PACKAGING BAG AND USE OF THE PACKAGING BAG

Abstract

A packaging bag includes a web having a front wall, a rear wall projecting beyond the front wall on an open top bag edge, stacking openings disposed in the section of the rear wall projecting beyond the front wall, the web being formed at least in part of paper. The front wall and the rear wall have chamfered corners at a bottom bag edge opposite the top bag edge.

Claims

1. A packaging bag comprising a web having a front wall (1), a rear wall (2) projecting beyond the front wall (1) on an open top bag edge, stacking openings (4) disposed in the section of the rear wall (2) projecting beyond the front wall (1), the web being formed at least in part of paper, wherein the front wall (1) and the rear wall (2) have chamfered corners (7) at a bottom bag edge (6) opposite the top bag edge.

2. The packaging bag according to claim 1, wherein the front wall (1) and the rear (2) wall are joined together at the bottom edge of the bag by a bottom gusset (8).

3. The packaging bag according to claim 1, wherein the proportion of paper is at least 90% by weight.

4. The packaging bag according to claim 1, wherein the web comprises a layer (15) of paper at least partially coated with a sealing layer (16) made of a heat sealable material on a side adjacent to the packaging space.

5. The packaging bag according to claim 4, wherein the sealing layer covers said layer (15) of paper completely on a side adjacent to the packaging space.

6. The packaging bag according to claim 5, wherein an additional layer (20) made of a heat sealable material is coated only in sections on the sealing layer (16).

7. The packaging bag according to claim 6, wherein the sealing layer (16) is applied via an extrusion lamination and the additional layer (20) is applied via an extrusion lamination or a dispersion coating.

8. The packaging bag according to claim 4, wherein the front wall (1) and the rear wall (2) are connected to one another at the lateral edges via longitudinal sealing seams (5).

9. The packaging bag according to claim 4, wherein bottom gusset (8) portions of the bottom gusset (8) are joined at the corners (11) to the adjacent front wall (1) or to the adjacent rear wall (2) via inclined seal seams (7).

10. The packaging bag according to claim 9, wherein the inclined seal seams (7) comprise unsealed portions.

11. The packaging bag according to claim 4, wherein the heat sealable material is polyethylene.

12. The packaging bag according to claim 1, wherein the paper is kraft paper.

13. The packaging bag according to claim 4, wherein the layer (15) of paper has a basis weight of between 60 and 120 gsm.

14. The packaging bag according to claim 4, wherein the sealing layer has a basis weight between 1 and 16 gsm is applied to the layer (15) of paper.

15. The packaging bag according to claim 1, wherein a heat seal lacquer is applied to the front wall (1) and/or the rear wall (2) in at least one region (12) adjacent the top edge of the bag below the protruding section (3) on an outer side.

16. The packaging bag according to claim 1, wherein the front wall (1) and the rear (2) wall are joined together at the bottom edge of the bag by a bottom gusset (8), and wherein bottom gusset (8) portions of the bottom gusset (8) are at least partially joined together at side edges of the bottom gusset (8).

17-19. (canceled)

Description

[0046] In the following, the invention is explained in more detail with reference to an example of an embodiment. It shows:

[0047] FIG. 1A, 1B a packaging bag according to the invention in an unfilled state

[0048] FIG. 2A, 2B, 2C the essential steps for producing a packaging bag according to FIG. 1

[0049] FIG. 3A, 3B a sectional view through a packaging bag according to the invention in the region of a longitudinal seam

[0050] FIG. 4 the packaging bag according to the invention in a filled state with a view of the base of the stand

[0051] FIG. 5, 6 alternative designs of the packaging bag

[0052] FIG. 7A, 7B designs of the bottom with a separate bottom panel

[0053] FIG. 8 a further design of the bottom

[0054] FIG. 1A, 1B show a packaging bag according to the invention in a laid-flat and unfilled state with a front wall 1 and a rear wall 2, which protrudes with a section 3 opposite the front wall 1 and wherein stacking openings 4 are arranged in the protruding section 3.

[0055] The stacking openings 4 are provided so that several packaging bags arranged one above the other can be gripped by bars in order to be able to simplify the packaging process considerably.

[0056] The front wall 1 and the rear wall 2 are connected to each other at the lateral edges by longitudinal sealing seams 5, which merge into inclined sealing seams 7 in a bottom bag edge 6. The special feature here is that the inclined sealing seams 7 do not connect the front wall 1 to the rear wall 2. Rather, a bottom gusset 8 with bottom gusset sections 9, 10 is provided, the bottom gusset section 9 being connected to the front wall 1 via the inclined sealing seam 7 and the bottom gusset section 10, which is not shown in greater detail in FIGS. 1A and 1B, being connected to the rear wall 2. In contrast to FIG. 1A, FIG. 1B shows an embodiment in which the front wall 1 and the rear wall 2 are connected not only by the inclined sealing seam 7 but also by a cross seam 19 to the bottom gusset section 10.

[0057] By means of the inclined sealing seams 7 it is possible for the packaging bag to be formed with chamfered corners 11 at the bottom bag edge 6. Its special feature becomes clear in particular from the further figures.

[0058] With reference to FIGS. 1A and 1B, it is further possible to identify regions 12 with a heat seal lacquer, which are applied to the outer surface of the front wall 1 and also to the outer surface of the rear wall 2. Furthermore, ventilation openings 13 are provided which are arranged in the inclined sealing seams 7 according to FIG. 1A and in the cross seams 19 according to FIG. 1B.

[0059] FIGS. 2A, 2B, 2C show the manufacturing process for forming a packaging bag according to FIG. 1A. For this purpose, an endless web 14 is provided, which extends in machine direction MD and is already provided with the bottom gusset sections 9, 10 for the formation of the front wall 1, the rear wall 2 and the bottom gusset 8. In addition, the stacking openings 4 are already located in the web 14. FIGS. 2A, 2B, 2C describe the transport and the production of the packaging bag in machine direction MD. According to FIG. 2B, the web 14 is folded over, whereby the bottom gusset 8 is formed. In addition, the areas 12 with the heat-seal lacquer are now also shown at least on the front wall 1. Then, according to FIG. 2C, the longitudinal sealing seams 5 and the diagonal sealing seams 7 are heat-sealed and then individual packaging bags are separated from the web 14. In a final step, the corners of the bottom bag edge 6 can then be chamfered.

[0060] The packaging bag according to the invention is a packaging bag which is at least partially formed from paper. In particular, the aim is to create a packaging bag which is formed from at least 80% by weight, particularly preferably 90% by weight, very particularly preferably 95% by weight, of paper. Paper is a renewable raw material. In addition, a good recyclability can be ensured by the highest possible proportion of paper. FIGS. 3A, 3B show a section through the packaging bag in the region of the longitudinal sealing seams 5, whereby a closer representation of the regions 12 with the heat-sealing lacquer on the outer sides has been omitted. The bag consists in particular of a layer 15 of paper. Although multilayer designs are also conceivable, only one layer of paper 15 is provided in the example shown.

[0061] Since paper itself has no heat-sealing capability, it is necessary to apply a heat-sealable material in the form of a sealing layer 16 to the layer of paper 15. There are various possibilities for this. Polyethylene in particular is used as the heat-sealable material for the sealing layer 16, whereby the proportion of this polymer should be kept as low as possible due to the previously mentioned aim of a high paper content.

[0062] According to FIG. 3A, the coating 16 is therefore only provided in areas in which heat-sealing seams, e.g. longitudinal sealing seams 5 or inclined sealing seams 7, are subsequently to be made. Since the packaging bag is also to be finally closed with a transverse sealing seam, the application of a sealing layer 16 is also necessary there. In areas where no heat sealing is to be carried out, a sealing layer 16 can generally be dispensed with.

[0063] However, paper has only a very poor water vapor barrier, so it may be useful to provide a full-surface sealing layer 16 as shown in FIG. 3B. It should be noted here that such packaging bags are frequently used for packaging diapers. This use is also within the scope of the present invention. Diapers in particular but also other hygiene articles have a high proportion of super absorbent material, which tends to absorb moisture from the environment due to its hydrophilic property. Accordingly, by applying a thin sealing layer 16, the water vapor barrier can be considerably.

[0064] Due to the full-surface arrangement, however, a comparatively thin sealing layer 16 is aimed for in order to keep the proportion of polymeric materials as low as possible. At the same time, however, this also impairs the heat-sealability or the stability of the heat-sealing seams to be applied. In principle, this can be compensated for by wider heat-sealing seams. The embodiment according to FIG. 3B, however, provides for an embodiment in which an additional layer 20 made of heat-sealable material is coated on the sealing layer only in sections. This leads to regions with a thicker layer of heat-sealable material, which are designed for a heat-sealing seam, and regions with a thinner layer of heat-sealable material in which no heat-sealing seam is to be introduced. According to FIG. 3B, this is the case, for example, in the protruding section 3.

[0065] Accordingly, a packaging bag is formed which can nevertheless be closed to a large extent by heat-sealing seams. Only at a bottom edge 6 are the front wall 1 and the rear wall 2 joined by a bottom gusset 8. The advantage of the chamfered corners 11 with the inclined sealing seams 7 can be seen in particular in FIG. 4. FIG. 4 shows an embodiment of the packaging bag in accordance with FIG. 1B. The omission of the excess material results in the formation of a bottom 17 which, despite the use of a relatively stiff paper, permits an essentially cuboid configuration. The packaging bag according to FIG. 4 has been filled with diapers stacked one on top of the other and closed in the top area 18 by a transverse seal seam.

[0066] The following table shows a comparison between a conventional packaging bag formed entirely of polyethylene and a packaging bag according to the invention formed of a kraft paper having a thickness of 80 gsm and provided with a sealing layer 16 of polyethylene having a basis weight of 4 gsm. The sealing layer 16 extends over the entire layer of kraft paper. In the areas of the heat-sealing seams, no additional material was applied for the sealing layer 16. Instead, correspondingly wide heat-sealing seams were formed.

TABLE-US-00001 TABLE Paper- Method PE bag Bag Thickness micron ASTM E 75 109 252 Base weight gsm ASTM D 80 84 1505 Tensile N/inch ASTM D 68 224 strength (MD) 882 Tensile N/inch ASTM D 66 107 strength (CD) 882 Elongation % ASTM D 758 3 at break (MD) 882 Elongation % ASTM D 817 7 at break (CD) 882 Gloss at 60 GU ISO 2813 60 13 Bag seal N/25 mm ASTM F 88 44 8 strength 2 ply Seam width mm 1 5

[0067] On the basis of the comparative values, it is clear that the bags have a similar material thickness, but differ substantially from one another, particularly with regard to strength, toughness and also with regard to the sealing seam strength. Despite the advantages of a bag made entirely of polyethylene, it was possible within the scope of the invention to provide a packaging bag which has sufficiently good material properties and, in contrast to a bag made of polyethylene, was produced to a substantial extent from renewable raw materials. The disadvantages of using paper, in particular the high stiffness has been eliminated with respect to the desired dimensional stability by the use of chamfered corners 11. The regions 12 with the heat-seal lacquer also contribute in an advantageous manner to the fact that the head area 18 can be closed securely and with a constant shape.

[0068] According to FIGS. 5 and 6, the packaging bags do not have chamfered corners 7. Rather, the bottom gusset 8 is reinforced by connecting the bottom gusset 8 portions together. According to FIG. 5, openings 21 are provided in the bottom gusset 8 portions so that the front wall 1 and the rear wall 2 are sealed together through the bottom gusset. According to FIG. 6, the bottom gusset sections 9, 10 have a coating of a heat-sealable material and can thus be joined to one another via sealing seams 22.

[0069] FIGS. 7A, 7B show an alternative embodiment of the bottom gusset 6, which is not integrally formed with the front wall 1 and the rear wall 2 but rather is formed via a separate bottom panel 25. The connection is made via joining seams 23, wherein according to FIG. 7A the front wall 1 and the rear wall 2 are formed straight at a lower joining portion 24, while according to FIG. 7B the front wall 1 and the rear wall 2 are folded over at the lower joining portion 24.

[0070] According to FIG. 7A, the joining seams 23 are stressed in shear, and according to FIG. 7B, the joining seams 23 are stressed in peel. Stressing in shear is particularly advantageous for the joining seams 23, since higher loads can be absorbed. In addition, the design according to FIG. 7A also produces a rounder bottom shape.

[0071] According to FIG. 8 a different embodiment of the bottom gusset is provided, wherein the front and/or the rear walls 1, 2 are connected to the bottom gusset sections 9, 10 via a transversely extending secondary cross seam 26, wherein the secondary cross seam 26 is spaced from the cross seam 19 such that a compensation chamber 27 is formed in each case. The secondary cross seam 26 has a number of breakthroughs through which air can be transported outwards to the bag edges. This greatly simplifies the packing process, since there is usually sufficient space available at the edges. This helps to avoid excessive pressure in the center of the bottom, which could cause the seams or the creased edges to burst. Equally, however, pressure peaks can also occur on the outside, so that the air can then flow in the opposite direction to the center, thus relieving the corners of the base.