Method for producing a side-gusseted bag and flat, unfilled side-gusseted bag

Abstract

A longitudinal method for producing a side-gusseted bag includes providing an incision extending in a transverse direction in a bag film for each side-gusseted bag in such a way that, in the case of a subsequently formed side-gusseted tube, the incision extends over both side gussets and a first front wall that is situated between the side gussets. Proceeding from the incision, the first front wall, together with the corresponding parts of the side gussets, is folded back, on which a separate film section is placed and fastened in the folded-open region. The folded-over section is folded back in such a way that all connecting seams of the separate film section extend in parallel to each other in the transverse direction.

Claims

1. A method for producing a side-gusseted bag, comprising the steps of: supplying a material web of a bag film supplied in a production direction (p); folding the bag film to yield a side-gusseted tube comprising a first front wall, a second front wall and side gussets, which are disposed between and connect the first and the second front walls; and individual side-gusseted bags separated from the side-gusseted tube (14); wherein an incision extending in a transverse direction is produced in the bag film for each side-gusseted bag such that, in the side-gusseted tube, the incision extends over both side gussets and the first front wall, which is situated between the side gussets; wherein in the side-gusseted tube, the first front wall, which is parted by the incision, is lifted on one side of the incision and is at least partially folded over, whereby sections of the underlying second front wall and the side gussets are exposed; wherein to form a flat base, a separate film section is connected via first connecting seams to the folded-over section of the first front wall and the second front wall and via second connecting seams to the exposed side gussets, and wherein the folded-over section is folded back in such a way that the second connecting seams extend in parallel to the first connecting seams in the transverse direction.

2. The method according to claim 1, further comprising trimming edges of the separate film section, and the lower edges of the front walls and side gussets, during the separation of individual side-gusseted bags from the side-gusseted tube.

3. The method according to claim 2, further comprising implementing a double cut along two cutting lines extending in the transverse direction to trim and separate the individual side-gusseted bags.

4. The method according to claim 1, further comprising arranging reclosure strips extending transversely to the production direction (p) on the material web with uniform spacing, such that after the formation of the side-gusseted tube, the reclosure strips extend on one of the side gussets and over a portion of each of the two front walls.

5. The method according to claim 4, further comprising providing the side gusset positioned opposite the reclosure strip, in a case of the side-gusseted tube, with handles.

6. The method according to claim 1, further comprising closing the side-gusseted tube closed around a circumference by use of a heat-sealed seam.

7. The method according to claim 1, further comprising fastening the separate film section to the front walls and the side gussets using heat-sealed seams.

8. A flat, unfilled side-gusseted bag, comprising two front walls positioned opposite each other, a first side gusset and a second side gusset, wherein the first and the second side gussets are positioned opposite each other, extend along a bag longitudinal direction (l), and connect the two front walls to each other a film section provided in a form of a flat base, wherein the film section is connected via first heat-sealed seams to lower ends of the front walls and via second heat-sealed seams to lower ends of the side gussets; wherein the film section is situated between the front walls in such a way that the first heat-sealed seams and the second heat-sealed seams are arranged in parallel to each other along a bag transverse direction (q).

9. The flat, unfilled side-gusseted bag according to claim 8, wherein the front walls and the side gussets are formed from a bag film.

10. The flat, unfilled side-gusseted bag according to claim 8, wherein at least one reclosure device comprising a reclosure strip is provided in a region of the first side gusset that extends along the bag transverse direction (q) across only a portion of a width of the front walls and allows the first side gusset to be folded outward to form a reclosable spout.

11. The flat, unfilled side-gusseted bag according to claim 10, characterized in that an upper bag edge is closed above the reclosure device by a top sealing seam.

12. The flat, unfilled side-gusseted bag according to claim 11, wherein the side gussets extend from the flat base up to the top sealing seam on the upper bag edge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Further features and advantages of the invention will become apparent from the description of embodiments that follows, with reference to the attached figures, wherein:

[0051] FIG. 1 presents a perspective view of a side-gusseted bag, according to the invention, in a filled state;

[0052] FIG. 2 presents the side-gusseted bag according to FIG. 1 in an unfilled, flat state;

[0053] FIG. 3A presents a method step in an exemplary method for producing a side-gusseted bag of FIGS. 1 and 2;

[0054] FIG. 3B presents another method step for producing the side-gusseted bag of FIGS. 1 and 2;

[0055] FIG. 3C presents another method step for producing the side-gusseted bag of FIGS. 1 and 2;

[0056] FIG. 3D presents another method step for producing the side-gusseted bag of FIGS. 1 and 2;

[0057] FIG. 3E presents another method step for producing the side-gusseted bag of FIGS. 1 and 2; and

[0058] FIG. 3F presents another method step for producing the side-gusseted bag of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims.

[0060] FIG. 1 presents a side-gusseted bag comprising two front walls 1a, 1b, positioned opposite each other, a first side gusset 2a and a second side gusset 2b, wherein the side gussets 2a, 2b, positioned opposite each other, extend along a bag longitudinal direction l and each connect the two front walls 1a, 1 b to each other.

[0061] While FIG. 1 shows a filled side-gusseted bag closed in the bag longitudinal direction l by a top sealing seam 3, FIG. 2 shows a flat, unfilled side-gusseted bag according to the invention, as a pre-made bag in a flat state for a subsequent filling. To arrive at the filled bag according to FIG. 1, proceeding from FIG. 2, the pre-made flat bag is filled at the upper edge, which is initially not yet closed, and is closed by the top sealing seam 3. The lateral edges between the front walls 1a, 1b and the side gussets 2a, 2b are reinforced by longitudinal sealing seams 4.

[0062] It should be apparent from FIGS. 1 and 2, that the bag comprises a reclosure device comprising a reclosure strip 6. The reclosure strip 6 is located in the region of the first side gusset 2a and extends across the two wings of the first side gusset 2a, which are inserted between the front walls 1a, 1b, and along the front walls 1a, 1b. In the exemplary embodiment shown, the reclosure strip 6 on the front walls 1a, 1b, extends beyond the first side gusset 2a, and therefore the two front walls 1a, 1b can also be directly connected to each other there, in a region adjoining the first side gusset 2a. In the region of the first side gusset 2a, however, the two wings of the corresponding side gusset 2a are connected to one of the two front walls 1a and 1b, respectively.

[0063] For opening the side-gusseted bag for the first time, a line of weakness 7 is situated above the reclosure strip 6, by which a corner section 8 above the reclosure strip 6 can be removed. The line of weakness 7 can be formed, for example, by a punching, a perforation, or a laser, wherein the different measures can also be combined with one another. A notch 9 also is provided for initiating the tear.

[0064] To provide for a sufficient closure of the side-gusseted bag after a first-time opening, a transverse sealing seam 10, which extends from the end of the reclosure strip 6 to the opposite bag edge, is formed adjacent to the reclosure strip 6.

[0065] After a first-time opening, the first side gusset 2a can be folded outward by opening the reclosure device formed by the reclosure strip 6, thereby forming a spout, and can be re-inserted between the two front walls 1a, 1b, to permit closure again. According to the invention, the side-gusseted bag comprises a flat base, which is formed from a separate film section 11. The film section 11 is connected to the lower edges of the front walls 1a, 1b, and the side gussets 2a, 2b, by heat-sealed seams 12a, 12b. While the flat base is particularly advantageous for filling, transport, storage, and handling, and makes it possible to reliably stand the side-gusseted bag upright, the product can be easily removed by the reclosure device, wherein the removal of partial quantities, in particular, is also precisely possible due to the formation of a spout. Depending on the filling weight, the side-gusseted bag can also be equipped with a handle (not shown), which is advantageously located on the second side gusset 2b positioned opposite the reclosure device.

[0066] The reclosure strip 6 can comprise continuous closure formations in the form of grooves or projections or also a large number of individual closure elements that can be interlocked with each other, wherein such individual closure elements that can be interlocked with each other can have the shape, for example, of mushrooms or gripping hooks.

[0067] It should be apparent from FIG. 2 that the side gussets 2a, 2b, extend along the entire length of the front walls 1a, 1b, and also are not bent outward in the region of the separate film section 11. Instead, the separate film section is folded back onto itself in the region of the side gussets 2a, 2b, in such a way that all heat-sealed seams 12a, 12b, provided for the connection of the film section to the front walls, on the one hand, and for the connection of the film section 11 to the side gussets 2a, 2b, on the other hand, extend one above the other along the bag transverse direction q and can therefore be jointly trimmed in order to remove overhangs resulting from dimensional and positional deviations.

[0068] A preferred method for producing the side-gusseted bag shown in FIGS. 1 and 2 is represented in FIGS. 3a to 3f.

[0069] In the method, a material web of a bag film 13 is fed in a production direction p, the orientation of which corresponds to the bag longitudinal direction l. The corresponding method, therefore, also is referred to as a longitudinal method.

[0070] According to FIG. 3a, folding the bag film 13 yields a side-gusseted tube 14, which comprises a first front wall 1, a second front wall 1b, and two side gussets 2a, 2b, connecting the front walls 1a, 1 b. According to FIG. 3a, the bending lines are already indicated. Outer edges 15 of the bag film 13 are provided as overhang and are removed after the formation of the side-gusseted tube 14.

[0071] Further according to FIG. 3a, an incision 16 extending in a transverse direction is produced in the bag film 13 for each side-gusseted bag before folding in such a way that the incision 16 in the subsequently formed side-gusseted bag 14 extends across the two side gussets 2a, 2b, and the first front wall 1a, which is situated between the side gussets 2a, 2b. As described in the following in greater detail, the individual side-gusseted bags are separated from each other in the region of the incisions 16, wherein the incision 16 is provided for forming a flat base.

[0072] Alternatively, in a modification of the step depicted in FIG. 3a, it also is possible to form a side-gusseted tube 14 first and to then produce the incisions 16. The side-gusseted tube 14 can be pulled, for example, over a type of core, which is then provided as a type of abutment for producing the incisions 16, for example, by stamping. The incisions 16 also can be formed by a laser or a particularly precise punching after the formation of a side-gusseted tube, wherein a cut completely through the side-gusseted tube should always be avoided.

[0073] The bag film 13 is formed of at least two layers and comprises a heat-sealable inner layer made of polyolefin, in particular, polyethylene, and an outer layer made of polyester, in particular, polyethylene terephthalate (PET). The film section 11 can be formed from an identical or similar material having a corresponding layered design. According to FIG. 3a, in the case of the bag film 13 which is supplied in the flat state, the heat-sealable inner layer is initially exposed, and therefore a reclosure strip 6 extending in the transverse direction can also be sealed thereon at that point for each side-gusseted bag. The line of weakness 7 is also already produced in the flat bag film 13, adjacent to the reclosure strip 6, by which the upper corner section 8 can be subsequently removed from the finished side-gusseted bag to expose the reclosure strip 6 during a first-time opening.

[0074] Since the incisions 16 extend across the first front wall 1a and both side gussets 2a, 2b, the first front wall 1a can be lifted, for which grippers or vacuum cups, for example, can be utilized.

[0075] In FIG. 3a, it is also indicated that longitudinal sealing seams 4 can be produced already during the formation of the side-gusseted tube 14. If the first front wall 1a, which is lying on top, is now partially folded over at the incisions 16, sections of the two side gussets 2a, 2b, and the second front wall 1b thereunder are exposed (see FIG. 3b), whereby the side gussets 2a, 2b then extend outwardly at an angle of 45° proceeding from a bending line 17. A separate film section 11 is placed on the bottom region, which has been folded open along the bending line 17 in this way, it being possible to supply the film section from the side, in particular, according to FIG. 3b.

[0076] According to the exemplary embodiment depicted in FIG. 3a, the side-gusseted tube is moved in such a way that the bottom region lies in front of the top region relative to the individual film bags to be separated from the side-gusseted tube 14. The production of the film bag also can take place in such a way, however, that the production direction is precisely reversed with respect to the upper edge and the lower edge of the side-gusseted bag to be formed, and therefore, after the formation of the side-gusseted tube 14 from the bag film 13, the top lies at the front relative to the individual side-gusseted bags to be formed. Such a reversed direction can be advantageous to fold the folded-over section back, within the scope of the invention, in such a way that the second connecting seams extend in parallel to the first connecting seams in the transverse direction q.

[0077] Based on FIG. 3c, which is described in detail in the following, a reversal of the production direction p would then also result, and therefore the folding-back of the side gussets 2a, 2b indicated by an arrow can take place more easily in the region of the separate film section 11. According to FIG. 3c, this separate film section 11 is connected to the folded-open side gussets by heat-sealed seams 12b, wherein this heat sealing can be carried out on a flat side-gusseted tube 14.

[0078] To avoid the undesired production of a heat-sealed seam within the side-gusseted tube 14 during the connection of the separate film section 11 to the first front wall 1a, it can be provided according to FIG. 3d that the folded-over section of the first front wall 1a is positioned upright and then, in the upright state, is connected to the separate film section 11 along a heat-sealed seam 12a (FIG. 3e).

[0079] As represented in FIG. 3e, the previously folded-over section is folded back in such a way that the second heat-sealed seams 12b are located on themselves on the lower edge, due to an inward bending of the separate film section 11, and therefore the first heat-sealed seams 12a and the second heat-sealed seams 12b finally lie one over the other.

[0080] In this context, it is indicated in FIG. 3f that the individual, successive, flat, unfilled side-gusseted bags are separated from each other by means of a double cut D, on the one hand, and, simultaneously, an outer edge is removed at the first and second heat-sealed seams 12a, 12b to remove any overhangs and “fringes” connected thereto (see also FIG. 2).

[0081] As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that.