ES2401732T3 - Film bag - Google Patents

Abstract

Film bag, which is formed by folding a film, has a front surface (1), a rear surface (2), a first side fold (3) tucked, as well as a second side fold (4) tucked in and sealed 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) an applicable closure strip (7) is fixed ) that joins the first lateral fold (3) detachably to the front surface (1) and the rear surface (2) adjoining the bag, in which the outer edges between the first lateral fold (3) and the front or rear surface (1, 2) adjoining consist of folded edges, in which the first lateral fold (3) forms a spout, which can be closed again, when a bag sector (8) above the reapplicable closure strip (7 ) is torn along a line of weakening or (9) contained in the film for the extraction of the loading material, and in which the film consists of a film composed of at least two layers that on the inner side of the bag has a layer (14) of a sealable plastic and by The outer face of the bag is 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 longitudinal sealing seams (10 ) that extend to the upper sealing seam (6) and are interrupted in the area of the reapplicable closure strip (7) and in which the ends of the replicable closure strip (7) are adjacent to a sealing seam (19 , 21) that joins the front and back surface (1, 2) of the film bag and extends to the upper sealing seam (6) or to the second lateral fold (4), characterized in that where the line of weakening ( 9) reach the folded edges reinforced by costur The longitudinal sealing (10) notches (20) are provided in the longitudinal sealing seams (10) for the initiation of cracks

Description

Bag of film.

The invention relates to a film bag that is formed by folding a film, has a front surface, a rear surface, a first side fold folded, as well as a second side fold tucked in and is closed by a longitudinal sealing seam, as well as by an upper sealing seam, on the inner surface of the film bag below the upper sealing seam a reapplicable closure strip is attached that joins the first lateral fold detachably to the front surface and to the adjacent rear surface of the bag, in which the outer edges between the first lateral fold and the adjacent front or rear surface are formed by folded edges, in which the first lateral fold forms a spout, which can be closed again , when a bag sector above the reapplicable closure strip is torn along a line of weakening contained in the pe licle 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 sealable plastic on the inner side of the bag and on the outer side of the bag a layer of a non-sealable material

A film bag with the structure described is suitable for packaging bulk material, for example dry animal feed and has a reapplicable closure that allows pouring or extracting the contents of the package in partial quantities, that is, in portions. The extraction is carried out through an opening in the first lateral fold, so that after opening the reapplicable closure, the lateral fold can be pulled out and used as a spout. The opening can be closed again. The reapplicable closure can be made as a so-called zipper closure that features groove and tongue elements shaped as a molding that can be manually joined by pressure and form a retaining or clip joint. Other reapplicable closures are also imaginable, for example velcro closures or reapplicable 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 folded film forming a tube. The tube generated by the folding has recessed lateral folds and is closed at the periphery by means of a longitudinal sealing seam. A reapplicable closure strip is attached to the inner surface of the film bag, which separably joins one of the side folds to the adjacent front and rear surfaces of the bag. The reapplicable closure strip is longer than the width of the lateral fold and is fixed to the inner faces of the lateral fold, as well as to the adjacent surfaces of the bag that constitute 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 entire width of the film bag.

For the first use a sector of the bag is torn along a line of weakening above the reapplicable closure disposed on the inner side of the bag. It is unfavorable that after the separation of the film sector, an opening is formed in the film bag that extends from the vertically reapplicable closure to the upper 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 spout peak opens a lot, so the bag largely loses its shape on the extraction side. Due to the poor shape stability, handling the open bag is difficult. In particular, in the case of large bags, the manipulation of the open bag and the dosed extraction of the cargo material require great skill on the part of the user.

From DE 201 15 181 U1 a bag of lateral folds is also known which has an extraction opening in a lateral fold that can be closed again. The top sealing seam is a straight seam and closes the top edge of the film bag. Parallel to it is provided another horizontal seam that extends from the outer face of the second lateral fold to the ends of the reapplicable closure strip fixed to the inner face of the front and rear surface. Since this sealing seam is adjacent to the ends of the reapplicable closure, when the reapplicable closure is closed the bag is relatively tight even in use. The side folds consist of separate folded V-shaped film strips that are tucked between the front surface and the back surface of the bag and are attached thereto by longitudinal sealing seams. Wide seams are necessary for sealing the film bag that form the rigid outer edges of the bag and give the film bag good shape stability. It is unfavorable that the sealing seams considerably limit the opening width of the reapplicable closure, which makes it difficult to remove, especially large-piece loading material. Also the sealing seams between the side folds and the front or rear surface are not always gas tight.

A film bag similar to that of the embodiments described above with an extractable opening in the lateral fold that can be closed is known from WO 02/079049 A1.

The resealable film bags that are used for example to package dry animal feed are made in the practice of high quality composite films having an easily printable polyester outer layer, a sealable inner layer of a polyolefin and often a metal 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 performed as perforation that is air permeable. Also, the reapplicable closure disposed inside the film bag does not constitute a tight seal

gas, so that in case of prolonged storage the cargo material can be dried and the properties of the products that make up the cargo material can be modified.

A reusable film bag with the features of the preamble of claim 1 is known from the old WO 2007/047393 A2, although not previously published.

Against the technological background explained the invention proposes the object of improving the properties of use of film bags. In particular, the film bag must be able to open easily and during the extraction of the loading material it must 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 hot stamping and a laser seam made with the same extension. By hot sealing the film is deformed by the influence of pressure and temperature and in the laser process a partial erosion of the material on the outer side of the composite film is carried out in the area of the stamped line. The combination according to the invention of a laser seam with a hot stamped line results in a weakening line characterized by a very good tearing behavior. The tearing spreads easily and is performed with a defined extension along the line of weakening. Since the erosion of the laser is limited to the outer layer of the composite film, the weakening line remains air tight. The permeation of oxygen and water vapor through the area of the weakening line is negligible. In the longitudinal sealing seams, crack initiation grooves are provided where the weakening line reaches the folded edges reinforced by longitudinal sealing seams.

The weakening line can extend parallel to the reapplicable closure strip and a transverse sealing seam adjacent to it that closes on the upper side the space of the cargo material across the entire width of the film bag to the edges of the second lateral fold. However, it is also within the framework of the invention that the weakening line extends parallel to the reapplicable closure strip and then converges towards the upper sealing seam with a vertical sector.

The replicable closure on the first side fold of the film bag is released by tearing a sector of the bag along the weakening line. After releasing the reapplicable closure, the lateral fold can be deployed as a spout, resulting in a spout opening that is at least twice as long as the width of the lateral fold. The large opening facilitates the extraction of the load material formed by pieces. The longitudinal sealing seams provided for the reinforcement of the edges give the film bag even in the open state considerable stability, 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 reapplicable closure strip. This has no influence on the sealing of the film bag, since the outer edges of the first lateral fold are folded edges and the longitudinally sealed seams additionally provided do not have any sealing function.

The reapplicable closure strip is preferably formed by a zipper closure and has a film support that can be fixed to the inner surface of the bag and molding-shaped closure elements formed in the film support. The molding-shaped closure elements can by manual pressure be interlocked together in the manner of a groove and tongue joint. Conveniently the film support is attached to the film that forms the film bag by two sealing seams that are arranged on both sides of the molding-shaped closure elements.

The film bags are manufactured as flat bags and then in filling facilities they are filled with loading 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. Superior sealing. For transport the flat arranged film bags are stacked. Thus the reapplicable closure elements are severely combined in the fold or bend edges of the film bag. The reapplicable closure strip for a zipper closure has considerable elastic recoil forces that oppose the bending and can result in the flat disposed film bag being deployed in the area of the first lateral fold. As the stack height increases, there is a danger that the bags stacked on top of each other will slip. To avoid this, the molding-shaped closure elements of the reapplicable closure strip may be interrupted by a cut or section in the bending edges of the film bag. In the manufacture of the film bag the reapplicable closure strip after being placed on a film strip in principle still flat is cut or sectioned in the place where then the bending edge of the lateral fold is or the band of folded is folded movie.

Several possibilities result in the placement of the reapplicable closure strip. A preferred embodiment of the invention provides that the length of the reapplicable closure strip is greater than the width of the first lateral fold, so that a central sector of the reapplicable closure strip is fixed to the inner surface of the lateral fold and so which final sections of the reapplicable closure strip adjacent to it on both sides

they are attached to the inner face of the front surface or the back surface of the bag. The reapplicable closure strip can be made as a velcro strip, as a strip with a self-adhesive upper surface or as a zipper closure, whose positively connected elements can be joined together. However, it is also within the scope of the invention that the reapplicable closure strip fixed to the inner side of the first lateral fold has a length corresponding to the width of the lateral fold and extends to the outer edges of the bag and that on the faces Inside the front surface and the back surface are fixed reapplicable closure strips that cooperate with reapplicable closure strips placed on the first side fold. Profiles suitable for reapplicable closure strips and 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 by the periphery can be integrated into a edge that limits the second lateral fold. In this embodiment the longitudinal sealing seam that closes the film bag by the periphery joins the second side fold to the front face or the back side 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 sealing seam adjacent to the reapplicable closure strip to the upper sealing seam and separates the area of the side folds above the reapplicable closure of the bag load material space. The transverse sealing seam that closes the space of the load material above runs parallel to the upper sealing seam. However, within the framework of the invention, this inclined transverse sealing seam is also oriented relative to the upper sealing seam, so that the distance between the transverse sealing seam and the upper sealing seam at the first end, which is adjacent to the additional vertical sealing seam, be smaller than at the other end in the area of the second lateral fold. The film bag sector limited by the top seal seam and the cross seal seam can also be used for a handle cut.

The invention will now be explained by virtue of a drawing that represents only one embodiment. They show schematically:

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

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

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

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

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

The film bag represented 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, as well as a second side fold 4 tucked. The film bag is closed by a longitudinal sealing seam 5, an upper sealing seam 6 and a sealing seam by the base not shown. On the inner surface of the film bag below the upper sealing seam 6 a reapplicable closure strip 7 is attached that joins the first lateral fold 3 detachably to the front and rear surfaces of the bag that are adjacent thereto. . For the extraction of the load material, a sector 8 of the bag must be torn over the reapplicable closure strip 7 along a line of weakening 9 contained in the film. Then the first lateral fold 3 forms a spout that can be closed again. 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 sealing seam of the base not shown to the upper sealing seam 6 and are interrupted in the area of the reapplicable closure strip 7. Also the second lateral fold 4 is limited by outer edges that are reinforced by longitudinal sealing seams . From the cross-sectional representation of Fig. 3 it follows that the longitudinal sealing seam 5 that closes the film bag on the periphery at the outer edge of the second lateral fold is displaced inward and the second lateral fold 4 joins 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 reapplicable closure strip 7 has a film support 11 that can be fixed to the inner surface of the bag and mold-shaped closure elements 12 formed in the film support. The closure elements 12 in the form of a molding constitute a zipper closure of positively connected elements so that they can be interlocked by manual pressure. In the bending edge 13 of the lateral fold 3 tucked the

closure elements 12 in the form of a molding may be interrupted by a cutout or section. This measure prevents the area of the lateral folds from being separated as a result of a bending effort of the molding-shaped projections of the closure elements. The length of the reapplicable closure strip 7 is greater than the width of the first lateral fold 3, so that a central sector of the reapplicable closure strip is fixed on the inner surface of the lateral fold and so that the final sectors of the Reapplicable closure strip 7 adjacent to it 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 reapplicable closure strip 7 are made so that they can be joined by themselves.

The film, from which the bag is manufactured, is a film composed of at least two layers that on the inner side of the bag has a layer 14 of a sealable plastic and on the outer face of the bag a layer 15 of a non-sealable material Polyolefin, such as polyethylene, polypropylene, polyethylene copolymers, polypropylene copolymers, as well as mixtures of these polymers, are suitable in particular for the inner layer. The outer layer is preferably composed of a polyester, biaxially oriented polypropylene (BOPP) or an oriented polyamide (OPA). The mentioned materials can be printed inside or outside. The composite film may have one or several intermediate layers, for example a thin metal layer to improve the barrier action in relation to oxygen permeability and water vapor permeability. The weakening line 9 for opening the film bag is formed by the combination of a stamped line 17 formed by hot stamping 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 very enlarged scale a cross section through the weakening line 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 'of a thickness of approximately 100 nanometers and glued to a layer of PE 14. In the cross section the deformation of the film composed by the line-shaped stamping can be recognized by sealing in hot. At the center of the deformation the layers of PET 15, 16 are separated by the combination of hot stamping and laser radiation to the metallic coating constituting an intermediate layer 16 ’. The weakening line described is characterized by good tearing behavior and is impermeable to gas.

In the exemplary embodiment of Fig. 1, the weakening line 9 extends parallel to the reapplicable closure strip 7 and a transverse sealing seam 19 adjacent thereto which closes the space of the load material above the entire 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, grooves 20 are provided in the longitudinal sealing seams 10 for the initiation of fissures

In the exemplary embodiment of Fig. 5 the weakening line 9 extends parallel to the reapplicable closure strip 7 and then converges with a vertical sector towards the upper sealing seam 6. The front surface and the back surface of the bag of film are joined by a vertical sealing seam 21 that borders the ends of the reapplicable closure strip and extends to the upper 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, extends from a transverse sealing seam 19 adjacent to the reapplicable closure strip 7 to the upper sealing seam 6 and separates the area of the lateral folds above the replicable closure of the space of the bag loading material. The transverse sealing seam 9 runs inclined with respect to the upper sealing seam 6, so that the distance between the transverse sealing seam and the upper sealing seam at the first end, which is adjacent to the additional vertical sealing seam 22 , is smaller than at the other end in the area of the second lateral fold 4. The sector of the film bag adjacent to the upper sealing seam 6 and the transverse sealing seam 19 contains a handle cutout.

Claims (9)

one.

 Film bag, which is formed by folding a film, has a front surface (1), a rear surface (2), a first side fold (3) tucked, as well as a second side fold (4) tucked in and is closed by a longitudinal sealing seam (5), as well as by a superior sealing seam (6), in which a strip of material is fixed on the inner surface of the film bag below the upper sealing seam (6) reapplicable closure (7) that joins the first lateral fold (3) detachably to the front surface (1) and the rear surface (2) adjacent to the bag, in which the outer edges between the first lateral fold (3) and the adjacent front or rear surface (1, 2) consist of folded edges, in which the first side fold (3) forms a spout, which can be closed again, when a bag sector (8) above the reapplicable closure strip (7) is torn along a weak line Itching (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 inner side of the bag has a layer (14) of a sealable plastic and on the outer face 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 sealing seams longitudinal (10) that extend to the upper sealing seam (6) and are interrupted in the area of the reapplicable closure strip (7) and in which the ends of the reapplicable 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 side fold (4), characterized in that there where the line of weakening (9) reaches the folded edges refor grooves for longitudinal sealing seams (10) are provided notches (20) in the longitudinal sealing seams (10) for the initiation of cracks.

2.

Film bag according to claim 1, characterized in that the weakening line (9) consists of a combination of a stamped line (17) formed by hot stamping and a laser seam (18) introduced into the outer layer of the composite film and superimposed on the stamped line.

3.

Film bag according to claim 1 or 2, characterized in that the weakening line (9) extends parallel to the reapplicable closure strip (7) and a transverse sealing seam (19) adjacent thereto which closes the space of the material of Load from the top, across the entire width of the film bag to the edges of the second side fold (4).

Four.

Film bag according to one of claims 1 to 3, characterized in that the weakening line (9) extends parallel to the reapplicable closure strip (7) and then converges with a vertical sector towards the upper sealing seam (6).

5.

 Film bag according to one of claims 1 to 4, 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 sealing seam (19) adjacent to the reapplicable closure strip (7) to the upper sealing seam (6) and separates the area of the lateral folds above the reapplicable closure of the space of the load material of the bag.

6.

Film bag according to claim 5, characterized in that the transverse sealing seam (19) runs inclined with respect to the upper sealing seam (6), so that the distance between the transverse sealing seam and the upper sealing seam in the First end, which is adjacent to the additional sealing seam, is smaller than at the other end in the area of the second lateral fold (4).

7.

 Film bag according to claim 5 or 6, characterized in that the film sector limited by the upper sealing seam (6) and the transverse sealing seam (19) contains a handle cutout (23).

8.

Film bag according to one of claims 1 to 7, characterized in that the length of the reapplicable closure strip (7) is greater than the width of the first lateral fold (3), such that a central sector of the reapplicable closure strip it is fixed to the inner surface of the lateral fold and so that the final sectors of the reapplicable closure strip adjacent to it on both sides are attached to the inner face of the front or rear surface (1, 2).

9.

 Film bag according to one of claims 1 to 8, characterized in that the longitudinal sealing seam

(5) Closing the film bag by the periphery joins the second lateral fold (4) to the front or rear surface (1, 2,) of the bag and constitutes an outer edge.