Abstract
A bag for bulk material made of paper and/or other sheet material, having at least one bottom formed in a cross bottom or block bottom folding manner, the bottom fold having two side flaps which are folded about side fold lines extending in the longitudinal direction of the bottom to form the bottom, the side flaps forming an overlap in the closed state, the width of the overlap being a maximum of 10 millimeters, preferably a maximum of 6 millimeters and further preferably a maximum of 4 millimeters.
Claims
1. Bag (10) for bulk material of paper and/or other sheet material, with at least one bottom formed in a cross or block bottom folding manner, wherein the bottom folding comprises two side flaps (25, 26) which are folded about side fold lines (28, 29) extending in the longitudinal direction of the bottom for bottom formation, wherein the side flaps form an overlap in the closed state, and the width of the overlap is at most 10 millimeters, preferably at most 6 millimeters and further preferably at most 4 millimeters.
2. Bag according to claim 1, wherein the width of the overlap is at least 1 millimeter, preferably at least 2 millimeters and further preferably at least 4 millimeters.
3. Bag according to claim 1 ,wherein the bottom is formed as a valve bottom in which a valve (50) for filling the bag is incorporated.
4. Bag according to claim 1, wherein the valve (50, 52) is inserted in the region of a corner turn-in (22, 23) of the bottom fold, the inner end of the valve (54, 56) extending substantially to the inner edge (24) of the corner turn-in.
5. Bag according to claim 3, wherein the valve (50, 52) is inserted in the region of a corner turn-in (22, 23) of the bottom fold, the inner end (54, 56) of the valve (50, 52) being shortened relative to the inner edge (24) of the corner turn-in (22), the shortening being preferably 3 mm, further preferably 6 mm and still further preferably 1 cm.
6. Bag according to claim 1 wherein the valve (50) is formed as a valve tube (50) and/or as a valve patch (52).
7. Bag according to claim 1, comprising two opposite bottoms between which a side wall (16) of the bag extends.
8. Bag according to claim 1, wherein the bag is designed as an open cross-bottom or block-bottom bag.
9. Bag according to claim 1 ,wherein the bag is designed as a multilayer bag, the material layers preferably selected from the group consisting of paper, coated paper, plastic, and mixtures thereof.
10. Bag according to claim 9, wherein the bag is formed of three layers, the innermost and the outermost material layer being formed of paper and intermediate material layer being formed of plastic film.
11. Bag according to claim 1, wherein the bag is formed of compostable and/or recyclable materials, in particular paper and/or coated paper.
12. Bag according to claim 1, wherein at least one of the bottoms is provided with an inner latch (40) and/or a cover sheet (45).
13. Bag according to claim 1, wherein the inner latch comprises uncoated paper, PE-coated paper and/or film.
14. Bag according to claim 1, wherein wherein the bag is formed from a piece of tubing which has a smooth cut at least one, preferably both ends (13, 14).
15. Bag according to claim 2, wherein the bottom is formed as a valve bottom in which a valve (50) for filling the bag is incorporated.
16. Bag according to claim 15, wherein the valve (50, 52) is inserted in the region of a corner turn-in (22, 23) of the bottom fold, the inner end of the valve (54, 56) extending substantially to the inner edge (24) of the corner turn-in.
17. Bag according to claim 15, wherein the valve (50, 52) is inserted in the region of a corner turn-in (22, 23) of the bottom fold, the inner end (54, 56) of the valve (50, 52) being shortened relative to the inner edge (24) of the corner turn-in (22), the shortening being preferably 3 mm, further preferably 6 mm and still further preferably 1 cm.
18. Bag according to claim 17, wherein the valve (50) is formed as a valve tube (50) and/or as a valve patch (52).
19. Bag according to claim 16, wherein the valve (50) is formed as a valve tube (50) and/or as a valve patch (52).
20. Bag according to claim 15, wherein the valve (50) is formed as a valve tube (50) and/or as a valve patch (52).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Examples of embodiments of the invention are explained in more detail with reference to the figures below. Thereby show:
[0024] FIG. 1: A bag with unfolded cross bottom according to the prior art.
[0025] FIG. 2: The open cross bottom of a bag according to the invention.
[0026] FIG. 3: The open cross bottom of a bag according to the invention with inner latch
[0027] FIG. 4: The feeding of the cross bottom of a bag according to the invention
[0028] FIG. 5: The closing of a cross bottom of a bag according to the invention
[0029] FIG. 6: The closed cross bottom, glued over with a cover sheet
[0030] FIG. 7: The open cross bottom of a bag according to the invention with valve
[0031] FIG. 7a: The open cross-bottom of a bag according to the invention with a valve tube extending to the inner edge of the corner turn-in.
[0032] FIG. 7b: The open cross bottom of a bag according to the invention with a valve tube that does not extend to the inner edge of the corner turn-in.
[0033] FIG. 8: The open cross bottom of a bag according to the invention with inserted valve patch.
[0034] FIG. 8a: The open cross-bottom of a bag according to the invention with inserted valve patch, which extends to the inner edge of the corner turn-in.
[0035] FIG. 8b: The open cross bottom of a bag according to the invention with inserted valve patch, which does not extend to the inner edge of the corner turn-in.
[0036] FIG. 9: A paper web section for the production of a bag according to the invention.
Description of the Preferred Embodiments
[0037] FIG. 1 shows a bag 1 with an unfolded cross bottom 3 according to the prior art. To close the bottom, first the front side flap 8 is folded in and then the rear side flap 7 is folded onto it, and in their overlap area the two side flaps are glued with the adhesive strip 9. Common bag making machines require a comparatively wide overlap in order to be able to apply an adhesive strip in a practicable manner.
[0038] FIG. 2 shows a bag 10 according to the invention with an open cross bottom 20. The bottom 20 is divided into two halves by the longitudinal bottom axis 21. Characteristic of the cross bottom fold are the corner turn-ins 22 and 23 as well as the side flaps 25 and 26, which are folded closed around the side fold lines 28 and 29 for closing the bottom 20. Extending downward from the bottom 20 is the sidewall 16 of the bag.
[0039] In FIG. 3, an inner tack 40 is inserted into the open cross bottom 20. The inner tack 40 covers the inner edges of the folded-in corner turn-ins 22 and 23 and extends from the bottom longitudinal axis 21 to above the side fold lines 28 and 29. Advantageously, the inner tack is glued to the inner edges of the corner flaps and the side flaps with a frame glueing. This provides good protection for the filling contents.
[0040] FIG. 4 shows the closing of the side flaps 25 and 26 of the cross bottom 20 of a bag 10 according to the invention. An inner bolt 40 is inserted into the bottom 20. First, the front side flap 26 is folded shut and then the rear side flap 25 is folded onto it.
[0041] FIG. 5 shows the closed cross bottom 20 of a bag 10 according to the invention. In the closed state, the side flaps 25 and 26 overlap only to a small extent. The width of the overlap of the side flaps results from the distance between the edge 35 of the rear side flap 25 and the edge 36 of the front side flap 26. Since the front side flap 26 is folded in first, its edge 36 is covered by the rear side flap 25 folded in afterwards. Therefore, the edge 36 of the front side flap 26 is shown as a dashed line, and the unconcealed edge 35 of the rear side flap 25 is shown as a solid line. According to the invention, the distance between the edges 35 and 36 or the width of the overlap of the side flaps 25 and 26 is at most 10 millimeters. Preferably, the overlap is a maximum of 4 millimeters and further advantageously a maximum of 2 millimeters.
[0042] Due to the smaller side flap overlap, the bag can be formed in an overall more material-saving way. Due to the small width of the overlap, an adhesive strip cannot be suitably applied with the machines commonly used in bag production. It is therefore provided in accordance with the invention to fix the bottom fold in a way other than by mutual gluing of the side flaps in the overlap area. For example, the bottom fold can be fixed by gluing-on a cover sheet. This is illustrated in FIG. 6. There, the added cross bottom 20 has a cover sheet 45 glued over it, which fixes the bottom fold.
[0043] FIG. 7 shows a variant of a bag 10 according to the invention with a still open cross bottom 20 into which a valve 50 in the form of a prefabricated valve tube is inserted. As a result of the narrower design of the side flaps 25 and 26, the corner turn-ins 22 and 23 are also narrower in the longitudinal direction of the bottom. As a result, the valve tube 50 also only has to travel a shorter distance in order to insert the filling material into the bag without any problems. In this way, the valve 50 can also be manufactured in a more material-saving manner. FIG. 7a shows a variant in which the valve hose 50 extends as far as the inner edge 24 of the corner turn-in 22. This means that slightly more valve material can be saved in this variant than in the variant shown in FIG. 7, in which the valve hose protrudes beyond the inner edge 24 of the corner turn-ins 22. FIG. 7b shows a variant in which the valve hose 50 is shortened at its inner end 54 relative to the inner edge 24 of the corner turn-ins 22. Preferably this shortening is 3 mm, further preferably 6 mm and still further preferably 1 cm. Even more valve material can be saved by the design according to FIG. 7b.
[0044] FIG. 8 shows a variant of the bag 10 according to the invention with the cross bottom 20 still open, into which a valve patch 52 is inserted to form a valve. When the side flaps 25 and 26 are closed, the valve patch 52 is formed into a valve tube. In the variant shown in FIG. 8, the inner edge 56 of the valve patch extends slightly further to the center of the material base than the inner edge of the corner turn-in 22. FIG. 8a shows a variant with a valve patch 52 in which the inner edge 56 of the valve patch extends to the inner edge 24 of the corner turn-in 22, so that the valve patch 52 and the corner turn-in 22 are flush with each other at the edges 24 and 56. FIG. 8b shows a variant in which the valve patch 52 does not extend with its inner edge 56 as far as the inner edge 24 of the corner turn-ins 22, so that the valve tube 52 is shortened at its inner end 54 relative to the inner edge 24 of the corner turn-ins 22. Particularly advantageously, the shortening is 3 mm, further advantageously 6 mm and even further advantageously 1 cm. As a result, even more valve material can be saved in this embodiment.
[0045] FIG. 9 shows a paper web section 12 for producing a bag according to the invention on a continuous paper roll 11. The fold lines of the cross bottom fold are indicated in dashed lines. The rectangular panels 16 form the sidewall 16 of the bag. Along the cut lines 13 and 14, the paper web sections 12 are cut to form individual tube pieces. Accordingly, the cut lines 13 and 14 represent the cut lines of the tube pieces perpendicular to the tube direction. FIG. 7 shows cut lines 13 and 14 formed with a smooth cut, which run continuously perpendicular to the tube direction. With a reduced tube length, a smooth cut can save material both in the area of the side flaps and in the area of the corner turn-ins.
