WO2007147568A1

WO2007147568A1 - Film bag

Info

Publication number: WO2007147568A1
Application number: PCT/EP2007/005405
Authority: WO
Inventors: Marcus Kujat; Alfons Kruse; Jochen Brauer
Original assignee: Nordenia Deutschland Halle Gmbh
Priority date: 2006-06-22
Filing date: 2007-06-20
Publication date: 2007-12-27
Also published as: EP2032454B1; ES2401732T5; PL2032454T3; DE102006029119A1; DK2032454T3; DE202006020936U1; ES2401732T3; EP2032454B2; PT2032454E; EP2032454A1; PL2032454T5

Abstract

The invention relates to a film bag which is formed by folding a film, is provided with a front surface (1), a rear surface (2), an inserted first lateral fold (3), and a second inserted lateral fold (4), and is closed by means of a longitudinal sealing seam and a top sealing seam (6). A reclosure strip (7) which removably connects the first lateral fold (3) to the adjacent front surface and rear surface of the bag is fastened to the internal surface of the film bag, below the top sealing seam. The first lateral fold (3) forms a reclosable chute when a bag section (8) located above the reclosure strip (7) is torn open along a weakened line (9) contained in the film in order to remove filled material. The outer edges between the first lateral fold (3) and the adjoining front or rear surface (1, 2) are composed of folded edges which are reinforced by longitudinal sealing seams (10). A sealing seam (19, 21) which connects the front surface and rear surface of the film bag and extends to the top sealing seam (6) or the second lateral fold (4) borders the ends of the reclosure. The weakened line (9) is made up of a combination of an embossed line formed by means of a heat sealing process and a laser seam which is introduced into the outer layer of the composite film and is superimposed on the embossed line.

Description

foil pouch

Description:

The invention relates to a foil pouch which is formed by folding a foil, has a front surface, a back surface, an inserted first side fold and an inserted second side fold and is closed by a longitudinal sealing seam and a top seal seam,

wherein a reclosable strip is attached to the inner surface of the film bag underneath the top seal, releasably connecting the first side gusset to the adjacent front and back surfaces of the bag,

wherein the outer edges between the first gusset and the adjacent front or rear surface consist of folded edges,

wherein the first gusset forms a resealable chute when a bag portion above the reclosing strip for material removal is torn open along a line of weakness contained in the film, and

wherein the film consists of an at least two-layered composite film which has a layer of a sealable plastic on the inside of the bag and a layer of a non-sealable material on the outside of the bag.

A film bag with the described structure is suitable for the packaging of bulk material, such as dry food for animals, and has a reclosure, which allows the contents of the package in portions, ie pour out in portions or remove. The removal takes place through an opening in the first gusset, wherein the gusset can be pulled out after opening the reclosure and can be used as a chute. The opening is resealable. The reclosure can be performed as a so-called zipper, the strip-shaped groove and Has spring elements which can be manually connected by pressure with each other and then form a locking or clip connection. Other reclosures, z. As Velcro closures or reclosures with a self-adhesive strip, are conceivable.

A foil bag with the features described at the outset is known from WO 2004/092025 A2. It consists of a film folded into a tube. The hose produced by folding has on-side gussets and is closed on the shell side by means of a longitudinal sealing seam. Attached to the inner surface of the foil pouch is a reclosing strip which removably connects one of the side folds to the adjacent front and back surfaces of the pouch. The reclosure strip is longer than the width of the gusset and is secured to the insides of the gusset as well as the adjacent bag surfaces that form the front and back surfaces of the bag. The top seal closes the upper edge of the film bag and extends as a straight seal over the entire width of the film bag. For initial use, a bag section is torn open along a line of weakness above the reclosure located on the inside of the bag. The disadvantage is that after the separation of Folienab- cut an opening in the foil bag forms, which extends from the reclosure vertically up to the upper edge of the foil bag and can not be closed. Another disadvantage is the unsatisfactory dimensional stability of the film bag. In use, the chute opens very far, the bag largely loses its shape on the sampling side. Due to the low dimensional stability, the handling of the opened bag is difficult. Especially with large bags, the handling of the opened bag and the metered removal of contents requires considerable skill of the user.

From DE 201 15 181 U1, a gusseted bag with a resealable removal opening in a side gusset is also known. The top seal is a straight seam and closes the top edge of the foil pouch. Parallel to it, another horizontal seam is provided, extending from the outside of the second gusset to the inside of the gusset Front and rear surface fastened ends of the reclosure strip extends. Since this seal seam is adjacent to the ends of the reclosure, the bag is relatively tight in closed reclosure even in use. The gussets consist of separate, V-shaped film strips, which are inserted between the front surface and the rear surface of the bag and connected to the latter by longitudinal sealing seams. To seal the film bag wide seams are necessary that form dimensionally stable outer edges of the bag and give the film bag good dimensional stability. The disadvantage is that the sealed seams considerably limit the opening width of the reclosure, which makes it difficult to remove, in particular, larger, lumpy contents. Also, the seal seams between the gussets and the front and rear surfaces are not always gas-tight.

A similar film bag as the previously described embodiments with a reclosable removal opening in the gusset is known from WO 02/079049 A1.

Resealable foil pouches, used, for example, for packaging animal dry food, are in practice comprised of high quality composite films comprising a readily printable polyester outer layer, a sealable polyolefin innerliner, and often a metallic barrier layer having a good barrier effect Have oxygen and water vapor. The problem is the weakening line. It is often formed in the known film bags as a perforation, which is permeable to air. The reclosure, which is arranged in the interior of the film bag, likewise does not constitute a gas-tight closure, so that the contents can dry out during prolonged storage and the product properties of the contents can change.

Against the background of the described technological background, the invention has for its object to improve the performance characteristics of foil bags, which are opened by tearing a film section and have a reclosure in a gusset. The foil bag should be up to first opening to be largely airtight and water vapor tight. He should be easy to open and easy to handle when removing contents.

The object is achieved by a foil bag with the features of claim 1. Starting from a film bag with the features described above, the folded edges between the first gusset and the front and rear surfaces are stiffened according to the invention by longitudinal sealing seams, which extend to the top seal. Adjoining the ends of the reclosure strip is a sealed seam which connects the front and back surfaces of the film bag and extends to the top seal seam or to the second side gusset. Furthermore, the weakening line consists of the combination of an embossing line formed by heat sealing and a laser seam introduced into the outer layer of the composite film and overlying the embossing line.

The weakening line consists of an embossing line produced by heat-sealing and a laser seam of congruent design. By heat sealing, the film is deformed under the action of pressure and temperature, and in the laser process takes place in the region of the embossing line, a partial removal of material on the outside of the composite film. The inventive combination of a laser seam with a heat-sealed embossing line results in a line of weakness, which is characterized by a very good tear behavior. The tearing is smooth and takes place with a defined propagation along the weakening line. The fact that the laser ablation is limited to the outer layer of the composite film, the weakening line remains airtight. The permeation of oxygen and water vapor through the area of the line of weakness is negligible. Where the line of weakness reaches the folded edges reinforced by longitudinal sealing seams, it is expedient to provide notches in the longitudinal sealing seams for crack initiation.

The weakening line can extend parallel to the reclosing strip and an adjoining transverse seam, which closes the filling material space on the upper side, over the entire width of the film bag up to the edges of the second side fold. However, it is also within the scope of the invention the weakening line extends parallel to the reclosing strip and then ends with a vertical portion towards the top seal.

By tearing a bag section along the line of weakness, the reclosure in the first gusset of the foil bag is exposed. After exposing the reclosure, the gusset can be unfolded as a chute, resulting in a pouring opening, which is at least twice as long as the width of the gusset. The large opening facilitates the removal of lumpy contents. The provided for edge reinforcement longitudinal sealing seams give the film bag in the open state a considerable dimensional stability, so that a good handle of large plastic bags is guaranteed. The longitudinal sealing seams provided for edge reinforcement can be recessed in the region of the reclosing strip. On the tightness of the film bag, this has no effect, since the outer edge of the first side fold folding edges and additionally attached longitudinal sealing seams have no sealing function.

The reclosure strip preferably forms a zipper closure and has a film carrier attachable to the inner surface of the bag and strip-shaped closure elements integrally formed on the film carrier. The strip-shaped closure elements are manually latched together by pressure in the manner of a tongue and groove connection. The film carrier is expediently connected with two sealing seams, which are arranged on both sides of the strip-shaped closure elements, with the film forming the film bag.

The foil pouches are manufactured as flat-laid pouches and filled with filling material later in filling systems, which is filled at the upper end of the pouch, for example, by a bottom-side opening or, before attachment of the head sealing seams. For transport, the flat foil bags are stacked. The reclosing elements are strongly bent at the folding or folding edges of the film bag. The reclosing strip for a zipper closure has considerable elastic restoring forces, which counteract the kinking and can cause the flat lying Spread foil bag in the area of the first gusset. With increasing stack height then there is a risk that the stacked bags slip. To avoid this, the strip-shaped closure elements of the reclosable strip can be interrupted at the bent edges of the film bag by a punched or cut. In the manufacture of the film bag, the closure strip is after being applied to a first still flat film web, at the point at which later the bending edge of the gusset is or the film web is folded, punched or cut.

With regard to the attachment of the reclosable strip, there are several possibilities. A preferred embodiment of the invention provides that the length of the reclosure strip is greater than the width of the first gusset, with a central portion of the reclosure strip attached to the inner surface of the gusset and having end portions of the reclosure strip contiguous therewith with the inside of the front surface and the back surface of the bag are connected. The reclosure strip can be designed as a Velcro strip, as a strip with a self-adhesive surface or as a zipper closure whose form-locking elements can be connected to themselves. However, it is also within the scope of the invention that the reclosing strip fastened to the inner surface of the first gusset has a length corresponding to the width of the gusset and extends to the outer edges of the bag and fastened to the insides of the front surface and the back surface which cooperate with the reclosable strip attached to the first gusset. Suitable profiles for the reclosure strips and closure strips are described in DE 201 15 181 LM.

According to an advantageous embodiment of the invention, all four outer edges of the film bag are stiffened by longitudinal sealing seams. The longitudinal sealing seam closing the foil bag on the shell side can be integrated into an edge which bounds the second side fold. In this embodiment, the longitudinal seam seam closing the foil bag on the shell side connects the second side fold with the front or back surface of the bag. The front and back surfaces of the bag may be joined by a vertical additional seam which is disposed adjacent the first gusset and extends from a transverse seam adjacent the reclosure strip to the top seal and separates the gusset portion above the reclosure from the bag contents space. The transverse sealing seam, which closes the filling material space on the upper side, runs parallel to the top-seal seam. However, it is also within the scope of the invention to align this transverse sealing seam obliquely to the top-seal seam, wherein the distance between the transverse seal seam and the top-seal seam at the first end adjoining the vertical additional seal seam is smaller than at the other end in the region of the second side fold. The section of the film bag which is delimited by the top seal seam and the transverse seal seam can also be used for a handle punching.

In the following the invention will be explained with reference to a drawing showing only one embodiment. They show schematically:

1 is a side view of a still sealed original film bag,

2 shows the bag shown in Fig. 1 in the open state in a perspective view,

Fig. 3 shows a section through the opened foil bag in the cutting plane

A-A from FIG. 1,

4 is a sectional view through the composite film in the region of

Line of weakness in a greatly enlarged representation and

Fig. 5 and 6 further embodiments of a still originally sealed foil bag in each case in the side view.

The film bag shown in the figures is formed by folding a film and has a front face 1, a rear face 2, an inserted first side fold 3 and an inserted second side fold 4. The foil bag is through a longitudinal sealing seam 5, a top seal 6 and a bottom seal, not shown closed. On the inner surface of the film bag below the top seal 6, a reclosing strip 7 is fixed, which removably connects the first gusset 3 to the adjacent front and back surfaces of the bag. To remove the filling material, a bag section 8 must be torn open above the reclosing strip 7 along a weakening line 9 contained in the film. Thereafter, the first gusset 3 forms a resealable chute. From a comparative examination of FIGS. 1 to 3, it is clear that the folded edges between the first side fold 3 and the adjacent front or rear face 1, 2 are stiffened by longitudinal sealing seams 10. The longitudinal sealing seams 10 extend from a bottom seam, not shown, to the top seam 6 and are interrupted in the region of the reclosing strip 7. The second gusset 4 is limited by outer edges, which are reinforced by longitudinal sealing seams. The cross-sectional view in FIG. 3 shows that the longitudinal sealing seam 5 closing the film pouch on the shell side is laid in the outer edge of the second side fold and connects the second side fold 4 to the front or back surface 1, 2 of the pouch. The longitudinal sealing seam 5 fulfills a sealing function, while the sealing seams assigned to the other outer edges only reinforce folding edges and have no sealing function.

The reclosable strip 7 has a film carrier 11 which can be fastened to the inner surface of the bag and strip-shaped closure elements 12 which are integrally formed on the film carrier. The strip-shaped closure elements 12 form a zipper closure of form-fitting elements, which can be latched together manually by pressure. At the bending edge 13 of the inserted gusset 3, the strip-shaped closure elements 12 may be interrupted by a punched or cut. This measure prevents a spreading of the gusset area as a result of a bending stress of the strip-shaped projections of the closure elements. The length of the reclosure strip 7 is greater than the width of the first gusset 3 with a central portion of the reclosure strip attached to the inner surface of the gusset and having end portions of the reclosure strip 7 connected thereto on both sides with the inner surfaces of the gusset. surface 1 and the rear surface 2 of the bag are connected. The closure elements 12 of the reclosure strip 7 are formed so that they can be connected to themselves.

The film from which the film bag is made is an at least two-layer composite film which has a layer 14 of a sealable plastic on the inside of the bag and a layer 15 of a non-sealable material on the outside of the bag. Polyolefins such as, for example, polyethylene, polypropylene, polyethylene copolymers, polypropylene copolymers and mixtures of these polymers are particularly suitable as polymer for the inner layer. The outer layer is preferably made of a polyester, biaxially oriented polypropylene (BOPP) or an oriented polyamide (OPA). The materials mentioned can be printed on the inside or outside. The composite film may have one or more intermediate layers, eg. B. a thin metal layer to improve the barrier effect in terms of oxygen permeability and water vapor permeability. The weakening line 9 for opening the film bag consists of the combination of an embossing line 17 formed by heat sealing and a laser seam 18 introduced into the outer layer 15 of the composite film and overlying the embossing line 17.

4 shows, on a greatly enlarged scale, a cross section through the line of weakness 9. The layer structure of a composite film having a sealable inner layer 14 of polyethylene and an outer layer 15 of polyethylene terephthalate (PET) printed on its inner surface and having an intermediate layer 16 is shown is glued from PET. The intermediate layer 16 is provided with an about 100 nanometer thick metallization 16 'and bonded to the PE layer 14. In cross section, the deformation of the composite film by the linear embossing by heat sealing can be seen. In the middle of the deformation, the PET layers 15, 16 are severed by the combination of heat sealing and irradiation by a laser down to the metallic coating which forms an intermediate layer 16 '. The described weakening line is characterized by a good tear-open behavior and is gas-impermeable. In the embodiment of FIG. 1, the weakening line 9 extends parallel to the reclosure strip 7 and an adjoining transverse seam 19 which closes the Füllgutraum on the upper side, over the entire width of the film bag to the edges of the second side fold 4. There, where the line of weakness. 9 reaches the folded by longitudinal sealing seams 10 folded edges, notches 20 are provided in the longitudinal sealing seams 10 for crack initiation.

In the exemplary embodiment of FIG. 5, the weakening line 9 extends parallel to the reclosing strip 7 and then runs out with a vertical section to the head seam 6. The front surface and the rear surface of the film bag are connected by a vertical sealing seam 21 which abuts the ends of the reclosing strip and extends to the top seal 6.

In the embodiment of FIG. 6, the front surface 1 and the back surface 2 of the bag are connected by a vertical additional sealing seam 22, which is arranged next to the first gusset 3, extending from a subsequent to the reclosure strip 7 transverse seam 19 to the top seal 6 and separates the gusset area above the reclosure from the filling space of the bag. The transverse sealing seam 19 runs obliquely to the head seam 6, wherein the distance between the transverse seam and the top seal at the first end adjacent to the vertical additional sealing seam 22 is smaller than at the other end in the region of the second side fold 4. Der von der Kopfsiegelnaht 6 and the transverse seam 19 limited portion of the film bag contains a handle punching 23rd

Claims

claims:

A film bag which is formed by folding a film, a front surface (1), a back surface (2), an inserted first side fold (3) and an inserted second side fold (4) and by a longitudinal sealing seam (5) and a top seal seam (6) is closed,

wherein on the inner surface of the film bag below the top seal (6) a reclosure strip (7) is attached, the first gusset (3) releasably connected to the adjacent front surface (1) and back surface (2) of the

Bag connects,

wherein the outer edges between the first gusset (3) and the adjacent front or rear surface (1, 2) consist of folding edges,

said first gusset (3) forming a reclosable chute when a bag portion (8) above the reclosing strip (7) for filling discharge is torn along a line of weakness (9) contained in the film, and

wherein the film consists of an at least two-layered composite film which has on the inside of the bag a layer (14) of a sealable plastic and on the outside of the bag a layer (15) of a non-sealable material,

characterized in that the fold edges between the first gusset (3) and the front and rear surfaces (1, 2) are stiffened by longitudinal sealing seams (10) extending to the top seam (6) that abut the ends of the reclosure strip (7) ) adjoins a sealing seam (19, 21) which connects the front and rear surfaces (1, 2) of the film bag and extends to the top seam (6) or to the second side fold (4) and that the weakening line (9) from the Combination of an embossing line (17) formed by heat sealing and a laser seam (18) introduced into the outer layer of the composite film and overlapping the embossing line.

2. foil bag according to claim 1, characterized in that arranged at the folding edges longitudinal sealing seams (10) in the region of the reclosure strip (7) are interrupted.

3. foil bag according to claim 1 or 2, characterized in that where the line of weakness (9) by the longitudinal sealing seams (10) reinforced folding edges, notches (20) in the longitudinal sealing seams (10) are provided for crack initiation.

4. foil bag according to one of claims 1 to 3, characterized in that the weakening line (9) parallel to the reclosure strip (7) and an adjoining transverse seam (19), which closes the Füllgutraum on the upper side, over the entire width of the foil bag to extends to the edges of the second gusset (4).

5. foil pouch according to one of claims 1 to 3, characterized in that the weakening line (9) extends parallel to the reclosure strip (7) and then terminates with a vertical portion to the top seal (6).

6. foil pouch according to claim 5, characterized in that the front and back surface (1, 2) of the bag by a vertical additional sealing seam (22) are connected, which is arranged next to the first gusset (3), from the at the reclosure strip (7) subsequent transverse sealing seam (19) extends to the top seal seam (6) and separates the side fold region above the reclosure of the filling material space of the bag.

7. foil bag according to claim 6, characterized in that the transverse sealing seam (19) extends obliquely to the top seal seam (6), wherein the distance between the transverse seal and top seal at the first end adjacent to the vertical additional sealing seam (22) is smaller as at the other end in the area of the second gusset (4).

8. foil bag according to claim 6 or 7, characterized in that of the top seal seam (6) and the transverse seam (19) limited portion of the foil bag contains a handle punched (23).

A film bag according to any one of claims 1 to 8, characterized in that the length of the reclosure strip (7) is greater than the width of the first gusset (3) with a central portion of the reclosure strip secured to the inner surface of the gusset and being thereon On both sides subsequent end portions of the reclosure strip with the inside of the front surface or rear surface (1, 2) are connected.

10. foil pouch according to one of claims 1 to 9, characterized in that the film bag shell side closing longitudinal sealing seam (5) connects the second side fold (4) with the front or rear surface (1, 2) of the bag and forms an outer edge.