Bag

Abstract

In a bag with a jacket wall composed of at least two layers closed in each case by means of a longitudinal adhesive seam to form a tube and having two front ends, and with folded bottoms closing the bag at the front ends, and with a filling opening for introducing a filling material, wherein the jacket wall has at least one paper layer and the at least one paper layer at least largely determines the load-bearing capability with filled weight and the mechanical stability of the bag, the usefulness of the bag is improved by the fact that the jacket wall has, on its outside, a layer of a plastic film with a thickness of 60 pm or less, which surrounds the at least one paper layer and protects it from moisture and, in an area of overlapping ends, has adhesion points (K) between which air removal paths (Z) are formed.

Claims

1. A bag with a jacket wall composed of at least two layers closed in each case by a longitudinal adhesive seam to form a tube and having two front ends, and with folded bottoms closing the bag at the two front ends, and with a filling opening for introducing a filling material, wherein the at least two layers of the jacket wall includes at least one paper layer which limits a load-bearing capability of the bag with a filled weight and a mechanical stability of the bag, wherein the jacket wall has one an outer surface a layer of a plastic film with a thickness of 60 ?m or less, which surrounds the at least one paper layer and protects the at least one paper layer from moisture, wherein in an area of overlapping adhesion points (K) are positioned forming the longitudinal adhesive seam, wherein between which air removal paths (Z) are formed between the adhesion points (K), wherein the layer of plastic film is incorporated into the folded bottoms closing the bag at the two front ends, and wherein the layer of one plastic film is unperforated.

2. The bag as claimed in claim 1, wherein the layer of plastic film has a thickness of between 10 and 50 ?m.

3. The bag as claimed in claim 1, wherein the layer of plastic film is affixed to the at least one underlying paper layer only at a plurality of points and is removable from the at least one paper layer.

4. The bag as claimed in claim 1, wherein the layer of plastic film is transparent.

5. The bag as claimed in claim 1, wherein the layer of plastic film is made of polyethylene.

6. The bag as claimed in claim 1, wherein the at least one paper layer is made of bleached paper.

7. A bag with a jacket wall composed of at least two layers closed in each case by a longitudinal adhesive seam to form a tube and having two front ends, and with folded bottoms closing the bag at the two front ends, and with a filling opening for introducing a filling material, wherein the at least two layers of the jacket wall includes at least one paper layer which limits a load-bearing capability of the bag with a filled weight and a mechanical stability of the bag, wherein the jacket wall has one an outer surface a layer of a plastic film with a thickness of 60 ?m or less, which surrounds the at least one paper layer and protects the at least one paper layer from moisture, wherein in an area of overlapping adhesion points (K) are positioned forming the longitudinal adhesive seam, wherein between which air removal paths (Z) are formed between the adhesion points (K), wherein the folded bottoms include at least has two folded bottoms, a first folded bottom of the two folded bottoms includes a valve opening into which a flat valve is inserted which can be bent open in a the shape of a tube to form a filling channel filling and where the valve has a first end facing toward an interior of the bag with respect to the valve opening and a second end facing toward the jacket wall, wherein the valve has a paper layer which forms the first end of the valve and which at the second end of the valve is overlapped by a folded film layer having a first film portion and a second film portion connected to the latter via a fold line, and wherein the film layer has a thickness of 30 to 50 ?m and the paper layer has a density of between 50 and 100 g/m.sup.2.

8. The bag as claimed in claim 7 wherein the layer of plastic film is incorporated into the folded bottoms closing the bag at the two front ends.

9. The bag as claimed in claim 7 wherein the folded bottoms includes at least two folded bottoms, a first folded bottom of the two folded bottoms includes a valve opening into which a flat valve is inserted which can be bent open in a shape of a tube to form a filling channel for filling and where the valve has a first end facing toward an interior of the bag with respect to the valve opening and a second end facing toward the jacket wall, wherein the valve has a paper layer which forms the first end of the valve and which at the second end of the valve is overlapped by a folded film layer having a first film portion and a second film portion connected to the latter via a fold line.

10. The bag as claimed in claim 7, wherein the first and second film portions each extend over only part of a length of the paper layer.

11. The bag as claimed in claim 7, wherein the film layer is wider than the paper layer.

12. The bag as claimed in claim 7, further comprising a reinforcement sheet made of paper, and ending at a distance from the second end of the valve, wherein the reinforcement sheet is inserted into the folding of a bottom in an the area of the valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail below on the basis of illustrative embodiments shown in the drawing, in which:

(2) FIG. 1 shows a purely schematic view of the design of a longitudinal adhesive seam in an overlapping area of the plastic film;

(3) FIG. 2 shows a crossbottom partially folded by folded-in bottom corners and with open bottom flaps and the positioning of a reinforcement sheet for the valve opening;

(4) FIG. 3 shows the crossbottom in the view in FIG. 2 with the positioning of a valve of a paper layer and a film layer overlapping the paper layer at one end;

(5) FIG. 4 shows a perspective view of the bottom according to FIGS. 2 and 3 in an exploded view with the reinforcement sheet and the valve to be fitted, formed from the paper layer and the film layer;

(6) FIG. 5 shows a side view of a bag according to the invention with, for illustrative purposes, a slightly opened valve opening with the reinforcement sheet and with the fitted valve.

DETAILED DESCRIPTION THE INVENTION

(7) FIG. 1 shows a purely schematic view of the design of the longitudinal adhesive seam in an overlapping area of the plastic film. The adhesive points K, which are here arranged in a strip shape to form a longitudinal adhesive seam, are separated from one another by small gaps Z through which air can pass from the bag interior to the outside, as is indicated by the arrows P in the drawing. The little clouds shown in the drawing represent air or gas from the bag interior before passing through the gaps Z to the outside.

(8) Of course, other patterns of adhesion points, for example patterns which do not extend linearly but instead are planar in the overlapping strip, are also suitable for implementing the invention.

(9) FIGS. 2 to 4 show the structure of a folded bottom of a bag according to the invention in a preferred embodiment. The bottom is designed as a crossbottom and arises from the fact that the bag wall has been produced as an open, flat tube with two fold lines 1. Starting from the fold lines 1, triangular pockets 2 are folded inward and cut out such that bottom flaps 3 are obtained which are connected pivotably to the large side walls of the bag via fold lines 4. The bottom flaps 3 are turned in perpendicularly with respect to the pockets 2, resulting in the design as a crossbottom.

(10) FIGS. 2 and 3 show a folded state of the bottom in which the bottom flaps 3 have not yet been turned in. According to FIG. 2, a reinforcement sheet 5 of paper is affixed to one of the pockets that is intended to form a valve opening for an inserted valve, which reinforcement sheet 5 extends laterally over the fold lines 4 into the area of the bottom flaps 3 and is also affixed there. The reinforcement sheet 5 is preferably provided, toward the folded-in bottom corner 6, with a turned-back end, such that the corresponding end of the reinforcement sheet 5 is reinforced in a two-layer form. Upon subsequent folding back of the bottom flaps to form the crossbottom, the respective edge strip of the reinforcement sheet 5 located on the bottom flaps 3 is also turned back. The reinforcement sheet 5 is preferably made of a paper layer with a grammage of between 20 and 40 g/m.sup.2, preferably 30 g/m.sup.2.

(11) According to FIG. 3, a material combination is now placed onto the arrangement according to FIG. 2 in order to form a valve.

(12) The material combination consists of a film layer 8 and a paper layer 9. The film layer 8 is turned back about a fold line 10 and thus has an upper first film portion 11 and a lower second film portion 12. The film layer 8 configured in this way in the shape of a horizontal V receives the paper layer 9, with the first film portion 11 engaging over the upper face of the paper layer 9 and the second film portion 12 engaging over the lower face of the paper layer 9. For reinforcement reasons, the paper layer 9 also has a turned-back front end 13, which is pushed in as far as the front end of the film layer 8. The paper layer 9 is longer than the film layer 8 in the longitudinal direction of the valve, such that the paper layer 9 protrudes from the film layer 8 toward the bag interior. The film layer 8 is wider than the paper layer 9 perpendicularly with respect to the longitudinal direction of the valve. The film layer 8 and the paper layer 9 both extend laterally over the fold lines 4 of the bottom flaps 3 and are thus folded in about the fold lines 4 with the bottom flaps 3 in the formation of the folded bottom.

(13) A valve arrangement is thus formed which, in the longitudinal direction of the valve, i.e. in the outward direction in FIG. 3, has a first end 13 and an opposite second end 14 directed toward the bag interior.

(14) The first end 13 protrudes in this case over the front edge of the reinforcement sheet 5 and, in the unopened state of the valve opening, completely covers the reinforcement sheet 5, as a result of which the latter is protected from the effects of moisture. The second end 14 is formed by the paper layer 9 and the reinforcement sheet 5, such that a paper-on-paper seal is formed. The film layer 8 extends over only part of the paper layer 9, such that a substantial part of the length of the valve in the area of the second end 14 consists only of paper. The length of the film layer 8 is preferably between ? and ? of the length of the paper layer 9.

(15) FIG. 5 shows a side view of a filled bag which has assumed its box shape through being filled. The typical fold lines can thus be seen which run from the middle fold line 1 to the corners of the bottom. The figure schematically illustrates the reinforcement sheet 5, the valve composed of film layer 8 and paper layer 9 and having upwardly turned edge strips, and the bottom flaps 3 located over the latter, which bottom flaps 3 form the bottom closure and are optionally covered with a bottom cover sheet (not shown). In order to distinguish the layers of the reinforcement sheet 5, of the valve 8, 9 and of the folded back edge strips, the valve opening is shown slightly opened. The closure of the valve is effected in the usual way, by means of the bag being placed standing on the bottom formed with the valve, such that the filling material introduced into the bag closes the valve, with the paper layer 9 being pressed against the reinforcement sheet 5.