EP3478596B1 - Valve bag - Google Patents

Description

The invention relates to a valve bag for bulk material such as cement, plaster of paris, granules, animal feed or the like, with a stand base and a valve base opposite the stand base. Stand and / or valve bases are preferably formed in a cross or block base fold manner. A valve tube is incorporated into the valve base and forms a valve for filling the valve bag in the area of a first corner of the base fold.

Such valve bags, mostly made of paper, are generally known and are used in particular for the packaging and distribution of fine-grain bulk goods such as cement, plaster of paris, granules, animal feed or the like. The usual sizes are 5 kilos, 10 kilos and 25 kilos.

The valve base comprises a valve for attaching the valve sack to the filler neck of a filling system. After the filling process, the valve can be closed, e.g. B. with a hose-like thermal valve, the inside of which is coated with a hot-melt material, to the valve by action to weld from heat. Alternatively, sealable materials can be used for lining and closing the valve tube on the inside.

To improve the stability of the valve hose, in particular to be able to attach it to a filling support of a filling system, a piece of paper is regularly placed around the thermal material as a carrier material. Both materials are designed so wide that both overlap each other when the side flaps of the valve base are closed and consequently form two valve tubes lying one inside the other.

A previously known valve construction is exemplified in the Figures 1 a and b shown. A carrier material 2 is glued as a slip into the open valve base 3 and then a thermal material 6 is applied to the carrier material 2 in the open base 3. Both materials are designed so wide that after the side flaps 4, 4 'have been closed, they each overlap according to the arrows a and b and form the valve tube 7 with two tube layers lying one inside the other.

If the valve tube 7 is welded to the filling system after the filling process, the lower part X of the thermal material 6 fuses flat with the upper part Y of the thermal material 6. The carrier material 2 has an exclusively supporting function. A disadvantage of this construction is the high cost of material that is necessary for the valve formation. This not only causes high production costs, but is also disadvantageous from an ecological point of view.

From the EP 0 233 170 A2 a valve bag is known, the valve tube of which consists of a metal foil and a corresponding thermal coating. When the valve hose is folded and welded, the thermal material is welded to an opposing thermal material coating. Similar valve bags are from the publications U.S. 6,164,823 , DE 20 2013 006 198 U1 such as US 2010/008603 A1 known.

The object of the present invention is to propose a valve bag with an improved valve, which can in particular be manufactured with less material and / or more cost-effectively and / or more environmentally friendly.

This object is achieved by a valve sack with the features of claim 1. Advantageous embodiments of the valve sack are the subject of the subclaims.

Based on the generic valve sack, the invention provides for the valve hose to be formed from a thermal material and a material different therefrom, the thermal material being weldable or sealable to the material different therefrom to close the valve. In contrast to the prior art, two layers of the thermal material are no longer welded or sealed to one another in order to bring about a valve closure, but the thermal material is welded or sealed with a different material. This procedure can reduce the amount of thermal material required. This not only reduces production costs, but the valve bag is also more environmentally friendly.

Any material which can be welded or sealed with a suitably selected different material can function as thermal material. Preferably, the thermal material can be a plastic material, e.g. B. polyethylene (PE), or a plastic coating.

According to the invention, the different material is a carrier material made of paper. The thermal material is applied to this carrier material in a suitable manner. However, the application of the thermal material is chosen so that it neither overlaps when the side flaps of the floor are closed nor forms a closed valve tube made of thermal material. Consequently, the valve hose comprises one or more recesses in the thermal material over its hose circumference. The resulting hose is thus made of the thermal material and the carrier material, the latter closing the recesses of the thermal material to complete the hose. When the valve is closed, the thermal material can be welded or sealed to the different material or carrier material. When welding or sealing the valve, the valve hose is compressed, so that opposite inner sides of the valve tube come into contact with one another and are welded or sealed. The thermal material and the recesses are advantageously distributed over the inner circumference of the valve tube in such a way that in the contact area there is at least one strip running over the entire width of the valve, along the entire length of which there is thermal material. This enables a tight weld or seal.

The application of the thermal material to the carrier material can be done, for example, in such a way that it is applied to the carrier material approximately symmetrically or centrally with respect to the fold lines of the side flaps of the valve base and / or approximately symmetrically or centrally to the longitudinal axis of the valve base with the valve base still open and / or in the middle of the surface of the carrier material facing the bag interior. The width of the thermal material, e.g. B. the expansion of the thermal material transversely to the valve axis is chosen so that the end faces of the thermal material neither overlap nor close to form a tube when it is inserted. The valve circumferential area that remains free from the thermal material is closed by the carrier material. When the valve is compressed and closed, the thermal material is welded or sealed to the carrier material located in the opposite recess.

Alternatively, the thermal material in the open valve base can also be applied to the edge in two or more parts of the carrier material, in particular in the part of the carrier material located in the area of the side flaps of the valve base, which overlaps when the side flaps are closed and forms the tube and its from the bag body opposite half-circumference forms. In this case, the surface of the carrier material facing the sack body remains free of thermal material, so that here, too, the valve closes by welding or sealing the thermal material to the carrier material, with a strip extending over the entire center of the compressed valve Thermal material is located. In this case, the thermal material is preferably terminated flush with the side edges of the carrier material.

Instead of gluing the thermal material to the carrier material, the carrier material can also be provided with a corresponding weldable / sealable coating. The carrier material can be paper or any other suitable material that can be welded / sealed with the thermal material.

Alternatively, the use of a separate carrier material for the valve construction is not absolutely necessary. For example, the thermal material can be applied directly to the side flaps and / or corner folds of the valve base, either by gluing a thermal material or by suitable coating of the corresponding base surface. After the side flaps have been attached, the valve tube is advantageously formed by applying a cover sheet in order to complete the valve tube. In this embodiment, when the valve is closed, the thermal material is welded or sealed to the cover sheet.

In the case of the previously described embodiments with a separate carrier material, too, a cover sheet can be applied, in particular glued, to the closed valve base. In the case in which the cover sheet is not required to complete the valve, it can also be shortened and preferably only protrude as far as the outer edge of the corner entry provided with the valve. Otherwise the cover sheet preferably protrudes to the outer valve inlet edge.

Figur 1a, 1b:

einen Ventilsack gemäß dem Stand der Technik;

Figur 2a, 2b:

schematische Ansichten eines erfindungsgemäßen Ventilsackes,

Figur 3a, 3b:

Darstellungen des erfindungsgemäßen Ventilsackes mit offenem und geschlossenem Ventilboden gemäß einer ersten Ausführungsform;

Figur 4a, 4b:

Darstellungen die gegenüber den Figuren 3a, 3b modifizierten Ausführungsform;

Figur 5a, 5b

Darstellungen des erfindungsgemäßen Ventilsackes mit offenem und geschlossenem Ventilboden gemäß einer zweiten Ausführungsform;

Figur 6a, 6b:

Darstellungen des erfindungsgemäßen Ventilsackes mit offenem und geschlossenem Ventilboden gemäß einer dritten Ausführungsform;

Figur 7:

ein weiteres Ausführungsbeispiel des erfindungsgemäßen Ventilsackes mit zugelegtem Ventilboden.

Further advantages and properties of the invention are explained in more detail below with reference to the exemplary embodiments shown in the figures. Show it:

Figure 1a, 1b:

a valve bag according to the prior art;

Figure 2a, 2b:

schematic views of a valve bag according to the invention,

Figure 3a, 3b:

Representations of the valve bag according to the invention with an open and closed valve base according to a first embodiment;

Figure 4a, 4b:

Representations opposite the Figures 3a , 3b modified embodiment;

Figure 5a, 5b

Representations of the valve bag according to the invention with an open and closed valve base according to a second embodiment;

Figure 6a, 6b:

Representations of the valve bag according to the invention with an open and closed valve base according to a third embodiment;

Figure 7:

Another embodiment of the valve bag according to the invention with an added valve base.

The Figures 2a and 2 B show the basic structure of a valve bag 10 according to the invention, which has a stand base 20 and a valve base 30, the valve 50 for filling the valve bag being accommodated in the valve base 30. Apart from the valve 50 according to the invention, that in FIG Fig. 2 a / b shown essentially the solution known in the prior art. In Fig. 2 Both the stand base 20 and the valve base 30 are folded onto the front side 12 of the sack 10. The rear side of the sack, which lies under the front side 12, cannot be seen. A hose valve 50 according to the invention is inserted into the valve base 30, specifically in the area of the first corner entry 32 of the base fold. With the hose valve 50, the sack 10 can be plugged onto the filler neck of a filling plant, and after filling the hose valve can be welded dust-tight by the action of heat.

Figure 2b shows the open valve bottom 30 of a sack 10 according to the invention in a cross-bottom fold, with neither a valve tube or label nor a thermal material being used. The cross-bottom fold forms the two corner folds 32 and 33, as well as the side flaps 38 and 39, which are closed around the side fold lines 35 and 36 to close the bottom.

The Figures 3a , 3b show a first specific embodiment of the valve 50 according to the invention. To illustrate the valve structure, the valve base 30 is shown in FIG Fig. 3a not folded, but - as in Figure 2b - shown open. A carrier material 52, in the exemplary embodiment a piece of paper, is glued into the open floor 30 on the left corner envelope 32. Subsequently, the sealable or weldable thermal material 54, in this case a PE label 54, is also glued in the open base 30 centrally or symmetrically to the central axis 37 of the base 30 on the carrier material 52. The PE label 54 is much narrower than the prior art, i.e. it is shorter in the transverse direction to the valve axis and only protrudes to a small extent (preferably 0.5 to 1 cm) over the two side fold lines 35, 36 into the side flaps 38 , 39 into it.

In the exemplary embodiment shown, the PE label 54 must be at least as wide as the valve base 30 between the two side fold lines 35, 36. However, if the valve 50 is narrower than the distance between the side fold lines 35, 36 of the valve base 30, the PE label 54 be made narrower than the valve base 30, but must be at least as wide as the valve 50 in order to achieve a complete welding along the contact line of the closed valve.

By adding the side flaps 38, 39 according to the arrows a and b, the valve base 30 and thereby also the valve, ie the valve hose 50, are formed. The cover sheet 40, which extends from the valve inlet edge to the rear corner entry 33, is glued onto the closed side flaps 38, 39. The valve tube 50 is completed by the carrier material 52. Due to the narrower design, the PE label 54 can no longer overlap and thus also cannot form a second tube. If the valve or the valve hose 50 is after the filling of the Valve bag 10 welded to the filling system, the welding does not take place, as known from the prior art, on the basis of a single material (thermal material 2 in Fig. 1a , b ), but based on two different materials. In the Figure 3b it can be seen that when the valve 50 is welded, the underlying thermal material 54, here identified as area X ', is welded to the overlying area of the carrier material 52, identified with the reference symbol Y'. The welding of two different materials harbors a high savings potential, since less PE or thermal material 54 is required for the formation of a sufficiently tightly closing valve 50. This has a high cost advantage and at the same time makes the valve bag more environmentally friendly.

A slightly modified version of the design according to FIG Figures 3a , 3b is in the Figures 4a , 4b shown. In this case, a PE label 54 is not glued to the carrier material 52, but instead the carrier material 52 is provided with a coating 56. The positioning of the coating 56 is identical to the positioning of the label 54 in the Figures 3a , 3b , which is why the effect achieved is identical to the embodiment of Figure 3a , 3b is. To close the valve 50, the coating 56 is welded or sealed to the carrier material 52.

Another embodiment of the valve bag according to the invention is shown in Figures 5a , 5b shown. Here, the PE label 54 is not glued in one piece to the center of the valve base 30 on the carrier material 52, but instead divided into two separate areas 54, 55, each of which is flush with a side edge of the carrier material 52. In this variant, the PE material 54, 55 does not lie at the bottom when the valve bag is inserted, as in FIG Figure 3b shown, but instead at the top of the valve tube 50. However, in this embodiment too, the PE material 54, 55 lying on top is glued to the carrier material 52 lying at the bottom in the valve tube. Instead of the glued-on PE material, a coating analogous to the Figures 4a , 4b be used. Also here, the cover sheet 40, which extends from the valve inlet edge to the rear corner entry 33, is glued onto the closed side flaps 38, 39.

Another embodiment of the invention is shown in Figures 6a , 6b shown. In this embodiment, unlike in the above variants, the carrier material 54 is completely dispensed with and the PE label 54 is instead glued directly approximately centrally into the open base 30, in particular onto the corner entry 33. In this case, the cover sheet 40, which is glued onto the side flaps 38, 39 that has already been closed, serves as a replacement for the carrier material 54. The valve hose 50 is thus completely closed by the cover sheet 40, with the thermal material 54 lying below being welded or sealed to the cover sheet 40 when the valve 50 is closed. Here, too, the cover sheet 40 extends from the valve inlet edge to the rear corner entry 33.

In all of the above embodiments, the cover sheet 40 is always made up to the valve inlet edge. However, this is only used in the exemplary embodiment Figure 6a , 6b to weld the valve 50 or the thermal material 54. With the design variants of the Figures 3a to 5b this can also be made shorter for further material savings, as in Figure 7 shown. Here the cover sheet 41 extends only to the ends 31, 31 ′ of the side flaps 38, 39.

The exemplary embodiments described use a PE material as the thermal material, but other weldable or sealable materials are also conceivable. The carrier material or the cover sheet does not necessarily have to be made of paper either, but can alternatively be made of a different material.

Claims (7)

1. A valve sack (10) for bulk material such as cement, gypsum, pellets, animal feed, or similar having a stand-up base (20), preferably a cross-base or a block base, and having a valve base (30) that is disposed opposite the stand-up base (20) and into which a valve hose (50) is worked that forms a valve (50) for filling the valve sack (10) in the region of a first corner fold (32) of the base fold,
   wherein the valve hose (50) is formed from a thermal material (54, 55, 56) and from a material (52, 40, 41) different therefrom, with both materials (40, 41, 52, 54, 55, 56) being weldable or sealable with one another to close the valve (20),
   characterized in that the different material (52, 40, 41) is paper on which a thermal material (54, 55, 56) is applied and one or more cut-outs of the thermal material (54, 55, 56) are provided over the hose periphery of the formed valve (50).
2. A valve sack (10) in accordance with claim 1, characterized in that the thermal material (54, 56) is applied to the carrier material (52) centrally to the center axis (37) of the valve base (30), with the applied thermal material (54, 56) neither overlapping nor closing to form a hose with a folded closed valve base (30).
3. A valve sack (10) in accordance with claim 1, characterized in that the thermal material (54, 55) is applied to the carrier material (52) in two or more separate regions over the valve periphery, with the thermal material regions (54, 55) preferably terminating flush with at least one side edge of the carrier material (52).
4. A valve sack (10) in accordance with one of the preceding claims 1 to 3, characterized in that the thermal material (54, 55) is adhesively bonded to the carrier material (52) or is formed by a coating (56) of the carrier material (52).
5. A valve sack (10) in accordance with one of the preceding claims, characterized in that the thermal material (54, 55, 56) is polyethylene.
6. A valve sack in accordance with one of the preceding claims, characterized in that the different material is a top sheet (40, 41) that is applied to the side flaps (38, 39) after their folding closed.
7. A valve sack in accordance with claim 6, characterized in that the top sheet (40, 41) extends up to the outer valve inlet edge or up to the ends (27, 27') of the side flaps 38, 39.

Images