Bag for bulk goods

Abstract

A bag for bulk goods of paper and / or other flat material, having at least one bottom formed in a cross-bottom or block-bottom folding, wherein the bottom fold has two lateral flaps which are folded about lateral fold lines running in the longitudinal direction of the bottom in order to form the bottom, wherein the lateral flaps in the closed condition form an overlap, wherein the width of the overlap is at most 10 mm, preferably at most 6 mm and more preferably at most 4 mm.

Description

TECHNICAL FIELD

[0001] The invention relates to a bag for bulk goods, such as cement, granular material or other powdery or particulate building material, chemical agents or food, which has at least one cross bottom or block bottom. BACKGROUND

[0002] Such bags are typically formed from flat or web-shaped material, preferably paper and / or plastic. The bags are used, inter alia, for the packaging and sale of powdery or particulate bulk goods. Common sizes are 5 kg, 10 kg and 25 kg.

[0003] In order to manufacture such bags, a one- or multi-layered web of material consisting of flat material, such as paper and / or film web, is formed in a so-called tube former into a continuous tube and cut into tube pieces of the appropriate length in a known manner, from which tube pieces the bags are finally formed, for example by means of cross bottom or block bottom folds. Adjacent to the end of the bag manufacturing process, the bottom folds are usually fixed by means of suitable adhesive. For this purpose, the lateral flaps of the bottom folds are usually brought together in succession and adhered to one another in the region of a relatively wide overlap.

[0004] On the one hand, so-called open cross bottom or block bottom bags are known, which have a cross bottom or block bottom as standing bottom and which are open in the upper region for filling the bag and are closed, for example sewn and / or glued, only after filling. Furthermore, so-called valve bags are known, which have two opposite cross bottom or block bottoms, one of which is formed as standing bottom and the other as opposite valve bottom, in which valve bottom a valve tube for filling the bag is inserted, which is closed, for example by welding, after filling.

[0005] Figure 1 A cross bottom according to the prior art is shown being covered. In the case of the previously known cross bottom or block bottom fold, the lateral flaps are typically brought together in succession at the end. Here, the two lateral flaps usually have a relatively wide overlap in the brought-together state, in the region of which overlap there is an adhesive for fixing the bottom fold.

[0006] For the mutual adhesion of the lateral flaps, a sufficiently wide overlap is required. In the known bags, the width of the overlap is up to 2.5-5 cm. This requires sufficiently wide lateral flaps, which are associated with a corresponding material outlay. Since such bags are produced and sold in large quantities, a small material saving already leads to a significant cost advantage. Bags are also known in which a gap is left between the covered lateral flaps, so that the covered lateral flaps do not overlap. However, in such bags, sufficient protection of the filled goods in the region of the bottom is usually not ensured, in particular in the case of multi-layer bags with a film or waterproof layer sublayer. Furthermore, the bag bottom is less stable in the region of the gap. SUMMARY

[0007] In the context of the above, it is the object of the present invention to propose a bag in which material can be saved in the bottom region, in which good protection of the filled article and sufficient strength should also be ensured in the bottom region.

[0008] According to the invention, the object is achieved by a bag having the features according to the invention. Advantageous design variants are the subject matter of the present text.

[0009] The bag according to the invention is formed from a one- or multi-layer web of material, in particular paper and / or other flat material, and has at least one bottom formed in a cross-bottom or block-bottom folding. At both end portions of the bottom longitudinal axis, there are the corner folds of the bottom fold, and the lateral flaps of the bottom fold run essentially parallel to the bottom longitudinal axis, which lateral flaps are closed about the lateral fold lines of the bottom fold when the bottom is closed. The closed lateral flaps have an overlap. According to the invention, the width of the overlap is at most 10 mm, preferably at most 6 mm and more preferably at most 4 mm.

[0010] By means of the folding width, the width of the fold is reduced to a value which is significantly lower than is usually required for the adhesion of the lateral flaps to one another on common bag-making machines. By reducing the overlap width relative to known bags, a significant material saving is achieved, which also improves the environmental friendliness of the bag, in particular when these bags comprise material layers consisting of plastic or other materials which are less environmentally friendly. The length of the tube from which the bag is manufactured is significantly reduced in the case of the same filled volume of the bag compared to the previously known bags with an adhesive overlap. At the same time, due to the presence of the narrow overlap, sufficient protection of the filled article is also ensured, since the gap between the closed lateral flaps is avoided. Preferably, the lateral flaps are not adhesively bonded to one another in the region of their overlap. The securing of the bottom fold can be carried out in any manner different from the adhesion of the folds of the lateral flaps, for example by means of an adhesive cover sheet.

[0011] It is advantageously proposed that the overlap of the lateral flaps is at least 1 mm, preferably at least 2 mm, more preferably at least 4 mm and more preferably at least 6 mm. By means of the minimum width of the overlap, a better protection of the filled article and a good strength of the bag bottom are ensured.

[0012] In a preferred design, the bottom of the bag is configured as a valve bottom, into which a valve for filling the bag is worked. Advantageously, the valve serves as a valve tube, which is inserted in the region of the corner of the bottom fold. Particularly advantageously, the inner end of the valve tube extends substantially only up to or shortly before the inner edge of the corner. The corner also requires less material by virtue of the smaller overlap of the lateral fold or the reduced length of the tube used to form the bag. In particular, the corner has a smaller width in the direction of the longitudinal axis of the bottom, i.e. the corner extends from the end of the longitudinal axis of the bottom not so far in the direction of the centre of the bottom. In the case of a valve bag, the valve tube must normally be passed over this width of the corner, by means of which the filling product can be introduced into the bag as problem-free as possible. By virtue of the less wide corner, the path to be passed over by the valve tube is shortened in the bag according to the application, so that the valve material can be saved. The valve tube is normally formed from a relatively expensive material, for example from a hot material, in order to be able to weld the valve after filling the bag. The shortening of the valve tube according to the application is therefore associated with a significant saving in material and costs. In correspondence therewith, the bottom configuration according to the application is particularly advantageous in the case of a valve bottom. Advantageously, the shortening of the valve tube is configured such that the inner end of the valve tube is shortened with respect to the inner edge of the corner, wherein the amount of shortening is preferably 3 mm, more preferably 6 mm and even more preferably 1 cm.

[0013] The valve can be inserted into the still open bottom fold as a prefabricated, closed valve tube. Alternatively, it is also possible to place a so-called valve sheet into the still open bottom fold in order to form the valve, so that the valve sheet is formed into a tube by covering the lateral fold. In this design, a saving in material can also be achieved by virtue of the valve sheet being configured less wide transversely to the longitudinal axis of the bottom.

[0014] In a preferred design, the bag has two opposite bottoms, which are configured according to the application. The side wall of the bag extends between the two bottoms. By virtue of the design of the two bottoms according to the application with a small overlap of the lateral fold, a saving in material can be achieved in the two bottoms according to the application. Particularly advantageously, one of the two bottoms is configured as a valve bottom and the other as a standing bottom.

[0015] In a further preferred design, the bag is configured as an open cross-bottom or block-bottom bag, which is filled via an opening opposite the bottom.

[0016] The bag according to the application can be configured in one layer. In a preferred design, the bag is configured as a multilayer bag, wherein the material layers are preferably configured from paper and / or coated paper and / or plastic. In a multilayer bag, a saving in material particularly advantageously comes into play when forming the bottom.

[0017] In another preferred embodiment, the bag is three-layered, wherein the innermost and the outermost material layer are formed from paper or coated paper and the material layer in between is formed from plastic. Thereby, in the area of the bag, including the bottom region, a particularly good product protection is achieved while at the same time the strength of the bag is high.

[0018] Advantageously, the bag is formed from compostable and / or recyclable material, in particular from paper and / or coated paper.

[0019] In another preferred embodiment, at least one of the bottoms is provided with an inner ridge and / or a cover flap. The inner ridge is known to be glued into the still open bottom fold. The closed lateral flaps of the bottom fold are glued from above by means of the cover flap. By means of the inner ridge and / or by means of the cover flap, the protection of the filled article in the bottom region can be improved and / or the bottom fold can be fixed. In a bag with two bottoms, the inner ridge and / or the cover flap are present at one or both bottoms. In the case of a bottom with an inner ridge, an opening aid, preferably a tear line, can also be provided in the bottom, preferably in the standing bottom.

[0020] In a preferred embodiment, the inner ridge and / or the cover flap can be formed from paper, in particular simple and / or less resistant paper, since a good protection of the filled article is ensured due to the overlap of the lateral flaps. In another preferred embodiment, the inner ridge and / or the cover flap are formed from PE-coated paper and / or film. Thereby, an even better protection of the filled article can be achieved.

[0021] Another advantageous embodiment is that, essentially over the entire bottom, the inner ridge and the adhesive cover flap are dispensed with, whereby the bottom fold can be fixed well and the filled article can be well protected.

[0022] In another preferred embodiment, the tube for forming the bag has a smooth cut at at least one, preferably both ends, wherein the cutting line perpendicular to the tube direction has a stepless extension at the end of the tube. This smooth cut allows, in a simple manner of production, a corresponding material saving in the corner of the bottom fold, in addition to the lateral flaps. BRIEF DESCRIPTION OF DRAWINGS

[0023] Embodiments of the present application are explained in detail below with reference to the following drawings. Shown here is:

[0024] Figure 1 a bag with an unfolded cross bottom according to the prior art is shown,

[0025] Figure 2 an open cross bottom of a bag according to the present application is shown,

[0026] Figure 3Open cross bottom of a bag according to the application with inner latches,

[0027] Figure 4 Covered cross bottom of a bag according to the application,

[0028] Figure 5 Covered cross bottom of a bag according to the application,

[0029] Figure 6 Covered cross bottom of a bag according to the application,

[0030] Figure 7 Open cross bottom of a bag according to the application with valve,

[0031] Figure 7a Open cross bottom of a bag according to the application with valve tube,

[0032] Figure 7b Open cross bottom of a bag according to the application with valve tube,

[0033] Figure 8 Open cross bottom of a bag according to the application with valve flap,

[0034] Figure 8a Open cross bottom of a bag according to the application with valve flap,

[0035] Figure 8b Open cross bottom of a bag according to the application with valve flap,

[0036] Figure 9 Paper web section for manufacturing a bag according to the application. DETAILED DESCRIPTION

[0037] Figure 1 A bag 1 with an unfolded cross bottom 3 according to the prior art is shown. For closing the bottom, first the front lateral fold 8 is brought over and then the rear lateral fold 7 is brought over it and in the area of their overlap the two lateral folds are glued by means of a tape 9. Common bag making machines require relatively wide folds in order to be able to apply the tape in a practical manner.

[0038] Figure 2A bag 10 according to the application is shown with an open cross bottom 20. The bottom 20 is divided into two halves by a longitudinal bottom axis 21. Characteristic for the cross bottom fold are the corner folds 22 and 23 and the lateral flaps 25 and 26, which are closed about lateral fold lines 28 and 29 in order to cover the bottom 20. The side wall portions 16 of the bag extend downward from the bottom 20.

[0039] In Figure 3 the inner bar 40 is placed in the open cross bottom 20. The inner bar 40 covers the inner edges of the folded corner folds 22 and 23 and extends from the longitudinal bottom axis 21 over the lateral fold lines 28 and 29. Advantageously, the inner bar is glued to the inner edges of the corner folds and to the lateral flaps by means of a frame adhesive. By this, a good protection of the filled goods can be achieved.

[0040] Figure 4 A cross bottom 20 of a bag 10 according to the application is shown, which is closed. In the bottom 20, an inner bar 40 is placed. First, the lateral flap 26 of the front portion is closed and subsequently the lateral flap 25 of the rear portion is closed thereon.

[0041] Figure 5 A closed cross bottom 20 of a bag 10 according to the application is shown. In the closed state, the lateral flaps 25 and 26 overlap only in a small range. The width of the overlap of the lateral flaps is derived from the spacing between the edge 35 of the lateral flap 25 of the rear portion and the edge 36 of the lateral flap 26 of the front portion. Since the lateral flap 26 of the front portion is closed first, its edge 36 is covered by the subsequently closed lateral flap 25 of the rear portion. Therefore, the edge 36 of the lateral flap 26 of the front portion is shown in dashed lines and the uncovered edge 35 of the lateral flap 25 of the rear portion is shown as a solid line. According to the application, the spacing between the edges 35 and 36 or the width of the overlap of the lateral flaps 25 and 26 is at most 10 mm. Preferably, the overlap is at most 4 mm and more preferably at most 2 mm.

[0042] By the small lateral flap overlap, the bag can be constructed in a material-saving manner overall. Due to the small width of the overlap, it is not suitable to apply adhesive tape by means of machines which are common in bag production. Therefore, according to the application, it is proposed to fix the bottom fold in a different manner than by gluing the lateral flaps to each other in the overlap region. For example, the fixing of the bottom fold can be carried out by gluing on a cover sheet. This is illustrated in Figure 6 There, the closed cross bottom 20 is covered from above by a cover sheet 45, which fixes the bottom fold.

[0043] Figure 7One variant of the bag 10 according to the application is shown, which has a still open cross bottom 20, into which a valve in the configuration of a preformed valve tube is placed. By virtue of the narrower configuration of the lateral flaps 25 and 26, the corners 22 and 23 are more narrow in the longitudinal direction of the bottom. As a result of this, the valve tube 50 also has to cover only a shorter path in order to introduce the filling product into the bag without problems. The valve can thus also be produced in a material-saving manner. Figure 7a One variant is shown, in which the valve tube 50 extends to the inner edge 24 of the corner 22. As a result of this, in this variant, slightly more valve material can be saved compared to the variant according to Figure 7 the application, in which the valve tube extends beyond the inner edge 24 of the corner 22. Figure 7b One variant is shown, in which the valve tube 50 is shortened at its inner end 54 with respect to the inner edge 24 of the corner 22. Preferably, the shortening is 3 mm, more preferably 6 mm and even more preferably 1 cm. By virtue of the design according to Figure 7b the application, even more valve material can be saved.

[0044] Figure 8 One variant of the bag 10 according to the application is shown, which has a still open cross bottom 20, into which a valve in the configuration of a preformed valve tube is placed. By virtue of the narrower configuration of the lateral flaps 25 and 26, the corners 22 and 23 are more narrow in the longitudinal direction of the bottom. As a result of this, in this variant, slightly more valve material can be saved compared to the variant according to Figure 8 the application, in which the valve tube extends beyond the inner edge 24 of the corner 22. Figure 8a One variant is shown, in which the inner edge 56 of the valve flap extends to the inner edge 24 of the corner 22, so that the valve flap 52 and the corner 22 are flush with one another at the edges 24 and 26. Figure 8b One variant is shown, in which the inner edge 56 of the valve flap 52 does not extend to the inner edge 24 of the corner 22, so that the valve tube 50 is shortened at its inner end 54 with respect to the inner edge 24 of the corner 22. Especially advantageously, the shortening is preferably 3 mm, more advantageously 6 mm and even more advantageously 1 cm. As a result of this, even more valve material can be saved in this design.

[0045] Figure 9 A paper web section 12 for producing bags according to the application at a continuous paper roll 11 is shown. The folding lines of the cross bottom fold are indicated in dashed lines. The rectangular area 16 forms a side wall portion 16 of the bag. Along the cutting lines 13 and 14, the paper web section 12 is cut off to form individual tubes. The cutting lines 13 and 14 are accordingly cutting lines of the tubes perpendicular to the tube direction. Figure 7The cutting lines 13 and 14, which are formed by means of a smooth cut, are shown, which run steplessly perpendicular to the tube direction. By means of a smooth cut, material can be saved in the region of the lateral turn- unders and in the region of the corner angles at a reduction in the tube piece length.

Claims

1. A bag (10) for bulk goods, composed of paper and / or other flat material, having at least one bottom formed in a cross-bottom or block-bottom folding, wherein the bottom fold has two lateral flaps (25, 26) which are folded about lateral fold lines (28, 29) running in the longitudinal direction of the bottom in order to form the bottom, wherein the lateral flaps form an overlap in the closed condition, wherein the width of the overlap is at most 10 mm, wherein the bottom is formed as a valve bottom in which a valve for filling the bag is accommodated, characterized in that the valve is inserted in the region of the corner (22, 23) of the bottom fold, wherein the inner end (54, 56) of the valve extends to or is shortened with respect to the inner edge (24) of the corner.

2. The bag according to claim 1, characterized in that the width of the overlap is at most 6 mm.

3. The bag according to claim 1, characterized in that the width of the overlap is at most 4 mm.

4. The bag according to claim 1, characterized in that the width of the overlap is at least 1 mm.

5. The bag according to claim 4, characterized in that the width of the overlap is at least 2 mm.

6. The bag according to claim 4, characterized in that the width of the overlap is at least 4 mm.

7. The bag according to claim 1, characterized in that the shortening is 3 mm.

8. The bag according to claim 1, characterized in that the shortening is 6 mm.

9. The bag according to claim 1, characterized in that the shortening is 1 cm.

10. The bag according to claim 1, characterized in that the valve is formed as a valve tube (50) and / or a valve flap (52).

11. The bag according to any one of claims 1 to 6, having two mutually opposite bottoms between which the side wall (16) of the bag extends.

12. The bag according to any one of claims 1 to 6, characterized in that the bag is formed as an open cross-bottom or block-bottom bag.

13. The bag according to any one of claims 1 to 6, characterized in that the bag is formed as a multilayer bag.

14. The bag according to claim 13, characterized in that the material layers of the multilayer bag are composed of paper and / or coated paper and / or plastic.

15. The bag according to any one of claims 1 to 6, characterized in that the bag is formed in three layers, wherein the innermost and outermost material layers are formed from paper and the material layer located therebetween is formed from a plastic film.

16. The bag according to any one of claims 1 to 6, characterized in that the bag is composed of compostable material.

17. The bag according to any one of claims 1 to 6, characterized in that the bag is composed of recyclable material.

18. The bag according to any one of claims 1 to 6, characterized in that the bag is composed of paper and / or coated paper.

19. The bag according to any one of claims 1 to 6, characterized in that At least one of the bottom parts is provided with an inner latch (40) and / or a cover (45).

20. The bag according to claim 19, characterized in that the inner latch comprises uncoated paper, PE-coated paper and / or film.

21. The bag according to any one of claims 1 to 6, characterized in that the bag is formed from a tube which has a smooth cut at at least one end (13, 14).

22. The bag according to claim 21, characterized in that the tube has a smooth cut at both ends (13, 14).

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