Valve Bag

Abstract

The present invention relates to a valve bag for bulk material such as cement, gypsum, granulate, animal feed or similar, having a standing bottom, preferably a cross bottom or a block bottom, and having a valve bottom which is disposed opposite the standing bottom and into which a valve hose is inserted for filling the valve bag, wherein the valve hose is formed from a thermo material and a carrier material enveloping the thermo material, wherein the area proportion of the thermo material is smaller than the area proportion of the carrier material.

Description

The invention relates to a valve bag for bulk material such as cement, gypsum, granulate, animal feed or similar, having a standing bottom, preferably a cross bottom or a block bottom, and having a valve bottom which is disposed opposite the standing bottom and into which a valve hose is inserted for filling the valve bag, wherein the valve hose is formed from a thermo material and a carrier material enveloping the thermo material.

Such valve bags, typically produced from paper, are generally known and are widely used in commerce for fine-grain bulk material such as cement, gypsum, granulate, animal feed or similar. The standard sizes in this respect are 5 kg, 10 kg and 25 kg.

The valve bottom comprises a hose-like thermo valve whose inner side is coated with a hot-melting material and which can melt by the action of heat and can close the valve hose. The thermo material, however, does not provide any sufficient stiffness and strength to be able to plug the valve hose onto a filler nozzle of a filling plant. A slip of paper is additionally placed around the thermo material for reinforcement for this purpose.

A corresponding valve bottom is sketched in FIG. 1. The Figure shows the valve bottom 2 of the valve bag 1 which is folded onto the front side of the valve bag 1. The valve bottom 2 is open to illustrate the valve structure. The whole valve bag 1 has a fold of a cross-bottom type.

The valve 5 substantially comprises the thermo material 6 which forms the inner side of the valve hose and which is adhered to the carrier material 7. It can be recognized that the thermo material 6 takes up a larger area proportion with respect to the carrier material 7. The thermo material area in particular projects beyond the inner edge of the carrier material 7 in the axial valve direction, i.e. in the direction of the inwardly disposed valve end. The thermo material 6 consequently forms the main component of the valve hose 6 and the comparatively high unit price of the thermo material 6 causes high production costs for the valve hose 5 and for the valve bag 1.

It is the object of the present invention to optimize the cost ratio of the materials used and to lower the cost effort overall for the manufacture of a valve bag having a thermo valve.

This object is achieved by a valve bag in accordance with the features of claim 1. Advantageous embodiments of the valve bag are the subject of the dependent claims.

The reduction of the manufacturing costs should be achieved by the reduction of the required thermo material. In accordance with the invention, the area proportion of the thermo material is therefore selected as smaller with respect to the area proportion of the carrier material.

The thermo material area is ideally shorter in the axial valve direction with respect to the carrier material area. The larger material proportion of the resulting valve hose is thereby mainly determined by the natural carrier material, in particular paper. The chemically treated, and typically high-cost thermo material consequently only takes up a smaller material proportion. The manufacturing costs can thereby be reduced, which is in particular noticeable in products with high volumes. The desired valve properties, in particular its leak-tightness and handling, can be ensured despite the changes of the material proportions of the individual valve components.

Particularly preferably the thermo material is shortened with respect to the embodiment in the prior art, whereas the carrier material is extended accordingly. The resulting total valve length is maintained by the compensating shortening/extending of the valve materials. This is in particular desirable with respect to the backward compatibility with hitherto filling plants.

The thermo material area is preferably shortened toward the inner end of the valve hose. Since the thermo material area and the carrier material area typically represent rectangular areas whose lengths define the valve hose periphery and whose widths determine the valve length, a shortening of the thermo material takes place by a reduction of the width of the thermo material area, i.e. in the axial valve direction. The area proportion is in particular reduced in the region of the valve hose end disposed inwardly in the valve bag body.

It is particularly advantageous if the resulting valve hose has an almost constant strength or stiffness in the axial direction. A constant strength is desirable and necessary in order not to destroy the valve after the plugging of the valve hose onto the filler nozzle of the filling plant and after the subsequent strain by an inflatable cuff.

A constant strength was previously ensured by the use of the thermo material as the main component of the valve hose. It is expedient in the variant in accordance with the invention to design the now overhanging region of the carrier material as reinforced in order nevertheless to be able to ensure a constant strength in the axial valve direction.

There is the possibility of applying additional reinforcements on the overhanging region. It is, however, better if the carrier material is folded over in the overhanging region, in particular over the total width, i.e. over the complete valve periphery at the inner valve end. The strength in this region is increased, in particular doubled, by the folding over of the carrier material. A largely constant strength is thereby achieved in a particularly simple manner over the total length of the valve. In addition, an improvement of the backward compatibility with existing filling plants can be achieved in a simple manner.

Further advantages and properties of the invention will be explained in the following with reference to the embodiments shown in the drawings. There are shown:

FIG. 1: a sketched representation of a valve bag in accordance with the prior art;

FIG. 2: a sketched representation of the valve bag in accordance with the invention;

FIGS. 3a, b: a first example for the folding over of the carrier material with a valve bag in accordance with the invention; and

FIGS. 4a, b: a second example for the folding over of the carrier material with a valve bag in accordance with the invention.

The representation of FIG. 2 shows the valve bag in accordance with the invention with the shortening in accordance with the invention of the thermo material used. Beside the modified valve hose, the design of the valve bag substantially corresponds to the solution known from the prior art.

The Figure representation shows the valve bag 10 in accordance with the invention with a standing bottom 20 folded to the front at the lower end and a valve bottom 30 at the upper end. Both bottoms 20, 30 are connected to one another via the front side 40 and a rear side, not shown, and are folded in the manner of a cross bottom. The valve bottom 20 is not shown folded closed, but rather open, to illustrate the valve structure.

In a similar manner to the prior art, the valve hose 50 projects beyond the upper corner and lower corner of the valve bottom 20 on the left valve bottom side. The valve hose 50 is also composed of a thermo material 60 here, for example a weldable plastic material, and of a carrier material 70, for example paper, wherein the thermo material 60 envelopes the inner surface of the valve hose 50 and the carrier material 70 envelopes the thermo material 60. With this valve hose 50, the valve bag 10 can be plugged onto a filler nozzle of a filling machine for filling. After the filling process, the thermo valve 50 is welded by the effect e.g. of ultrasound energy, whereby the valve hose 50 is reliably closed.

The proportions of the used valve materials 60, 70 are modified with respect to the known embodiment of FIG. 1 to lower the unit prices per manufactured valve bag 10. In accordance with the invention, the main component of the valve hose is now formed by the natural carrier material 70. The otherwise larger material proportion of the chemically treated thermo material 60, weldable plastic material as a rule, has been reduced.

Both the carrier material 70 and the thermo material 60 have a rectangular shape whose long sides extend transversely to the axial direction of the valve hose 50. FIG. 2 shows the valve bottom 20 in the open state. The valve hose 50 is shaped by the rectangular materials 60, 70 folded in over the length by folding the valve bottom 20.

To save product costs, the width of the thermo material 60 is shortened and the carrier material 70 is in turn widened. The total valve length Y is not changed due to the equal shortening/widening of the valve materials 60, 70. Nevertheless, a substantial portion of the thermo material 60 can be saved, which not only brings about advantages in an economic respect, but rather also appears sensible in an ecological respect since e.g. the required energy effort in the manufacture of the thermo material and its disposal is reduced.

To be able to ensure a strength of the valve hose 50 which is as constant as possible over the total valve length Y, the overhanging region X of the carrier material 70 is advantageously reinforced since the thermo material 60 otherwise contributing to the reinforcement is missing in this region. In the specific embodiment of FIG. 2, the overhanging margin X f the carrier material 70 is folded over for this purpose to achieve a sufficient strength in this region. A double-layer carrier material 70 that has approximately the same strength values as the multilayer region of thermo material 60 and carrier material 70 is gained by the folding over in the region not coated with thermo material. The carrier layer 70 can naturally also be folded over a multiple of times.

FIGS. 3a, b and 4a, b show by way of example possibilities for the implementation of the above-described folding over of the carrier material 70. FIG. 3b shows a section through the carrier material 70 and the thermo material 60 along the line A-A in FIG. 3a. As shown in FIG. 3b, the carrier material 70 is folded over downwardly in the region of the carrier material overhang X, that is onto the side remote from the thermo material 60. The carrier material is two-ply and thereby reinforced in the overhanging region X by the folding over.

FIGS. 4a, b show a different embodiment of the folding over, with FIG. 4b again showing a section along the line A-A in FIG. 4a. As can be seen in FIG. 4b, the carrier material 70 is folded over upwardly in the region of the overhang X, that is onto the side facing the thermo material 60. At the same time the folding over is drawn beneath the thermo material 60 in a slightly overlapping manner. It is alternatively also possible to place the folding over of the carrier material and the thermo material 60 in an abutting manner or to place the folding over in a slightly overlapping manner over the thermo material 60.

Claims

1. A valve bag (10) for bulk material such as cement, gypsum. granulate, animal feed or similar, having a standing bottom (30), preferably a cross bottom or a block bottom, and having a valve bottom (20) which is disposed, opposite the standing bottom (30) and into which a valve hose (50) is inserted for filling the valve bag (10), wherein the valve hose (50) is formed from a thermo material (60) and a carrier material (70) enveloping the thermo material (60), andthe area proportion of the thermo material (60) is mailer than the area proportion the carrier material (70).

2. A valve bag (10) in accordance with claim 1, wherein the thermo material area in the axial valve direction is shorter than the carrier material area.

3. A valve bag (10) in accordance with claim 2, wherein the thermo material area in the region of the valve hose end facing the bag interior is shortened with respect o the carrier material (70).

4. A valve bag (10) in accordance with claim 1, wherein the carrier material (70) substantially comprises a natural material, in particular paper.

5. A valve bag (10) in accordance with claim 1, wherein the valve hose (50) has an almost constant strength in the axial direction.

6. A valve bag (10) in accordance with claim 1, wherein the region of the earner material (70) overhanging with respect to the thermo material (60) is reinforced.

7. A valve bag (10) in accordance with claim 1, wherein the carrier material (70) is folded over for reinforcement.

8. A valve bag (10) in accordance with claim 7, wherein the carrier material (70) is folded over in the full valve periphery at the valve end facing the bag interior.

9. A valve bag (10) in accordance with claim 3, wherein the carrier material (70) substantially comprises a natural material, in particular paper.

10. A valve bag (10) in accordance with claim 2, wherein the carrier material (70) substantially comprises a natural material, in particular paper.

11. A valve bag (10) in accordance with claim 10, wherein the valve hose (50) has an almost constant strength in the axial direction.

12. A valve bag (10) in accordance with claim 9, wherein the valve hose (50) has an almost constant strength in the axial direction.

13. A valve bag (10) in accordance with claim 4, wherein the valve hose (50) has an almost constant strength in the axial direction.

14. A valve bag (10) in accordance with claim 3, wherein the valve hose (50) has an almost constant strength in the axial direction.

15. A valve bag (10) in accordance with claim 2, wherein the valve hose (50) has an almost constant strength in the axial direction.

16. A valve bag (10) in accordance with claim 15, wherein the region of the carrier material (70) overhanging with respect to the thermo material (60) is reinforced.

17. A valve bag (10) in accordance with claim 14, wherein the region of the carrier material (70) overhanging with respect to the thermo material (60) is reinforced.

18. A valve bag (10) in accordance with claim 13, wherein the region of the carrier material (70) overhanging with respect to the thermo material (60) is reinforced.

19. A valve bag (10) in accordance with claim 12, wherein the region of the carrier material (70) overhanging with respect to the thermo material (60) is reinforced.

20. A valve bag (10) in accordance with claim 11, wherein the region of the carrier material (70) overhanging with respect to the thermo material (60) is reinforced.