EP2168885A1 - Packaging for bulk material - Google Patents

Abstract

The package i.e. side foldable bag or pouch (1) has a package wall (2) that wraps bulk goods, where the package is made of plastic foil. The wall has a multi-layer wall area (3) equipped with gas passages i.e. perforation, for ventilation from an inner side of the package. The wall area consists of inner and outer layers (4, 5). The layers are connected with each other via a seal (6). One of the surfaces of the layers has a surface area for a closure of the passages. The surface area is provided with a connecting unit (11). The layers lie top of one another, and the surfaces face each other. The connecting unit is provided as a layer of plastic foil or thermo-resin. The seal is provided as a bond seam and weld seam. The perforation is formed as a slot or circular hole.

Description

The invention relates to a package for bulk materials, in particular a bag or bag made of plastic film, with at least one bulk material enveloping the packaging wall, which has at least one multilayer, equipped with gas passages for venting from the packaging interior wall region of at least one inner and one outer layer, wherein the superimposed layers are interconnected by means of at least one sealing seam.

Packages of known type are for example bags or sacks made of a film, in particular a weldable plastic film, which serve, inter alia, for receiving or wrapping a variety of bulk or filling goods, such as fertilizers, flours or the like granular products, which, for example, in the chemical industry or the food industry. During the filling process of such packages, a certain amount of air often gets into the interior of the packaging in addition to the contents to be absorbed therein. This creates on the inside of the packaging wall, at least temporarily, an overpressure. In order to prevent damage to or possibly rupture of the packaging wall, by the applied pressure on the inside, it is always necessary to ensure adequate ventilation from the interior of the packaging.

For this purpose, the packagings usually have at least one multilayer wall region of at least one inner layer and one outer layer in an area of their packaging wall, the layers resting on one another lying layers are connected to each other by means of at least one sealing seam. For venting from the interior of the packaging, the multi-layered wall area is equipped with gas passages. For this purpose, gas passages designed as perforations, for example, may be provided in the inner layer of the multi-layered wall region, the outer layer of the multi-layered wall region covering the inner layer in the manner of a flutter valve. Although this prevents a direct transfer of moisture into the interior of the packaging, however, despite the covered gas passages, the further problem is that moisture can pass through the gap between the loosely superimposed layers, due to capillary action, to the gas passages in the inner layer and penetrates through these into the packaging interior. In particular, the presence of moisture in the ambient air can also pass unhindered through the gas passages in the interior of the packaging, whereby a reaction of these is caused especially in hygroscopic contents, which then possibly the usability of the product contained in the package can result.

The invention has for its object to improve a package of the aforementioned genus in that the penetration of moisture through the gas passages is effectively prevented.

The object is achieved by a packaging with the features of claim 1. Advantageous developments and refinements of the invention are set forth in claims 2 to 12.

In a package for bulk materials, in particular a bag or bag made of plastic film, with at least one bulk material enveloping the packaging wall, which has at least one multi-layer, equipped with gas passages for venting from the packaging interior wall portion of at least one inner layer and an outer layer, said lying on top of each other by means of at least one sealing seam are connected to one another, it is provided according to the invention that at least one of the mutually facing surfaces of the superimposed layers has at least one surface area, which is provided with an activatable connection means for a closure of a respective gas passage.

With the aid of a multi-layered wall region designed in accordance with the invention, an advantageous closure of the gas passages, in particular after venting of the packaging, can be achieved. Thus, at the same time the penetration of moisture into the packaging interior is advantageously prevented, so that even with hygroscopic contents no longer the risk of an unwanted reaction. The cohesive connection produced by the activatable connection means is based on a chemical reaction of the connection means. The mutually facing surfaces of the superimposed layers enter into a non-detachable connection with each other, which also gives the packaging material according to the invention in the region of its multilayer wall region increased strength.

According to an advantageous development of the invention, it is provided that the activatable connection means is a connection means reacting to physical influences. The use of such a bonding agent, which can be activated for example by radiation, such as heat radiation or UV radiation, or by compressive forces or by moisture, is an advantageous possibility, a permanently solid and moisture-impermeable connection between each other facing surfaces of the example produced from a plastic film to produce superimposed layers. By a specific treatment of a respective surface area equipped with the bonding agent, a hermetic closure of the filling material in the packaging interior is advantageously effected, in particular after the filling and the closure of the packaging according to the invention. It is also conceivable that act on the connecting means several physical state variables, such as heat and pressure, at the same time to ensure a secure closure of the passages.

In this case, the activatable connection means may be formed as a coating applied to at least one surface area of a layer, whereby a relatively simple equipment of the multilayer, serving for ventilation wall area is given with a connecting means. During the production of the flat web or film tube required for the packaging, the coating can be applied to at least one predetermined surface area, which then forms at least one section between the superimposed layers of the wall region.

Alternatively, there is the possibility that the bonding agent, instead of a coated coating, is a layer of a multi-layered, at least the layers of the wall region forming plastic film. In particular, in the case of a plastic composite film used, a cover layer of the composite film forming the package wall can preferably consist of an activatable connecting means. In this case, this layer of plastic film at ambient conditions similar advantageous mechanical properties, in terms of, for example, their strength, as the other film layers, so that no adverse effects on the handling or use of packaging so configured and thus always ensures a safe long-term function derer. In addition, can be dispensed with the formation of the bonding agent as a cover layer of a plastic film on the additional application of the bonding agent in the form of a coating in the production of packaging.

Each gas passage may in particular be part of a gas-permeable surface piece formed in at least one of the layers. A gas-permeable material introduced into at least one of the layers in the form of perforations Patch always ensures an advantageous ventilation function of the package from its interior, each perforation can be formed, for example, as a circular holes or slits. With the help of perforations a structurally simple design of an air-permeable surface piece is given, wherein the perforations can be introduced into the packaging wall via appropriate needle or cutting tools.

Both alternatively and optionally, there is the possibility that the gas passages are formed in a closing seam interrupting their material connection. Such a closure seam, which has at least one gas passage which interrupts the material connection, provides a further, advantageous possibility for venting from the interior of the packaging. In addition, once the packaging has been vented, an advantageous closure can again be achieved in the region of the gas passages by means of the connecting means connecting the superimposed layers. In this case, at least one chamber-like widening is formed in the passageway of each gas passage in the closing seam, which may preferably have a labyrinth-like course within the closing seam. In addition to the hermetic conclusion of the filling material in the packaging interior can thus be implemented with such a packaging according to the invention, a venting process in which the dusting of Füllgutpartikeln is reduced to a minimum. The closure seam in particular has connecting elements which each have at least one interruption forming at least one section of the passage.

Another development of the invention provides that the superimposed layers are connected to each other by means of two approximately mutually parallel sealing seams for forming a channel-like gas passage region. With the help of the channel-like passage region, which preferably extends in the longitudinal direction of the package is a prevents direct exit of entrained in the venting process from the inside of the packaging solid particles of the contents in the environment. With the formation of a channel-like gas passage region in the multi-layered wall region of the packaging, the proportion of the dusty filling material can thus advantageously be further reduced. A large part of the discharged solid particles now collects in the venting channel between the superimposed layers. Furthermore, the connection means applied to one of the mutually facing surfaces of the layers and thus lying within the channel-like gas passage region is protected from any environmental conditions acting on the outside of the packaging during the filling process.

In addition, it can be provided that at least one continuous connecting seam is formed in the channel-like gas passage region, which subdivides the gas passage region into a plurality of chambers which are at least partially connected to one another via media, wherein the gas-permeable surface pieces in the different layers are each assigned to separate chambers. About such, in particular curved seam sections having connecting seam, which is formed between the superimposed layers can be in the gas passage area in an advantageous manner produce chambers that due to the specific and at the same time always uninterrupted course of the seam, over tortuous and thus relatively long ventilation paths with each other gas are conductively connected. The connecting seam which preferably divides the gas passage region into two venting regions separated from one another thus prevents a straight-line connection between the gas passages of the chambers, so that the dusting out of the filling material is advantageously further reduced. Again, one of the mutually facing surfaces of the layers is in turn equipped with a connecting means, which can be achieved by the activation of the bonding agent, an optimal closure of the gas passage area after the venting process.

In addition, between the inner and the outer layer, at least one intermediate layer formed as a guide element for a gas flow passing through the gas passage region can be arranged in the channel-like gas passage region. The intermediate layer acting as a guide organ influences the flow of the gas stream escaping from the interior of the packaging in such a way that once again a straight or direct gas passage is prevented between the gas-permeable surface pieces concealed in the inner and outer layer of the wall region. The intermediate layer, which may for example be part of a film, at the same time serves as a separating element for the solid particles of the filling material discharged with the gas stream. In this case, by deflecting the gas flow within the gas passage area flow-free areas arise in which then preferably the entrained during the venting process in the gas passage area solid particles are eliminated. The connection means which protects the package from unwanted ingress of moisture after it has been activated can for example be applied on one of the sides of the guide member in the form of a coating. Thus, a cohesive, the packaging interior hermetically separating connection between the intermediate layer and the inner or outer layer of the multilayer wall area is then generated.

The intermediate layer is preferably a film strip introduced separately into the gas passage region and fixed to at least one of the layers by means of a connecting seam running in the longitudinal direction of the gas passage region. The use of a separate film strip for forming the intermediate layer creates an advantageous possibility of placing a guide element, which can be flowed around on both longitudinal sides, in the gas passage region, by means of which an optimum venting performance is ensured. The film strip along its center at one of the layers defining connecting seam, which may be both a weld and an adhesive seam, also fixes the film strip always safe within the Gas passage area. The connecting seam can be designed to be interrupted both continuously and in sections.

Another development of the invention provides that the coating applied to a respective surface of the inner or outer layer or the intermediate layer is a thermal resin. With the use of a thermal resin is an advantageous possibility for forming a relatively easy to apply to predetermined surface areas connecting means. When activated by z. B. the entry of heat liquefies the thermal resin accordingly and provides a sealing connection with the respective contact surfaces ago. The melting temperature of the thermal resin is generally lower than the melting temperature of the plastic film used to produce the packaging wall, so that at any time the optimal functionality of the packaging enveloping the product is guaranteed. Of course, it is also possible to use other types of coatings, such as, for example, acrylates or paints, which can likewise preferably be activated with the aid of physical state variables.

It is further within the scope of the invention that the packaging wall is a folded flat web whose mutually overlapping edge regions form the multilayer wall region. By means of the folded flat web is always a simple production of a filling material receiving the packaging wall allows. The layers of the multilayer wall region produced by means of the overlapping edge regions and of the guide element optionally arranged between the layers can be fixed to one another in a desired arrangement with the aid of a material connection. It is also conceivable, instead of a flat web, to form the packaging from a film tube, on the inside or outside of which, preferably in the packaging longitudinal direction, a film strip is arranged to form a multilayer wall region.

Fig. 1:

eine perspektivische Ansicht einer erfindungsgemäßen Verpackung;

Fig. 2:

eine Ansicht eines mehrlagigen Wandbereiches der Verpackung nach Figur 1 im Querschnitt;

Fig. 3:

eine Ansicht eines zweiten Ausführungsbeispiels für einen erfindungsgemäßen Wandbereich im Querschnitt;

Fig. 4:

eine Ansicht eines weiteren erfindungsgemäßen Wandbereiches im Querschnitt;

Fig. 5:

eine Ansicht eines anderen Ausführungsbeispiels für einen Wandbereich im Querschnitt;

Fig. 6:

eine Ansicht eines möglichen fünften Ausführungsbeispiels für einen erfindungsgemäßen Wandbereich, und

Fig. 7:

eine Ansicht einer anderen Ausführungsform eines erfindungsgemäß ausgebildeten Wandbereiches im Querschnitt.

Embodiments of the invention, from which further inventive features result, are shown in the drawing. Show it:

Fig. 1:

a perspective view of a package according to the invention;

Fig. 2:

a view of a multi-layer wall portion of the packaging FIG. 1 in cross-section;

3:

a view of a second embodiment of a wall portion according to the invention in cross section;

4:

a view of another wall portion according to the invention in cross section;

Fig. 5:

a view of another embodiment of a wall portion in cross section;

Fig. 6:

a view of a possible fifth embodiment of a wall portion according to the invention, and

Fig. 7:

a view of another embodiment of an inventively designed wall portion in cross section.

1 designates a gusseted bag or sack whose packaging wall 2 is formed, in particular, from a folded flat web, wherein its mutually overlapping edge regions form a multi-layered wall region 3 extending in the packaging longitudinal direction. The wall region 3 has an inner layer 4 and an outer layer 5, wherein the superimposed layers 4, 5 by means of at least one sealing seam 6 with each other are connected. Furthermore, the packaging wall 2, both in the head region 7 and in the bottom region 8 of the gusseted bag, for example, via a respective transverse weld seam 9, 10 cohesively closed.

Fig. 2 shows a view of the side gusseted bag 1 in cross-section and is intended to illustrate in particular the embodiment of the multi-layer, serving for venting from the bag interior wall portion 3. In the formed between the inner layer 4 and the outer layer 5 sealing seam 6, which may be an adhesive or weld, at least one the fabric connection of the closure seam 6 interrupting, chamber-like passage is provided. The closure seam 6 provided with a multiplicity of gas passages is formed in particular in the region of the peripheral edge 12 of the inner layer 4, wherein a predetermined section of the overlapping layers 4, 5 are fixed to one another in a closing manner. The outer layer 5 is on its inner layer 4 side facing, in particular at the free end 13, equipped with a coated in the form of a coating, subsequently activatable connection means 11 which causes a hermetic completion of the packaging interior to the environment after the venting process and, accordingly, no moisture can get into the packaging interior.

Fig. 3 shows a second embodiment of an inventively designed multi-layer wall portion 14, wherein the inner layer 15 and the outer layer 16 are connected to each other via a conventional closure seam 17. For venting the packaging, in particular at least one gas-permeable area piece 18 with gas passages 19 formed as perforations in the inner layer 15 is provided. The outer layer 16 in turn has an activatable connecting means 11 on its side facing the inner layer 15, which forms a covering layer of the inner layer 15 and, after its activation, also ensures a secure closure of the gas passages 19.

Fig. 4 shows a further embodiment of a multi-layer wall portion 20, the inner and outer layer 4, 5 are connected to each other by means of two mutually parallel sealing seams 6, 6 'and thus a gas passage region 21 between the layers 4, 5 is formed. The closure seams 6, 6 'are in turn equipped with their material connection compounds interrupting gas passages. The channel-like gas passage region 21 can in particular serve as a support for the entrained with the exiting gas flow solid particles of the filling material. For a hermetic closure of the packaging, in turn, the bonding agent 11 applied in this case as a coating on the inner layer 4 is used.

In Fig. 5 shows a further embodiment of a multi-layered wall region 22 according to the invention for venting from the packaging interior. The wall portion 22 forms with its inner layer 15 and its outer layer 16 also a channel-like gas passage region 23, on a longitudinal side 24 by a conventional, in particular designed as a weld or adhesive seam seal 17 and along the opposite of its other longitudinal side 25 by a with Gas passages provided closure seam 6 'is limited. The inner layer 15 has at least one gas-permeable surface piece 18, so that via the gas passages 19, a gas flow from the bag interior into the gas passage region 23 is possible and from there venting into the environment via the closure seam 6 'is guaranteed. For closing the gas-permeable surface pieces 18, an activatable connection means 11 is provided, in particular on the inside of the outer layer 16, which instead of a coating may also be a cover layer of a multilayered plastic film forming at least the superimposed layers 15, 16 of the wall region 22.

Fig. 6 and Fig. 7 show another embodiment of a gusseted bag 26, the multi-layer wall portions 27, 28 of a For example, produced by means of blow extrusion film tube 29 and a patch on the inside of separate film strip 30 are made. Each of the inner layer 31 forming film strip 30 is connected via conventional closure seams 17, 17 'with the inside of the outer layer 32 of the multi-layer wall portions 27, 28 forming film tube 29. Both the inner layers 31 and the outer layers 32 each have gas-permeable surface pieces 18, 18 'with gas passages 19, 19' formed as perforations. The in FIG. 7 Trained gas passage region 34 additionally has an intermediate layer 35 inserted between the inner layer 31 and the outer layer 32, which serves as a guide element for the gas flow passing through the gas passage region 34. The intermediate layer 35 is fixed on the connecting seam 36 at one of the layers 31, 32. Both gas passage areas 33, 34 are in turn equipped with a hermetically sealing the packaging interior connecting means 11, wherein Fig. 7 illustrates that the connecting means 11 may also be applied to the intermediate layer formed as a guide member 35 or may be formed on this in the form of an intermediate layer forming cover layer.

Claims (12)

Packaging for bulk materials, in particular a bag or pouch made of plastic film, having at least one bulk material enclosing the packaging wall, which has at least one multilayer, equipped with gas passages for venting from the packaging interior wall portion of at least one inner and one outer layer, wherein the superimposed layers means at least one sealing seam are connected to each other,
characterized,
in that at least one of the mutually facing surfaces of the superimposed layers (4, 5, 15, 16, 31, 32) has at least one surface region, which is provided with an activatable connecting means (11), for a closure of a respective gas passage (19, 19 '). Packaging according to claim 1, characterized in that the activatable connection means (11) is a physical influences reacting connection means. Packaging according to claim 1 or 2, characterized in that the connecting means (11) as on at least one surface region of the layers (4, 5, 15, 16, 31, 32) applied coating is formed. Packaging according to claim 1 or 2, characterized in that the activatable connecting means (11) is a layer of a multilayer, at least the layers (4, 5, 15, 16, 31, 32) of the wall portion (14, 22, 28) forming plastic film , Packaging according to one of claims 1 to 4, characterized in that each gas passage (19, 19 ') is part of a in at least one of the layers (15, 31, 32) formed, gas-permeable surface piece (18, 18'). Packaging according to one of claims 1 to 5, characterized in that the gas passages are formed in a closure seam (6, 6 ') interrupting its material connection. Packaging according to one of claims 1 to 6, characterized in that the superimposed layers (4, 5, 15, 16, 31, 32) by means of two approximately mutually parallel closure seams (6, 6 ', 17, 17') for training a channel-like gas passage region (21, 23, 33, 34) are interconnected. Packaging according to claim 7, characterized in that in the channel-like gas passage region at least one continuous connecting seam is formed, which subdivides the gas passage region into a plurality, at least partially together medially connected chambers, wherein the gas-permeable surface pieces in the different layers are each assigned to separate chambers. Packaging according to claim 7, characterized in that in the channel-like gas passage region (34) between the inner and the outer layer (27, 28) at least one intermediate element (35) formed as a guide member for the gas passage region (34) passing gas flow is arranged. Packaging according to claim 9, characterized in that the intermediate layer (35) is a separately in the gas passage region (34) introduced film strip which is fixed by means of a connecting seam (36) on at least one of the layers (31, 32). Packaging according to one of claims 3 to 10, characterized in that the coating is a thermal resin. Packaging according to one of claims 1 to 11, characterized in that the packaging wall (2) is a folded flat web, the one another overlapping edge regions form the multilayer wall region (3, 14, 20, 22).

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