WO2013004248A1

WO2013004248A1 - Support tray for a stack of containers

Info

Publication number: WO2013004248A1
Application number: PCT/DK2012/050253
Authority: WO
Inventors: Lars Krogh
Original assignee: Ikadan Plast A/S
Priority date: 2011-07-04
Filing date: 2012-07-04
Publication date: 2013-01-10

Abstract

A support tray (13) for a stack of containers, where the support tray ( 13) at its upper side has a plateau (14) as an upper, plane termination of the support tray (13) and on its underside has a plurality of identical, downwardly-facing concavities (15) with downwardly-facing support surfaces (18). The support tray (13) has a cross-section constituted by consecutively repeated units, each unit comprising one of the concavities (15) and a connecting member (19) to the next one of the concavities (15). The support tray (13) is shaped in a thin plastic material with a wall thickness less than 3 mm and the plateau (14) is in the form of a grid (20) having masks (21), where each mask (21) has an open area in a plane of the plateau (14) and the connecting members (19) and the support surfaces (18) are placed vertically offset relative to the open area of the masks (21). The masks (21) are formed substantially by straight profiles (22) to which there are connected stiffeners (23) comprising a stiffener frame (25) that extends from the straight profiles (22) and extends in the same plane as the grid (20), the stiffener frame (25) enclosing a surface area that is less than a quarter of the area of the mask (21). Each stiffener (23) has a downward-bending hollow (24) surrounded by and extending from the stiffener frame (25).

Description

SUPPORT TRAY FOR A STACK OF CONTAINERS

Field of the Invention

The present invention relates to a stack of containers in several layers one above the other. The containers have a flat bottom with a rectangular or square base and four vertical sides, wherein the container is closed at the top by a folding. The folding has a vertically upright centre joint and two inclined surfaces connecting the centre joint and two opposite of the vertical sides. The layers of a plurality of such containers are separated by support trays, wherein such a support tray as its upper side has a plateau as an upper, plane termination of the support tray, and on which plateau are provided an upper layer of containers. On its underside, the support tray has a plurality of identical, downwardly-facing concavities that receive the vertical centre joints and at least a portion of the inclined surfaces of the containers in a lower layer. The support tray as part of the concavities has downwardly-facing support surfaces, which rest on the inclined surfaces which support the tray. Further, the container has a cross section which is constituted by consecutively repeated units, each unit comprising one of the concavities and a connecting member to the next one of the concavities. The invention also concerns such a support tray and a stack of such support trays. Background of the Invention

Juice, milk and yoghurt are typically transported in containers of cardboard wherein the container has a flat bottom with a rectangular or square base and four vertical sides which are closed at the top by a fold. The fold has a vertically upright centre joint and two inclined surfaces connecting the centre joint with two opposite vertical sides. Such type of containers is typically called a ridge roof type container and disclosed in U.S. 4,811,849 of AB Tetrapak.

For transportation and storage, stacked layer of such containers are assembled on pallets. As the containers have a centre joint, which makes stacking difficult; it is com- mon to provide the pallets of such containers with a insertion tray of foam polymer. Such a tray is shown in FIG. la and lb. The insertion tray 1 has a flat top surface 2 and an underside 3 which comprises a plurality of concavities 4 that are substantially V-shaped. FIG. 2 illustrates the functionality of the substantially downwardly facing V-shaped concavity. The container 5 has a rectangular, rather square, base of the four vertical sides 6, which are closed at the top by a folding 7 comprising a centre joint 8 and two inclined surfaces 9 connecting the centre joint 8 and two opposite 6A, 6B of the verti- cal sides 6. The approximate V-shaped concavity 4, the support surfaces 10 which rests on the inclined surfaces 9 of the container 5.

Such insertion trays have the disadvantage that they take up much space during storage because the height is quite considerable, which is illustrated in FIG. 3. It would therefore be desirable to find a way in which such containers can be stacked without these insertion trays.

Furthermore, the known insertion trays are sensitive to influence by pressure from the upper edge of the centre fold, which is relatively sharp. The foam polymer material can be cut partly through and is then easily broken by a break area in the form of a notch or indentation, which is established by action of the sharp edge against the insertion tray. This has given rise to palletized stack overturning. In order to solve this problem, one has been previously used insertion trays with even greater thickness to counteract the cutting / breaking. This, however, yields an even greater need for the storage and contributes to increasing the height of a stack, so that there may be fewer layers on a pallet, which is subject to a given height.

For transportation and storage, layers of such ridge roof type, not only polymer foam insertion trays are known but also insertion trays made of cardboard or made of poly- mer grids.

Such grids are disclosed in International patent application WO89/08053 describing a tray for resting upon a stack of ridge roof type containers. The underside of the tray comprises elongated slots for taking up the upstanding flanges of the containers and comprises formations that extend away from the slots to form sloping support sections to rest upon the upper side of the containers. When such trays are not in use, and these trays are stacked without containers, they take up relatively much space, because the height of the trays is relatively large due to the high side walls of the trays. This is a severe disadvantage, because storage of such trays would require relatively large store rooms.

A grid structured top protector is disclosed in US patent No. 3384229, and another intermediate tray for ridge roof containers is disclosed in European patent application EP1623934. Stacking of these top protectors takes up less space that the tray of WO98/080053 due to a smaller height.

US patent No. 3384229 also discloses a polymer foam top protector. Generally, poly- mer foam support trays are known in the art. However, foam trays are sensitive to pressure influence from the upstanding flange from the containers, which is relatively sharp. Thus, the foam polymer material is at risk to be cut partly by the upstanding flange and then easily break. In order to minimize risk for breakage of the foam trays, the thickness of the trays has been increased in some cases, leading to an even greater need for storage room when the trays are stacked while not in use; the larger height also has the disadvantage of fewer layers on a pallet, as the total allowable height of a pallet is limited.

An improvement with respect to stacking under storage of support trays for beverages in general is disclosed in US patent No. 5230601, where the lower part of the tray is taken up by the upper part of an underlying tray such that only about one third of the total height of the tray contributes to the height of the stack. However, there is still a desire for improvement in the art, especially for decreasing the height of stacked container trays during storage.

A tray for made in a relatively thin material is disclosed in European Patent application EP2017189. Stacking of such trays takes up relatively small space. The tray is plate-like, and relatively large amount of plate material is used for the plate like appearance, which is an advantage for stability but relatively high costs involved, which is not optimal. Also, the tray rest on six containers at once and gets less stable if the tray is not supported by full groups of six containers. Other trays are disclosed in International patent applications W091/06487, W099/15428, WO0058173, and WO2010/055204; US patent No. 5230610 and 5038961; European patent application EP1466837; German Utility models DE20314879U1 and DE202007006183U1; German laid open documents DE19808013 and DE102005029304; South African patent document ZA9810175; Swedish patents SE525568 and SE504281; and Spanish patent application ES2168202.

Objective of the Invention

It is an objective of the invention to provide an improved method for forming stacking of such containers. Especially, it is the objective of to provide a support tray that does not require much space during storage of a number of such support trays. Further, the support tray should require relatively little material in production but still has a high degree of mechanical stability.

Description of the Invention

This object is achieved by a support tray as explained in the following, which relates to a stack of such support trays and stack of containers in several layers one above the other in which such a container has a flat bottom with a rectangular or square base and four vertical sides which extend upwards from the base. The container is closed at the top by a fold, wherein the fold has a vertical upright centre joint, and two inclined surfaces which connect the centre joint and two opposite of the vertical sides. The support tray is designed for separation of layers of a plurality of such containers, for example, stacked on a pallet.

The support tray is explained in relation to its proper orientation in use, where the term "upper surface" of the tray is used for the surface that is used for supporting containers when applied between stacks of layers of ridge roof type containers. This terminology has been used due to its logic in relation to the normal use of the support trays, although the tray may be oriented differently during storage or transport when not used as an intermediate tray in a stack of containers. The support trays, on their upper side have a plateau, configured for supporting an upper layer of containers. Such a plateau forms an upper, flat termination of the support tray; that is, no parts of the support tray protrude above this plateau. For example, the support tray is free from any upstanding frame or elevated edge around the pla- teau, in contrast to the prior art, for example as disclosed in WO89/08053. Although, an optionally elevated edge at the rim of the tray may be used which prevents the containers from sliding off of the support tray, this is normally not preferred in order to assure proper and tight stackability for the support tray.

The support tray has on its underside a plurality of identical, downwardly facing concavities, for example, shaped approximately like an inverted V or U, which are configured to take up the vertical joints and at least a portion of the inclined surfaces of the containers in a lower layer. The support tray has as part of concavities downwards-facing support surfaces that rest on the inclined surfaces of the container.

The support tray is shaped as a grid having masks and being made in a thin plastic material with a cross-section consisting of consecutively repeating units, each unit comprising a downwards facing concavity and a connecting member to the next concavity. For example, the concavity is substantially shaped like an inverted V or inverted U. Advantageously, the repetition distance is equal to the dimension of a container. It should be pointed out that this cross section is outside the plane of the plateau but need not be strictly normal to the plane of the plateau, as it may also be inclined relatively to the normal. By the term "thin plastic material" is meant a plastic material that is thinner than 3 mm, for example thinner than 2 mm. This allows a close and compact stacking as compared to the prior art foam support trays or top protectors. Advantageously, the material can be a thermoplastic material, which can be cast, or a solid polymeric foam material. A thermoplastic polymer material has the advantage that it can be reused in a recycling process. For the convenient stacking, the support tray has on its upper side a plateau in the form of a grid with masks, through which the concavities of other, likewise trays may extend during stacking of a plurality of identical support trays. It is advantageous that both the connecting members and the support surfaces are provided vertically offset relative to an open area of the masks. For example, the connecting members and the support surfaces are provided centred relative to the masks, although this is not strictly necessary. When a support tray is viewed from above perpendicularly onto the upper side, the connecting members will be visible through the masks, for example, centred in the masks, but at a lower level than the grid.

In order to place and support the containers safely on the plateau, the grid is advantageously formed of profiles that are flat, for example having a thickness of less than 3 mm normal to the plane of the plateau and a width of 2 to 4 cm in the plane of the plateau.

In some embodiments, the profiles of the grid comprise first profiles parallel in a first direction and second profiles parallel in a second direction perpendicular to the first direction. For example, the grid is formed with substantially rectangular or square masks. Optionally, each of the masks is substantially formed by four profiles with right angles between the profiles. The straight profiles define the area of the mask.

For a stack of containers, it may be an advantage if the downwards facing support surfaces of the concavity are inclined correspondingly to the inclined surfaces such that they are in contact with the inclined surfaces not only in a point or line but are in contact by an extended contact area

This also ensures avoidance of contact with the sharp outermost edge of the centre joint. Thereby, risk is avoided of creation of a concentrated pressure on a small part of the insertion tray. Thus there will not be a risk that the insertion tray breaks as there are not created breakage areas. As an alternative or additional measure to support the tray, optionally, there are provided further downwards facing support surfaces in the upper part of the concavity in order to support on top of the centre joint. However, in order not to risk that the centre joint is bent to one side because of this load, such additional support surfaces are typi- cally avoided.

In principle, a support tray according to the above can be produced in a single piece of pressed or moulded plate without holes. However, in order to minimize weight and avoid superfluous material, the entire support tray is preferably formed of a three- dimensional network of thin profiles. The following embodiments have been found useful in this regard.

In some embodiment, each of the concavities is substantially formed by inclined ribs that are connected with an upper concavity part; for example, the concavity part is thereby provided mainly as an inverted V or U with a flat base. For example, the concavity member constitutes a flat upper end of the inverted V or U shape of the concavities, and the inclined ribs constitute the legs of the inverted V or U. It may then be advantageous that these upper concavity parts of all the concavities are interconnected in the form of flat profiles, which form the grid with the masks.

For example, the ribs advantageously extend from the corners of each mask to a set of support surfaces, for example, a set of two support surfaces which are interconnected by the above-mentioned connecting member. In order to provide increased stability, the ribs of further embodiments are provided as angle profiles with a bent along the length of the ribs.

In order to save material, as part of the three-dimensional network of profiles, each two neighbouring inclined ribs from each mask in combination with an adjacent sup- port surfaces and an adjacent upper concavity member, such as first or second profile, may define a plane and are surrounding an opening in this plane. It is further advantageous if the grid masks are substantially formed by profiles that are straight and there are connected stiffeners that counteracts bending of the profiles and thereby increase the stability of the support tray despite use of a thin polymer material; thin in this case advantageously means that the profiles have a material thick- ness of less than 3 mm or less than 2 mm. For example, such stiffeners, provided like terraces, have a stiffener frame that surrounds a downward-bending hollow. The stiffener frame may then extend from the straight profiles in the same plane as the grid. The hollows are tapering in a downwards direction in order for the upper region of the downwards bending hollow to take up the downwards bent part of a second hollow belonging to a second support tray when support trays are stacked. In other words, when a number of such support trays are stacked upon each other in close configuration, the downwards bent hollows of the stiffeners would extend through the stiffener frames of the underlying support tray and into hollows of the underlying, adjacent support tray.

For example, each of the four straight profiles in each mask may be provided with such a stiffener. The stiffener frame encloses advantageously an area which is less than a quarter of the mask, so as to leave an open area of the mask, which is important when the trays are stacked, as the concavities and the masks can be formed co- operating in such a way such that the concavities from one tray extend through the mask of the underlying support tray, and preferably extend through several, for example at least 5 or at least 10, underlying support trays. The latter leads to a significant space saving in storage and transportation of the support trays before or after use for container stacks. The area of the mask is defined by the straight profiles, for example defined as a square or rectangular are, in which the stiffeners are provided.

For example, the support trays are designed so that the concavities from an upper support tray is passed through the masks of an underlying supporting tray, until the support surfaces from the upper tray rests directly on top of the upper surface of the mate- rial of the support surfaces of the underlying support tray. Due to the thin material, a stack of 5, 6, 10 or 11, or even more trays have an overall height less than twice the height of one support tray. Aspects

In the following, the invention is defined as a number of interrelated aspects, which is one but not the only possible combination of options. Aspect 1 : A stack of containers in several layers one above the other, wherein the container has a flat bottom with a rectangular or square base and four vertical walls, wherein the container is closed at the top by a folding, the folding having a vertically upright centre joint and two inclined surfaces connecting the centre joint with two opposite vertical walls;

wherein the layers of a plurality of such containers are separated by support trays; wherein each support tray as its upper side has a plateau as an upper, plane termination of the support tray, and on which plateau are provided an upper layer of containers, and on its underside has a plurality of identical, downwardly-facing concavities that receive the vertical centre joints and at least a portion of the inclined surfaces of the containers in a lower layer; wherein the support tray, as part of the concavities has downwardly-facing support surfaces, which supports the inclined surfaces, which support the tray has a cross section which is constituted by consecutively repeated units, each unit comprising one of the concavities and a connecting member to the next one of the concavities; wherein the plateau is in the form of a grid having masks; wherein optionally, the support tray is shaped in a thin plastic material with a wall thickness of less than 3 mm.

Aspect 2: A support tray for a stack of containers as in aspect 1, wherein the support tray in proper orientation, at its upper side has a plateau as an upper, plane termination of the support tray and on its underside has a plurality of identical, downwardly-facing concavities with downwardly-facing support surfaces for being supported on the containers; wherein the support tray has a cross section that is constituted by consecutively repeated units, each unit comprising one of the concavities and a connecting member to the next one of the concavities; wherein the plateau is in the form of a grid having masks; wherein, optionally, the support tray is shaped in a thin plastic material with a wall thickness of less than 3 mm. Aspect 3: A support tray according to aspect 2, wherein the connecting members and the support surfaces are provided vertically offset relative to an open area of the masks. Aspect 4: A support tray according to aspect 3, wherein the connecting members and the support surfaces are provided centred with respect to the masks.

Aspect 5: A support tray according to aspect 3 or 4, wherein each of the concavities are formed approximately as an inverted V substantially formed by inclined ribs and an upper concavity member that connects the inclined ribs, where the upper concavity members of all the concavities are interconnected in the form of flat profiles forming the grid.

Aspect 6: A support tray according to aspect 5, wherein the flat profiles comprise first profiles parallel in a first direction and second profiles parallel in a second direction perpendicular to the first direction.

Aspect 7: A support tray according to aspect 5 or 6, wherein the inclined ribs extend from the corners of the grid masks to a set of support surfaces.

Aspect 8: A support tray according to aspect 7, wherein the ribs from the corners are angle profiles.

Aspect 9: A support tray according to any one of aspects 5-8, wherein the grid masks are substantially formed by straight profiles to which there are connected stiffeners in the form of terraces with a terrace frame that extends from the straight profiles in the same plane as the grid, wherein the terrace frame encloses a surface area that is less than a quarter of the mask area, and wherein the terraces comprise downwardly bending hollows surrounded by stiffener frame.

Aspect 10: A stack of trays of identical support trays according to any one of aspects 2-9, wherein the concavities from an upper support tray extend through the masks of a plurality of underlying number of support trays. Description of the Drawing

The invention will be explained in more detail with reference to the drawing.

FIG. 1 shows a a) the upper side and b) the underside of an insertion tray according to the prior art;

FIG. 2 shows a container in contact with the underside of an insertion tray according to the prior art;

FIG. 3 shows a stack of three insertion trays according to the prior art;

FIG. 4 is a photograph of the two layers of a stack of containers having a support tray according to the invention between the two layers shown;

FIG. 5a is a drawing of a support tray according to the invention, and FIG. 5b is an enlarged section therefrom;

FIG. 6 shows a stack of two support trays according to the invention on top of three insertion trays according to prior art; and

FIG. 7 shows a further embodiment of a support tray, where a) is a view normal to the plateau, b) is a perspective side view, and c) is a perspective view from below.

Detailed Description of the Invention

FIG. 1, FIG. 2 and FIGS. 3 was described in the introduction in connection with the description of the prior art.

FIG. 4 shows a part of a stack of containers 5 in which the layers 11, 12 are separated by a support tray 13 according to the invention. The support tray 13 is shown in FIG. 5a and in greater detail in FIG. 5b. The support tray 13 has on its upper part, a plateau 14 substantially formed by straight flat profiles 22 on which there is an upper layer 12 of containers 5. On its underside, the support tray 13 has a number of identical, concave downwardly oriented concavities 15 which are shaped approximately as an inverted V with inclined ribs 16 as leg of the inverted V and with an upper concavity part 17 connecting the ribs 16. The concavity 15 takes up the vertical joints 8 and at least a portion of the inclined surfaces 9 of the containers 5 in a lower layer 11. The support tray 13 has as part of the concavities 15 downwardly-facing support surfaces 18 which rest on the inclined surfaces 9, and a connecting member 19 which connects the support surfaces 18. In the illustrated embodiment, the connecting member 19 is very narrow so that the support surfaces 18 form an almost sharp edge, but the connecting member 19 may be designed differently and wider so as to form a larger distance between the support surfaces 18.

The inclined ribs 16 are connected to an upper concavity part 17. These upper concavity parts 17 from all the concavities 15 are interconnected and form a support surface in the form of a grid 20 with first flat profiles 22, which are parallel in a first direction, and the second flat profiles, which are parallel in the other direction perpendicular to the first direction to form approximately square masks 21. This grid 20 forms the supporting surface for the upper layer 12. Each of the masks 21 is substantially formed by four equal profiles 22 at right angles.

To the straight profiles 22 there are connected stiffeners 23, much like in the form of terraces, with a stiffener frame 25 that extends from the straight profiles 22 in the same plane as the grid 20. The stiffener frame 25 surrounds a surface area that is smaller than a quarter of the mask area. The stiffeners 23 have downwardly bending hollows 24 surrounded by the terrace frame 25. These hollows 24 counteract bending of the profiles 22, which gives the tray a high degree of rigidity, in spite of the thin material that it is made of. When a number of support trays are stacked, the hollows 24 of an upper tray in the stack of trays extend through the stiffener frame 25 of the underlying support tray and into the upper region of the downwardly bending hollow 24 of the underlying support tray. This ensures a tight stacking.

The ribs 16, 16 'extend from the corners 21 of the mask to the support surfaces 18. The support surfaces 18 are substantially centred in the mask but downwardly displaced relative to the plane of the grid 20. In order to provide increased stability, the ribs 16, which extend from the corners 29 of the mask 21, are shaped as angle profiles with a bending 28 along the length of the rib 16. FIG. 6 illustrates a stack of two support trays 13, 13 ', which are stacked. It is noted that they are stacked upside-down relatively to FIG. 4 and 5. As is clearly seen, the support trays 13, 13' are stacked very tightly so that the surfaces lie directly on top of each other. As the material is very thin, it is very space-saving in relation to the insertion trays 1, 1 ', 1" of the prior art, which are also shown in FIG. 6.

The thickness of the material is typically less than 3 mm or 2 mm. The straight profiles around the mask are typically flat, having a thickness of less than 3 mm or 2 mm and with a width of between 2 and 4 cm.

FIG. 7 illustrates an alternative embodiment, where a) is a view normal to the plateau, b) is a perspective side view, and c) is a perspective view from below. The tray 13 comprises straight profiles 22 that have perforations 26, 26' along their longitudinal direction. The grid 20 is provided with perforations 26, 26' as breaking lines in order to easily modify the size of the tray 13 by breaking the straight profiles 22 along their longitudinal direction.

Claims

PATENT CLAIMS

1. A support tray (13) for a stack of containers,

- wherein each container (5) has a flat bottom with a rectangular or square base and four vertical sides (6), wherein the container is closed at the top by a folding, the folding having a vertically upright centre joint (8) and two inclined surfaces (9) connecting the centre joint (8) with two opposite vertical sides (6A, 6B);

- wherein the support tray (13) in proper orientation at its upper side has a plateau (14) as an upper, plane termination of the support tray (13) and on its underside has a plu- rality of identical, downwardly-facing concavities (15) with downwardly-facing support surfaces (18) for being supported on the inclined surfaces (9) of the containers (5);

wherein the support tray (13) has a cross section that is constituted by consecutively repeated units, each unit comprising one of the concavities (15) and a connecting member (19) to the next one of the concavities (15);

wherein the support tray (13) is shaped in a thin plastic material with a wall thickness of less than 3 mm;

wherein the plateau (14) is in the form of a grid (20) having masks (21), wherein each mask (21) has an open area in a plane of the plateau (14) and the connecting members (19) and the support surfaces (18) are provided vertically offset relative to the open area of the masks (21);

wherein the grid masks (21) are formed substantially by straight profiles (22) to which there are connected stiffeners (23) comprising a stiffener frame (25) that extends from the straight profiles (22) and extends in the same plane as the grid (20), the stiffener frame (25) enclosing a surface area that is less than a quarter of the area of the mask (21), and wherein the stiffeners (23) have downwards-bending hollow (24) surrounded by and extending from the stiffener frame (25).

2. A support tray according to claim 1, wherein the hollows (24) are tapering in a downwards direction in order for the upper region of the downwards bending hollow to accommodate the downwards bent part of a second hollow belonging to a second support tray (13') when in stacking conditions.

3. A support tray according to claim 1 or 2, wherein each of the concavities (15) are formed approximately as an inverted V, substantially formed by inclined ribs (16) and an upper concavity part (17) that connects the inclined ribs (16), where the upper concavity parts (17) of all the concavities (15) are interconnected in the form of flat, straight profiles (22) forming the grid (20).

4. A support tray according to claim 3, wherein the straight profiles (22) comprise first profiles parallel in a first direction and second profiles parallel in a second direction perpendicular to the first direction.

5. A support tray according to claim 3 or 4, wherein the inclined ribs (16) extend from the corners (29) of the grid masks (21) to a set of support surfaces (19).

6. A support tray according to claim 5, wherein the ribs (16) from the corners (29) are angle profiles that are bent (28) along a longitudinal direction of the rib (16).

7. A support tray according to any one of the claims 3-6, wherein each two neighbouring inclined ribs (16) from each mask (21) in combination with an adjacent support surfaces (19) and an adjacent first or second profile (22) define a plane and surround an opening (27) in this plane.

8. A support tray according to any preceding claim, wherein no parts of the support tray extend above this plateau (14).

9. A support tray according to any preceding claim, wherein the connecting members (19) and the support surfaces (18) are provided centred with respect to the masks (21).

10. A support tray according to any one of the preceding claims, wherein the masks (21) are identical and consecutively repeated with a repetition distance equal to the dimension of a container (5).

11. A support tray according to any preceding claims, wherein the grid (20) is defined substantially by straight profiles (22), wherein the straight profiles (22) are provided with perforations (26) ) along a longitudinal direction of the straight profiles for facilitating breakage of the straight profiles (22) along the longitudinal direction.

12. A support tray (13) according to any one of the preceding claims in combination with at least five further, identical support trays (13'), wherein the support tray has a height measured perpendicular to the plane of the plateau (14); wherein the support tray (13) and the additional five identical support trays (13') form a tray stack of six support trays (13, 13') in abutting configuration; wherein the support surfaces (19) from the support tray (13) extends through the masks (21) of all five further support trays (13') and rest directly on top of the support surfaces of the underlying support trays.

13. A support tray in combination with at least five further identical support trays (1 ') according to claim 11, wherein the overall height of the tray stack is less than twice the height of one support tray.

14. A support tray according to any preceding claim as part of a stack of containers in multiple layers one on top of the other, wherein two layers of such containers are separated by the support tray.

15. Use of a support tray according to any one of the claims 1-13 for separating layers in a stack of containers of the ridge roof type.