Paper bag provided with an airtight closable opening

Abstract

 The invention relates to a bag (1) having the dimensions of a jumbo-sack.
The bag (1) is preferably provided with closing means (9) for dust-tight closure of the filling opening (8).
This has the advantage that materials can be transported in dust-tight manner. This is of particular importance in the transport of material sensitive to moisture or contamination, such as cement products and food products such as tea.
Preferably the bag (1) is at its upper side provided with an inlet valve (8,9), the outflow valve (11,26) is provided with fastening means (12,27) for causing mutual fastening of the walls of the valve (11,26).

Description

[0001] The invention relates to a bag having substantially the dimensions of a jumbo-sack.

[0002] Such bags are generally known; they are used for example for packaging cement products, cereals or other natural products.

[0003] The shape of such bags of the prior art is in principle undefined, wherein the bag acquires its shape through filling. This shape is generally not rectangular. This means that when such bags are stacked the filling factor is not optimal.

[0004] The object of the present invention is to provide such a bag, wherein the shape of the filled bag is as rectangular as possible.

[0005] This object is achieved in that the bag is provided with an upper surface and in that a filling opening is arranged in the upper surface.

[0006] As a result of these steps the filled bag acquires the most rectangular possible form so that a number of such bags, when stacked, fills as much as possible of the available space.

[0007] Preferably such a bag is made from multi-layer material. Preferably the multi-layer material is selected from paper, plastic, metal foil or a natural fabric like jute preferably in combination. The use of paper avoids the environmental problems associated with plastic bags.

[0008] It must of course be possible to fill such a bag, for which purpose a filling opening is arranged in the upper surface.

[0009] According to a preferred embodiment the bag is provided with closing means for dust-tight closure of the filling opening. This has the advantage that materials can be transported in dust-tight manner. This is of particular importance in the transport of material sensitive to moisture or contamination, such as cement products and food products such as tea. The bag is, however, also usable for transporting other materials, like granulates, powders or soft toys.

[0010] According to a further preferred embodiment the closing means are formed by a flap fixed to the bag and adherable to the top part of the bag in order to close the filling opening. It will be apparent that this results in a bag which can be readily closed. According to another embodiment the bag is at its upper side provided with an inlet valve, the outflow valve is provided with fastening means for causing mutual fastening of the walls of the valve.

[0011] Preferably the bag is provided on its underside with an outflow valve, the outflow valve is provided with fastening means for causing mutual fastening of the walls of the valve.

[0012] According to another prefered embodiment the fastening means are formed by a self-adhesive layer arranged on the inside of the valve.

[0013] These features have further the advantage that such a closure is tamperproof, that is that an attempt to open the closure can later easily be detected.

[0014] Other attractive preferred embodiments of the discharge opening will be found in the sub-claims.

[0015] The present invention will subsequently be elucidated with reference to the annexed drawings, in which:

figure 1 shows a partly broken away perspective view of a first embodiment of the present invention;

figure 2 shows a perspective view of a second embodiment of a bag according to the present invention;

figure 3 is a detail view of a first embodiment of a discharge opening in the bag according to the present invention;

figure 4 shows a detail view of another embodiment of a filling opening in the bag according to the present invention; and

figure 5: a view similar to figure 2, wherein the outflow valve is tucked away between the bottom of the bag and the pallet.

[0016] A bag 1 according to the present invention is shown in figure 1. Bag 1 is formed by a front wall 2, two side walls 3, 4 respectively and a rear wall 5. The walls are joined at their bottom to a base 6, while the walls are each joined at their top to an upper surface 7.

[0017] An opening 8 is arranged in upper surface 7, while a flap 9 can be arranged over opening 8, which flap coincides with upper surface 7 and is joined thereto on one side. Arranged in the bottom surface 6 is an outflow opening 10 to which a valve 11, joined to the bottom surface 6, is arranged close-fittingly. A pull cord 12 is arranged round the valve 11.

[0018] The bag according to the invention is preferably manufactured from multilayer paper. The number of layers can vary, as can the dimensions of the bag, and the material, or the weight of the material which must be carried with the bag. The number of layers could lie for instance between 3 and 12, although these figures must in no way be deemed as limiting.

[0019] It is even possible to use layers of different types of material; it is thus possible to manufacture one of the layers from a natural fabric like jute, and to manufacture for example the inner layer of a metal foil or another moisture-resistant material, for example a plastic. It is of course even possible to combine more than two different types of layers of material in a bag.

[0020] The bag is formed to an integral unit by means of glued seams. Several of the glued seams, designated with numeral 13, are shown in the drawing. Further shown in the figure are fold lines 14 as an example of fold lines for folding the bag together. Before the bag is filled it is hereby possible to fold up the bag as flat as possible. It is of course possible to use another fold line pattern.

[0021] The flap 9 is manufactured from the same material as the bag itself. The flap is provided on its inside with a layer of self-adhesive material 15. The self-adhesive material 15 does not of course extend over the part of the flap which is arranged above the opening 8 in order to prevent adhering of the contents of the bag to the self-adhesive material. The flap 9 may, of course, also be connected to the edge of the opening 8.

[0022] In the non-used situation of the bag the self-adhesive material is covered by cover films 16. These can be removed when the bag is closed. When trying to open the flap 9 the material of the flap 9 or the upper surface 7 will tear due to the self-adhesive material. This implies that any attempt to gain access to the contents of the bag is clearly visible. For a re-use of the sack, the flap 9 should be cut out at the location of the aperture, and for closing a new flap or a new sheet of paper should be used.

[0023] As already stated, an outflow opening 10 is arranged on the underside of the bag in the base 6, in which opening a valve 11 is fixed by means of glued strips 17. The cord 12 is fastened around valve 11 by means of a strip of paper 18. Preferably the cord is made of natural fibre.

[0024] In figure 2 is shown a second embodiment of the bag according to the invention. This embodiment differs from the embodiment shown in figure 1 in the fact that the base 6 of the sack a pallet 19 has been provided. This pallet 19 consists of a top plate 20 in which an aperture 21 has been provided for the closure 10. Further, a number of blocks 22 has been provided under the top plate at the corners thereof and along the edges thereof between the corners. Below those blocks 22 planks 23 have been provided.

[0025] This structure allows the fork 24 of a fork lift truck not depicted in the drawings to shift under the top plate 20 of the pallet to be able to lift the pallet together with the sack 1 by means of a fork lift truck. This allows not only to be able to stack the filled sacks and to transport them with the fork lift truck as other goods handled by a fork lift truck, but also to gain access to the discharge opening 10. By lifting with the fork lift truck it is possible to raise the sack, so that the discharge opening is available from underneath. By opening the discharge opening the contents of the sack can be discharged. It is even possible by using the strap to stop discharging from the sack, so that only a part thereof may be discharged and the rest thereof may remain behind in the sack.

[0026] Further shown in figure 3 is how the valve 11 can be folded together for a good closure. It can be seen herein how cord 12 is wound round the valve and how, when knotted, the cord fully closes the valve.

[0027] The use of a cord has the advantage that the contents of the bag do not have to be discharged all at once; this can take place portion-wise. The valve can in any case be reclosed after each release of the contents of the bag.

[0028] The same advantages are also gained when instead of a cord a flexible, for instance metal or plastic, strap is used which is fastened with a clamp or clasp.

[0029] As shown in figure 5 of the drawings, the use of an outlet valve together with a pallet base allows the closed valve to be fitted or tucked away between the bag and the pallet with the help of a strap or bracket made for instance of metal, wood, rubber, twine, etcetera.

[0030] Finally, figure 4 shows another embodiment of the discharge opening of the bag according to the invention. In order to close the valve 26 a layer of adhesive material 27 is arranged on the inside thereof which, after removal of a strip of covering material 28, can be moved to the opposite portion, whereby the valve 26 is closed. By using a suitable adhesive material, opening of the closure will lead to the tearing of the closure, so that tampering is immediately visible. For subsequent use one could use a new separate closure with a pipe-like structure to be adhered to the rest of the original closure by means of a new layer of adhesive material.

[0031] According to another embodiment the outflow valve can be closed by glue. For opening the valve the glued part thereof can be cut off. The remainder of the valve can subsequently be glued for closure of the valve for further use.

[0032] Although not depicted in the drawings, it is possible to use a valve used as outflow valve also as an inflow valve. The valve function per se is not so important in this respect, but the valve is easier to manufacture, as the construction is similar to the construction of the outflow valve. Also glue could be used here for closing the valve instead of self-adhesive material.

[0033] It will be apparent that the bag according to the present invention is versatile in use. This is firstly because of the fact that the bag can be used various times since the filling and discharge openings take a reclosable form, while it is also possible to empty the bag portion-wise due to the fact that the discharge opening can be reclosed. In addition, the bag is preferably manufactured from paper, which is particularly advantageous material. It is possible due to the good closure to transport moisture- and dust-sensitive materials. After the possibly multiple use the bag can easily be recycled or burned without environmental impact. By arranging straps round the bag, as elucidated with reference to figure 2, the bag can be used for transporting heavy materials, whereby the field of application of the bag is considerably enlarged.

Claims

1. Bag having substantially the dimensions of a jumbo-sack, characterized in that the bag is provided with an upper surface and that a filling opening is arranged in the upper surface.

2. Bag as claimed in claim 1, characterized in that the bag is made of multi-layer material.

3. Bag as claimed in claim 1 or 2, characterized in that the bag is made of paper, plastic, metal foil, a fabric like jute, or a combination thereof.

4. Bag as claimed in claim 1, 2 or 3, characterized in that the bag is provided with closing means for dust-tight closure of the filling opening.

5. Bag as claimed in claim 4, characterized in that the closing means are formed by a flap fixed to the bag and adherable to the top part of the bag in order to close the filling opening.

6. Bag as claimed in claim 5, characterized in that the flap is provided with a self-adhesive layer.

7. Bag as claimed in claim 6, characterized in that the adhesive layer of the flap is provided with a removable sheet.

8. Bag as claimed in claim 4, characterized in that the bag is at its upper side provided with an inlet valve, the outflow valve is provided with fastening means for causing mutual fastening of the walls of the valve.

9. Bag as claimed in claim 8, characterized in that the fastening means are formed by a self-adhesive layer arranged on the inside of the valve.

10. Bag as claimed in any of the foregoing claims, characterized in that the bag is provided on its underside with an outflow valve, the outflow valve is provided with fastening means for causing mutual fastening of the walls of the valve.

11. Bag as claimed in claim 10, characterized in that the fastening means are formed by a flexible pulling element, for instance a cord or strap, which extends round the valve.

12. Bag as claimed in claim 10 or 11, characterized in that the fastening means are formed by a self-adhesive layer arranged on the inside of the valve.

13. Bag as claimed in any of the foregoing claims, characterized in that the bottom of the bag is provided with an extra layer.

14. Bag as claimed in any of the foregoing claims, characterized in that the bottom of the bag is connected with a pallet.

15. Bag as claimed in claim 14, characterized in that the outflow valve is located within the center of the pallet.

16. Bag as claimed in claim 14 or 15, characterized in that that the outflow valve is provided with a strap for tucking the valve between the bottom of the bag and the pallet.

17. Method for re-using a bag as claimed in one of the claims 4-16, characterized in that after emptying the bag, the discharge means are reinstated by using glue.

18. Method for re-using a bag as claimed in one the claims 10-16, characterized in that after reloading the bag, the filling means are re-instated by using glue.

Drawing