WO2007031805A1

WO2007031805A1 - Double-wall container

Info

Publication number: WO2007031805A1
Application number: PCT/HU2005/000105
Authority: WO
Inventors: Katalin Szokonya
Original assignee: NEFAB PACKAGING HUNGARY KFT
Current assignee: NEFAB PACKAGING HUNGARY KFT
Priority date: 2005-09-16
Filing date: 2005-09-16
Publication date: 2007-03-22
Anticipated expiration: 2008-03-16
Also published as: CN101282884A; HUP0800215A2

Abstract

The object of the invention is a double-wall container for storing and shipping products, comprising a collapsible, open-top outer frame (1) attached to a pallet (2), an inner frame (3) assembled from elements and inserted into the outer frame (1) with a clearance, and a lid (4) covering both the inner and the outer frames, where the section of the outer frame (1) and of the inner frame (3) taken along a plane parallel with the pallet has a rectangular shape, and where the outer frame (1), the inner frame (3), and the lid (4) are made of corrugated paper. The inner frame (3) of the container according to the invention is assembled from an U-insert (6), end panels (12), and a top panel (15), the base panel (7) of the U-insert is seated on the pallet (2), with the side panels (8) of the U-insert, the end panels (12), and the top panel (15), being set parallel with the first side panel (24) of the outer frame, the second side panel (25) of the outer frame, and the base panel (7) of the U-insert, respectively. Edge protection elements (5) are slid into the clearance space between the edges of the outer frame (1) and the inner frame (3) perpendicular to the pallet (2).

Description

Double-wall container

The object of the invention is a double-wall container for storing and shipping products, comprising a collapsible, open-top outer frame attached to a pallet, an inner frame assembled from elements and inserted into the outer frame with a clearance, and a lid covering both the inner and the outer frames, with the section of the outer frame and of the inner frame taken along a plane parallel with the pallet having a rectangular shape. The outer frame, the inner frame, and the lid are made of corrugated paper.

Shipping and storage containers made of corrugated paper are widely known in the industry. A double-wall corrugated container is disclosed in patent description EP 1,522,498 Al. The container according to the document comprises an open-top bottom portion having a rectangular base and four rectangular side walls perpendicular to the base panel. According to this known solution a first reinforcement insert and a second insert comprising a horizontal top sheet are inserted into the container, which is then capped by a lid covering the edges of the side walls.

The solution disclosed by the above document has the disadvantage that the container produced accordingly cannot resist larger amounts of compression stress and particularly transverse and shear stress. A further drawback is that edges and corners of the large integral inserts are especially vulnerable to damage as they can easily get crushed or cracked during handling, and in that case the insert needs to be discarded and replaced with a new one. A further drawback is that assembling the container, especially the placement of the inserts, involves close attention and accurate handwork.

The aim of our invention is to provide by the modification of the known container an improved shipping and storage device that has increased stability and improved transverse and shear stress resistance. The container produced according to the invention can be used for increased-safety storage and shipping of goods. Our further aim was to make the production of the container simpler and cheaper.

The above aims are fulfilled by the provision of a double-wall container described in the introductory paragraph, where

- the inner frame of the container is assembled from a U-insert, end panels, and a top panel, - the base panel of the U-insert is seated on the pallet, and the side panels and end panels of the U-insert and are set parallel with the first and second side panels, respectively, of the outer frame, and the top panel is disposed parallel with the base panel of the U-insert,

- edge protection elements are slid into the clearance space between the parallel edges of the outer and inner frames that are located perpendicular to the pallet.

The double-wall container produced according to the invention is approximately twice as strong as known containers, due to the special configuration of the inner frame and to the edge protection elements disposed between the inner and outer frames. Production and assembly of the multiple-piece inner frame is simple. The elements making up the outer and inner frames of the container can be cut out using a simple tool, and in case an element becomes damaged only the damaged part has to be replaced.

The double wall container is assembled from an outer frame attachable to a pallet, an inner frame that is inserted with a clearance to the outer frame, edge protection elements slid between edges of the outer and inner frames, and a lid covering the outer and inner frames.

According to a preferred embodiment, the outer frame is assembled from two portions, with both portions comprising a first side panel corresponding in length to the length of the container, and a second side panel corresponding in length to the width of the container, said first and second side panels being connected to each other along a folding line. Gluing tabs, foldable along folding lines are connected to the first and/or to the second side panels. The two portions of the outer frame are secured together prior to usage by means of the gluing tabs. For securing together the portions any known adhesive suitable for gluing paper can be applied. In case of smaller-sized containers the outer frame can be made of a single portion.

According to another preferred embodiment, folding lines are disposed on one of the sides of the outer frames to facilitate the collapsing of the outer frame. Folding lines can be made by means of creasing, an operation widely used in relation to corrugated packaging materials. The folding lines thus produced function as hinges and make simpler the folding and opening of the corrugated paper panels.

According to a further preferred embodiment of the invention folding lines facilitating the formation of a storage space inside the outer frame are disposed on the first and second side panels of the outer frame of the container. In the erected position of the container these folding lines run parallel with the pallet and they provide that sufficient storage space is produced between the pallet and the inwardly folded side panels in the collapsed position of the outer frame. This empty storage space may be applied for containing the elements of the inner frame before the container is put into use or the elements can be stacked therein when the container is bound for recycling. The collapsed container housing the inner frame elements can be capped with the lid. The resulting compact box takes up small space, can be transported easily with minimal risk of damage, and is ready for use because it contains all the necessary elements. Use of the container is made easier by the instant availability of the elements (no need for collecting the necessary parts from all over the place and no need for watching out for potentially missing parts). No extra parts or tools are needed to assemble the container. After use the container can be collapsed again and is ready to be used once more for repackaging.

The outer frame is secured to the pallet by means of adhesive binding. However, the outer frame and the pallet can be secured together by alternative means, e.g. by stapling.

The pallet can be a conventional wooden pallet, preferably of with a size of 1200 x 800 mm, which type is widely used in transportation industry. Pallet size puts no constraint on the claimed scope of our invention and thus pallets of any size can be applied. The base panel of the container's outer frame is configured such that it fits the pallet in size. From the aspect of manufacturing feasibility it is advantageous to keep to the following relations among the container's length (L), width (W), and height (H):

L+ W < 2400 mm

H < Sz - 200 mm

W + 2 x H < 2470 mm

L + 2 x H < 2470 mm

A possible configuration of the double-wall container, where the outer wall is not secured directly to the pallet but an intermediate sheet is inserted between the outer wall and the pallet, is also regarded as falling within the scope of our invention. Also, the material of the pallet is not a restricting factor; the pallet can be made of metal, plastic or a similar material.

The assembled inner frame is inserted into the outer frame that is secured to the pallet. The inner frame consists of a U-insert, end panels for closing the two ends of the U-insert, and a top panel that is adapted for closing the open top of the U-insert. The blank of the U- insert is preferably rectangular, with the folding lines produced by means of creasing. The blank of the end and top panels is also rectangular, and the folding lines are produced by creasing here as well. Elements of the inner frame are dimensioned such that they can be fitted into the outer frame.

According to a preferred embodiment the side panels of the U-insert comprise flaps foldable along folding lines parallel with the edges of the side panels perpendicular to the pallet. It is also a preferred embodiment where the end panels comprise flaps foldable along folding lines parallel with the edges of the side panels perpendicular to the pallet. With the help of the foldable flaps disposed on the U-insert and the end panels size differences that are the effect of manufacturing tolerance can be handled easily.

The multiple-piece inner frame, which has a rectangular cross-sectional shape, is inserted with a clearance into the outer frame secured to the pallet. By "insertion with a clearance" it is meant that the shape of the assembled inner frame corresponds to the shape of the outer frame, and the inner frame can be inserted into the outer frame in such a way that a small gap remains between the outer wall of the inner frame and the inner wall of the outer frame. The size of the gap or clearance is chosen such that the edge protection elements can be easily slid between the parallel edges (being perpendicular to the pallet) of the two concentrically placed frames, in such a way that there is substantially no gap remaining between the elements and the frame walls. After the edge protection elements have been inserted, the container, having an outer and an inner wall, forms a rigid structural element that has extremely high stability. The thus produced container resists not only higher-than- conventional compression stress but withstands high transverse and shear stress as well.

According to a preferred embodiment of the invention, the edge protection elements are made of paper. However, the edge protection elements can of course be made of other material. The edge protection element has an L-shaped cross section, where the length of the two stems of the L can be chosen arbitrarily. In a particular case the stems can have equal length. The height of the edge protection element is 1 cm greater than the height of the outer frame.

According to a further preferred embodiment of the invention, the top panel of the inner frame comprises flaps foldable along folding lines. Similarly to what has been described above, the folding lines are produced by creasing. The flaps of the top panel can be introduced into the gap between the outer and inner frames of the container. This configuration may further enhance the stability of the container. The length of the flaps connected to the top panel is smaller than the length of the corresponding side edges, preferably by an amount corresponding to the length of the edge protection element. Thus it can be achieved that, when the top panel is placed on the container with the flaps being introduced between the outer and the inner frames, the top sheet covers the entire top surface of the container, including the top of the inserted edge protection elements.

The outer frame, the inner frame, and the lid are equally made of corrugated paper.

A preferred embodiment of the invention is explained in detail with reference to the attached drawings, where

Fig. 1 is the axonometric view of the inventive double-wall container with the outer frame partially unfolded,

Fig. 2 is the axonometric view of the inventive double- wall container with the outer frame fully unfolded and the U-insert partially inserted,

Fig. 3 shows the axonometric view of the inventive double- wall container with the U-insert fully inserted and the end panels partially inserted,

Fig. 4 shows the axonometric view of the inventive double-wall container, with the edge protection elements half-inserted,

Fig. 5 is the axonometric view of the inventive double-wall container, with the top panel partially mounted,

Fig. 6 is shows the axonometric view of the inventive double-wall container in its fully erected state, with the lid placed on the top,

Fig. 7 shows the blank of the outer frame of the inventive double- wall container, Fig. 8 is the blank of the U-insert, Fig. 9 shows the blank of the end panel, Fig. 10 shows the blank of the top panel, and Fig. 11 shows the blank of the lid.

Fig. 1 shows the axonometric view of the inventive double-wall container with the outer frame partially unfolded. The outer frame 1 is attached to the pallet 2. The open-top and open-bottom body of the outer frame 1 has a rectangular base, is conjoined from two portions, and is glued to the pallet 2 with Palma Tex adhesive. Further details of the configuration of the outer frame 1 are explained in relation to Fig. 7. The outer frame 1 has two first side panels 24 and two second side panels 25 that are connected to one another along folding lines 26. The folding lines 26 are produced by creasing and function as- a hinged joint between the panels. Collapsing and erecting the container is facilitated by folding lines 33 disposed on the (longer) first side panels 24 of the outer frame 1 along which the panels can be folded upon one another. Additional folding lines 31 are disposed on the first side panels 24 and second side panels 25. These folding lines 31 are located parallel with the pallet 2 and are relatively close to the pallet. In the collapsed position of the container the side panels are folded inward along folding lines 31 in such a way that a rectangular storage space remains free between the pallet and the folded panels. The distance between folding lines 31 and the pallet 2 is chosen such that the remaining elements of the container can be fitted in the storage space.

Fig. 2 shows the axonometric view of the inventive double-wall with the outer frame 1 in its fully open, erected position. Elements are identified using the same reference numerals in all drawings. The U-insert 6 is halfway inserted into the outer frame 1. Details of the U- insert 6 will be described in relation to Fig. 8. The outer frame 1 and the U-insert 6 are dimensioned such that the insert fits loosely into the outer frame, that is, there is a lateral clearance between first and second side panels 24, 25 and side panels 8. The height of the side panels 8 of the U-insert is substantially the same as the height of the sides of the outer frame 1. When the U-insert 6 is fully inserted, the base panel 7 thereof is seated on the pallet 2. The drawings show only a schematic representation of the container and its constituent parts, without indicating wall thicknesses. For the exact dimensioning of the elements, however, wall thickness of the individual elements should be taken into account.

Fig. 3 is an axonometric view of the inventive double- wall container with the U-insert completely inserted and end panels 12 partially inserted. The end panels 12 correspond in size to the size of the second side panels 25 of the outer frame 1.

Fig. 4 shows the axonometric view of the inventive double-wall container, with the outer frame and the already inserted inner frame 3 that includes the U-insert 6 and end panels 12 constituting an open-top double- wall container. The edge protection elements 5 are in half- inserted position. The height of the edge protection elements 5 is the same as the height of the container. The cross-section of the edge protection elements 5 is L-shaped, with the horizontal and vertical stems of the L being equal in length. The thickness of the stems of the edge protection elements is chosen such that it substantially fills the gap between the outer frame 1 and inner frame 3.

Fig. 5 shows the axonometric view of the inventive double- wall container with the top panel 15 partially mounted. As it will be described in more detail referring to Fig. 10, the top panel 15 comprises flaps 18, 19 connected along folding lines 16, 17. For mounting the top panel 15 the flaps 18, 19 are folded downward at 90 degrees and are introduced into the gaps between the side panels of the outer frame 1 and the inner frame 3. The length of flaps 18, 19 is smaller than the length of the first side panel 24 and second side panel 25 by an amount corresponding to twice the "stem length" of the edge protection element 5.

Finally, Fig. 6 shows the axonometric view of the double- wall container according to the invention in its fully erected state. The container is capped with a lid 4. Products enclosed in the completed container are surrounded by a double wall from all sides, with edge protection elements 5 being disposed between the walls in such a way that the container has extremely high stability.

In Figs 7-11 the blanks of the individual elements are shown. Fig 7 shows the blank of one portion of the outer frame. The first side panel 24 and second side panel 25 are connected along a folding line 26. Gluing tabs 28, 27 are connected along folding lines 32 to the first side panel 24 and second side panel 25, respectively. Gluing tab 27 is separated from gluing tab 28 by means of a slit 34. The outer frame 1 cab be glued to the pallet 2 by means of the gluing tabs. The second side panel 25 also comprises a further gluing tab 29 connected thereto along a folding line 30 and being applied for conjoining the two portions of the outer frame. To facilitate the collapsing of the outer frame 1, folding lines 33 are disposed on the first side panel 24, with folding lines 31 being disposed on the first side panel 24 and second side panel 25 to facilitate the forming of the storage space.

Fig. 8 shows the blank of the U-insert. The insert comprises a base panel 7 and side panels 8 connected to the base panel 7 along folding lines. Flaps 11 are connected along folding lines 9 to the edges of the side panels 8. Slits 35, extending from the edge of base panel 7 to folding lines 9, are disposed in line with folding lines 10. The slits 35 enable the flaps 11 to be turned with respect to the base panel 7 and side panel 8. Fig. 9 shows the blank of end panel 12. Flaps 13 are connected along folding lines 14 to the end panel 12. The role of the flaps 11, 13 is to allow the ends of the side panels 8 and end panels 12 to be moved more flexibly and therefore to facilitate the insertion of the edge protection elements 5.

Fig. 10 shows the blank of the top panel 15. Flaps 18, 19 are connected along folding lines 16, 17 to the top panel. Fig. 11 shows the blank of lid 20. On the lid 20 folding lines 21, 22 are disposed, said folding lines 21, 22 being produced by means of creasing. The folding lines 21, 22 are located in such a configuration with respect to the edges of the lid that, after the edges have been folded downward, the lid fits against the outer frame 1 of the container, or in other words the rim of the lid 20 covers the edges of the sides of the outer frame 1.

The outer frame 1 and inner frame 3 of the container are made of different materials. Measurements have indicated that the stability and load capacity of the container are not affected by manufacturing the outer frame from lower-quality material. Specific parameters of an actual manufactured container are shown in Table 1. Dimensions are specified in mm. Abbreviations in the "Quality" and "Flute" columns stand for the following: KL kraftliner WL fluting from recycled paper HZ semichemical fluting

C parameter related to flute size

BC parameter related to flute size

Table 1

Relevant parameters of the materials appearing in Table 1 are shown in Table 2, where ECT stands for Edge Crush Test.

Table 2

Characteristics of the edge protection element: Material Brown kraft

Compression strength 620 kg/m

Strapping strength 350 kg/m

The advantage of the inventive double- wall container over known solutions is that it provides for increased-safety storage and shipping of the products contained therein. List of references

outer frame 19 flap pallet 20 lid inner frame 21 folding line lid 22 ^• folding line edge protection element 23 slit

U-insert 24 first side panel base panel 25 second side panel side panel 26 folding line folding line 27 gluing tab folding line 28 gluing tab flap 29 gluing tab end panel 30 folding line flap 31 folding line folding line 32 folding line top panel 33 folding line folding line 34 slit folding line 35 slit flap

Claims

1. Double- wall container for storing and shipping products, comprising a collapsible, open- top outer frame (1) attached to a pallet (2), an inner frame (3) assembled from parts and inserted with a clearance into the outer frame (1), and a lid (4) covering both the inner and the outer frames, where the section of the outer frame (1) arid of the inner frame (3) taken along a plane parallel with the pallet has a rectangular shape, and where the outer frame (1), the inner frame (3), and the lid (4) are made of corrugated paper, characterised by that

- the inner frame (3) is assembled from an U-insert (6), end panels (12), and a top panel (15),

- the base panel (7) of the U-insert is seated on the pallet (2), with the side panels (8) of the U-insert, the end panels (12), and the top panel (15), being set parallel with the first side panel (24) of the outer frame, the second side panel (25) of the outer frame, and the base panel (7) of the U-insert, respectively,

- edge protection elements (5) are slid into the clearance space between the edges of the outer frame (1) and the inner frame (3) perpendicular to the pallet (2).

2. The container according to Claim 1, characterised by that the outer frame (1) is assembled from two portions, with both, portions having a first side panel (24) corresponding in length to the length of the container and a second side panel (25) corresponding in length to the width of the container, the two portions being connected to each other along a folding line (26), with gluing tabs (27, 28, 29) foldable along folding lines (30, 32) being connected to the first side panel (24) and/or to the second side panel (25).

3. The container according to Claims 1 or 2, characterised by that folding lines (33) are disposed on the first side panel (24) to facilitate the collapsing of the outer frame (1).

4. The container according to any one of the previous Claims, characterised by that folding lines (31) are disposed parallel with the pallet (2) on the first side panel (24) and the second side panel (25) to facilitate the forming of a storage space in the outer frame (1).

5. The container according to any one of the previous Claims, characterised by that in the collapsed state of the outer frame (1) the elements making up the inner frame (3) are located in the storage space of the outer frame (1), and the collapsed outer frame (1) is covered by the lid (4).

6. The container according to any one of the previous Claims, characterised by that the side panels (8) of the U-insert comprise flaps (11) foldable along folding lines (9) parallel with the edges of the side panels (8) perpendicular to the pallet (2).

7. The container according to any one of the previous Claims, characterised by that the end panels (12) comprise flaps (13) foldable along folding lines (9) parallel with the edges of the end panels (12) perpendicular to the pallet (2).

8. The container according to any one of the previous Claims, characterised by that the top panel (15) comprises flaps (18, 19) foldable along folding lines (16, 17) and insertable between the outer frame (1) and the inner frame (3).

9. The container according to any one of the previous Claims, characterised by that the edge protection elements (5) are made of paper, have an L-shaped cross-section, and their height corresponds to the height of the outer frame (1).

10. The container according to any one of the previous Claims, characterised by that the outer frame (1) and the inner frame (3) are made of different materials.