US20100226598A1

US20100226598A1 - Film package

Info

Publication number: US20100226598A1
Application number: US12/652,929
Authority: US
Inventors: Detlef STOEPPELMANN
Original assignee: Individual
Current assignee: Mondi Jackson LLC
Priority date: 2009-01-10
Filing date: 2010-01-06
Publication date: 2010-09-09
Also published as: DE202009000302U1

Abstract

A film bag has a multi-layered film whose outer layer forms and outer side of the film bag and whose inner layer forms the inner side of the film bag. The bag further has two oppositely directed face panels on which weld seams are disposed laterally and having a linear tearing aid which is disposed in the face panels in the region of the top of the film bag and which has three weakening lines spaced apart from one another. The two outer weakening lines begin at a distance A from a lateral edge of the face panels, and the middle weakening line begins directly at the lateral edge of the face panels and merely extends along a part of the tearing aid.

Description

FIELD OF THE INVENTION

The present invention relates to a film bag.

BACKGROUND OF THE INVENTION

A typical film bag comprises a multi-layered film whose outer layer forms the outer side of the film bag and whose inner layer forms the inner side of the film bag. The film comprises two oppositely directed face panels on which weld seams are disposed laterally. The film further comprises a linear tearing aid which is disposed in the face panels in the region of the top of the film bag and which comprises three weakening lines spaced apart from one another.
Film bags are known in various designs from practice and are used inter alia for airtight and moisture-proof packagings of fodder and foodstuffs. In order that the consumer can open the bag more easily, the film is frequently weakened along one line so that it can be opened by tearing movements. Such a tearing aid is described in the document EP 0 473 517 (U.S. Pat. Nos. 5,158,499 and 5,630,308). This discloses the use of a laser for producing the tearing aid whereby a laminated packaging film is notched or weakened along one, but in particular three, identically formed lines. The additional weakening lines are intended to improve the tearing aid. Nevertheless it can occur with such tearing aids that during the tearing movement of the user, the tear does not run along one of the weakening lines but begins at one of the outer weakening lines, departs from this and from there propagates uncontrollably in the film. This is particularly the case when the tearing movement is executed too vigorously and the forces acting on the film are too large. However, the tear propagation can also be perturbed by an orientation of the tearing forces which deviates from the conventional orientation. A possible consequence of this uncontrolled tear propagation is, for example, that the opening of the bag becomes too large, with the result that the contents can emerge uncontrollably from the bag.

OBJECT OF THE INVENTION

Against this background, it is the object of the invention to provide a film bag in which the function of the tearing aid is improved, whereby in particular uncontrolled tear propagation should be avoided.

SUMMARY OF THE INVENTION

The object is achieved by the two outer of the three weakening lines beginning at a distance A from a lateral edge of the face panels and by the middle weakening line beginning directly at the lateral edge of the face panels and merely extending along a part of the tearing aid. In this way it is achieved that the tear produced by the tearing movement begins initially at the middle weakening line. From there it propagates preferably as far as the end of the middle weakening line, wherein this merely extends along a part of the entire tearing aid. The tear line moves from there either to the first or to the second outer weakening line. On which of the two outer weakening lines the tear propagates after leaving the middle weakening line is dependent on the direction of the acting tearing forces. If the forces are too strong in this case, it can occur that at any point between the initial and the end point of the middle weakening line, the tear line departs from the weakening line. In this case, the tear line only propagates uncontrollably until it reaches one of the outer weakening lines and from there is again guided along the tearing aid. Thus the outer weakening lines which are preferably disposed at a distance of a few millimeters from the middle weakening line also continually take on the function of a security weakening line which is used precisely when the tear line leaves the middle weakening line. Since the outer weakening lines according to the invention are at a distance from the lateral edge of the bag, this ensures that when tearing, the tear always propagates initially along the middle weakening line. The arrangement of the three weakening lines according to the invention therefore ensures that when tearing the bag, the tear does not initially propagate along one of the outer weakening lines and if possible leaves the weakening line in an uncontrolled manner from there.
In a preferred embodiment of the film bag according to the invention, it can be provided that the two outer weakening lines end at a top edge of the face panels of the film bag. The tearing aid thus begins at one of the lateral edges and ends at the top ends of the bag. This arrangement brings about advantageous ergonomics since the consumer can hold the bag with one hand and can tear the top or one corner of the packaging pouch with the other hand in a swing movement. On the other hand, the arrangement of the tearing aid specifies a defined pouring region which can have the function of a pouring spout.
In this context, it can be expedient if the two outer weakening lines have at least one bend and/or are curved in an arcuate manner in certain areas. In this way, it is possible to assign a specific shape or a specific profile to the entire tearing aid which in addition to the shorter middle weakening line, comprises the two substantially continuous outer weakening lines, which improves the entire handling of the bag during the tearing process.
It is also expedient if the two outer weakening lines pass through the outer layer at least in part. In this way, the bag is only weakened in the region of the outer layer of the film along the outer weakening lines extending substantially over the entire length of the tearing aid. The seal of the bag is not substantially impaired by the outer weakening lines which merely penetrate into the outer layer of the films.
In a preferred embodiment of the film bag according to the invention, it is additionally provided that the two outer weakening lines are formed by a laser seam. The film should preferably be selected in this case so that the laser radiation of a laser tool used is strongly absorbed by the outer layer of the film and weakly absorbed by the inner layer of the film. This avoids the film being completely cut through by the action of the laser tool. The avoidance of completely cutting through is particularly important when the film bag according to the invention is to be used for the bag of fodder, foodstuffs or liquids and must be tightly sealed in this case.
In the film bag according to the invention, it can preferably be provided that the middle weakening line is formed by punching. A punched weakening line can be produced in a particularly simple and comparatively cost-effective manner. At the same time, it can be expedient if the middle weakening line passes completely through the outer layer and at least incompletely through the inner layer. Since the middle weakening line consequently also weakens the lower film layer, the tearing process is made easier. The film is accordingly significantly thinner in the region of the middle weakening line compared with that at other locations and can therefore be torn without a large expenditure of force. Since the lower film layer is not completely but only partially weakened in the region of the middle weakening line, the seal of the film bag is still ensured. According to the invention, it is provided that the middle weakening line only extends over the length of the entire tearing aid in certain areas. In this way, the region of the tearing aid where both the upper and also the lower film layer is weakened is reduced. As a result, the local diffusion of gas or liquid, for example, which can enter into the bag or escape from the bag, is is merely restricted to the small region formed by the comparatively short middle weakening line. The risk of a leak in the region of the tearing aid is reduced by the arrangement of the three weakening lines according to the invention of which only the middle weakening line weakens the lower film. In addition, the risk of unintentional opening of the bag is reduced by the short design of the weakening line. Such accidental opening can possibly occur when carrying a packaging pouch. Lifting the bag is therefore not critical and an intentionally executed tearing movement is required to open it.
A particularly preferred embodiment of the film bag according to the invention is characterized in that V-shaped inset side gussets are disposed at the edge on the face panels, which gussets are delimited by the weld seams at their edges. Such a side-gusseted pouch has the advantage that it has a larger packing volume and at the same time can be stood up or stacked more effectively.
It can be provided that the outer layer of the film bag pouch according to the invention, which forms the outer side of the pouch, is formed from polyester, in particular from polyethylene terephthalate (PET). PET is a layer having good functional properties and attractive appearance which can be printed on the inside if desired and thus forms an expedient material for film bags. It can furthermore be provided that the inner layer of the film bag forming the inner side of the bag is formed from a polyolefin, in particular from polyethylene (PE) and/or polypropylene (PP). Polyolefins are comparatively tough but they are also characterized in that they are inexpensive and at the same time have good sealing properties which are very important for processing.
With a view to facilitating the tearing process, the tearing aid of the film bag according to the invention can have at least one notch and/or an incision at the end. The notch or the incision is more appropriately disposed completely in the weld seam so that no leaks occur. The user of the film bag clearly perceives this notch with the result that he intuitively begins the tearing process in the region of the notch. The notch should in this case preferably adjoin the middle weakening line, i.e. should be disposed at the edge in the region of the lateral weld seams. The tear line thus begins in the notch, propagates from there along the middle weakening line and from there passes to one of the neighboring outer weakening lines until the tearing process is terminated at the end of the tearing aid. In principle, a reclosure can also be provided in the bag in a manner known per se in the region of the opening that is formed.

BRIEF DESCRIPTION OF THE DRAWING

The invention is explained hereinafter with reference to a drawing showing merely one illustrated embodiment. In the figures:

FIG. 1 is a side view of a film bag,

FIG. 2 a is a side view according to FIG. 1 with an alternative embodiment of the tearing aid,

FIG. 2 b is an enlarged section of the tearing aid from FIG. 2 a,

FIG. 3 is a vertical section A-A through the film bag according to FIG. 2 a,

FIG. 4 is a horizontal section B-B through the film bag according to FIG. 2 a and

FIG. 5 is a section of a material web for producing a film bag according to FIG. 2 a.

SPECIFIC DESCRIPTION

The figures show schematically a film bag comprising a multi-layer film, whose outer layer 1 forms the outer side of the film bag and whose inner layer 2 forms the inner side of the film bag. At the same time the film has two oppositely directed face panels 3 on which weld seams 4 are disposed laterally as well as a linear tearing aid which is disposed on the face panel in the region of the top 5 of the film bag and which comprises three weakening lines 6, 6′, 7 spaced apart from one another. It can be deduced from FIG. 1 that the two outer of the three weakening lines 6, 6′ begin at a distance a from a lateral edge 8 of the face panel 3 and that the middle weakening line 7 begins directly at the lateral edge 8 of the face panel 3 and extends at least along a part of the tearing aid.
An advantageous embodiment of the film bag according to the invention can be deduced from FIG. 2 a, wherein the two outer weakening lines 6, 6′ end at the top edge 9 of the face panels 3. At the same time, the two outer weakening lines 6, 6′ have a bend 10. Alternatively to this, it can also be provided that the weakening lines 6, 6′, 7 are curved in an arcuate manner in some areas or along their entire course. An enlarged section of the film bag can be deduced from FIG. 2 b. The two outer weakening lines 6, 6′ which can preferably be formed by a laser seam begin at a distance a from the lateral edge 8 of the film bag. The middle weakening line 7 which is preferably formed by punching begins directly at the lateral edge 8 of the face panel 3 of the film bag. It can also be deduced from FIG. 2 b that the tearing aid comprises at least one notch 11 and/or an incision at one end, wherein the notch 11 directly adjoins the middle weakening line 7 and is formed completely in the region of the associated longitudinal weld seam 4.
FIG. 3 is a vertical section A-A through the film bag according to FIG. 2 a in the section shown enlarged. It can be seen there that the middle weakening line 7 passes completely through the outer layer 1 and at least incompletely through the lower film layer 2. The two outer weakening lines 6, 6′ on the other hand pass through the upper film layer 1 at least in part.
FIG. 4 is a horizontal section along the line B-B in FIG. 2 a. It can be seen here that V-shaped inset side gussets 12 are disposed at the edges on the face panels, which are delimited by the weld seams 4 at their edges. Both the outer two weakening lines 6, 6′ and also the middle weakening line 7 run along the inserted side gussets 12 in this case. In the region of the face panels 3 of the film bag, the middle weakening line 7 extends over a partial region of the tearing aid. With regard to the manufacture of the film bag according to the invention, it is advantageous if the outer layer 1 of the film is not sealable whilst the inner layer 2 of the film is sealable. Consequently, the film can easily be sealed even with an inserted side gusset 12 along the lateral edges 8 without modifying the structure of the outer layer 1. In this case, it is possible that the outer layer 1 of the film is formed from polyester, in particular from polyethylene terephthalate (PET). The inner layer 2 of the film bag can be formed from a polyolefin, in particular from polyethylene (PE) and/or polypropylene (PP).
FIG. 5 is a section through a material web 13 such as is formed to produce a film bag according to FIGS. 2 a, 2 b, 3 and 4. The material web 13 comprises a multi-layered film comprising an outer layer 1 forming the outer side of the film bag and a inner layer 2 forming the inner side of the film bag. The two face panels 3 of the film bag are initially disposed adjacently on the material web 13. The tearing aid is disposed at the upper edge of the material web section shown which subsequently forms the top end 9 of the film bag. This comprises three weakening lines 6, 6′, 7 spaced apart from one another, of which the two outer 6, 6′ of the three weakening lines begin at a distance a from the lateral edge 8 of the face panels 3 of the bag.
It can also be deduced from FIG. 5 that the middle weakening line 7 merely extends along a part of the tearing aid and begins directly at the lateral edge 8 of the face panel 3. To produce a film bag according to FIG. 2 a it is provided that the tearing aid is produced by punching the film in some areas or by providing it with a laser seam. The two outer weakening lines 6, 6′ are preferably produced by a laser tool and the middle weakening line 7 is produced by a punching tool. The two outer weakening lines 6, 6′ are provided with gaps 14. These gaps 14 are located at those places where the lateral edges 8 of the film bag are formed subsequently by folding and sealing the film.
The side gussets 12 are also produced when folding the film bag, these being disposed subsequently between the face panels 3 of the bag. The lateral edges of the face panels 3 are then provided with weld seams 4. The bag is then provided with a notch 11 or an incision in the region of the middle weakening line 7.

Claims

1. A film bag comprising a multi-layered film, whose outer layer forms the outer side of the film bag and whose inner layer forms the inner side of the film bag, comprising two oppositely directed face panels on which weld seams are disposed laterally and comprising a linear tearing aid which is disposed in the face panels in the region of the top of the film bag and which comprises three weakening lines spaced apart from one another, wherein the two outer of the three weakening lines begin to at a distance A from a lateral edge of the face panels and that n the middle weakening line begins directly at the lateral edge of the face panels and merely extends along a part of the tearing aid.

2. The film bag defined in claim 1, wherein the two outer weakening lines end at a top edge of the face panels.

3. The film bag defined in claim 1, wherein the two outer weakening lines have at least one bend or are curved in an arcuate manner in certain areas.

4. The film bag defined in any claim 1, wherein the two outer weakening lines are formed by a laser seam.

5. The film bag defined in claim 1, wherein the two outer weakening lines pass through the outer layer at least in part.

6. The film bag defined in claim 1, wherein the middle weakening line is formed by punching.

7. The film bag defined in claim 1, wherein the middle weakening line passes completely through the outer layer and at least incompletely through the inner layer.

8. The film bag defined in claim 1, wherein V-shaped inset side gussets are disposed at the edge on the face panels, which gussets are delimited by the weld seams at their edges.

9. The film bag defined in claim 1, wherein the outer layer is formed from polyester.

10. The film bag defined in claim 9 wherein the polyester is polyethylene terephthalate (PET).

11. The film bag defined in claim 1, wherein the inner layer is formed from a polyolefin.

12. The film bag defined in claim 11 wherein the polyolefin is polypropylene (PP).

13. The film bag defined in claim 1, wherein each tearing aid has at least one notch or an incision at the end.