EP0240960B1 - Thin-walled pallet container for receiving fluid or pourable bulk material - Google Patents

Abstract

1. Thin-walled container (1), preferably capable of being paletted for receiving material to be transported in bulk, flowable, pourable and granular form, the contour of which container is defined by an annular casing (2) (external ring) of corrugated cardboard, cardboard or similar foldable or flexible material, the casing having one bottom opening and one cover opening, each, which can be closed, if necessary, by bottom or cover parts (4 and 3, respectively), respectively, and surrounding an insert (5) (internal ring) corresponding essentially to the contour of the container, in such a manner that there is formed a hollow space (6) between the casing and the insert and that the insert (5) is positioned in a floating manner relative to the container casing (2), characterised in that the insert (5) forms a downwardly open ring, stands on the bottom (4, 22) with its lower edge (53) and consists of a deformable material, which, when stressed statically by the material to be transported, has a resiliency inside the limits of the hollow space (6).

Description

The invention relates to a preferably palletizable thin-walled container for receiving bulk, flowable, pourable or pourable transport goods, the contour of which is determined by an annular casing (outer ring) made of corrugated cardboard, cardboard or similar foldable or bendable material, the casing each have a bottom and lid opening, which can optionally be closed by bottom or lid parts, and surrounds an insert (inner ring) corresponding essentially to the container contour such that a cavity is formed between the jacket and insert and the insert is floating in relation to the container jacket is stored.

Large-volume containers made of corrugated cardboard, which can hold a bulk weight of one tonne and above, are increasingly being used in practice by the large chemical industry because of their relatively low material price and weight. The bulk material is preferably stored in bags or sacks made of polyethylene or similar material in the container. Because of the dynamic loads occurring during the transport of the regularly palletized containers, there is a requirement for dangerous goods packaging that a container loaded with a ton of material must not crack or burst during a drop test from a height of 0.8 m or more - depending on the danger level. In many cases, this regulation cannot be complied with for normal corrugated cardboard containers, which are very often used today in the form of polygonal, in particular octagonal, structures in horizontal section. Rather, due to the compression of the bulk material, bulges of the container shell occur at static load and tears in the grooved corner areas at the latest when there is dynamic load (fall, impact), i.e. the shell bursts, so that the filled sack is then exposed.

A great variety of efforts have been made in the past to avoid such deformations, in particular the bursting of the container shell.

Thus, in the case of a container of the type described at the beginning (DE-GM 1 886 464), but without any distance or cavity between the casing and the insert, the latter is provided as a one-part or multi-part arch arrangement which is provided with reinforcement strips produced by folding. The various parts of the arch lie essentially flat against the inner surface of the container wall.

Another known reinforcement arrangement in a palletable container (DE-PS 2 550 009) provides for a polygonal corrugated container jacket a corresponding polygonal receptacle made of corrugated cardboard connected to the pallet, which extends at least over part of the jacket height.

It has been shown in practice, and in particular when carrying out the aforementioned drop tests to comply with the safety criteria for dangerous goods packaging, that such insert and reinforcement arrangements, which practically create a double wall, do not eliminate the problems of tearing / bursting, particularly along the container edges can. Although the bulges remain within the frame when the container wall is subjected to static loads, sudden dynamic stresses lead to the above-mentioned disadvantageous destruction phenomena in the container wall that are not permissible for the faultless shipping of dangerous goods.

A certain departure from the aforementioned reinforcement arrangements is shown by some known container designs in which there is a spacing, albeit a small one, between the inner and outer walls.

For example, a known container of the type described in the introduction (US Pat. No. 3,937,392) is provided as a collapsible container with a double wall, the main purpose of which is the foldability of the individual containers and thus improved storage stability and transportability in the empty state and to accommodate materials, especially bulk goods, serves. There is a narrow cavity between the casing and insert, which essentially corresponds to the material thickness of the insert / inner container at its upper and lower opening, closing folding covers for the purpose of easier, free insertion of the flaps of the bottom cover or the flaps of the inner upper cover in the is provided by the outer container enclosed interior. This is an inner container which is closed on all sides and which can slide back and forth on its base cover within the small dimensions of the cavity existing between the flaps and the jacket on the base of the outer container; the inner container thus forms a closed whole with its enclosed packaging material volume, which, in the event of sudden dynamic loading of the entire container and the deformation energy occurring on the inner jacket, leads to the closed inner container as a whole immediately without any deformation forces being absorbed or reduced effectively on the inner jacket , preferably with the lower edge area, against the outer container and destroys it. However, this is precisely what should be avoided according to the safety regulations for dangerous goods packaging set out above.

In a known container of the type described at the beginning (DE-PS 684 550) there is a cavity between a container jacket and a hollow cylinder arranged in it over a substantial part of the height of the container. This container is intended to hold any substance and to be sufficiently resistant for repeated use. For this purpose, a secure and reliable connection of the two hollow bodies is described at their respective upper and lower ends, which can be an adhesive connection or the outer and inner jacket can also be manufactured so tightly that one another that displacements of the container parts can be prevented. Therefore, the container is easily damaged under impact loads possible after overcoming the cavity. The main aim of this known object is, as can be seen in connection with the description of a container based on the same development and construction (DE-PS 156 179), to protect the material against the outer wall being pressed in from the outside and less to deform the inner body bring about.

In another known arrangement of similar construction (US Pat. No. 3,800,994), lateral displacement of the inner pocket is possible as a result of a spring-floating suspension of an inner pocket. It is a plastic container intended for liquids, semi-liquid substances or other bulk goods, in which the inner container does not stand on the floor. Palletizability is not possible. Due to the suspension of the inner container, it can only be loaded relatively weakly and is not suitable for large-volume arrangements, especially not for the drop tests mentioned.

The invention is based on the object, while eliminating the disadvantages of the known constructions to create a palletizable container of the type described above, which, in addition to sufficient static structural safety and above all increased resistance to damage to the outer wall of the container under dynamic load, with a structurally simple and therefore inexpensive construction due to suddenly increased internal pressure due to the contents and consequently fulfills the safety regulations for dangerous goods packaging, in particular according to the IMDG code (International Maritime Dangerous Goods).

This object is achieved in that the insert forms a ring open at the bottom, stands with its lower edge on the floor and consists of a deformable material which has a flexibility below the boundaries of the cavity under static loading by the transported goods. With such an arrangement, it is possible that when the container is subjected to dynamic loads, part of the deformation energy is initially absorbed by the inner ring before the remaining energy acts on the outer ring after the same has been destroyed and the cavity has been overcome, but the total deformation energy has already been reduced so far that the rest is no longer sufficient to destroy the outer ring. In other words, due to the deformation / destruction of the insert, the energy released upon impact of the container is partially reduced immediately, so that, based on the total energy, a gradual energy degradation takes place and the last "energy level", which affects the outer ring, possibly becomes one certain bulge or bulge, but no longer leads to destruction. A centering of the inner ring is not necessary, only the presence of the cavity between the inner and outer ring is sufficient for the gradual energy dissipation. The fact that the inner ring can be completely destroyed has no disadvantage since the container shell remains undamaged. The inner ring thus acts practically as an energy absorption element. By inserting such an insert, the packaging weight is changed just as little as the manufacturing and thus the cost of the packaging compared to double-walled containers of this type having a connection between the inner and outer wall. A major advantage of using energy absorption elements is that the outer appearance of the container casing, insofar as its printing, labeling and any warnings are concerned, remains unchanged when the insert is destroyed.

Various measures for the formation of cavities in double-walled containers are known, but this does not, however, achieve the object of the invention. For example, DE-AS 1 141 221 shows a container with a double wall and a honeycomb rib structure arranged in between in the cavity. The inside and outside wall should consist of corrugated cardboard. A gradual energy dissipation through the honeycomb structure is only conceivable to a limited extent, since it is relatively stiff and is supported on the walls. It also represents a considerable constructive and costly additional effort. A support between the inner and outer wall also takes place in the container according to DE-GM 1 638 117. Furthermore, US Pat. No. 3,155,305 shows a double-walled container which has a bottom arrangement to avoid damage to the outer container from the inner container. However, a direct stand-up of the inner container on the bottom closing the outer container and thus a floating bearing are not shown. Rather, the latter is just excluded by a connection in the floor area.

Finally, US-A 2 406 758 shows a cavity between the inner and outer container, similar to the construction of the previously discussed US-A 3 937 392; the bottom of the inner container is in both cases in sliding connection with the outer container, so that a floating movement of the inner container is not possible without direct loading of the outer wall.

As stated, it is essential that a cavity be formed between the inner and outer rings. Of course, this may only move within technically and economically sensible limits. On the one hand, its minimum size is determined by the fact that no static contact between the inner ring and the outer ring may occur when the inner ring is subjected to static loads, because precisely at such points, in the event of suddenly occurring loads, the force transmission takes place and would lead to the outer ring being subjected to destruction. In this respect, depending on the weight of the goods to be transported and the deformability of the material of the inner ring, a minimum dimension must be provided for the cavity. On the other hand, the cavity cannot be provided as wide as this would significantly reduce the capacity of the container. Therefore, in a preferred embodiment of the invention, the circumference of the insert / inner ring should be approximately 2 to 7% less than the circumference of the casing / outer ring, with an approximately 4% smaller circumference of the inside ringes has proven to be particularly advantageous in terms of material selection and resilience as well as economy.

Due to the load conditions in such packaging, in which the focus of the pressure attack is about 1/3 of the height, the height of the insert / inner ring advantageously only needs to be a part of the height of the jacket / outer ring, thereby saving on packaging material and weight can. In view of these loading conditions, the inner ring should therefore preferably extend from the bottom of the container to the height of the center of pressure attack of the goods to be transported.

In an expedient embodiment of the invention, the inner ring can be provided along its upper edge with wing flaps which can be folded against the inner wall of the outer ring and cover the cavity. This creates a harmonious transition from the inner to the outer ring, which, for example, prevents damage to the plastic bag into which the goods to be transported are stored, since this bag cannot get stuck in the cavity.

However, depending on the intended use and load requirements, it is equally possible that the insert / inner ring extends over the entire height of the jacket / outer ring. This is e.g. conceivable with increased demands on the load-bearing capacity of the entire container, especially when loading from above (stacking).

In order to meet the requirements placed on such containers, the outer ring can advantageously be made from corrugated cardboard laminated on both sides, possibly with multiple corrugations.

The lower edge of the outer ring can stand in a tray-like base part which can be connected to the outer ring and which in turn can be connected to a pallet. Such a bottom part then forms the lid for the bottom opening of the container and serves to securely hold and secure the position of the container shell. An expedient possibility is that the lower edge of the outer ring is provided with bottom flaps which can be folded into the interior of the container and which can preferably be designed as stub flaps on which the inner ring can stand. But it is also possible that the outer ring is formed with a narrow, circumferential lower edge and stands with this on the bottom part, in which case the inner ring in turn stands directly on the bottom part. Decisive for the choice between these design options are essentially parameters such as material expenditure and costs, strength in the floor area, type of fastening relative to the pallet and quality of the material used for the rings, in particular the outer ring.

The insert can advantageously consist of a material similar to that of the outer ring, that is to say, for example, of high-strength corrugated cardboard, and depending on the load requirements and conditions, single- or multi-corrugated cardboard can be used. This corrugated cardboard used for the inner ring can have a tear-resistant inner and / or outer cover in order to meet the strength requirements in a particularly expedient manner.

However, it is equally possible that the insert consists of tissue-reinforced paper with which a relatively high degree of independence from the moisture content can be achieved compared to corrugated cardboard.

For many applications, however, it can also be expedient to completely separate from the use of corrugated cardboard or paper when the insert is designed and, particularly since the filling material is usually accommodated in the container in separate film bags, as a film bag receiving the filling material to be trained with an additional stiffening outer layer. Such a double-layer film sack, the inner film of which has the usual closed sack shape and the outer layer of which is made of a fabric-reinforced plastic material in the manner of a belt, is fastened in the upper region of the container using suitable means accessible to the person skilled in the art.

The overall advantages that can be achieved with the invention are that a container with an inner and outer wall separated by a cavity is obtained, the inner wall of which serves for dynamic force absorption and the outer wall of which is predominantly a quasi-static carrier.

• Fig. 1 einen erfindungsgemäß aufgebauten Behälter im Vertikalschnitt,
• Fig. 2 den Behälter der Fig. 1 in Draufsicht bei weggelassenem Deckel,
• Fig. 3 einen Vertikalschnitt durch eine andere Ausführungsform des erfindungsgemäßen Behälters,
• Fig. 4 eine Draufsicht des Behälters der Fig. 3 bei weggelassenem Deckel,
• Fig. 5 eine weitere Ausführungsform des erfindungsgemäßen Behälters im Vertikalschnitt und
• Fig. 6 eine Draufsicht auf den Behälter der Fig. 5 bei weggelassenem Deckel.

Further advantages and embodiments or possibilities of the invention emerge from the following description of the exemplary embodiments shown in the schematic drawing. It shows

• 1 is a container constructed according to the invention in vertical section,
• 2 is a top view of the container of FIG. 1 with the lid omitted,
• 3 shows a vertical section through another embodiment of the container according to the invention,
• 4 is a plan view of the container of FIG. 3 with the lid omitted,
• Fig. 5 shows a further embodiment of the container according to the invention in vertical section and
• Fig. 6 is a plan view of the container of FIG. 5 with the lid omitted.

The reference symbols used in the drawing for the three different embodiments are used in the same way for functionally identical parts.

Thus, a container 1 comprises a jacket or outer ring 2, which determines the outer contour of the container. This contour is octagonal in the exemplary embodiments. The contour can just as well be the shape of any other polygon, a circle, an oval or the like. have, of course, purpose and practicality are decisive. The outer ring 2 is open at the top and bottom and is closed here by a cover 3 and a base 4, respectively, which are tray-like in the examples. The floor 4 is usually on a for transport purposes Pallet, not shown, with which it is firmly connected.

In the outer ring 2, an insert or inner ring 5 can be used, the contour of which essentially corresponds to that of the outer ring 2, but which has an order of magnitude of 2 to 7%, preferably about 4% smaller, so that between the inner ring 5 and the outer ring 2 a cavity 6 is formed. The inner ring 5 is not centered in the outer ring 2, but rather is "floating" in it. In the interior of the container 1 determined by the outer ring 2 and inner ring 5, flowable, pourable, pourable or pourable goods such as any granular chemicals, sludges, powders or liquids can be stored for transport and storage purposes, namely in the As a rule, this filling material is introduced into a film bag (not shown here) which, after filling, lies closely against the inner wall of the inner ring 5.

The focus of the compressive force of such contents is with a reasonably uniform distribution and complete filling of the container 1, which can hold a ton or more of such contents, at about a third of the container height. Therefore, the inner ring 5 extends at least to this height, but as a rule and for safety purposes, as shown in the exemplary embodiments of FIGS. 1 and 3, it is extended beyond half the height, but it is just as good as in the exemplary embodiment of FIG 5 and 6 shown, can take up the entire height of the outer ring 2 and then increases the overall load-bearing capacity of the container 1, in particular also with regard to its vertical load-bearing capacity. In order to avoid jamming of the film bag in the opening area of the cavity 6 when the inner ring 5 is lower in height than the outer ring 2, the inner ring 5 is formed along its upper edge 51 with wing flaps 52 which can be folded outward and cover the cavity 6. In the embodiment of FIGS. 5 and 6, such wing flaps are not necessary, since the upper edge 51 of the inner ring 5 closes with the upper edge 23 of the outer ring 2 and can be closed here directly by the container 3.

The outer ring 2 can either, as shown in the embodiments of FIGS. 3 and 4 or 5 and 6, stand directly on the bottom part 4 with its lower edge 21, the bottom edge here forming a narrow, circumferential ring. The same applies to a lower edge 53 of these embodiments formed on the inner ring 5.

In the example of FIGS. 1 and 2, however, the lower edge 21 of the outer ring 2 is provided with bottom flaps 22 which can be folded inwards and which rest on the bottom part 4 or interposed inserts (not described here in greater detail) and are thus fastened relative to the pallet. The lower edge 53 of the inner ring 5 then stands on these base plates 22.

The outer ring 2 is made of single or multi-layer corrugated cardboard with appropriate lamination / cover, the choice of material depending on the purpose of the container and the required strength conditions. An identical or similar material, which, for example, can also be tissue-reinforced paper, is used for the inner ring 5. However, it must be ensured that this material can deform / bulge only to such an extent under the static loading of the container that a cavity 6, that is to say a distance from the outer ring 2, is always maintained and, in particular, no two-sided diametrical flat contact of the inner ring 5 on the outer ring 2 is done. The same naturally also applies to the embodiment of FIGS. 5 and 6, in which case the inner ring 5 practically replaces the film bag (not shown) of the exemplary embodiments of FIGS. 1 and 2 or 3 and 4 and in the manner of a “belt” made of fabric, fabric-coated special paper or film can be formed. Decisive for the choice of material are the strength ratios with regard to the maintenance of the cavity 6 under static loading of the inner ring 5 by the filling material.

In the event of dynamic loading of the container due to impact or falling, the energy to be absorbed is gradually absorbed due to the center of gravity of the filling material and the formation of the cavity 6 between the inner ring 5 and the outer ring 2, in that the inner ring 5 first moves into the cavity 6 until it is destroyed deformed into it before the residual energy is collected after overcoming the cavity 6 on the outer jacket. However, this residual energy is no longer sufficient to destroy the outer casing 2, and this remains undamaged.

Claims (17)

1. Thin-walled container (1), preferably capable of being palletted for receiving material to be transported in bulk, flowable, pourable and granular form, the contour of which container is defined by an annular casing (2) (external ring) of corrugated cardboard, cardboard or similar foldable or flexible material, the casing having one bottom opening and one cover opening, each, which can be closed, it necessary, by bottom or cover parts (4 and 3, respectively), respectively, and surrounding an insert (5) (internal ring) corresponding essentially to the contour of the container, in such a manner that there is formed a hollow space (6) between the casing and the insert and that the insert (5) is positioned in a floating manner relative to the container casing (2), characterised in that the insert (5) forms a downwardly open ring, stands on the bottom (4, 22) with its lower edge (53) and consists of a deformable material, which, when stressed statically by the material to be transported, has a resiliency inside the limits of the hollow space (6)..

2. Container according to claim 1, characterised in that the circumference the insert or the internal ring (5) is smaller by approximately 2 bis 7% than the circumference of the casing or external ring (2).

3. Container according to claim 2, characterised in that the circumference of the insert or internal ring (5) is by approximately 4% smaller that the circumference of the casing or external ring (2).

4. Container according to any one of claims 1 to 3, characterised in that the height of the insert or internal ring (5) extends over only part of the height of the casing or external ring (2).

5. Container according to claim 4, characterised in that the insert or internal ring (5) extends from the bottom of the container (1) beyond the height of the center of application of pressure of the material to be transported.

6. Container according to claim 4 or 5, characterised in that the insert or internal ring (5) is provided, along its upper edge (51) with pivoted flaps (52) adapted to be pivoted against the inner wall of the casing or external ring (2) and overlapping the hollow space (6).

7. Container according to any one of claims 1 to 3, characterised in that the insert or internal ring (5) extends over the total height of the casing or external ring (2).

8. Container according to any one of claims 1 to 7, characterised in that the casing or external ring (2) is made from corrugated cardboard laminated on both sides and, if necessary, having a plurality of undulation layers.

9. Container according to any one of claims 1 to 8, characterised in that the casing or external ring (2) is positioned, with its lower edge (21) in a tray- shaped bottom part (4) capable of being connected to the external ring (2).

10. Container according to claim 9, characterised in that the lower edge (21) of the external ring (2) is provided with bottom straps (22) foldable into the interior of the container.

11. Container according to claim 10, characterised in that the bottom straps are formed as stub flaps (22), on which the internal ring (5) stands.

12. Container according to claim 9, characterised in that the external ring (2) is formed with a narrow, circuxlferential lower edge (21), by which it stands on the bottom part (4).

13. Container according to any one of claims 1 to 12, characterised in that the insert (5) consists of high-tensile corrugated cardboard.

14. Container according to claim 13, characterised in that the insert (5) consists of corrugated cardboard having one or a plurality of undulation layers.

15. Container according to claim 13 or 14, characterised in that the insert (5) consists of corrugated cardboard having a tearing-resistant inner and/or outer cover layer.

16. Container according to any one of claims 1 to 12, characterised in that the insert (5) consists of fabric-reinforced paper.

17. Container according to any one of claims 1 to 12, characterised in that the insert (5) consists of a foil bag receiving the filling material and having an additional, stiffening outer layer.

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