CN110040341B

CN110040341B - Multi-layer bag

Info

Publication number: CN110040341B
Application number: CN201910039263.6A
Authority: CN
Inventors: 爱德华·利塞克; 格哈德·舒尔特; 迈克尔·默施曼
Original assignee: Dy Pack Verpackungen Gustav Dyckerhoff GmbH
Current assignee: Dy Pack Verpackungen Gustav Dyckerhoff GmbH
Priority date: 2018-01-17
Filing date: 2019-01-16
Publication date: 2022-06-07
Anticipated expiration: 2039-01-16
Also published as: DE102019100193A1; CN110040341A; DE202018100246U1

Abstract

The invention relates to a multi-layered bag (10) for bulk material, having at least two material layers consisting of coated or uncoated paper or paper-like material, which is produced from a multi-layered paper web (1), wherein the multi-layered paper web comprises: -a first layer (2) having an air-permeable zone (4) having a higher air permeability than other zones (6) of the first layer (2), and-a second layer (3) having an air-permeable zone (5) having a higher air permeability than other zones (7) of the second layer (3), wherein the first layer (2) and the second layer (3) are arranged one above the other, and the air-permeable zone (4) of the first layer (2) is arranged completely staggered with respect to the air-permeable zone (5) of the second layer (3).

Description

Multi-layer bag

Technical Field

The present invention relates to a multi-ply paper bag for bulk materials such as cement, plaster, granular material, animal feed and the like.

Background

Such paper bags are widespread in the market and here have, in particular, the usual dimensions in the case of gypsum or cement fill quantities of 5kg, 10kg or 25 kg. Typically, such bags have one or more paper layers formed from paper, paper composites, and/or coated paper. In addition, a material layer made of another material, for example a plastic film, can be provided.

For filling such bags, a valve tube can be provided which is machined into the valve bottom and which is plugged onto a filling nipple of a filling plant for filling the bag. The bulk material, for example in powder or granular form, is then conveyed by the air stream into the bag. It is very important for rapidity and economy that air escape rapidly during the filling process. On the other hand, the bag should be as sealed as possible after filling in order to protect the filling from external influences, in particular from moisture. In order to achieve better product protection or longer product stability of the filling located in the bag, a barrier layer, for example in the form of a plastic film, can be provided in the single-layer or multi-layer paper surrounding the filling.

It has proven to be impossible to ensure sufficient product protection with previously known bags in the case of sensitive filling, or the bags are very complicated in their construction. Examples of such sensitive fillers are fast setting products in the field of building materials, such as gypsum or cement, but also foodstuffs which must be protected against loss of odour.

From WO 2015/104038 a1 a paper bag is known which, although providing adequate product protection, is nevertheless complex in its structure, thereby requiring costly and more costly manufacture.

Disclosure of Invention

The invention thus relates to improvements in known paper bags. In particular, by means of the improved construction of the paper bag, particularly economical production and good venting during filling should be achieved, and this should be achieved while the product protection of the filling remains unchanged or is improved.

According to the invention, said object is achieved by a sack for multiwall paper having the features according to the invention. Preferred embodiments are also obtained below.

Thus, the multi-ply bag according to the invention is made of a multi-ply paper web (papierbachn). The multi-ply paper web comprising: a first layer having a breathable zone having a higher breathability than other areas of the first layer; and a second layer having an air-permeable region having a higher air permeability than other regions of the second layer, wherein the first layer and the second layer are arranged one above the other, and the air-permeable region of the first layer is arranged completely offset from the air-permeable region of the second layer.

Preferably, it can be provided that the principle structure and/or components of the first layer are identical to the principle structure and/or components of the second layer.

According to a further development of the invention, in the case of a multi-ply paper web, the air-permeable regions of the first ply are arranged spaced apart from the air-permeable regions of the second ply in the web plane. The air-permeable areas of the first layer and the air-permeable areas of the second layer are therefore not directly adjacent to each other, but are at a distance from each other. The spacing can be the same in the longitudinal direction of the web, but can also vary.

It can be provided here that the first and second layers of the multi-layer web have no further regions, apart from at least one air-permeable region and at least one further region with less or no air permeability. In other words, the first layer and/or also the second layer can thus be composed of only two regions which differ in their breathability.

The complete offset of the air-permeable areas of the first layer relative to the air-permeable areas of the second layer in a multiply web results in the air-permeable areas of the respective layers not having an overlapping area with one another in the arrangement of the first and second layers which are overlaid one on top of the other. Thus, the air-permeable areas of the first layer are located above the less air-permeable or air-impermeable areas of the second layer, and the air-permeable areas of the second layer are located below the less air-permeable or air-impermeable areas of the first layer. By arranging the ventilation zones side by side so that there is no overlapping area of the ventilation zones of the two layers, a multi-layer paper web is obtained from which particularly advantageous paper bags according to the invention can be produced in a simple manner, which are particularly well ventilated because large ventilation areas are possible and at the same time good product protection is ensured by the staggered arrangement of the ventilation zones.

The exhaust air flow can flow from one side of the web to the other, because it can flow through the first air-permeable area of one layer, the flow in the plane of the web between the two layers, and the air-permeable area of the other layer next to it.

The invention also includes the following cases: the first and second layers do not have the same width and/or are not oriented flush with each other. However, it is preferably provided that the width of the first layer corresponds to the width of the second layer and/or that the first and second layers are aligned flush.

According to another refinement of the invention, the air-permeable areas of the first layer and/or of the second layer extend continuously in the longitudinal direction of the layer of the paper web.

This is advantageous for the manufacture of a multi-layered paper web, since the first and/or second layer, respectively, can then be unwound from a roll and during the processing steps carried out when unwinding the layers, for example by perforation, areas with lower air permeability can be provided.

According to a further development, the first and/or the second layer has a plurality of mutually separated air-permeable regions, wherein the air-permeable regions of one layer preferably extend parallel to one another in the longitudinal direction of the paper web, so that a strip-shaped division of the paper web is obtained.

For sufficient breathability, it can be provided that a plurality of breathable zones are present in each of the first and second layers. It can thus be provided, for example, that the air-permeable areas running parallel to the paper web in one layer have the same spacing from one another as the air-permeable areas running parallel to the paper web in the other layer. Such a zigzag or also labyrinth flow profile through two different layers is advantageous for pockets made of paper web. The number of air-permeable areas of one layer can also be equal to the number of air-permeable areas of another layer. However, the basic idea of the present invention also includes: the number of breathable zones of the two layers is different.

According to a further development of the invention, the two plies of the multi-ply paper web are firmly arranged relative to one another in such a way that, for example: the layers are affixed or directly affixed to each other. The adhesive layer or the adhesive lines here preferably extend parallel to the longitudinal direction of the paper web.

The invention can also be improved in that the air-permeable regions of the first layer and/or of the second layer are formed by perforations, coating recesses and/or highly porous materials.

In particular, the perforation of the plies can also be carried out in a simple manner during the continuous unwinding of the plies from a roll, in that: the layer to be peeled is rolled with a roller provided with needles in a specific width range. The introduction of perforations is a particularly simple and easy to handle way in order to improve the breathability of specific areas of the layer.

It can also be provided that the multi-layer paper web has an outer layer and an inner layer, between which a first layer and a second layer are arranged, wherein preferably the outer layer and the inner layer are made of paper.

According to a further development of the invention, the first layer is arranged directly on the second layer. There are no other layers between the first layer and the second layer.

According to an advantageous further development of the invention, the first and/or second layer consists of paper or coated paper, preferably paper coated with a gas-tight material, preferably paper coated with polyethylene.

The air-permeable region can then be realized, for example, in the case of a layer made of coated paper, by introducing perforations into the desired range. However, it is also conceivable for the uncoated region to form a gas-permeable region. This can be done by: first no coating is applied to the layer at all in the desired areas or, if the coating is already present, it is peeled off again.

Advantageously, the bag according to the invention is made of a multilayer tube consisting of a multilayer paper web. The tube can be formed by a connection, in particular by gluing two connection regions running parallel to the longitudinal edges of the paper web. This is implemented as: furthermore, the gas-permeable regions of the first layer are arranged completely offset from the gas-permeable regions of the second layer in the circumferential direction of the tube.

According to one development, the respective connecting region comprises or is arranged close to a longitudinally running edge region of the paper web. It can also be provided that the connecting region adjoins an edge region at the longitudinal edge of the paper web.

It can also be provided that the connecting region of the paper web does not have an overlap with the air-permeable region of the first layer and/or of the second layer, respectively. Thereby ensuring that: even in the connecting region of the web, air cannot pass through both layers without forming the labyrinth flow pattern typical for the present invention.

When filling the bag according to the invention, air can escape from the interior of the bag via the regions arranged offset from one another and at the same time the interior of the bag is well protected from external influences. The disposable filled bag closes off a flow channel (zigzag or labyrinth) that allows air to flow out. In the filled state, the filling material is pressed from the inside toward the layers, so that the region arranged between the gas-permeable regions of the two layers is closed from the inside by the pressure. Thus, after filling the bag, the flow channel is closed, as the inner layer is pressed towards the outer layer. It is possible to prevent moisture from entering from the outside or to lose the fragrance of the bulk.

According to an alternative development of the invention, the paper bag further comprises opposite bottoms, preferably a cross-shaped bottom or a block-shaped bottom, and side walls between the bottoms. Here, at least the side walls are formed by a paper web or a tube according to one of the variants discussed above. However, it is also advantageous if the base is formed in the form of a cross-shaped base or a block-shaped base folded from a plurality of layers of paper webs or a plurality of layers of tubes.

It can be provided that the coating of the first layer and/or of the second layer faces the interior of the bag.

Furthermore, according to a development of the bag, the valve tube for filling the paper bag is arranged in the bottom, which is subsequently called valve bottom.

When filling the bag according to one of the variants discussed above, the air introduced during filling can leave the bag via the air-permeable areas of the two layers. But because the gas permeable areas do not have an overlapping area, protection of the bulk material in the bag is ensured in the filled state.

Drawings

Other details, advantages and features of the invention will be apparent from the following description of the drawings. The figures show:

figure 1 shows a prior art paper tube section for making paper bags;

figure 2 shows the manufacture of a multi-layered paper web for a bag according to the invention;

FIG. 3 shows a cut-out web section with a first layer being peeled from half of a second layer;

figure 4 shows a tube for making a paper bag made of a multilayer paper web according to the invention; and

figure 5 shows a paper bag according to the invention, with the outer layer torn on the front side wall of the paper bag.

Detailed Description

Fig. 1 shows a tube 30 known from the prior art for the production of paper bags.

Here, the single-coated paper is formed into a tube 30 such that an overlap region a results. The overlap region is here affixed in an air-tight and waterproof manner to the edge region of the inner edge by means of a continuous adhesive strip 31. In addition to this, another discontinuous adhesive tape 32 is provided, which extends in the middle section of the overlap a. A further continuous adhesive strip is provided at the edge region of the outer edge in order to fix said edge region to the inner stretched section of the single-ply paper.

In the inner edge region, between the adhesive portion 31 and the non-continuous adhesive portion 32 in the middle section of the overlap a, a ventilation region (B, the region shown by the dashed line) is provided, the ventilation of which is increased compared to the other regions of the paper ply. Furthermore, in the outer edge region, between the adhesive portion 33 and the non-continuous adhesive portion 32 in the middle section of the overlap A, a ventilation region (in FIG. 1: region provided with oblique lines) is likewise provided. Air can thus escape outwards during the filling process of the bag made of tube via the air-permeable area B in the inner edge area, the discontinuous adhesive portion 32 and the air-permeable area (in fig. 1: provided with oblique lines).

The precise arrangement of the multiple application points of the tube 30, which are previously known from the prior art in fig. 1 and are also discontinuous, and the gas-permeable regions in the overlap region a is very complex in terms of its production. It is also desirable to protect the interior of the tube from external influences more effectively and to improve venting by increasing the gas permeable area or placing it outside the seam area of the tube.

Fig. 2 shows a schematic manufacturing process of a multilayered paper web for a bag according to the invention.

Visible is the first layer 2 rolled up on the drum 21, which is partially unwound in the figure. The unwound section of the first layer 2 is guided onto a first perforation roller 22 in such a way that the first layer 2 is perforated in a certain width range as a function of length. The perforated or also the breathable zone 4 has a higher breathability than the non-perforated zone 6 of the first layer 2.

Also visible is the second layer 3 rolled up on the drum 23, which is likewise partially unwound. Similarly to the first layer 2, the unwound part of the second layer 3 is also guided onto a further perforation roller 24, so that here the second layer 3 is also perforated in a certain width range as a function of the length. The perforated or also the air-permeable areas 5 of the second layer 3 have a higher air permeability than the non-perforated areas 7 of the second layer 3.

As can be seen from the lower section of the figure, the second layer 3 is arranged above the first layer 2. The air-permeable area 4 of the first layer 2 does not overlap the air-permeable area 5 of the second layer 3. The air-permeable areas are not directly adjacent to each other, but are at a distance from each other in the width direction of the web. Such a spacing extending in the width direction is not important to the present invention, but improves the present invention.

The multi-ply paper layer 1 according to the invention for forming the bag according to the invention is therefore shown in the lower section of the drawing (below the perforating roller 23 co-acting with the second ply 3).

Fig. 3 shows a cut-out section of a multi-ply paper web 1, wherein the second ply 3 is peeled off half way from the first ply 2. It is clear to the person skilled in the art that for better processability the first layer 2 and the second layer 3 can be fixed against each other, for example by placing adhesive dots or lines. The glue points or glue lines preferably extend in the edge region of the longitudinal edges of the paper web or, as a so-called transverse glue portion, extend transversely to the longitudinal direction of the paper web adjacent to a cutting edge extending transversely in the drawing, which is provided for forming a tube section made up of a multi-layered paper web 1.

In the figures, the broken lines show the folding edges required for creating a cruciform bottom pocket. In addition, it is necessary here for the vertically running edge regions to be connected or glued to one another.

Also visible in fig. 3 is that the second layer 3 is placed on the first layer 2 such that the plurality of breathable regions 5 of the second layer 3 do not overlap the breathable regions 4 of the first layer 2. The

breathable zones

4, 5 of one

layer

2, 3 are placed over the whole area on the "non-breathable"

zones

6, 7 of the

other layer

3, 2.

Fig. 4 shows a schematic view of a tube 8 made from a section of a multi-layered paper web 1.

Along the circumference of the tube 8, the air cannot directly flow straight from the inside radially outwardly expanding. This is prohibited for the following reason, since the gas-permeable area 5 of the inner (second) layer 3 is covered by the gas-impermeable area 6 of the outer (first) layer 2. Therefore, the flow direction of the air flowing from the inside to the outside must take a zigzag or labyrinth shape in order to reach the outside from the inside. Only in this way is it possible to reach the outside via the air-permeable regions 5 of the inner (second) layer 3 and the air-permeable regions 4 of the outer (first) layer.

Compared to the prior art as shown in fig. 1, the tube according to the invention is less complex in its structure and thus also less costly in its manufacture. Furthermore, the interior is better protected from external influences by the gas

permeable areas

4, 5 which do not directly adjoin one another.

Fig. 5 shows a perspective view of a pocket 10, which is formed by a tube 8 (see fig. 4) or by a section of a multilayered paper web 1. The front side wall 12 is here partially torn off in order to be able to identify the structure of the side wall 12. As can be seen, the air-permeable areas (4) of the outer layer (2) are arranged offset from the air-permeable areas (5) of the inner layer (3) in order to create the above-mentioned flow and cover conditions.

The bag 10 has two opposing bottoms (11 and 13) and a sidewall (12) therebetween. The bottom of the upper part is designed as a valve bottom (13), in which a valve tube (15) for filling the bag is machined.

Claims

1. A multi-ply paper bag (10) for bulk material having at least two material layers consisting of coated or uncoated paper, manufactured from a multi-ply paper web (1), wherein the multi-ply paper web comprises:

a first layer (2) having a breathable zone (4) having a higher breathability than other zones (6) of the first layer (2), and

a second layer (3) having an air-permeable zone (5) having a higher air permeability than other zones (7) of the second layer (3), wherein

The first layer (2) and the second layer (3) are arranged one above the other and

the air-permeable region (4) of the first layer (2) is arranged completely offset from the air-permeable region (5) of the second layer (3), and

wherein in the multilayered paper web the air-permeable areas (4, 5) of the first layer (2) and of the second layer (3) extend continuously in the longitudinal direction of the layers of the paper web (1).

2. Paper bag (10) according to claim 1, wherein in the multilayered paper web (1) the first layer (2) and/or the second layer (3) have a plurality of mutually separated permeable areas (4, 5).

3. Paper bag (10) according to claim 2, wherein the air-permeable areas (4, 5) of one ply (2, 3) extend parallel to each other in the longitudinal direction of the paper web (1).

4. Paper bag (10) according to claim 1 or 2, wherein in the multilayered paper web (1) the air-permeable areas (4, 5) of the first layer (2) and/or of the second layer (3) are formed by perforations, coating voids and/or highly porous material.

5. Paper bag (10) according to claim 1 or 2, wherein it further has an outer layer and an inner layer between which the first layer (2) and the second layer (3) are arranged.

6. Paper bag (10) according to claim 5, wherein the outer and inner layers are made of paper.

7. Paper bag (10) according to claim 1 or 2, wherein in the multilayered paper web (1) the first layer (2) is disposed directly on the second layer (3).

8. Paper bag (10) according to claim 1 or 2, wherein in the multilayered paper web (1) the first layer (2) and/or the second layer (3) consist of coated paper.

9. Paper bag (10) according to claim 8, wherein in the multilayered web (1) the first layer (2) and/or the second layer (3) consist of paper coated with an airtight material.

10. Paper bag (10) according to claim 8, wherein in the multilayered paper web (1) the first layer (2) and/or the second layer (3) consist of paper coated with polyethylene.

11. Paper bag (10) according to claim 1 or 2, made of a multi-layered tube (8) shaped from the multi-layered paper web (1), wherein the tube (8) is formed by joining two joining areas running parallel to the longitudinal edges of the paper web (1).

12. Paper bag (10) according to claim 11, wherein the tube (8) is formed by gluing two connecting areas running parallel to the longitudinal edges of the paper web (1).

13. Paper bag (10) according to claim 11, wherein the tube (8) is formed by connecting two connecting areas running parallel to the longitudinal edges of the paper web (1) so that the air-permeable area of the first layer (2) is also arranged completely offset from the air-permeable area of the second layer (3) in the circumferential direction of the tube (8).

14. Paper bag (10) according to claim 11, wherein in the tube (8) the respective connection area comprises or is arranged close to a longitudinally extending edge area of the paper web (1).

15. Paper bag (10) according to claim 11, wherein in the tube (8) the connecting areas of the paper web (1) do not have an overlap with the breathable areas of the first layer (2) and/or of the second layer (3), respectively.

16. Paper bag (10) according to claim 1 or 2, further having:

two opposite bottoms (11, 13), and

side walls (12) connecting the bottoms (11, 13), wherein

At least the side wall (12) is formed by a plurality of layers of the paper web (1) or a plurality of layers of the tube (8) formed by the plurality of layers of the paper web (1).

17. Paper bag (10) according to claim 16, wherein the bottom (11, 13) is formed foldingly in the form of a cross-shaped bottom or a block-shaped bottom.

18. Paper bag (10) according to claim 16, wherein the bottom (11, 13) is also formed foldingly by the paper web (1) or the tube (8) in layers, in the form of a cross-shaped bottom or a block-shaped bottom.

19. Paper bag (10) according to claim 16, wherein the coating of said first layer (2) and/or of said second layer (3) is directed towards the inside of the bag.

20. Paper bag (10) according to claim 16, wherein a valve tube (15) for filling the paper bag (10) is provided in a bottom (13) constituted as a valve bottom.