined almost exclusively by the brittle layers. Therefore, the film package manufactured in the FFS method can be opened only by tearing by a user with a very limited limit. It is generally preferred that the film package is opened by separating at least one sealing seam. This is for example known in the field of snack packaging.

It is desirable, however, to also provide certain tear characteristics in modern FFS packages. This may be necessary in order to reproducibly produce an opening of sufficient size, for example in a rod-shaped product. Whereby the product can be removed, for example, entirely. Openings defined in the bulk material are also indispensable in order to prevent uncontrolled pouring. At the same time, however, easy manufacturability should also be maintained.

Disclosure of Invention

The solution of this task and the subject of the invention is a film package comprising a front side extending in a longitudinal direction and a transverse direction and a back side extending in a longitudinal direction and a transverse direction, wherein the front side and the back side are connected to each other by a transverse sealing seam extending in the transverse direction, which forms a closing edge of the film package, at least two weakening lines extending in the longitudinal direction are provided on the front side and the back side, respectively, which weakening lines extend in the longitudinal direction over the entire front side and the entire back side, which weakening lines are limited in the transverse direction to the middle third of the front side and the back side of the film package.

In the method according to the invention for packaging a product in a film package according to the invention, a film material is supplied, to form a front side extending in the longitudinal and transverse directions and a back side extending in the longitudinal and transverse directions, thereby forming a package interior space between the front side and the back side, wherein the product is arranged in the package interior between the front side and the back side and the package interior is subsequently closed at least by a transverse sealing seam connecting the front side to the back side and extending in the transverse direction, at least two weakening lines extending in the longitudinal direction are provided on the film material supplied for forming the front side and on the film material supplied for forming the back side, respectively, the weakening lines extending in the longitudinal direction over the entire length of the front side and the back side, wherein the weakening line is arranged on the supplied film material in such a way that it is arranged in the transverse direction of the film package in the middle third of the front and back sides of the film package.

The same type of film package has a front side extending in the longitudinal and transverse directions and a back side extending in the longitudinal and transverse directions. The front side and the back side are connected to each other by a transverse sealing seam running in the transverse direction, which forms a closed edge of the film package. According to the invention, at least two weakening lines extending in the longitudinal direction are provided on the front side and the back side, respectively, said weakening lines extending in the longitudinal direction over the entire front side and the entire back side. The front side and the back side have preferably at least one plastic layer comprising an oriented polymer, in particular OPET or BOPP. With the arrangement according to the invention, reliable and reproducible tear properties can also be ensured in film packages of film material, such as OPET or BOPP, which are prone to uncontrolled crack formation. The transverse sealing seam forming the closure edge can be torn off simply and at a defined location, whereby a crack is guided between two adjacently arranged weakening lines.

The weakening lines are linear or strip-like regions of the film material, which regions have a reduced mechanical resistance. Crack propagation in the film material can be controlled by weakening lines, since cracks tend to propagate into the area with the smallest mechanical strength. The weakening lines may in particular be produced by a reduction of the material thickness and/or a local change of the material properties, as may occur either at the time of manufacture of the film material or afterwards. The weakening line can be formed in particular continuously or locally interrupted. A locally interrupted weakening line is understood here in the sense of the present invention as a perforation which has a uniformly repeating pattern over its entire longitudinal extension.

The at least two weakening lines are suitably provided on the same outer surface of the front side or the back side, respectively. Preferably, they have the same penetration depth into the material of the front side or back side and extend in a multilayer structure into the same partial layer. Particularly preferably, the at least two weakening lines are identically constructed.

By providing a plurality of weakening lines both on the front side and on the rear side according to the invention, a particularly advantageous opening of the film package is allowed. Here, the film package is separated longitudinally by tearing between two weakening lines. In this way, rod-shaped products can project only partially from the opening in the case of a partial opening from the head side and can thus be used in one piece. The food bar may be consumed, for example, like a partially opened banana. Alternatively, the product can be removed entirely in the transverse direction after completely separating half of the bag package.

It is particularly advantageous if the film wrapper has a greater extension in the longitudinal direction (longitudinal extension) than in the transverse direction (transverse extension). A particular advantage can be achieved in that the longitudinal extent is more than 1.5 times, in particular more than twice, the transverse extent, since then small deviations can already be prevented when cracks propagate, so that the film package can be cleanly separated in the longitudinal direction.

By means of the parallel guidance of at least two longitudinally running weakening lines on the front side and the rear side, respectively, a substantially straight tear behavior can be ensured in the film package according to the invention despite the presence of the rigid film part. At the same time the risk of tearing along the weakening line during the packaging process is minimal, since the film material is mainly subjected to tensile forces and is stabilized by the connecting means extending in the transverse direction for producing the transverse sealing seam. Shear forces or bending moments introduced perpendicular to the front side or the back side, which could cause cracks, hardly occur. This is particularly applicable when the longitudinal direction of the front side and the back side is the same as the machine direction in which the film material is transported during the packaging process.

The transverse sealing seam preferably extends over the entire width of the front side and the rear side. This makes it possible to achieve a sealed closure on the closure edge without further aids. Furthermore, the film package is stabilized over the entire width by the transverse sealing seam. Depending on the field of application, the transverse sealing seam can be constructed by heat sealing or cold sealing. Adhesive connections are also possible within the scope of the invention.

It is particularly preferred to provide the tear-off aid on the transverse sealing seam. The introduction of cracks into the transverse sealing seam can thereby be simplified. The tear-assisting means may be formed, for example, as at least one notch or a serrated cut edge. The tear-assist means can extend over the entire width of the transverse sealing seam or be limited to the region in which crack introduction should preferably take place. In particular, the tear-assisting means are arranged only in the region between the weakening lines and not in the edge region between the lateral outer edge of the film package and the nearest weakening line.

It is particularly preferred that the weakening lines are oriented parallel to each other. Thereby, zones with a constant width can be provided for crack propagation.

Particularly preferably, at least three weakening lines are arranged equidistantly in the transverse direction on the front side and/or the back side, respectively. Thereby, the location of crack introduction can be determined by the user in a larger area. However, the primary introduced crack in the channel formed by the two weakening lines located closest thereto propagates almost linearly up to the opposite closing edge of the film package.

Preferably, the weakening lines are distributed over the entire width of the front side and/or the back side in the transverse direction. The user is thereby given a particularly free choice as to which region he wishes to tear the package.

In another preferred design, the weakening line is limited to one area in the transverse direction. This makes it possible for the user to indicate that the film package is torn open in the region of the marking. This can additionally be assisted by correspondingly positioned tear-assist means and/or optical markings of the region. This occurs in particular if the product is to be contacted directly, preferably only in certain areas. Desirably, the region in which the line of weakness is provided is a half. It may also be expedient to provide the weakening line in the middle or one or both outer thirds of the film package.

Preferably, at least the outer, that is to say lateral, package edge is oriented parallel to the longitudinal direction at the next weakening line. The crack propagation thus takes place in each case in such a way that lateral bag edges are not reached here. Thereby, a complete separation of the film packages is possible.

It is particularly preferred that each weakening line on the front side is oriented in line with the weakening line on the back side. The same boundary conditions result from the crack formation not only on the front side but also on the rear side.

In a preferred embodiment, the front side and the rear side are formed by a single film section. The film section may be provided continuously over its entire width with weakening lines. The film section can be closed off expediently by means of a so-called slot, in which a part of the inner side of the film section is connected to another part of the inner side of the film section, or an overlap region with the film tube.

Preferably, the front side and the back side are connected by a lateral fold on at least one lateral edge. The lateral fold can be formed by the same film section as the front side and/or the back side or by a separate film section. By the lateral folding portion, the bag inner space can be enlarged and the stacking characteristic can be improved. Preferably, the lateral folds are not formed with weakening lines in order to limit crack propagation to the front side and the back side. Alternatively or additionally, the film package may be equipped with a test stand bottom on the side opposite the transverse sealing seam.

One preferred film material for forming the film package according to the invention is a multilayer laminate comprising an outer layer of BOPP having a thickness of 20 μm and an inner layer of metallised biaxially oriented polypropylene (metBOPP) connected to the outer layer by a composite adhesive layer, also having a thickness of 20 μm. The metallized polymer layer acts as a barrier to water vapor and oxygen transmission. The outer layer may be provided with impressions on the inner side facing the inner layer. The outer layer is substantially transparent so that the impression is visible from the outside and it is protected from damage by the outer layer. If the film package is to be closed in a cold-sealing process, a cold-sealing adhesive layer can additionally be applied on the inner side of the inner layer.

The invention proceeds from a method for packaging products in a film package, wherein film material is supplied for forming a front side extending in a longitudinal direction and a transverse direction and a back side extending in the longitudinal direction and the transverse direction, so that a package interior space is formed between the front side and the back side. The product is disposed in the package interior space between the front side and the back side. The package interior is subsequently closed by at least one transverse sealing seam connecting the front side and the rear side and extending in the transverse direction. According to the invention, at least two weakening lines extending in the longitudinal direction are provided on the front side and the back side, respectively, said weakening lines extending in the longitudinal direction over the entire length of the front side and the back side. The method is particularly suitable for providing a film package according to the invention.

In a preferred design, the film material for the front side and the back side is supplied continuously. After packaging, the film wrapper with the product contained therein is cut to length after or during the formation of the transverse sealing seam. Where the film material is slit in the region of the transverse sealing seam. Alternatively, it is also possible for the film material to be cut only partially, in particular in the form of perforations. This gives a theoretical breaking point which can be opened afterwards by the user or by the machine.

Suitably, a full or partial separation line extends through the sealing seam. This leaves regions on both sides of the separating line, in which the front side and the rear side are connected to one another. A part of the transverse sealing seam which thus closes the bag interior space of the film package can simultaneously function as a foot sealing seam for defining a film bag which is subsequently produced in a continuous process. At the same time, the sealing seam forms a closure of the film package in the longitudinal direction, so that the front side and the rear side are inseparable from one another and can be torn apart jointly.

It is furthermore expedient for the film package to be provided with tear-off aids on the closure edge. The tear-assisting means can be designed, for example, as a sawtooth profile. It is particularly preferred that this can take place simultaneously with the cutting of the continuously produced film packages. Preferably, the tear-assist means is arranged such that it can act between the longitudinally extending weakening lines. Thereby facilitating the initiation of a crack between the at least two weakening lines, so that the crack cannot be subsequently transferred uncontrolled to the lateral ends of the film package.

Preferably the film material with preformed weakening lines for the front and/or back side is supplied as a semi-finished product. The packaging device can thus be designed overall more compactly, since no prior manufacturing and/or reworking of the film material is necessary. It is also possible to use prefabricated multilayer laminates as film material in a particularly simple manner, the weakening lines being formed at the inner layers or at the inner boundary surfaces of the layers. Thereby creating a uniform and important impression outwardly through the film laminate. When the longitudinal direction coincides with the machine direction, the transport device can furthermore be designed very simply, since the front side and the rear side do not have to be arranged in a defined position relative to one another.

In a further preferred embodiment, the weakening lines are worked into the front side and/or the rear side before injection into the product. For this purpose, laser cutting, punching, mechanical material removal (so-called screening) or mechanical embossing are suitable in particular. It is also advantageous here that the longitudinal direction coincides with the machine direction, since the weakening lines can then be introduced continuously and without synchronization.

Suitably, the film hose is formed from a single web of material prior to injection of the product, said film hose having a front side and a back side. The membrane hoses can be closed by so-called wing seams or by an overlap connection.

Drawings

The invention is explained below with the aid of the figures, which only show exemplary embodiments. Wherein schematically:

FIG. 1 is a top view of a film package according to the present invention;

FIG. 2A is a method according to the present invention as a design of a VFFS process;

FIG. 2B is a design of the method according to the invention as a HFFS process;

FIG. 3A is another embodiment of an opened film package; and

fig. 3B is yet another embodiment of a partially opened film wrapper.

Detailed Description

Fig. 1 shows a film package 1 according to the invention, comprising a front side 2 extending in a longitudinal direction l and a transverse direction q. Here, the extension of the film package 1 in the longitudinal direction l (longitudinal extension) is greater than the extension in the transverse direction q (transverse extension). Behind and covered by the front side 2, a rear side 3 is provided, which likewise extends in the longitudinal direction i and the transverse direction q. The front side 2 and the rear side 3 are connected to one another at the lateral edges 4 of the film package 1, forming a circumferential film tube. On the upper and lower closing edge 5, the front side 2 and the rear side 3 are connected to each other by a transverse sealing seam 6. The package interior arranged between the front side 2 and the rear side 3 is thereby hermetically closed. According to the invention, a plurality of weakening lines 7 are provided not only on the front side 2 but also on the back side 3, said weakening lines extending in the longitudinal direction l over the entire front side 2 and the entire back side 3.

In the present exemplary embodiment, the transverse sealing seam 6 extends not only on the upper side but also on the lower side in the transverse direction q over the entire width of the front side 2 and the rear side 3. On the closing edge 5, a tear-off aid 15 in the form of a sawtooth incision into the transverse sealing seam 6 is provided, which likewise extends in the transverse direction q over the entire width of the film package 1. The weakening lines 7 are arranged parallel to each other and with respect to the longitudinal direction l of the film package 1 and are distributed equidistantly between the outer edges 4 in the transverse direction q over the entire width of the film package 1.

Fig. 2A shows an exemplary embodiment of a method according to the invention, with which an embodiment of a film package according to the invention can be produced. The film material 8 used to form both the front side 2 and the rear side 3 of the film package 1 is drawn off from the roll as a prefabricated semifinished product. Here, weakening lines 7 have been provided in the film material 8, which weakening lines extend parallel to the transport direction of the film material 8. The web of film material 8 is then folded such that its lateral edges 9 lie against one another in such a way that the inner faces of the film material 8 connected to the lateral edges 9 lie flat against one another. In this region, the film material is connected to itself by a so-called fin seam, so that a circumferential film hose 10 is produced. The product 14, which may also be in bulk, can be injected into the membrane hose through a filling funnel 11. In the subsequent combined cutting and sealing station 12, a transverse sealing seam 6 is formed on the film tube 10 transversely to the transport direction and is at the same time split approximately centrally in its direction of extent. The film package 1 according to the invention is thus separated from the film tube 10 and the film tube is simultaneously closed by the upper transverse sealing seam. At the same time, a foot seam is also formed, which closes the remaining film tube 10 and thus forms the basis for the subsequently produced film bag 1.

Synchronization between the movement of the web of film material 8 and the sealing station 12 is not necessary, since the weakening line 7 extends in the transport direction anyway. It is furthermore possible to produce film packages 1 of different sizes from the same film material 8 by: the tempo of the sealing station is varied in relation to the transport speed of the film material 8.

In fig. 2B, an alternative method embodiment is shown as an HFFS (horizontal FFS) device. Here, the film material 8, 8' provided for forming the front side 2 and for forming the back side 3 is supplied as separate film webs. Both of which have been provided with weakening lines 7 extending in the transport direction. The products 14 are deposited by means of a conveyor device, not shown, onto the film material 8 guided on the conveyor belt 13 for forming the rear side 3. The film material is subsequently covered with the film material 8' used to form the front side 2. The front side 2 and the back side 3 are connected to each other in the region of the lateral edges 4 by a longitudinal sealing seam. Subsequently, a transverse sealing seam running transversely to the transport direction is introduced into the combined cutting and sealing station 12, which transverse sealing seam connects the front side 2 to the rear side 3. While the transverse sealing seams 6 are divided for severing the respective film package 1 in its longitudinal direction.

Fig. 3A and 3B show possible variants for opening the film package according to the invention in two exemplary embodiments. In fig. 3A not only the weakening lines 7 but also the tear assisting means 15 are provided only in the left half of the film package 1. The film package can be separated in this region by tearing at the tear-assist means 15 and a crack running on or between the weakening lines 7. A smaller part of the film package is subsequently removed, so that in this embodiment the cuboid-shaped products 14 project laterally from the package interior between the front side 2 and the back side 3. The product 14 is already usable in this state or can be taken out in the transverse direction q.

In a further variant according to fig. 3B, the weakening line 7 and the tear-assisting means 15 are provided only in the middle third of the front side 2 and the rear side 3 of the film package 1. The film package 1 is partially torn from the closing edge 5 and pulled off on the upper edge. Whereby the product 14 in the form of a stick in the present embodiment protrudes in the longitudinal direction i from the opening. The product 14 can thus be handled reliably without having to touch it.

Claims

1. Film package (1) comprising a front side (2) extending in a longitudinal direction (l) and a transverse direction (q) and a back side (3) extending in the longitudinal direction (l) and the transverse direction (q), wherein the front side (2) and the back side (3) are connected to each other by a transverse sealing seam (6) extending in the transverse direction (4) forming a closing edge (5) of the film package (1), at least two weakening lines (7) extending in the longitudinal direction (l) being provided on the front side (2) and the back side (3), respectively, said weakening lines extending in the longitudinal direction (l) over the entire front side (2) and the entire back side (3), characterized in that the weakening lines (7) are limited in the transverse direction (q) to the middle third of the front side (2) and the back side (3) of the film package (1).

2. A film package (1) according to claim 1, wherein said transverse sealing seam (6) extends over the entire width of the front side (2) and the back side (3).

3. A film package (1) according to claim 1, wherein tear-assist means (15) are provided on the transverse sealing seam (6).

4. A film package (1) according to claim 1, wherein said weakening lines (7) are oriented parallel to each other.

5. A film package (1) according to claim 1, wherein at least three weakening lines (7) are provided on the front side (2) and the back side (3), respectively, wherein the weakening lines (7) on the front side (2) and/or the back side (3) are provided equidistantly in the transverse direction (q) between the leftmost weakening line and the rightmost weakening line.

6. A film package (1) according to claim 1, wherein at least the outer weakening line (7) is oriented parallel to the longitudinal direction (l).

7. A film package (1) according to claim 1, wherein said front side (2) and back side (3) are formed by a single film section.

8. A film package (1) according to claim 1, wherein said front side (2) and back side (3) are interconnected by a lateral fold on at least one lateral edge (4).

9. Method for packaging a product (14) in a film package (1) according to one of claims 1 to 8, wherein film material (8) is supplied to form a front side (2) extending in a longitudinal direction (l) and a transverse direction (q) and a back side (3) extending in the longitudinal direction (l) and the transverse direction (q) to form a package inner space between the front side (2) and the back side (3), wherein the product is arranged in the package inner space between the front side (2) and the back side (3) and is subsequently closed at least by means of a transverse sealing seam (6) connecting the front side (2) with the back side (3) and extending in the transverse direction (q), at least two weakening lines (7) extending in the longitudinal direction being provided on the film material (8) supplied for forming the front side (2) and on the film material (8, 8') supplied for forming the back side (3), respectively, the weakening line extending in the longitudinal direction over the entire length of the front side (2) and the back side (3), characterized in that the weakening line (7) is provided in the supplied film material (8, 8') in such a way that the weakening line (7) is provided in the transverse direction (q) of the film package (1) in the middle third of the front side (2) and the back side (3) of the film package (1).

10. A method according to claim 9, characterised in that the film material (8, 8') for the front side (2) and the back side (3) is supplied continuously and that the film package (1) containing the products (14) therein is cut to length during or after the formation of the transverse sealing seam (6).

11. A method according to claim 9, characterized in that the film material (8, 8') for the front side (2) and the back side (3) with preformed weakening lines (7) is supplied as a semi-finished product.

12. Method according to claim 9, characterized in that the weakening lines (7) are worked into the front side (2) and the back side (3) before the injection of the product.

13. A method according to claim 12, wherein the weakening line is produced by laser cutting, stamping, mechanical material removal or mechanical embossing.

14. Method according to claim 9, characterized in that a film hose (10) is formed from the single web of film material (8) before the injection of the product (14), said film hose having a front side (2) and a back side (3).