Packaging for Bulk Goods, Particularly Bag Made of Plastic Film

Abstract

Disclosed is a packaging (1) for bulk material, especially a bag made of plastic film, comprising a packaging wall (2) which envelops the bulk material and is provided with at least one multilayered wall area (6) that is composed of at least one inner layer (7) and at least one outer layer (8). Each layer has at least one air-permeable planar piece (9). At least one conducting element (12) for the air flow that penetrates the air-permeable planar pieces is disposed between the inner layer (7) and the outer layer (8). The conducting element (12) is embodied as at least one section of an airtight intermediate layer which is arranged such that at least the air-permeable planar pieces (9) of the inner layer (7) and/or the outer layer (8) are covered.

Description

The invention relates to a packaging for bulk goods, particularly a bag made of plastic film, having a packaging wall that sheathes the bulk goods, and at least one wall region configured in multiple layers, made of at least one inner layer and at least one outer layer, whereby each layer has at least one air-permeable planar piece.

Known packagings are sacks or bags made of a film, particularly a plastic film, which serve to wrap widely different kinds of bulk or filled goods, such as cement, fertilizer, or similar products, which are produced in the construction materials industry or the chemical industry, for example.

During the filling process of known packagings, a corresponding proportion of air gets into the interior of the packaging along with the filled goods, thereby causing an excess pressure to occur on the inside of the packaging wall. In order to prevent that the packaging wall is damaged and/or might tear open as a result of the excess pressure that is applied to the inside, or that palleting is made more difficult as the result of the air cushion enclosed in the interior of the packaging, sufficient ventilation from the packaging interior must always be assured. In EP 444 261, a packaging is described that is particularly used for accommodating filled goods in the form of fine dust. The known packaging has a two-layer region provided with perforations, for ventilation, by way of which the excess pressure prevailing in the interior of the packaging can be reduced. If the perforations of the inner and outer wall are disposed so that they cover one another, solid particles of the filled goods can also exit, along with the escaping air stream. The exit of smaller solid particles, in the form of dust, from the packaging, can be prevented by using a filter that is disposed in the two-layer region of the packaging. However, the use of filter material always means increased cost expenditure, and, at the same time, a more complicated design configuration of the packaging.

The invention is based on the task of improving a packaging of the aforementioned type, in such a manner that not only a simplified design configuration but also optimal ventilation are guaranteed, and, at the same time, the filled material is prevented from escaping in the form of dust.

The solution for this task is accomplished, according to the invention, by means of a packaging for bulk goods having the characteristics of claim 1. Advantageous further developments and embodiments of the invention are indicated in the dependent claims.

In the case of a packaging for bulk goods, particularly bag made of plastic film, having a packaging wall that sheathes the bulk goods, which wall has at least one wall region configured in multiple layers, made of at least one inner layer and at least one outer layer, whereby each layer has at least one air-permeable planar piece, it is provided, according to the invention, that at least one guide organ for the air stream that passes through the air-permeable planar pieces is disposed between the inner layer and the outer layer.

The guide organ disposed according to the invention influences the flow of the air escaping from the packaging interior, so that a straight-line, i.e. direct air passage through the wall region of the packaging wall that is configured in multiple layers, and the related exit of solid particles of the filled goods in the packaging are advantageously prevented. The great change, i.e. deflection of the flow of the escaping air stream brings about the result of almost complete precipitation of the solid particles out of the air stream that passes through the wall region configured in multiple layers, because of the greater mass inertia of the solid particles. For example, it is possible that multiple guide organs, disposed interlaced relative to one another, are present in the wall region configured in multiple layers, forming regions that overlap one another.

According to a first advantageous further development of the invention, it is provided that the guide organ is at least one section of an air-impermeable intermediate layer, which is disposed in such a manner that at least the air-permeable planar pieces of the inner layer and/or of the outer layer are covered by the intermediate layer. Each section of the air-impermeable intermediate layer, which can be a film, for example, furthermore also serves as a baffle surface or precipitation organ for the solid particles carried out with the escaping air stream. As a result of the intermediate layer, which projects into the air stream, and the related deflection of the air stream, areas with stronger flow, i.e. turbulences, and areas with weaker flow are formed in the multi-layer wall region. Particularly in the regions with a reduced flow velocity, the kinetic energy of the air stream is no longer sufficient to carry the solid particles along, because of their mass. A major portion of the solid, i.e. dust particles therefore settles primarily in the areas of the multi-layer wall region that have a weaker flow. The air stream, which is thereby almost completely freed of solid particles, exits into the surroundings by way of the air-permeable planar pieces of the outer layer, after it has flowed around the intermediate layer. Furthermore, the penetration of moisture from the outside into the interior of the packaging is advantageously made more difficult by the intermediate layer, which covers the air-permeable planar pieces of the inner and outer layer.

The guide organ is preferably formed by a folded-down edge of a flat web that forms the packaging wall, folded in the longitudinal direction. The guide organ is therefore part of the packaging wall, and folding down the edge region of the flat web allows the creation, in advantageously simple manner, of such a guide organ, disposed between the layers of the multi-layer wall region. The guide organ, which preferably extends continuously in the longitudinal direction of the packaging, guarantees optimal coverage of the air-permeable planar pieces of the inner and outer layer of the multi-layer wall region, which are disposed congruent to one another, if possible.

It is also possible that the guide organ is configured as a film strip disposed separately between the inner and outer layer of the wall region configured in multiple layers. Such film strips can advantageously be disposed extending both in sections and over the entire length of the wall region configured in a double layer, between the inner and outer layer. Using a gluing method, for example, the film strip can then be fixed in place on at least one of the layers of the multi-layer wall region, by way of one of its longitudinal sides.

It is furthermore provided that pre-determined partial surfaces of the guide organ are connected, at least in sections, with at least one of the layers of the multi-layer wall region. By way of such a connection, according to the invention, between corresponding partial surfaces of the guide organ and a layer, in each instance, the guide organ can be fixed in place, in advantageously simple manner, in the multi-layer wall region. Furthermore, in this way, two longitudinal sides around which the air stream can flow can be formed on the guide organ, so that improved ventilation during filling of the packaging is advantageously guaranteed. Preferably, a material-fit connection can be provided both between the inner layer and the related partial surfaces of the guide organ, in each instance, and between the outer layer and the related partial surfaces of the guide organ, in each instance.

The packaging wall is a folded flat web, whose edge regions, which overlap one another, form a multi-layer wall region. Simple production of the packaging wall that accommodates the filled goods is made possible by means of the folded flat web. The layers of the multi-layer wall region, produced by means of the edge regions that overlap one another, can be fixed in place relative to one another, in a desired arrangement, by means of a material-fit connection such as welding and/or gluing, for example. At the same time, sufficient strength is provided in the connection region of the packaging wall, by way of the material fit, so that the excess pressure that occurs in the packaging interior during the filling process can advantageously be absorbed over the entire packaging wall, without causing impairments. For example, it is also possible to produce the packaging wall from a film tube produced by means of extrusion blow-molding.

Furthermore, the inner layer of the multi-layer wall region can be formed by means of a material strip that is disposed in the interior region of the packaging. The production of the packaging is further simplified by disposing the material strip, which particularly extends in the longitudinal direction of the packaging, on the inside of the packaging, particularly one formed from a flat web. In this connection, the material strip completely covers the guide organ, formed as a film strip, for example, and can be connected with the packaging wall by means of a glue connection or weld connection, in each instance, over its entire length, in the region of the two side edges.

According to a further development of the invention, the possibility alternatively exists that the guide organ is formed from a part of a folded film strip that is disposed on the outside or inside of a film tube that forms the packaging wall, running in the longitudinal direction of the packaging, in order to form the multi-layer wall region. A separate film strip, folded in such a manner, can be produced using a simple production process, such as plastic extrusion, for example. Furthermore, the film strip produced, whose other part forms the outer or inner layer of the multi-layer wall region, in each instance, can be permanently connected with the film tube by means of a joining method, such as gluing or welding, for example, in advantageously simple manner. A material-fit connection, for example configured as a glued connection, can serve to form a firm connection between film tube and film strip. It is possible, for example, to use a film strip produced from plastic film as a guide organ, which strip is brought into a connection with a film tube, also produced from plastic film.

Each packaging wall has perforations in the air-permeable planar pieces, which are preferably configured as rows of circular holes and/or slits in the inner and outer layer, respectively. Using the perforations, a simple design configuration of an air-permeable planar piece is provided, whereby the perforations are made in the packaging wall, which is preferably configured as a plastic film, by way of corresponding needling or cutting tools. In this connection, the perforations can have different dimensions in the inner and outer layer of the packaging wall.

At least one spacer is disposed at least in partial regions of the air-permeable planar pieces of each layer and/or of the guide organ. Each spacer additionally improves the escape of the air that got into the packaging along with the filled goods, from the packaging interior. The spacers are preferably disposed between the guide organ configured as an intermediate layer, and an adjacent layer, in each instance, so that adhesion forces between the adjacent surfaces of the guide organ and the layers cannot occur. Such attraction forces can prevent passage of the air stream.

According to a further development of the invention, each spacer can be configured as an embossing made in the layers and/or the guide organ. The embossings, preferably formed in the longitudinal direction of the packaging, in the multi-layer wall region of the packaging wall, create an advantageously simple possibility for maintaining a distance between two film webs that touch one another, for example. The plastic and permanent deformation of the layers required for the production of an embossing can take place in advantageously simple manner, by means of embossing tools. The embossings can be made both in sections and continuously, in partial regions of a flat web, for example, which can be used to form the packaging wall.

Exemplary embodiments of the packaging according to the invention, from which additional inventive characteristics are evident, are shown in the drawing. This shows:

FIG. 1: a perspective view of a first exemplary embodiment of a packaging according to the invention;

FIG. 2: a view of the first exemplary embodiment according to FIG. 1 in cross-section, and

FIG. 3: a view of a second exemplary embodiment of a packaging according to the invention, in cross-section, and

FIG. 4: a view of another exemplary embodiment of a packaging, in cross-section.

FIG. 1 shows side-fold bag 1, whose packaging wall 2 can be closed off, with material fit, both in the bottom region 3 and in the head region 4, particularly by means of a weld 5, 5′. The packaging wall 2 has a wall region 6 configured with multiple layers (FIG. 2), which is formed from an inner layer 7 and an outer layer 8. The inner layer 7 and the outer layer 8 have an air-permeable planar piece 9, in the longitudinal direction of the packaging, in each instance. The air-permeability of the layers 7, 8 is guaranteed by means of 10 perforations made in them as holes, which allows exit of the air that got into the packaging interior 11 during the filling process. So that solid particles of the bulk goods filled in do not exit from the packaging interior together with the escaping air stream, an intermediate layer 12 is disposed between the layers 7, 8 of the wall region 6 configured in multiple layers. The intermediate layer 12 takes over the function of a guide organ for the escaping air stream, and, at the same time, a precipitation organ for the solid particles of the filled goods entrained in the air stream. In order to prevent occlusion of the perforations 10 in the layers 7, 8, as the result of adhesion forces that might be in effect between the layers 7, 8 and the intermediate layer 12, spacers configured as embossings 13 are disposed in predetermined partial regions of the layers 7, 8. By means of the perforation 10 and the embossings 13, which are preferably configured together in a planar piece of a layer 7, 8, in each instance, optimal ventilation of the packaging interior 11 is guaranteed at all times.

FIG. 2 shows the cross-section of the bag 1 according to the invention, according to FIG. 1, and is specifically intended to illustrate its structure. The packaging wall 2 is particularly produced from a material web that has been laid together, the edge regions of which form the overlap region having the multi-layer wall region 6. The intermediate layer 12, which is disposed between the inner layer 7 and the outer layer 8, is formed from a folded-down edge of the material web that forms the packaging wall 2. In order to be able to firmly connect the folded material web, particularly the edge regions, with one another in the overlap region, multiple material-fit connections 14, 14′ are provided in the multi-layer wall region 6.

Another exemplary embodiment of a bag 15 according to the invention is shown in the cross-section of FIG. 3. In this connection, the packaging wall 16 is formed from a tubular film produced by means of an extrusion method, on which film a separate, folded film strip 18 is disposed, on its outside, in the longitudinal direction of the packaging to form the multi-layer wall region 17. The multi-layer wall region 17 produced in this way again has an inner layer 19, an intermediate layer 20, an outer layer 21, whereby the intermediate layer 20 and the outer layer 21 are parts of the film strip 18, and the inner layer 19 is part of the tubular film that forms the packaging wall 16. In order to guarantee a firm connection between the folded film strip 18 and the packaging wall 16 configured as a film tube, material-fit connections 22, 22′ are formed between film strip 18 and packaging wall 16; these can be produced, for example, by means of a welding or gluing process. Of course, the inner layer 19 and the outer layer 21 of the bag 15, like the bag 1 in FIG. 1, also have perforations and embossings for ventilation; for the sake of simplicity, these are not shown.

FIG. 4 shows another possible embodiment of a bag 23, which is shown in cross-section, in order to makes its structure clear. The packaging wall 24 is produced from a flat web that has been laid together, the edges of which are connected with one another by way of a material-fit connection 25. To form the multi-layer wall region 26, a material web has been applied to the inside of the packaging wall 24, and forms the inner layer 27 of the bag. A firm connection between the inner layer 27, which is configured as a material strip, and the packaging wall 24 is assured by way of the material-fit connections 28, 28′. An intermediate layer 30 configured as a separate film strip is introduced between the inner layer 27 and the outer layer 29, and the air stream that passes through the multi-layer wall region flows around it. In this connection, the intermediate layer 30 is attached to the layers 27, 29 of the multi-layer wall region, with predetermined partial regions, by way of the material-fit connections 31, 31′, in such a manner that the intermediate layer forms two longitudinal sides around which the air stream flows.

Claims

1: Packaging for bulk goods, particularly bag made of plastic film, having a packaging wall that sheathes the bulk goods, which wall has at least one wall region configured in multiple layers, made of at least one inner layer and at least one outer layer, whereby each layer has at least one air-permeable planar piece,

wherein

at least one guide organ for the air stream that passes through the air-permeable planar pieces (9) is disposed between the inner layer (7, 19, 27) and the outer layer (8, 21, 29).

2: Packaging according to claim 1, wherein the guide organ is at least one section of an air-impermeable intermediate layer (12, 20, 30), which is disposed in such a manner that at least the air-permeable planar pieces (9) of the inner layer (7, 19, 27) and/or of the outer layer (8, 21, 29) are covered.

3: Packaging according to claim 1, wherein the guide organ is formed by a folded-down edge of a flat web that forms the packaging wall (2), folded in the longitudinal direction.

4: Packaging according to claim 1, wherein the guide organ is a separate film strip that runs between the layers (27, 29) of the multi-layer wall region (26), in the longitudinal direction of the packaging.

5: Packaging according to claim 4, wherein pre-determined partial surfaces of the guide organ are connected, at least in sections, with at least one of the layers (27, 29) of the multi-layer wall region (26).

6: Packaging according to claim 3, wherein the packaging wall (2) is a folded flat web, whose edge regions, which overlap one another, form the multi-layer wall region (6).

7: Packaging according to claim 4, wherein the inner layer (27) of the multi-layer wall region (26) is formed by means of a material strip that is disposed in the interior region of the packaging.

8: Packaging according to claim 1, wherein the guide organ is formed from a part of a folded film strip (18) that is disposed on the outside or inside of a film tube that forms the packaging wall (16), running in the longitudinal direction of the packaging, in order to form the multi-layer wall region (17).

9: Packaging according to claim 1, wherein the packaging wall has perforations (10) in the air-permeable planar pieces (9).

10: Packaging according to claim 1, wherein at least one spacer is disposed at least in partial regions of the air-permeable planar pieces (9) of each layer (7, 8, 19, 21, 27, 29) and/or of the guide organ.

11: Packaging according to claim 1, wherein each spacer is configured as an embossing (13) made in the layers (7, 8, 19, 21, 27, 29) and/or the guide organ.