AU2020100730A4 - Stackable produce container and retainer therefore - Google Patents

Abstract

A plastic container for holding fresh produce, the container having a height dimension for holding between one to five vertical layers of articles of fresh produce, the container being 5 configured to be stacked one on top of the other and each container comprises a first pair of opposing side walls, a second pair of opposing side walls and a floor, each side wall has a top edge and a bottom edge, wherein the floor comprises ventilation openings for allowing air to flow therethrough; wherein the ventilation openings are uniformly spaced. 10 Figure 5

Description

STACKABLE PRODUCE CONTAINER AND RETAINER THEREFORE

TECHNICAL FIELD

The present disclosure relates to a produce container and a retainer therefore.

DEFINITION

In the present specification and claims the term “comprising shall be understood to have a broad meaning similar to the term “including” and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer 10 or step or group of integers or steps. This definition also applies to variations on the term “comprising” such as “comprise” and “comprises”.

BACKGROUND

Plastic bins known as pallet bins are used for transport of bulk produce such as fruit and vegetables. They are known as pallet bins and they have the same footprint as a standard pallet for moving with a forklift. The pallet bins are configured for stacking on top of one another such that the floor design includes forklift recesses. The bins may hold up to 500kg of produce.

It will be appreciated that pallet bins are not suitable for transport of fruit or vegetables that are subject to compression damage.

The types of produce that are subject to compression damage include without being limited to 25 fruits such as mangos, paw paws and tomatoes. Produce of this type is generally transported in stackable cardboard trays. Mangos in particular are transported in single layer cardboard trays. The base of the trays may be contoured and/or lined to resist compression damage.

The carboard trays are sized for manual handling and that may be used for retail display. For 30 bulk transport, trays are loaded onto a pallet in a layered stacked grid arrangement (a palletised load). A palletised load my comprise 10 to 12 layers of individual stacks of trays. The palletised loads may be moved by forklift trucks and loaded for transport which may be road, air fright or shipping.

It will be appreciated that such stacks of trays will be unstable when being moved and transported. This may be of particular importance for relatively length sea voyages were load stability is important. One method of holding stacks together is to provide four corner posts

2020100730 08 May 2020 extending upwards from the pallet and then secure the load with horizontal straps about the posts. Pallets and trays may also be wrapped in plastic wrap. This method creates a significant amount of waste plastic.

SUMMARY

It would be desirable to provide an alternative container and method of transporting produce.

In one aspect, there is disclosed a retainer for use with at least two adjacent stacks of at least 10 two layers, and each container comprises a first pair of opposing side walls, a second pair of opposing side walls and a floor, each side wall has top edge, an upper side wall section a bottom edge and lower wall section;

at least one side wall comprises an open recess in the upper wall section or the lower wall section that is open to the bottom edge that has an upper inner surface and/or a top 15 recess in at least one side wall that is open to the top edge and having a base surface and a respective vertical dimension defined between the upper surface and the bottom edge of the crate or between the base of the recess and the top edge of the crate;

wherein the retainer comprises;

a lower part configured to receive the base surfaces of the top recess and at least part 20 of the upper wall section of adjacent containers so as to hold the adjacent containers together; and/or the lower part of the retainer is configured to receive top edges of adjacent containers and at least part of the upper wall section of adjacent containers so as to hold the adjacent containers together and;

a top part with a top surface having a linear dimension substantially consistent with the 25 vertical dimension such that in use, when the adjacent containers comprise a lower layer or a part thereof of containers in a stack, when the container is in a configuration having an upper recess, the bottom edge of an upper container bears on the top surface of a retainer and when the container is in a configuration having a lower recess, the top surface of the lower recess in the upper container bears on the top surface of the retainer.

The lower part of the retainer is suitably U shaped with spaced legs joined by a web.

Suitably the legs are configured to lie flush against the inner wall of the container. The legs may also have a low profile. This may reduce damage to the produce by minimising sharp 35 edges.

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The legs are suitably rectangular. The ratio of the width to the length of the legs may be between about 1:1 to about 1:3, preferably about 1:2.

In order to optimise retaining force against horizontal displacement of the container, the legs 5 maybe be configured to have a length no less than about % of the height of the wall, suitably about 1/3 to about ¹Z> the height of the wall.

The web suitably has a width configured to snugly accommodate the two walls of the adjacent held crates.

The retainer is suitably formed from an extruded thermoplastic, suitably a polyolefin. A polypropylene homopolymer (PPH) or a polypropylene copolymer (PPG) are preferred materials. PPH or PPC are light weight, have a low moisture absorption rate and high strength to weight ratio. Further such polymers have a low resilience (compared to rubbers) such that 15 the legs will resist deformation under a load. That is the retainers will retain their shape under a load so as to hold the containers in position.

Suitably there is no bias nor spring tension in the U shaped lower part.

In another embodiment, there is disclosed a retainer for holding adjacent plastic containers together, the retainer having a L) shaped section with spaced legs and a web, wherein there is no bias nor spring tension in the legs.

The retainer has an upper part with a top surface. The upper part may be any suitable 25 configuration that has a top surface and a length corresponding to the relevant vertical dimension.

Suitably the upper part is a T shaped section extending upwardly away from the web. There is an upstanding rectangular longitudinal member and a top rectangular support plate with a 30 top bearing surface.

The upstanding member and support plate suitably have the same longitudinal length as the web.

The containers with which the retainers are used have one or more side walls with a bottom recess, one more side walls with a top recess or a mixture thereof.

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Suitably, the container has an upper recess in each of opposing side walls. Suitably the container has an upper recess in each side wall. In this configuration the upper recesses may also be configured as handling recesses as known in the art. The handling recesses allow access to the underside of the upper most container in a stack for unloading.

When the container has upper recesses in the side walls, such the recess has a base surface, the upper part of the retainer is configured such that length of the upper part is the same as the vertical distance between the base surface and the top edge of the side wall. This means that when the retainer is in place, the top surface of the retainer is in line with the top of the 10 side walls of the crate. When a further container is stacked on top of the first container, part of the bottom edge of the further container will be supported by the top part of the retainer and the load will be transferred to the lower part. In this way, the retainer is held firmly in place by the weight of the crate(s) above.

When the container has lower recesses in the side walls, the upper part of the retainer is configured such that length of the upper part is the same as the vertical distance between the upper surface of the recess and the bottom edge of the side wall. This means that the top surface is in line with the bottom of the side walls of the container. This means that when a further container is stacked on top of the first container the upper part of the retainer will be 20 received within the recess and upper surface of the recess will bear on the upper part of the retainer and the load will be transferred to the lower part of the retainer. In this way, the retained is held firmly in place by the weight of the crate(s) above.

It may not be necessary for all crates in a layer or all layers to be retained together. It may 25 only be necessary for example the fourth and eight layers in a stack of 12 layers to be clipped together.

When the loaded pallets reach their destination, the retainers may be readily removed from the containers. In the embodiment where the upper part of the retainer is a T section, the top 30 plate may serve as a finger grip so as to more easily pull the retainers away from the containers.

In use, one or more bottom layers of containers may be placed on a pallet. The containers will be arranged so as to match the foot print of the pallet as is known in the art.

At predetermined layers, retainers will be placed on adjacent containers so as to hold them together.

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The loaded pallet will comprise a number of stacks of containers. An example is about 10 to 12 layers of 4 x 4 containers.

The retainers are able to hold respective stacks together such that all 16 stacks will behave as a common stack rather than “individual towers”.

The loaded pallets may be moved by forklift without or minimal tie down methods or plastic covering. This may reduce man hours (and cost). Still further, as the retainers are reusable 10 there is less waste of plastic packaging and ties.

As discussed above in relation to cardboard produce trays, different trays are used for different modes of transport. Stronger trays double walled cardboard trays are generally used to withstand longer shipping times. The use of double walls comprises the internal space.

Plastic containers made from a thermoplastic such as polypropylene may have the same or greater strength than a double walled carboard tray with a thickness the same as or less than a single walled carboard tray.

Further plastic trays are water resistant and therefore may be used for extended shipping times. Plastic containers are also lightweight such that the same containers may be used for airfreight, shipping and road transport.

The retainers may find particular application with containers as described in the applicant’s 25 AU2020900151 and AU2020900595, incorporated herein by reference. These containers have a particular application for use in Vapour Heat Treatment of produce for quarantine fruit fly infestation. However, it will be appreciated that this is by way of example only and no limitation is intended no implied.

Vapour heat treatment (HVT) fruit or vegetables to temperatures such that the internal temperature reaches above about 47°C for a predetermined period of time so as to kill any pests such as fruit flies.

Wooden crates and cardboard produce boxes as described in the background section above 35 that unsuitable for use in VHT treatment as they absorb moisture when subjected to the heat and humidity of the VHT treatment.

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It order to treat soft and easily damaged fruit such as mangos and paw paws, the fruit is manually unloaded from the cardboard trays or field bins and loaded into bulk pallet bins or large plastic tubs After treatment, the fruit is unloaded from the bulk bin, placed into new (sterile) cardboard trays and then covered with fruit fly resistant mesh in a quarantined area.

It is important that the fruit is not left in the bulk bins for any length of time post treatment so as to minimise compression damage. This is because, the fruit on the lowest layer that is in contact with the ventilated base of the bin is damaged by the by contact with the edges of the ventilation slots.

There are other practical problems associated with the use of bulk bins for VHT treatment. For some types of produce or produce that may be at a riper stage than usual, the propensity to damage may limit the number of layers of produce that may be stacked on top of one another in a bin. In some instances, there may be simply insufficient produce for treatment to fill all the bins.

The treatment process is carefully monitored to ensure the internal (pulp) temperature of all produce being treated reaches the required temperature for the required period of time. Probes are placed into the largest fruits at different heights and locations within the chamber. The treatment is continued until the sensor at the coldest location reaches the regulated temperature and held for the regulated minimum time. The “cold spots” or spots with the longest heat up time are determined during a certification procedure for each treatment chamber.

In practice this means that a significant amount of the fruit is held at a higher temperature for longer. This can adversely affect fruit quality. There may be up to about 20 to 30% loss of fruit after a VHT process.

It is therefore desirable to produce uniform airflow and efficient heating so that all fruit is heated to the same temperature at the same time. There are a number of variables that may affect 30 airflow within a treatment chamber, including air flow pattern such as vertical flow or horizontal flow through the chamber, lateral flow, design and arrangement of the plastic bins, relative sizes of fruit and the packing of the fruit into the plastic bins.

Another disadvantage where the filling of the bin is limited so as to avoid damage is that the 35 HVT treatment procedure can only treat half the maximum capacity of produce which is a commercial loss.

2020100730 08 May 2020

It is also impractical for a number of reasons to stock a range of different sized bins so as to accommodate different load sizes.

The present inventor has therefore proposed that by providing the plastic stackable produce 5 containers as described in AU2020900151 and AU2020900595 may make a substantial contribution to the working of an HVT procedure.

The contribution may include the reduction or avoidance of compression damage and/or loss of air flow through side vents.

The plastic container has a height dimension for holding between one to five vertical layers of articles of fresh produce, the container being configured to be stacked one on top of the other and each container comprises a first pair of opposing side walls, a second pair of opposing side walls and a floor, each side wall has a top edge and a bottom edge, wherein the floor 15 and/or side walls comprises ventilation openings for allowing air to flow therethrough; wherein the ventilation openings are uniformly distributed across the floor of the crate

By uniformly distributed means that the openings are configured such that the % open area is substantially constant across the floor.

An advantage of the uniform distribution means that there is a more uniform flow space. It also allows for optimisation of the air flow. This allows for maximisation of air flow space

The % open area of the floor and/or wall openings may be between about 60% to about 90%, 25 between about 70 to about 80%.

% open area refers to the total combined open area of the openings.

The plastic containers or crates have a height suitable for up to five layers of produce to be 30 placed therein. It will be appreciated that the height may vary depending upon the produce.

For example, mangoes, tomatoes, papayas, eggplants melons and the like are of different dimensions. A person skilled in the art would readily be able to calculate the required height for a specific produce.

The foot print dimensions of the crates are generally similar to those of transport boxes or trays as used for that produce in the respective industry. Such trays and boxes are dimensioned for stacking onto conventional transport pallets.

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In an embodiment where the floor of the crate comprises ventilation openings, the crate will be used for vertical air flow VHT treatment.

In an embodiment where the side walls of the crate comprise the ventilation openings, the crate will be used for horizontal air flow VHT treatment.

Suitably the ventilation openings are configured to minimise or avoid hard edges that may damage the produce.

The ventilation openings suitably have rounded edges, such as circular, ovoid, or rounded rectangle. This may avoid hard edges.

The ventilation openings may have a maximum major dimension (for example the length of a 15 rectangular opening or longer axis of an ovoid) of between about 2mm to about 25mm;

between about 5mm to about 20mm, between about 8mm to about 20mm, between about 10mm to about 18mm.

For shapes such as squares, it will be appreciated that the maximum direction is length of 20 each side wall and for circles, the dimension is the circumference.

In an embodiment, the openings are rounded rectangles having a length of between about 10mm to 20mm and a width of between about 4 to 10mm. In specific embodiments, the rounded rectangle may have dimensions of 20 x 3mm; 18mm x 4mm; 15mm x 5mm or 12mm 25 x 8mm.

It is also desirable to optimise the air flow through the ventilation openings so as to maximise contact of heated and humidified air with the produce as contained therein. Suitably the spacing between openings is about 1mm to about 5mm, suitably about 2mm to about 4mm.

Suitably, the spacing between openings is the same in both end to end and side to side directions.

The % open area of the floor and/or wall openings may be between about 60% to about 90%, between about 70 to about 80%.

The floor openings of the crate for use in a vertical air flow treatment as described herein may be compared with conventional types of fruit packing plastic crates that have a floor with

2020100730 08 May 2020 standard rectangular grid configuration with sharp or thin edges. This grid floor design is essentially concerned with minimising weight and material rather than protection of the contents. By way of example, some conventional grid may comprise rectangular openings with dimensions of between of about 50mm x 30mm with a land area between the openings 5 of about 1 mm to 5mm.

With vertical air flow VHT treatment it is desirable to minimise lateral air flow out of the crates.

This is an opposite requirement to that for refrigeration containers that operate with a horizontal flow of cold air from a refrigeration unit located at one end of the container. It is 10 therefore desirable that a produce crate for refrigerated storage has ventilation openings that optimise horizontal air flow.

The vertical air flow crate suitably has at least some openings in the side walls that allow for refrigerated air flow into the crate, without significantly adversely affecting air flow during a 15 VHT treatment process.

The openings in the side walls are suitably also configured so as to minimise damage or marking of the produce contained therein. Suitably the openings have the same or similar configuration as the ventilation holes in the floor.

The floor has a total open area for the ventilation openings. Each side wall has a total open area of ventilation openings. The total open area of the ventilation openings in the floor is suitable greater than the total area of the ventilation openings of the combined open area of the side walls by a factor of at least about 3, more suitably of at least about 4, at least between 25 about 6 to 8.

As discussed above, the crates generally have the same dimensions as conventional cardboard produce trays or boxes and are thus stacked in a grid on a pallet. For example 40cm x 50cm crates may be stacked in layers of 2 x 3 crates. When so stacked and placed 30 in a refrigeration container, the walls that are in line with the cold air flow will depend upon the orientation of the .pallet. In an embodiment, the present crate may therefore have a larger number of openings on one pair of opposed walls than the other. In an example, the end walls of a rectangular crate may have more openings than the side walls.

The crate is suitably made from a thermoplastics material that is readily able to be recycled. An example of such a material is virgin polypropylene or polyethylene. The crate may be granulated and added to a plastics masterbatch.

2020100730 08 May 2020

Suitably the crate is collapsible so as to minimise transport costs to the initial loading site.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a top perspective view of a container in the form of a crate as disclosed herein, Figure 2 is a bottom perspective view of the container as shown in Figure 5 Figure 3 is a schematic view of a stack of three crates.

Figure 4 is a detail from Figure 3;

Figure 5 is a perspective view of a clip as used to clip together the crates as shown in Figure 1;

Figure 6 is a top plan view of the clip as shown in Figure 5;

Figure 7 is a side view of the clip as shown in Figure 5 and

Figure 8 is and end view of the clip as shown in Figure 5.

DETAILED DESCRIPTION

Figures 1 and 2 show top and bottom perspective views of a produce container or crate 10 as disclosed herein. The container is formed from polypropylene.

The crate 10 has an open top and is rectangular with two side walls 12, 14, two end walls 16, 18 and a floor 20.

The crater 10 is intended for use for the transport and treatment of mangos. The container 10 25 is therefore sized similar to conventional cardboard mango trays. Suitably floor dimensions are inner 334mm x 402mm. The height may be about 100 to 200mm. In this way crates 10 may be stacked on top of each other ina3x2ora3x3 arrangement on a pallet for air freight or sea freight loading.

The bottom of the crate 10 has a surrounding lip 22 for fitting within the open top of the crate 10 below as is known in the art. The lip 22 is thicker of more pronounced at the corners.

The floor 20 has a plurality of vent openings 24 uniformly distributed across the floor 20. The openings 24 are rounded rectangles. Thus, there are no hard corners that may damage the 35 mango skin. The openings 24 are separated by a land section 25.

2020100730 08 May 2020

The floor vents 24 enable the crate 10 to be particularly suitable for use in a HVT chamber having a vertical airflow and in particular a bottom flow (that is flowing from the bottom to the top of a crate stack).

The openings 24 have a length of 12mm and a width of 8mm. The spacing between the openings is 1mm. The openings are provided in a uniform grid of 42 x 38 openings.

There are four sections 26 of the floor 20 that do not have any openings. These sections 26 are simply pads for engaging with suction pads of robotic arms during manufacturing as known 10 in the art.

It may be appreciated that the density of the openings 24 and width of the land 25 provides for minimal damage to mango skin. This may be compared to conventional crates that have larger openings with thin lands that provide a sharp that may easily damage a mango.

The side walls 12, 14 and end walls 16, 18 have recesses 30 to allow for manual stacking and unstacking of containers. On either side of the recesses 30 are two parallel longitudinal rows of further ventilation openings 32. At each corner of the crate 10, each wall has a vertical row of nine ventilation openings 34. The end walls 16,18 have a further lateral row 36 of ventilation 20 openings along the bottom edge.

The ventilation openings 34, 36 are also rounded rectangles and have the same dimensions as the openings in the floor. However, the openings 32, 34 are more widely spaced apart than the floor openings between 6mm and 12mm.

The bottom of the lower row of openings 32 aligns with the bottom of the ventilation recess 30 crates when they are placed in a refrigerated container for transport. As mentioned in the introductory section, refrigeration containers use a horizontal air flow. The wall openings are the minimum required to allow for chilling or cooling. On the other hand, the openings 24 in 30 the floor 20 optimise vertical warm air flow though the floor 20.

The outer face of each wall also has pick-up points 38 for automated robotic vacuum handling devices.

The crate 10 is collapsible to facilitate cost effective transport. The collapsed crates may be readily transported to a packing site and easily assembled prior to packing.

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The four walls 12, 14, 16, 18 are configured to be able to close flat over each other onto the floor 20. Figure 1 shows the location of hinge sections 42 on side wall 12 and end wall 18. Similar hinges 42 are also provided on end wall 16 and side wall 14.

As mentioned above, the crates 10 are configured similar to for example conventional cardboard trays as used for fruit transport. This allows for the crates to be manually sorted and packed and sorted at the farm or packing sheds using existing infrastructure such as conveyors, packing tables and the like.

It is therefore preferred that the crates disclosed herein are as light as possible whilst still having sufficient strength to support a load.

Figure 3 is a schematic view of three crates 10a, 10b 10c held together by retainers 100. Figure 4 is a detail thereof. The retainers 100 are located in the handling recesses 30 of each 15 crate 10. The handling recesses 30 are substantially L) shaped with a base 90 and curved end walls 92.

Two of the crates 10a, 10b are clipped together end to end. The third crate 10c is connected end wall to side wall of crate 10b. It will be appreciated that the crates may also be clipped 20 together in a side to side configuration (not shown).

Figures 5 to 8 show the retainer 100. The retainers 100 have a U shaped lower section 102 comprising opposing side walls or legs 104 and a web 106. The legs 106 have a planar rectangular shape so that they may lie flush against the walls with a low profile. The low profile 25 may minimise or reduce damage to the produce. The low profile of the legs 104 may be compensated by providing a relatively large surface area for the legs 104. The ratio of the width to the length of the legs may be between about 1:1 to about :1:3, preferably about 1:2.

In order to optimise retaining force against horizontal displacement of the crates 10, the legs 30 104 are configured to have a length no less than about % of the height of the wall, suitably about 1/3 to about ¹A the height of the wall.

The web 106 has a width configured to snugly accommodate the two walls of the adjacent held crates 10.

The retainer 100 is suitably formed from an extruded thermoplastic, suitably a polyolefin. A polypropylene homopolymer (PPH) or a polypropylene copolymer (PPC) are preferred

2020100730 08 May 2020 materials. PPH or PPC are light weight, have a low moisture absorption rate and high strength to weight ratio. Further such polymers have a low resilience (compared to rubbers) such that the legs will resist deformation under a load. That is the retainers 100 will retain their shape under a load so as to hold the crates 10 in position

The retainers 100 have an upper T shaped section 108 extending upwardly away from the web 106. That is the upper section 108 has an upstanding rectangular longitudinal member 110 and a top rectangular support plate 112. Both the upstanding member 110 and support plate 112 have the same longitudinal length as the web106.

The upper section 106 is configured such that height h of the upstanding member is the same as the vertical distance d the top of the support part 108 is in line with the top of the side and/or end walls of the crate 10. This means that when a further crate is stacked on top of the first crate the support section 104 will assist with bearing the weight of the crates above.

In this way, the clip 100 is held firmly in place by the weight of the crate(s) above.

The upper section also includes reinforcing ribs 110.

It may not be necessary for all crates in a layer or all layers to be clipped together. It may only 20 be necessary for example the fourth and eight layer in a stack of 12 layers to be clipped together.

In use, collapsed crates may be transported to a packing site or on site at a farm. The containers 10 are packed with produce and stacked on pallets for transportation to the site of 25 the VHT chamber. The pallets with stacked containers thereon may be placed directly in the

VHT chamber without requiring manual unpacking of the produce from the crates into which they were packed at the farm into pallet crates used only for the VHT treatment.

The stacked crates on the pallets may be loaded into a VHT chamber by forklift. The crates 30 are also sterilised by the VHT treatment. The treated produce therefore does not need to be unpacked and loaded into sterile containers for transport.

The treated produce and crates may simply be covered with mesh as required by quarantine regulations and transported to the point of sale site in the same crate.

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The produce may therefore remain in the same crate as packed on the farm and, VHT treated, transported and presented at point of sale. This minimises manual unpacking and repacking at the VHT sits, reducing costs and making the process more efficient.

It will be appreciated that the ability of using the same container from the farm, through the VHT treatment and transport to point of sale may enable efficient tracking of produce from the farm all the way through to point of sale that may be in a different country.

It will be appreciated that various changes and modifications may be made to the invention as 10 described and claimed herein without departing from the spirit and scope thereof.

Claims (5)

1. A retainer for use with at least two adjacent stacks of at least two layers, and each container comprises a first pair of opposing side walls, a second pair of opposing side 5 walls and a floor, each side wall has top edge, an upper side wall section a bottom edge and lower wall section;

at least one side wall comprises an open recess in the upper wall section or the lower wall section that is open to the bottom edge that has an upper inner surface and/or a top recess in at least one side wall that is open to the top edge and having a base surface and 10 a respective vertical dimension defined between the upper surface and the bottom edge of the crate or between the base of the recess and the top edge of the crate;

wherein the retainer comprises;

a lower part configured to receive the base surfaces of the top recess and at least part of the upper wall section of adjacent containers so as to hold the adjacent containers 15 together; and/or the lower part of the retainer is configured to receive top edges of adjacent containers and at least part of the upper wall section of adjacent containers so as to hold the adjacent containers together and;

a top part with a top surface having a linear dimension substantially consistent with the vertical dimension such that in use, when the adjacent containers comprise a lower layer 20 or a part thereof of containers in a stack, when the container is in a configuration having an upper recess, the bottom edge of an upper container bears on the top surface of a retainer and when the container is in a configuration having a lower recess, the top surface of the lower recess in the upper container bears on the top surface of the retainer.

25

2. The retainer of claim 1, wherein the lower part is L) shaped in cross section with opposing legs and a web.

3. The retainer of claim 2, wherein the legs are planar and rectangular.

30

4. The retainer of claim 1 or claim 2, wherein the upper part is T shaped in cross section.

5. A stacked pallet of containers comprising at least two containers in adjacent stacks held together by a retainer of any one of claims 1 to 4.