Bag container and process for making it

Abstract

 The present invention is an outer bag (1) for containing a plurality of packaged goods, for their transportation. The bag of the present invention is a flexible bag made of a sheet-like thermoplastic-containing or paper-containing material. The bag is closed at both ends (3,3'), and comprises a side wall (2). The side wall comprises a slit (4) in between overlapping portions (5,5') of said sheet like material, said slit allowing filling and emptying of said bag.

Description

Technical Field

[0001] The present invention relates to the field of packaging. More specifically, it relates to containers for the transportation of packaged goods.

Background

[0002] A great variety of containers for the transportation of packaged goods have been described in the art. There is a need for transportation containers which could be made in an economical manner, requiring no sophisticated manufacturing equipment. There is a need for transportation containers which could be reused several times, which could be folded and thus more easily handled in between two uses, which could be filled and emptied in a most convenient manner and, finally, which would not require a complicated separate closing operation, or preferably no closing operation at all, after they have been filled, but which would nevertheless prevent contained packaged goods from escaping.

Summary of the invention

[0003] In response to these numerous needs, the present invention proposes a reusable bag for containing a plurality of identical packaged goods. The bag comprises a side wall and two closed ends. The side wall is made of a sheet-like thermoplastic-containing or paper-containing material. The side wall comprises a slit in between overlapping portions of said sheet like material. The slit allows filling and emptying of said bag.

Brief description of Figures

[0004] 

• Fig.1 is a general perspective view of a bag according to the present invention.
• Fig.2 is a detailed perspective view of the slit in the side wall of the bag.
• Fig.3 illustrates a method of making a bag of the present invention.

Detailed description of the invention

[0005] The present invention is a transportation container made of a sheet-like flexible material, i.e. a bag. Thus the container according to the present invention can be folded and stored in between uses, requiring only very little space. The most suitable material used for making the bag of the present invention depends on the use envisioned, i.e. the packaged goods to be transported inside the bag, but generally suitable materials include paper-containing materials, and thermoplastic-containing materials. Paper-containing materials have the advantage that they are more biodegradable and cheaper than plastic, but they are less resistant. Nevertheless, suitable paper materials include simple ply or multyply paper complex made of kraft or recycled paper, resistant laminated paper or paper with reinforcing structure. Thermoplastic-containing materials have the advantages, amongst others, that they are resistant, fully flexible, and water-proof, whereby the contained goods are better protected from humidity. There are no restrictions on suitable thermoplastic materials for use herein. Preferred because cheapest are polyethylene or polyproylene based films.

[0006] Other materials are suitable too, although somewhat more expensive. Such materials include plastic-coated papers, as well as more sophisticated material such as Tyvek®.

[0007] The bag (1) according to the present invention comprises at least a side wall (2). The bag may comprise two side walls assembled together (2,2'), or the bag may comprise a single but continuous side wall, as when the bag is manufactured starting from a single sheet which forms a tube. The number of side walls is not an essential feature of the present invention. The bag further comprises at least two closed ends (3,3'). The side wall (2) comprises a slit (4) in between overlapping portions (5,5') of said sheet like material. The slit allows the filling and emptying of the bag. Both overlapping portions can belong to the sheet from which the bag is made, as for instance when the bag is made from a single sheet of material in the form of a tube where the ends of the sheet overlap; this method of manufacturing is disclosed hereinafter. In an alternative, a bag according to an invention can be made from a bag initially having a slit but no overlapping portion, i.e. a slit in between to proximal, but not overlapping, edges of sheet material. This arrangement can then be provided with an additional band of material which is fixed onto only one of the proximal edges and which extends over, i.e. which overlaps with, the other proximal edge. In both cases, it is necessary that the upper overlapping portion (i.e. towards the outside of the bag) is not articulated, with the result that the slit could be uncovered. In other words, the overlapping portions must be fixed together at least at both of said closed ends of said bag.

[0008] In Figs. 1 and 2, the upper, overlapping, portion of material (5) is drawn in full line, and the lower, overlapped, portion (5') is drawn in dotted line. It is not essential that the slit corresponds to the whole dimension of the side wall, i.e. from one closed end (3) to the other (3'), but it is essential that the slit be long enough to ensure an easy access to the interior of the bag, for filling it and emptying it.

[0009] A large overlapping portion favors a tight closure when the bag is filled as indicated hereinafter. Thus the size of the overlapping portion should be at least 1/30, preferably at least 1/15 of the length of the slit.

[0010] The side wall (2) of the bag is conveniently of a generally square or rectangular shape, and the slit can be arranged lengthwise, i.e. in a direction from one closed end (3) to the other (3'), or widthwise i.e. in a direction perpendicular to a direction from (3) to (3'), or crosswise, i.e. diagonal. However, in order to ensure optimum access to the interior of the bag and all its corners, the slit is preferably disposed lengthwise, and at equal distance from all corners. The total length of the slit is preferably equal to at least 1/2, preferably 2/3, most preferably 3/4 of the dimension of the side wall in the direction of the slit.

[0011] The slit (4) may extend to the ends (3,3') of the bag, in which case the overlapping portions (5,5') are fixed together only at the ends of the bag. However, it is preferred that the overlapping portions (5,5') are fixed together in a portion at the distal extremities of said slit, thereby providing reinforced extremities (6,6') for the slit. Such reinforcing extremities are hatched in Figs. 1 and 2. There can be only one reinforced extremity, i.e. extending from one end only, but a preferred embodiment herein comprises two reinforced extremities, one at each end of the slit. The overlapping portions in the reinforced slit extremities can be readily made by sealing or gluing together said overlapping portions.

[0012] When using the bag according to the present invention, the packaged goods to be contained are introduced through the slit into the bag, and the bag "automatically" closes itself when it is sufficiently filled. Indeed, the packaged goods contained in the bag create a tension inside the flexible bag, and this tension causes the overlapping portions to come together, thereby closing the slit. The bag is not actually closed in the sense that the inside of the bag is still accessible, but the tension and the juxtaposed overlapping portion provide a sufficient closure to prevent the contained goods from escaping from the bag, through the slit.

[0013] A particular advantage of the present invention is that this arrangement allows for large slits, actually much larger than the goods to be contained. This allows a particularly convenient access to the interior of the bag, for its filling and emptying, without compromising on the security of the closure. Thus the bags herein do not require a separate, possibly complicated, closing operation. Accordingly, in an embodiment of the bags herein, the slit remains completely permanently opened. However, it might be appropriate to close the slit in a simple manner, e.g. by means of an adhesive tape or a glue point in the overlapping portions, to prevent theft, in which case the slit may be closed, but in a non-permanent manner. By non-permanent, it is meant herein a closure which does not require physical destruction of the bag such that its subsequent use as herein described is prevented. A particularly suitable embodiment for a non-permanent closure is a double-faced adhesive tape. In particular, such a tape with different faces having different adhesive strength allows an easy opening. A further advantage from having the slit non-permanently closed is that an assembly of stacked bags non permanently closed has been found to be more stable than an assembly of identical bags, but not closed. It is believed that the closure of the bag creates additional rigidity to a stacked assembly of bags.

[0014] Referring to Fig.3, a convenient method for making a bag according to the present invention is to start from a sheet of material. In the simplest embodiment of the present invention, the sheet can then be arranged to form a tube, with the ends of the sheet overlapping each other. The degree of overlapping determines the size of the overlapping portions in the bag eventually manufactured, with the consequences discussed herein above. The tube is then flattened, to form a bag with a continuous side wall and opened ends. At this stage, it is preferred to ensure that the slit is positioned adequately as described before. The two extremities of the tube are then closed, and a bag according to the present invention is obtained.

[0015] In the preferred embodiment of the present invention where the slit has reinforced extremities, it is preferred to form the reinforced slit extremities before closing the ends of the bag. This can be achieved in a number of ways, such as selectively applying glue to the overlapping portions only at the extremities of the slit. Selective welding can be performed either by having welding plates of appropriate size, i.e. corresponding to the size of the overlapping portions. In the bags of the prior art, the overlapping portions are welded together so as to close the slit. Thus suitable machines for making bags have welding plates which correspond to the length of the slit. To avoid having to modify the existing machines to make new bags of the invention, one can apply a suitable coating to the end of the sheet which will eventually become the overlapped portion. That coating, for instance, a thermoplastic coating with a printed band will prevent both overlapping portions from being welded together, even if heat is applied, since the printing on the band prevents welding.

[0016] For any given embodiment of the present invention, said ends of said bag can be closed by simply fixing together the side walls, by e.g. gluing or sealing. However, the heavy duty use foreseen for the bags of the present invention may call for a more robust assembly. A robust end closure can be provided by first folding together the extremities of the side walls, then fixing a separate sheet of material onto said folded arrangement, whereby the folded arrangement is locked. Adhesive tapes can conveniently be used for this purpose. Apart from providing a more robust closing, this arrangement can be used to provide parallelepipedic bags, i.e. bags with a substantially constant thickness.

[0017] Also, bags according to the present invention are most likely to be stacked when used. Thus, to improve the stability of such stacking, it is preferred to have a plurality of embossed features, i.e. stripes or dots, arranged together in portions (7) on both side walls, which provide some grip between two bags, i.e. prevent them from slipping one on the other. The bags according to the present invention are transportation containers, thus they are useful for containing a plurality of packaged goods. We have found the bags herein particularly useful for containing identical packaged goods, preferably wherein said packaged goods are flexible bags containing a granular or liquid material, or wherein said packages used to package said goods are parallelepipeds. Indeed, in all these cases, the plurality of packaged goods in the bag of the present invention end up forming a regular shape which provides an optimum tension in the bag, thus an optimum "closing" for the slit.

Claims

1. A reusable bag for containing a plurality of packaged goods, said bag comprising a side wall made of a sheet-like thermoplastic-containing or paper-containing material, and two closed ends, characterized in that said side wall comprises a slit in between overlapping portions of said sheet-like material, said slit allowing filling and emptying of said bag.

2. A bag according to claim 1 which comprises a plurality of identical packaged goods.

3. A bag according to claim 2, wherein said packaged goods are flexible bags containing a granular or liquid material, or wherein said packages used to package said goods are parallelepipeds.

4. A bag according to any of the preceding claims wherein said slit remains permanently at least partially opened.

5. A bag according to claim 4 wherein said slit remains permanently and completely opened.

6. A bag according to the preceding claims wherein said slit extends throughout at least 1/2, preferably 2/3, most preferably 3/4 of a dimension of said side wall, lengthwise, or widthwise or crosswise.

7. A bag according to claim 6, wherein said side wall is generally of a rectangular shape, and wherein said slit extends lengthwise, at equal distance from all corners of said side wall.

8. A bag according to any of the preceding claims wherein said overlapping portions (5,5') are fixed together in reinforcing portions, at the distal extremities of said slit, thereby providing reinforced extremities for said slit.

9. A bag according to the preceding claims wherein each of said closed ends consists of a folded arrangement of the extremities of said side walls.

10. A bag according to claim 9 wherein a separate sheet of material fixed onto said folded arrangement, whereby said folded arrangement is locked.

11. A method for making a bag according to any of the preceding claims which comprises the steps of arranging a sheet of said material to form a tube, with two ends of said sheet overlapping so as to form said overlapping portions, flattening said tube and closing the extremities of said tube so as to form said closed ends.

12. A method according to claim 11 which comprises the steps of forming reinforced slit extremities before closing said ends of said tube.

13. A method according to claims 11-12 where each of said closed ends of said bag is formed by folding together the extremities of said side walls, then fixing a separate sheet of material onto said folded arrangement, whereby said folded arrangement is locked.

Drawing