ES2401732T5 - Film bag - Google Patents

Description

DESCRIPTION

Film bag.

The invention relates to a film bag which is formed by folding a film, having a front surface, a back surface, a first tucked side fold, as well as a second tucked side fold and which is closed by a sealing seam longitudinal, as well as by a top seal seam, in which, on the inner surface of the film bag and below the top seal seam, a re-applicable closure strip is attached which detachably binds the first side fold to the adjoining front surface and rear surface of the bag, in which the outer edges between the first lateral fold and the adjoining front or rear surface are formed by folded edges, in which the first lateral fold forms a pour spout, It can be closed again, when a sector of the bag above the re-applicable closure strip is torn along a line of weakening with Held in the film to extract the filler material, and in which the film consists of a film composed of at least two layers that has a layer of a sealable plastic on the inside of the bag and on the outside of the bag a layer of non-sealable material.

A film bag with the described structure is suitable for the packaging of bulk material, for example dry animal feed and has a re-applicable closure that allows the contents of the container to be poured or withdrawn in partial quantities, that is, in portions. The extraction is carried out through an opening in the first lateral fold, so that after the opening of the re-applicable closure the lateral fold can be pulled out and used as a pour spout. The opening can be closed again. The re-engageable closure can be realized as a so-called zip fastener which features molding-shaped tongue and groove elements that can be manually snapped together and form a clip or retention joint. Other reattachable closures are also conceivable, for example velcro closures or reattachable closures with a self-adhesive strip.

A film bag with the characteristics described at the beginning is known from WO 2004/092025 A2. This consists of a film folded into a tube. The tube generated by the folding has tucked side folds and is closed at the periphery by a longitudinal sealing seam. A reattachable closure strip is attached to the inner surface of the film bag that detachably joins one of the side folds to the adjacent front and rear surfaces of the bag. The reattachable closure strip is longer than the width of the side fold and is attached to the inner faces of the side fold, as well as to the surrounding bag surfaces that make up the front and rear surface of the bag. The top seal seam closes the top edge of the film bag and extends as a straight seal seam across the full width of the film bag. For the first use, a section of the bag is torn along a line of weakness above the reattachable closure provided on the inside of the bag. It is disadvantageous that upon separation of the film sector, an opening is formed in the film bag that extends from the vertically reattachable closure to the top edge of the film bag and cannot be closed. Another drawback is that the shape stability of the film bag is not satisfactory. During use, the pour spout opens wide, so the bag largely loses its shape on the extraction side. Due to the poor stability of shape, the manipulation of the open bag is difficult. In particular, in the case of large bags, the handling of the open bag and the metered extraction of the loading material require great skill on the part of the user.

DE 201 15181 U1 also discloses a side fold bag having a withdrawal opening in one side fold that can be closed again. The top seal seam is a straight seam and closes the top edge of the film bag. Parallel to it is a further horizontal seam extending from the outer face of the second side fold to the ends of the reattachable closure strip attached to the inner face of the front and rear surface. Since this sealing seam is adjacent to the ends of the reattachment, when the reattachment is closed the bag is relatively watertight even in use. The side folds consist of separate V-shaped folded film strips that are tucked between the front surface and the back surface of the bag and are attached to it by longitudinal seal seams. For sealing the film bag, wide seams are necessary to form the rigid outer edges of the bag and give the film bag good shape stability. It is disadvantageous that the sealing seams considerably limit the opening width of the reapplicable seal, making it difficult to remove, especially large piece filler material. Also the sealing seams between the side pleats and the front or back surface are not always gas tight.

A film pouch similar to that of the above-described embodiments with a re-closable extraction opening in the side fold is known from WO 02/079049 A1.

The resealable film bags which are used for example for packaging dry animal feed are practically made of high quality composite films having an easily printable outer polyester layer, a sealable inner layer of a polyolefin and often a metallic intermediate layer with a good barrier action with respect to oxygen and water vapor. The weakening line is problematic. In known film bags it is often made as a perforation that is air permeable. Likewise, the re-applicable closure arranged inside the film bag does not constitute a gas-tight closure, so that in the event of prolonged storage the filler can dry out and the properties of the products that make up the material can be modified. load.

A film pouch similar to that of the above-described embodiments with a re-closable extraction opening in the side fold is known from WO 2007/047393 A2 not previously published.

In view of the technological background explained, the invention proposes the object of improving the use properties of film bags. In particular, the film bag should be able to be opened easily and during the removal of the filler should be easy to handle.

The object is carried out according to the invention with a film bag with the characteristics of claim 1.

The weakening line consists of a stamped line generated by heat sealing and a laser seam made with the same extension. By heat sealing the film is deformed by the influence of pressure and temperature and in the laser procedure a partial erosion of material is carried out on the outside of the composite film. The combination according to the invention of a laser seam with a heat-sealed embossed line results in a weakening line characterized by very good tearing behavior. Tearing spreads easily and is done to a defined extent along the line of weakness. Since laser erosion is limited to the outer layer of the composite film, the line of weakness remains airtight. The permeation of oxygen and water vapor through the area of the weakening line is negligible. Fissure initiation notches are provided in the longitudinal seal seams where the line of weakness reaches the folded edges reinforced by longitudinal seal seams.

The line of weakness may extend parallel to the reattachable closure strip and to a transverse seal seam adjacent thereto which closes on the top side the space of the filler across the entire width of the film bag to the edges of the second side fold. However, it is also within the scope of the invention that the line of weakness extends parallel to the reattachable closure strip and then converges towards the top seal seam with a vertical sector.

By the tearing of a sector of the bag along the line of weakening, the replicable closure in the first lateral fold of the film bag is released. Upon release of the reattachable closure, the side fold can be deployed as a pour spout, resulting in a pour opening that is at least twice as long as the width of the side fold. The large opening makes it easy to remove the chunky filler material. The longitudinal sealing seams provided for reinforcing the edges give the film bag even stability in the open state, so that easy handling of large film bags is also guaranteed. The longitudinal sealing seams provided for the reinforcement of the edges can be interrupted in the area of the re-applicable closure strip. This has no influence on the sealing of the film bag, since the outer edges of the first side fold are folded edges and the additionally arranged longitudinal sealing seams do not have any sealing function.

The reattachable closure strip is preferably formed by a zip closure and has a film holder that can be attached to the inner surface of the bag and molding-shaped closure elements on the film holder. The molding-shaped closure elements can be manually interlocked in the manner of a tongue and groove joint. Conveniently the film holder is attached to the film forming the film bag by two sealing seams which are arranged on either side of the molding-shaped closure elements.

The film bags are manufactured as flat bags and then in filling facilities they are filled with filler material that is introduced, for example, through an opening in the base or through the upper end of the bag before the seams are arranged. top sealing. For transport, the flat film bags are stacked. Thus, the re-applicable closure elements are severely warped at the fold or bend edges of the film bag. The reattachable closure strip for a zip fastener has considerable elastic recoil forces that oppose kinking and may result in the flat lay film bag unfolding in the area of the first side fold. As the stacking height increases there is a danger that the bags stacked on top of one another will slip. To avoid this, the molding-shaped closure elements of the reattachable closure strip can be interrupted by a cutout or section in the film bag elbows. In the manufacture of the film bag, the re-applicable closure strip, after being placed on a film strip which is in principle still flat, is cut or sectioned in the place where the bend of the lateral fold is afterwards, or the band is folded. movie.

There are several possibilities when it comes to placing the re-applicable closure strip. A preferred embodiment of the invention foresees that the length of the re-applicable closure strip is greater than the width of the first lateral fold, so that a central sector of the re-applicable closure strip is fixed to the inner surface of the lateral fold and so that end sections of the reattachable closure strip adjacent to it on both sides are attached to the inside of the front surface or rear surface of the bag. The reattachable closure strip can be made as a velcro strip, as a strip with a self-adhesive upper surface or as zip closure, whose elements with positive shape connection can be joined together. However, it is also within the scope of the invention that the re-applicable closure strip attached to the inner face of the first lateral fold has a length corresponding to the width of the lateral fold and that it extends to the outer edges of the bag and that on the faces The interior of the front surface and the rear surface are fastened with reattachable closure strips that cooperate with re-applicable closure straps placed on the first side fold. Suitable profiles for the re-applicable closure strips and the closure strips are described in DE 201 15 181 U1.

According to an advantageous embodiment of the invention, the four outer edges of the film bag are reinforced by longitudinal sealing seams. The longitudinal sealing seam that closes the film bag at the periphery can be integrated into a rim that limits the second lateral fold. In this embodiment the longitudinal sealing seam that closes the film bag at the periphery joins the second side fold to the front or rear face of the bag.

The front and rear surfaces of the bag can be joined by an additional vertical seam that is arranged next to the first side fold and extends from a transverse seal seam adjacent to the reattachable closure strip to the top seal seam and separate the area. of the lateral folds above the re-applicable closure of the space of the load material of the bag. The transverse sealing seam that closes the filler material gap at the top runs parallel to the upper sealing seam. However, it is also within the scope of the invention to orient this inclined cross seal seam relative to the top seal seam so that the distance between the cross seal seam and the top seal seam at the first end, which is adjacent to the additional vertical sealing seam, be less than at the other end in the area of the second side fold. The film bag sector limited by the top seal seam and the cross seal seam can further be used for a handle cutout.

In the following, the invention will be explained by means of a drawing that represents only an exemplary embodiment. Schematically show:

Fig. 1, a side elevation of a film bag still with the original closure,

Fig. 2, the bag represented in Fig. 1 in an open state in a perspective representation,

Fig. 3, a cut through the open film bag through the plane of cut A-A in Fig. 1,

Fig. 4, a sectional representation through the composite film in the area of the line of weakening in a very enlarged scale representation, and

Fig. 5 and 6, other embodiments of a film bag even with the original closure, respectively, in side elevation.

The film bag shown in the figures is formed by folding a film and has a front surface 1, a rear surface 2, a first side fold 3 tucked in, as well as a second side fold 4 tucked in. The film bag is closed by a longitudinal sealing seam 5, an upper sealing seam 6 and a base sealing seam not shown. A reattachable closure strip 7 is attached to the inner surface of the film bag underneath the top seal seam 6 which joins the first side fold 3 in a detachable manner to the front and rear surfaces of the bag which are adjacent to it . For removal of the filler, a sector 8 of the bag must be torn above the re-applicable closure strip 7 along a line of weakness 9 contained in the film. The first side fold 3 then forms a pour spout that can be reclosed. From a comparative observation of Figures 1 to 3 it is clear that the folded edges between the first lateral fold 3 and the adjacent front or rear surface 1, 2 are reinforced by longitudinal sealing seams 10. The longitudinal sealing seams 10 extend from a base sealing seam not shown to the upper sealing seam 6 and are interrupted in the area of the re-applicable closure strip 7. Also the second lateral fold 4 is limited by outer edges which are reinforced by longitudinal sealing seams . From the cross-sectional representation of Fig. 3 it follows that the longitudinal sealing seam 5 which closes the film bag at the periphery at the outer edge of the second lateral fold is displaced inward and the second lateral fold 4 is joined to the front or rear surfaces 1, 2 of the bag. The longitudinal sealing seam 5 performs a sealing function, while the sealing seams associated with the other outer edges only reinforce the folded edges and have no sealing function.

The re-applicable closure strip 7 has a film holder 11 that can be fixed to the inner surface of the bag and molding-shaped closure elements 12 formed on the film holder. The trim elements 12 in the form of a molding constitute a slide fastener of elements with a positive connection so that they can be interlocked by manual pressure. At the crank edge 13 of the side fold 3 the molding-shaped closure elements 12 may be interrupted by a cutout or section. This measure prevents the area of the lateral folds from separating as a result of a bending effort of the projections with molding form of the closing elements. The length of the reattachable closure strip 7 is greater than the width of the first side fold 3, so that a central sector of the reattachable closure strip is fixed on the inner surface of the side fold and so that the end sectors of the Applicable closure strip 7 adjacent thereto on both sides are attached to the inner surfaces of the front surface 1 or the rear surface 2 of the bag. The closure elements 12 of the re-applicable closure strip 7 are made in such a way that they can be attached by themselves.

The film, from which the bag is manufactured, is a film composed of at least two layers that on the inside of the bag has a layer 14 of a sealable plastic and on the outside of the bag a layer 15 of a non-sealable material. Suitable polymers for the inner layer are, in particular, polyolefin, such as, for example, polyethylene, polypropylene, polyethylene copolymers, polypropylene copolymers, as well as mixtures of these polymers. The outer layer is preferably composed of a polyester, biaxially oriented polypropylene (BOPP) or an oriented polyamide (OPA). The mentioned materials can be printed on the inside or outside. The composite film can have one or more intermediate layers, for example a thin metallic layer to improve the barrier action in relation to oxygen permeability and water vapor permeability. The weakening line 9 for the opening of the film bag is formed by the combination of a stamped line 17 formed by heat sealing and a laser seam 18 produced in the outer layer 15 of the composite film and superimposed on the stamped line 17.

Fig. 4 shows on a greatly enlarged scale a cross section through the line of weakening 9. The layer structure of a composite film with a sealable inner layer 14 of polyethylene and an outer layer 15 of polyethylene terephthalate (PET) is shown. which is printed on its inner surface and is glued to an intermediate layer 16 of PET. The intermediate layer 16 is provided with a metallization 16 'with a thickness of approximately 100 nanometers and glued to a layer of PE 14. In the cross section, the deformation of the film can be recognized by the line-shaped stamping by sealing in hot. At the center of the deformation, the PET layers 15, 16 are separated by the combination of heat sealing and laser radiation to the metallic coating that constitutes an intermediate layer 16 '. The described weakening line is characterized by good tearing behavior and is impervious to gas.

In the exemplary embodiment of Fig. 1 the weakening line 9 extends parallel to the re-applicable closure strip 7 and to a transverse sealing seam 19 contiguous thereto which closes the space of the filler material through the entire top. width of the film bag to the edges of the second lateral fold 4. Where the weakening line 9 reaches the folded edges reinforced by the longitudinal sealing seams 10, notches 20 are provided in the longitudinal sealing seams 10 for the initiation of cracks .

In the exemplary embodiment of Fig. 5 the weakening line 9 extends parallel to the re-applicable closure strip 7 and then converges with a vertical sector towards the upper sealing seam 6. The front surface and the rear surface of the bag Films are joined by a vertical sealing seam 21 that borders the ends of the reattachable closure strip and extends to the top sealing seam 6.

In the exemplary embodiment of Fig. 6 the front surface 1 and the rear surface 2 of the bag are joined by an additional vertical sealing seam 22 which is arranged next to the first lateral fold 3, extending from a transverse sealing seam 19 adjoins the reattachable closure strip 7 to the top seal seam 6 and separates the area of the side folds above the replicable closure from the space of the bag loading material. The cross seal seam 9 runs inclined with respect to the top seal seam 6, so that the distance between the cross seal seam and the top seal seam at the first end, which is adjacent to the additional vertical seal seam 22 , is less than at the other end in the area of the second side fold 4. The sector of the film bag adjacent to the top seal seam 6 and the cross seal seam 19 contains a handle cutout 23.

Claims (8)

1. Film bag, which is formed by folding a film, which has a front surface (1), a rear surface (2), a first side fold (3) tucked in, as well as a second side fold (4) tucked in and which is closed by a longitudinal sealing seam (5), as well as by an upper sealing seam (6), in which on the inner surface of the film bag below the upper sealing seam (6) is affixed a re-applicable closure strip (7) that joins the first lateral fold (3) detachably to the front surface (1) and the adjacent rear surface (2) of the bag, in which the outer edges between the first fold lateral (3) and the adjacent front or rear surface (1, 2) consist of folded edges, in which the first lateral fold (3) forms a pour spout, which can be closed again, when a sector (8) of bag above the reattachable closure strip (7) is ripped along a line weakening ea (9) contained in the film for the extraction of the filler material, and in which the film consists of a film composed of at least two layers that on the inside of the bag presents a layer (14) of a sealable plastic and on the outside of the bag a layer (15) of a non-sealable material, in which the folded edges between the first lateral fold (3) and the front or rear surface (1, 2) are reinforced by seams longitudinal sealing seals (10) that extend to the upper sealing seam (6) and are interrupted in the area of the re-applicable closure strip (7) and in which the ends of the re-applicable closure strip (7) are adjacent to a sealing seam (19, 21) that joins the front and rear surface (1, 2) of the film bag and extends to the upper sealing seam (6) or to the second lateral fold (4), characterized because where the weakening line (9) reaches the edges ple Grooves reinforced by longitudinal sealing seams (10), notches (20) are provided in the longitudinal sealing seams (10) for the initiation of fissures and because the weakening line (9) is made up of a combination of a stamped line ( 17) formed by hot sealing and a laser seam (18) inserted in the outer layer of the bonding film and superimposed on the stamped line. Film bag according to claim 1, characterized in that the line of weakness (9) extends parallel to the re-applicable closure strip (7) and a transverse sealing seam (19) adjacent to it that closes the space of the material of top loading, across the entire width of the film bag to the edges of the second side fold (4). Film bag according to one of claims 1 or 2, characterized in that the weakening line (9) extends parallel to the re-applicable closure strip (7) and then converges with a vertical sector towards the upper sealing seam (6 ). Film bag according to one of Claims 1 to 3, characterized in that the front and rear surface (1,2) of the bag are joined by an additional sealing seam (22) which is arranged next to the first side fold (3 ), extends from the transverse seal seam (19) adjacent the reattachable closure strip (7) to the top seal seam (6) and separates the area of the side folds above the reattachable closure from the material space of the bag loading. Film bag according to claim 4, characterized in that the cross seal seam (19) runs inclined with respect to the top seal seam (6), such that the distance between the cross seal seam and the top seal seam at the first end, which is adjacent to the additional sealing seam (22), it is smaller than at the other end in the area of the second lateral fold (4). 6. Film bag according to claim 4 or 5, characterized in that the sector of the film limited by the upper sealing seam (6) and the transverse sealing seam (19) contains a handle cutout (23). Film bag according to one of claims 1 to 6, characterized in that the length of the re-applicable closure strip (7) is greater than the width of the first lateral fold (3), such that a central sector of the strip of Reapplicable closure is attached to the inner surface of the side fold and so that the end sectors of the reapplicable closure strip adjacent to it on both sides are attached to the inside of the front or rear surface (1,2). Film bag according to one of Claims 1 to 7, characterized in that the longitudinal sealing seam (5) that closes the film bag at the periphery joins the second lateral fold (4) to the front or rear surface (1, 2) of the bag and constitutes an outer edge.