EP2032454B2 - Film bag - Google Patents

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 folding edges,
wherein the first gusset forms a resealable chute when a bag portion above the reclosing strip is torn open for filling removal along a line of weakness contained in the film, and
wherein the film consists of an at least two-layer composite film having 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 carried out as a so-called zipper closure, which has strip-shaped tongue and groove elements, which can be manually connected to each other by pressure and then form a snap 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 above is made WO 2004/092025 A2 known. 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. Affixed to the inner surface of the film bag is a reclosable strip which removably connects one of the gussets to the adjacent front and back surfaces of the bag. 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 forms an opening in the film bag after the separation of the film section, which extends from the reclosure vertically up to the upper edge of the film 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.

Out DE 201 15 181 U1 Also, there is known a gusseted bag with a reclosable withdrawal opening in a side gusset. 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 ends of the reclosure strip attached to the inside of the front and back surfaces. 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 folded film strips, which are inserted between the front surface and the rear surface of the bag and connected 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 restrict 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 gusseted is made WO 02/079049 A1 known.

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

A resealable foil bag with the features of the preamble of claim 1 is from the older, but not previously published WO 2007/047393 A2 known.

Before the explained technological background, the invention has the object to improve the performance of plastic bags. The film bag should be particularly easy to open and be easy to handle when removing contents.

The object is achieved by a film bag with the features of claim 1.

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 folding edges reinforced by longitudinal sealing seams, notches are provided 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. In the context of the invention, however, it is also the case that the weakening line extends parallel to the reclosing strip and then ends with a vertical section towards the top-seal seam.

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 area of the self-locking 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 result in the flat-lying foil bag spreading 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, wherein a central portion of the reclosure strip is secured to the inner surface of the gusset and having end portions of the reclosure strip adjacent thereto and the inner surface of the gusset. the back surface of the bag are connected. The reclosable strip can be designed as a Velcro strip, as a strip with a self-adhesive surface or as a zipper closure, whose positive-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 closure strips are secured to the inner surfaces of the front surface and the back surface. those with the reclosable strip attached to the first gusset interact. Suitable profiles for the reclosure strips and closure strips are in DE 201 15 181 U1 described.

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.

Fig. 1

die Seitenansicht eines noch original verschlossenen Folienbeutels,

Fig. 2

den in Fig. 1 dargestellten Beutel in geöffnetem Zustand in einer perspektivischen Darstellung,

Fig. 3

einen Schnitt durch den geöffneten Folienbeutel in der Schnittebene A-A aus Fig. 1,

Fig. 4

eine Schnittdarstellung durch die Verbundfolie im Bereich der Schwächungslinie in einer stark vergrößerten Darstellung und

Fig. 5 und 6

weitere Ausgestaltungen eines noch original verschlossenen Folienbeutels jeweils in der Seitenansicht.

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

Fig. 1

the side view of a still sealed original foil bag,

Fig. 2

the in Fig. 1 illustrated bag in the open state in a perspective view,

Fig. 3

a section through the opened foil bag in the sectional plane AA Fig. 1 .

Fig. 4

a sectional view through the composite film in the region of the weakening line in a greatly enlarged view and

FIGS. 5 and 6

further embodiments of a still sealed original 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 film bag is closed by a longitudinal sealing seam 5, a top seal seam 6 and a bottom seam seam, not shown. 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 analysis of the FIG. 1 to 3 it is clear that the folded edges between the first gusset 3 and the adjacent front or rear surface 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 one takes that the film bag closing the shell side longitudinal sealing seam 5 is moved into the outer edge of the second side fold into and connects the second side fold 4 with the front or back surface 1, 2 of the bag. 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 reclosure strip 7 has a film carrier 11 which can be fastened to the inner surface of the bag and strip-shaped closure elements 12 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 end portions of the reclosure strip 7 abutting therewith the inner surfaces of the front surface 1 and the back surface 2 of the bag, respectively 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. As polymer for the inner layer, in particular polyolefins such as polyethylene, polypropylene, Polyethylene copolymers, polypropylene copolymers and mixtures of these polymers suitable. 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 foil may have one or more intermediate layers, e.g. 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 foil 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 foil and overlaying the embossing line 17.

The Fig. 4 Shown is the layer structure of a composite film with a sealable inner layer 14 of polyethylene and an outer layer 15 of polyethylene terephthalate (PET), which is printed on its inner surface and bonded to an intermediate layer 16 of PET , The intermediate layer 16 is provided with an about 100 nanometers 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 laser irradiation except for the metallic coating forming 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 extends 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 film bag to the edges of the second side fold 4. There, where the line of weakness 9 by the longitudinal sealing seams 10 reinforced folding edges are reached, notches 20 are provided in the longitudinal sealing seams 10 for crack initiation.

In the embodiment of Fig. 5 the weakening line 9 extends parallel to the reclosing strip 7 and then exits with a vertical portion 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 face 1 and the back face 2 of the bag are connected by a vertical additional sealing seam 22 which is arranged next to the first gusset 3, extends from a transverse seam 19 adjoining the reclosing strip 7 to the top seal 6 and the gusset region above the reclosure of the filling material space of the bag separates. 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 vom Kopfsiegelnaht 6 and the transverse seam 19 limited portion of the film bag contains a handle punching 23rd

Claims (8)

1. A film bag formed by folding a film, comprising a front surface (1), a rear surface (2), a laid-in first side fold (3) and a laid-in second side fold (4) and closed by a longitudinal sealing seam (5) and a top sealing seam (6),
   wherein a reclosure strip (7) is attached to the inside surface of the film bag below the top sealing seam (6), which reclosure strip (7) detachably connects the first side fold (3) with the adjacent front surface (1) and rear surface (2) of the bag,
   wherein the outer edges between the first side fold (3) and the adjacent front or rear surface (1, 2) consist of folded edges,
   wherein the first side fold (3) forms a reclosable chute, when a bag portion (8) above the reclosure strip (7) is torn open along a tear line (9) contained in the film for removing content, and
   wherein the film consists of an at least two-layer composite film, which comprises 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,
   wherein the folded edges between the first side fold (3) and the front or rear surfaces (1, 2) are stiffened by longitudinal sealing seams (10) which extend as far as the top sealing seam (6) and are interrupted in the region of the reclosure strip (7),
   and wherein the ends of the reclosure strip (7) lie adjacent to a sealing seam (19, 21) which connects the front and rear surfaces (1, 2) of the film bag and extends as far as the top sealing seam (6) or the second side fold (4), characterised in that at the point, where the tear line (9) reaches the folded edges strengthened by the longitudinal sealing seams (10), notches (20) are provided in the longitudinal sealing seams (10) for initiating the tear and in that the tear line (9) consists of the combination of an embossed line (17) formed by hot-sealing and a laser seam (18) produced in the outer layer of the composite film and overlaying the embossed line.
2. The film bag according to claim 1, characterised in that the tear line (9) extends in parallel with the reclosure strip (7) and the adjoining transverse sealing seam (19) closing the content chamber at the top, over the entire width of the film bag as far as the rims of the second side fold (4).
3. The film bag according to one of claims 1 to 2, characterised in that the tear line (9) extends in parallel with the reclosure strip (7) and then ends with a vertical section at the top sealing seam (6).
4. The film bag according to one of claims 1 to 3, characterised in that the front and rear surfaces (1, 2) of the bag are connected by a vertical additional sealing seam (22) which is arranged adjacent to the first side fold (3), extends from the transverse sealing seam (19) adjoining the reclosure strip (7) as far as the top sealing seam (6) and separates the side fold region above the reclosure from the content chamber of the bag.
5. The film bag according to claim 4, characterised in that the transverse sealing seam (19) extends obliquely to the top sealing seam (6), wherein the distance between the transverse sealing seam and top sealing seam is smaller at the first end adjacent to the vertical additional sealing seam (22) than at the other end in the region of the second side fold (4).
6. The film bag according to claim 4 or 5, characterised in that the section of the film bag delimited by the top sealing seam (6) and the transverse sealing seam (19) contains a hand grip punch-out (23).
7. The film bag according to one of claims 1 to 6, characterised in that the length of the reclosure strip (7) is greater than the width of the first side fold (3), wherein a central section of the reclosure strip is attached to the inside surface of the side fold and wherein end sections of the reclosure strip adjoining thereon on both sides are connected with the inside of the front surface or rear surface (1, 2).
8. The film bag according to one of claims 1 to 7, characterised in that the longitudinal sealing seam (5) closing the film bag on the shell side connects the second side fold (4) with the front or rear surface (1, 2) of the bag and forms an outer edge.

Images