Field of the invention The present invention relates to containers for transporting or storing material. In particular, although by no means exclusively, the present invention relates to collapsible containers for transporting or storing fluids. More particularly, although by no means exclusively, the present invention relates to an intermediate bulk container that is collapsible from an expanded operative position to a collapsed storage position.

Background of the invention

Intermediate bulk containers are used for shipping and storing liquids such as chemicals, beverages, or food products, or freely flowable solids such as grains, livestock feeds, chemicals in powder form, and minerals in powder form. Recent designs for rigid intermediate bulk containers have typically been rectangular in shape. It is desirable to be able to move bulk containers using a forklift and to stack them to maximize the use of storage and shipping space. To perform this function, many types of bulk containers include pallet-type bases that are compatible with standard fork lift tynes. Rigid bulk containers present a problem of wasted space in storing or shipping the containers when empty.

The problem of wasted space has been addressed by the development of flexible bag type bulk containers that are well known in the art. Examples include flexible bag containers having generally rectangular shaped large bulk bag formed from a tubular blank of woven fabric. Such flexible bag containers are used for dry material shipping and storage and are desirable for use in storing and shipping liquid or freely flowable solid materials. They cannot, however, be used for shipment or storage of liquid or freely flowable solid materials unless structural support is provided. Flexible bag containers can also be sterilized and used in conjunction with "tamper evident" seals on inlet and outlet fittings, for example, for use when holding food products.

In order to stack flexible bag containers and ensure the stability of a flexible bag container when full and in shipment, it is often desirable to reinforce the container by attaching it to a rigid frame. This is particularly important for storage and shipment of liquid materials. It is also desirable for the rigid frame to be capable of collapsing for transport or storage once the container is empty. Collapsible rigid frames for this purpose have been disclosed. Similarly, collapsible rigid frames for holding flexible bag containers are available commercially.

The aforementioned collapsible rigid frames, when used in conjunction with a flexible bag container, are not configured to be collapsed until the flexible bag is empty. This is a disadvantage because if the rigid frame could collapse gradually, the weight of components of the rigid frame disposed above the flexible bag could serve to provide a downward force on the flexible bag, thereby assisting in the emptying of the contents of the flexible bag.

In addition, the collapsible rigid frames require manual separation of components of the frame for collapsing, usually by two people, and this presents the possibility of losing components of the frame. The available collapsible rigid frames must also be set up before the container held by thereby can be filled.

As such, there is a need for an improved collapsible intermediate bulk container that is easy to collapse and yet sturdy enough to contain material and prevent leakage.

The above description is not an admission of the common general knowledge in Australia or elsewhere. Summary of the invention

In a first aspect, the invention provides a collapsible intermediate bulk container, the container comprising: (a) a top portion; (b) a bottom portion; and (c) a flexible medial portion disposed between the top and bottom portions, wherein the medial portion comprises a plurality of horizontal fold lines resulting in accordion pleats forming ridges and troughs to allow a substantially vertical expansion or collapse of the container under the action of a substantially vertical force on the container. In a second aspect, the invention provides a collapsible intermediate bulk container, comprising: (a) a top portion; (b) a bottom portion; and (c) a flexible portion disposed between the top and bottom portions, wherein the flexible portion is formed to allow a substantially vertical expansion and/or collapse of the container under the action of a substantially vertical force on the container.

In this specification, the term "material" includes, by way of example, fluids and freely flowable solids, including gels. The flexible portion of the container may be formed with a plurality of fold lines that allow the substantially vertical expansion and/or collapse of the container under the action of the substantially vertical force on the container.

The invention also provides a collapsible intermediate bulk container comprising: (a) a top portion; (b) a bottom portion; and (c) a flexible medial portion disposed between the top and bottom portions, wherein the medial portion comprises a plurality of horizontal fold lines resulting in accordion pleats forming ridges and troughs to allow a substantially vertical expansion and/or collapse of the container under the action of a substantially vertical force on the container. Further, the container may be resiliently biased to move from the collapsed position to the expanded position. The resilient bias may be provided through the orientation of the accordion pleats, the material properties of said pleats or a combination of both.

By "intermediate bulk container", it is meant to include any reusable industrial container designed for the transport and storage of bulk liquid and granular substances (e.g. chemicals, food ingredients, solvents, pharmaceuticals, etc.).

In an embodiment of the present invention, the collapsible intermediate bulk container may be able to contain hazardous chemicals. The container may be enclosed in an external skin or exoskeleton frame, and may subsequently be stackable. In addition, the container may be mounted on a pallet that is designed to be moved using a forklift or a pallet jack. Typically, the container may be in the range 275 US gallons (1000 litres) or 330 US gallons (1250 litres) in size and can hold up to 1.8 tonnes of fluids depending on the density of the fluids. The container itself may be approximately 25 kg when empty.

In an embodiment, the container of the present invention may be hollow having an enclosed interior volume or void and may be made from a seamless material. As such, being the hollow container that it is, the container typically has four walls and top and bottom portions that are formed integrally. Thus, in addition to top and bottom portions, the container may have a front, back and two sides - left and right. In a further embodiment, the top and bottom portions may be substantially more rigid than the medial portion. The rigidity may be provided through different thickness of the various components. For instance, the medial portion may be 0.8 mm and the top and bottom portions may be 3 mm or more. In this arrangement, the container may be made from high density polyethylene (HDPE), polypropylene (PP) or rubber. The material may also be a reinforced polymer, such as using nylon reinforcement to aid in piercing strength and/or resiliency of the medial portion.

The container may be formed using a blow molding technique. In the case of the reinforced polymer, the material may be coextruded prior to blow molding. In a further embodiment, the introduction of the reinforcement may be during the blow molding, such as in a sandwich construction whereby the reinforcement is positioned between an outer or inner layer of polymer.

In the present invention, the medial portion of the container may allow the container to be vertically expanded and collapsed under the action of a vertical pulling or a vertical compression force on the container along a central axis respectively.

Alternatively, the pleats may be arranged to apply a resilient bias from the collapsed position to the expanded position. In this embodiment, whilst the container is being returned to its origin, it may do so in the compressed psoton. To overcome the resilient bias, the containers may be strapped. The top and bottom portions may also include lugs which are interengageable to hold the container in the collapsed position during transport, and thus negate e the need for strapping. It is appreciated that the accordion pleats may allow for the collapsible feature of the container to be achieved without affecting the ability of the container to support material such as fluids contained therein. As described above, the accordion pleats may be formed from fold lines surrounding the circumference of the medial portion. By "circumference", it is meant to include any linear distance around the perimeter of the medial portion of the container. The medial portion, and hence the container, may be any shape (for example, rectangular, circular etc.).

The accordion pleats may be in any suitable form.

In one form, the accordion pleats may be in a spring arrangement in which the structure and/or the material forming the pleats are selected so that an applied force is necessary to retain the pleats in a collapsed position.

In another form, the accordion pleats are in a self-supporting arrangement in which the structure and/or the material forming the pleats are selected so that the pleats can hold any selected positon between a collapsed and a fully expanded positions without requiring an applied downward force. The pleats retain their position until a force is exerted to vertically expand or collapse the container. In this form, the pleats may be described as "buckling" pleats.

The second form allows the height of the container to be adjusted between and positioned in a fully collapsed position and a fully expanded position and any intermediate positions therebetween without using external fastening means such as straps, ropes or cables to hold the container under compression.

Furthermore, the second form may facilitate draining of the contents in the container. In this respect, successively collapsing the pleats via an applied force causes collapse of the container in a series of discrete steps corresponding to the height of each pleat. This arrangement is advantageous because it is not necessary to apply a continuous force over a period of time to discharge the contents of the container. The fold lines may be equally spaced apart. Preferably, the distance between the fold lines is between about 30 mm to 80 mm. Preferably, the distance between the fold lines is between about 50 mm to 80 mm. Still more preferably, the distance between the fold lines is about 70 mm. Even more preferably, the distance between the fold lines is 71.5 mm.

The wall of the medial portion may be about between 0.5 mm to 2.5 mm thick. Preferably, the wall of the medial portion is about between 0.8 mm to 1.2 mm thick. The container may be made from any moulding process to form a seamless container having all its parts integrally formed. As such, in an embodiment, the walls of the container (including its top and bottom portions) may be the same thickness. As such, in an embodiment, the container may be formed from a single sheet of material. Alternatively, the wall of the medial portion may be thinner than the walls of the top and bottom portions - allowing the medial portion more flexibility. Therefore, it can also be appreciated that the top, bottom and medial portions may be formed from different materials. In an embodiment, the height of the container in the expanded configuration may be about 1015 mm and the height of the container in the collapsed configuration may be about 450 mm. Preferably, the interior volume or void of the container is reduced by between about 40% to 70% when the container is collapsed. More preferably, the interior volume of the container is reduced by about 55% when the container is collapsed.

The container may be made from any thermoplastic elastomer material or any material that includes a thermoplastic elastomer. Preferably, the material is any one selected from the group comprising: high-density polyethylene, low-density polyethylene, polyvinyl chloride, polypropylene and nylon.

The top portion may comprise an inlet, which may be selectively sealable, and the bottom portion may comprise an outlet, which may be selectively openable,. To this end, the inlet may have a cap, such as a screw cap and the outlet may be a tap. The inlet and the outlet may be placed at any suitable positions on the top and bottom portions respectively. In an embodiment of the present invention, the inlet and the outlet are positioned such that the distance between them is kept to a minimum. As such, both inlet and outlet may be positioned on a same side of the container. In an embodiment, the same side is the front side of the container. Hence, the inlet and the outlet may be located adjacent a front side of the container. Preferably, the inlet and outlet are located along the front face of the container. More preferably, the inlet and outlet may be located such that they are substantially along the same axis. In an embodiment, the inlet and the outlet are aligned at or around the middle of the top and bottom portions, respectively.

The outlet may include a valve, spigot or faucet. In an embodiment, the outlet includes, or is, a ball valve. The outlet may be sealed to minimize leakage during transportation, for example, by securing a cover or membrane over the outlet. The sealed outlet may be unsealed by a user for later use.

In an embodiment, the container may further comprise a flexible bag, liner, or liner bag disposed within the interior volume or void of the container and containing the material, with the flexible bag including an inlet and an outlet in fluid communication with the respective inlet and outlet of the container. The flexible bag may be made from any material that is suitable for containing hazardous fluids. For example, the flexible bag can contain Class 3 fluids. The flexible bag may also be impervious to water.

Minimising the distance between the inlet and the outlet of the container facilitates the connection of the inlet and the outlet of the flexible bag to the inlet and the outlet of the container. More specifically, positioning the inlets and the outlets as previously described minimizes the manipulation required to connect the respective inlets and outlets. The inlet and/or the outlet of the flexible bag may include a seal for reducing leakage of material. Preferably, each of the inlet and the outlet includes at least one O-ring for reducing leakage of material from the flexible bag. The inlet and/or outlet of the container may also include a seal to provide secondary containment of material within the container if the flexible bag is punctured and material leaks into the container.

The flexible bag may include a siphon to minimise the presence of residual material in the flexible bag after draining. Preferably, the inlet of the siphon is positioned at the lowest point of the flexible bag to increase the amount of material removed from the container.

The flexible bag may include a cap for receiving the siphon to reduce physical damage to the bag by the siphon, for example, by abrasion.

The flexible bag may be attached to an internal surface of the container to enable the bag to expand and compress along with the container. This improves filling and drainage of material from the flexible bag by minimizing dead spaces within the bag. This would also allow the contents of the flexible bag to drain without the bag collapsing. In an embodiment, the flexible bag may include hooks that are attachable to loops or rings positioned on the internal surface of the container.

A section of the flexible bag may be attached to a structure, such as for example, a cage or frame located outside the container to support the flexible bag and to facilitate filling and/or draining of material from the flexible bag. The flexible bag may include a connector, for example, hooks, loops, rings, clips or the like, for connecting to the structure. For example, the flexible bag may include clips that enable a section of the flexible bag to be attached to a cage positioned outside the container. The section of the bag may extend from the inlet to be attached to the cage. This keeps the bag from collapsing during the filling and draining processes which in turn minimizes the time taken to fill the container during the filling process and the residual material in the container during the draining process. The container may have a retaining means for retaining the container when the container is collapsed.

The expanded and collapsible configurations may be achieved manually. Preferably, the top portion comprising at least one engagement means adapted to allow a user to engage the container for providing the vertical force for expanding or collapsing the container. More preferably, the engagement means includes at least one slot for allowing the insertion of at least one bar, the bar is adapted to allow the user to provide the vertical force for expanding or collapsing the container.

By "slot", it is meant to include any groove, cut or recess for allowing attachment, engagement or insertion of a bar allowing a user to pull up or press down for providing the vertical force necessary for expanding or collapsing the container. In an embodiment, the engagement means may accommodate straps for applying the vertical force to the container.

The bottom portion may further comprise at least one holding means for holding the bottom portion of the container to the ground while the container is being expanded from a collapsed position to an expanded position. In an embodiment, the holding means may comprise at least one slot in the bottom portion adapted to allow insertion of a user's foot for applying a downward force to the bottom portion to hold the bottom portion on the ground when a vertical force is applied for expanding the container. Preferably, the container includes two slots. Alternatively, the holding means may be any means for holding the container to the surface it stands or sits on.

Alternatively, the container may be expanded by other means. For example, a blower may be used to blow air into a collapsed container in order to expand the container. The air blown in the container may be of any suitable pressure necessary to allow such expansion.

In another embodiment, the bottom portion may further include at least two positioning slots for receiving forklift tynes to facilitate lifting and stacking of the container. Suitably, the positioning slots are located to extend inwardly from a side wall of the bottom portion that is opposite the outlet of the container. This arrangement minimizes the possibility of the forklift damaging the outlet.

The bottom portion may comprise a substantially flat bottom for placement on a flat surface. Alternatively, the bottom portion may have a complementary profile to the top portion to facilitate stacking of alike containers. For example, the top portion of one container may have an outwardly projecting profile that is receivable by a recessed profile of the bottom portion of an alike container when stacked on top of each other.

The bottom portion may be reinforced to increase rigidity. For example, the bottom portion may include a rib to increase rigidity of the container. Preferably, the container includes a concave rib located at the base of the bottom portion to reinforce the container.

The bottom portion may have an internal profile that facilitates flow of material towards a region in the container to facilitate draining of the material. Suitably, the region is located at or around the outlet. The internal profile may include a convex rib to facilitate flow of material towards the outlet.

Drainage of residual material may also be effected by inserting an inflatable balloon into the container such that the balloon is disposed between the internal surface of the bottom portion and the flexible bag. With this arrangement, in use, inflating the balloon displaces material in the container. Suitably, the balloon is positioned such that it causes material to flow towards the outlet when inflated.

The container may be substantially cuboid in shape with rounded corners.

In an embodiment, the container may be encapsulated in a metal frame when in the expanded configuration. Such a metal frame may also be known as a metal cage, and may be detachable from the container. Advantageously, the metal frame provides support to the container. Alternatively, the container may be encased or enclosed in any suitable outer structure. The present invention also provides a packaging system comprising the above- described intermediate bulk container.

Brief description of the figures

In order that the present invention may be fully understood and readily put into practical effect, there shall now be described by way of non-limitative examples only embodiments of the present invention, the description being with reference to the accompanying illustrative figures.

In the Figures:

Figures 1A and IB show perspective views of a container in accordance with embodiment of the present invention;

Figures 2A and 2B show front views of the container of Figures 1 A and IB;

Figure 3A and 3B show perspective views of a container in accordance with another, although not the only other, embodiment of the present invention;

Figures 4A and 4B show front views of the container of Figures 3 A and 3B;

Figure 5A shows a cross-section side view of accordion pleats of the container of Figures 3A, 3B, 4A and 4B having accordion pleats in a self-supporting arrangement;

Figure 5B shows a cross-sectional side view of accordion pleats of the container of Figures 1 A, IB, 2 A and 2B having accordion pleats in a spring arrangement;

Figure 6 shows a bottom view of the container of Figures 3 A, 3B, 4A and 4B;

Figure 7 is a cross-sectional side view of a container of Figures 3 A, 3B, 4 A and 4B;

Figure 8 is a perspective view of a number of alike containers according to the present invention being stacked by a forklift; Figure 9 is a cross-sectional side view of a siphon connecting the flexible bag to the outlet of a container according to another embodiment of the present invention; Figures 10A and 10B show various views of the container according to a further embodiment of the present invention;

Figures 11A and 11B show isometric views of the container according to a still further embodiment of the present invention, and;

Figures 12A to 12C show various views of the container according to a still further embodiment of the present invention.

Detailed Description of the Preferred Embodiments

With reference to the figures, the present invention relates to an intermediate bulk container 5 that can assume two configurations: an expanded configuration as shown in Figures 1 A, 2A, 3A and 4A; and a collapsed configuration as shown in Figures IB, 2B, 3B and 4B.

In an embodiment, the container 5 has a top portion 10, a bottom portion 15, and a medial portion 20 that may be made of a flexible material. The container 5 may be hollow having an enclosed interior volume or void and may be made from the same seamless flexible material, or of different material. The enclosed interior volume or void is defined by the top portion 10, bottom portion 15, and medial portion 20 of the container 5.

The medial portion 20 further comprises a plurality of horizontal fold lines 25 surrounding the circumference of the medial portion 20, the fold lines 25 resulting in accordion pleats 30 forming ridges 35 and troughs 40 to allow a substantially vertical expansion or collapse of the container 5 under the action of a substantially vertical force on the container. The medial portion 20 allows the container to be vertically expanded and collapsed under the action of a vertical pulling force A and compression force B on the container along a central axis respectively. The fold lines 25 may be spaced apart equally. In an embodiment, the distance between the fold lines is 71.5 mm. The walls of the container may be between 0.8 mm to 1.2 mm in thickness. These values are important as the walls must be thin enough to allow for flexibility (i.e. movement) of the medial portion 20 and yet confer strength to the container 5 for containing the materials.

In the embodiment illustrated in Figures 3A, 3B, 4A and 4B, the accordion pleats 30 are in a self-supporting arrangement (see Figure 5A) in which the pleats can hold any selected position between a collapsed and a fully expanded positions without requiring an applied downward force. In this embodiment, each pleat has an asymmetrical structure comprising a first end with a bulbous tip 28 and a second end with a non-bulbous tip 29. The bottom-most pleat is positioned above upwardly oriented section 31 of bottom portion 15 while the top-most pleat is positioned below upwardly oriented section 32 of the top portion. The structure of each pleat allows each pleat to flex and buckle when compressed to hold its collapsed position. In the embodiment illustrated in Figure 5A, the pleats buckle in a convex manner. This enables the height of container 5 to be adjusted and maintained without the use of external fastening means such as straps.

In the embodiment illustrated in Figures 1A, IB, 2 A and 2B, the accordion pleats 30 are in a spring arrangement (see Figure 5B) which biases the container towards the expanded position, wherein the compressed container has to be held in position by fastening means such as straps when adjusting the height of the container. In this embodiment, each pleat has a symmetrical structure comprising a first end and a second end with bulbous tips 28. The bottom-most pleat is positioned above downwardly oriented section 31 of bottom portion 15. The top-most pleat is positioned below upwardly oriented section 32 of the top portion. When compressed, each pleat maintains a substantially horizontal profile without flexing or buckling. When the compression force is removed, the pleats 30 expand and return to their expanded position.

In an embodiment, the height of the container 5 in the expanded configuration may be 1015 mm and the height of the container in the collapsed configuration may be 450 mm. As such, the interior volume or void of the container 5 may be reduced by about 55% when the container 5 is collapsed. This allows more empty containers to be packed and transported, thus affording savings on transportation costs. In an embodiment, the container 5 is made from a seamless single sheet of material. Any suitable method of manufacturing the container 5 may be contemplated. For example, methods such as rotomoulding or blow moulding may be carried out. Any thermoplastic elastomer such as high-density polyethylene, low-density polyethylene, polyvinyl chloride, polypropylene or nylon made be used to form the container 5.

The container 5 further comprises an inlet 45 and outlet 50 - which may be placed at any suitable position on the container 5. Having said that, in the illustrated embodiments of the invention, the inlet 45 and the outlet 50 are placed on the top portion 10 and bottom portion 15 of the container 5, respectively. Figures 1A, IB, 2A and 2B show the inlet 45 being placed in a centrally location on the top portion 10 of the container 5. Figures 3 A, 3B, 4A and 4B illustrate a preferred embodiment of the invention wherein the inlet 45 is placed adjacent a front side 55 of the container, on the same side or plane / axis as the outlet 50. The advantage of this configuration is to allow easy installation of a flexible bag, liner, or liner bag within the interior volume or void of container 5. This will be described in detail below.

The inlet 45 may include any suitable cap or lid, and the outlet 50 may include any suitable spigot, for example a ball valve. In an embodiment, a flexible bag (not shown in the Figures) may be disposed or placed within the interior volume or void of the container 5. The flexible bag may be made of any suitable material for containing materials that need to be transported and/or stored within the container 5. An advantage of such bags is to allow the container 5 to be reusable and the prevention of leakage. As such, in the collapsed configuration, it is advantageous to have the inlet 45 and outlet 50 closest to each other to allow for the easy installation of the flexible bag.

In this respect, Figures 3 A and 3B illustrate a preferred embodiment wherein the inlet 45 and outlet 50 are aligned along a vertical axis of the container and are centrally positioned about an edge of the top and bottom portions, respectively. This preferred arrangement minimizes the distance between the inlet 45 and outlet 50.

In an embodiment, collapsed containers with the flexible bags disposed in them may be transported to any desired location where the containers are then expanded together with the flexible bags in them, and filled with materials at that location.

Not shown in the Figures, but the container 5 may include any retaining means for retaining the container 5 when the container 5 is in the collapsed configuration.

The vertical force A and B may be provided by any suitable means, for example any machinery to provide that mechanical force.

In an embodiment, the force may be applied manually. The top portion 10 may comprise at least one engagement means that is adapted to allow a user to engage the container 5 when providing the vertical force for expanding or collapsing the container. The engagement means may be in the form of slots 60 on the top portion 10, each slot 60 allowing the insertion of one bar (not shown in the Figures) whereby the ends of the bar may extended out of the container 5 to allow the user to provide a pull or press vertical force for expanding or collapsing the container 5. The slot 60 illustrated in Figures 3A and 3B can also accommodate pallet straps which can be used to provide the vertical force for expanding or collapsing the container.

In order to provide leverage when pulling the container 5 up in order to expand the container 5, the bottom portion 15 may include a foot feature (not shown in Figures 1A and IB) for holding the container 5 to the ground it sits on. The foot feature, or securing means, may include any slot that is adapted to allow insertion of a user's foot for holding the container 5 to the ground when vertical force is applied for expanding the container 5. Figures 3 A and 3B illustrate container 5 with foot features 12 to allow insertion of a user's feet for holding the container 5 to the ground when vertical force is applied for expanding the container 5.

The container 5 may assume any suitable shape. For efficient transportation and storage, the container 5 is substantially cuboid in shape with rounded corners. The top portion 10, bottom portion 15 and sides of the container 5 may be substantially flat for placement with / on a flat surface.

In Figures 3 A and 3B, the top portion 10 of container 5 is has a profile comprising a number of projections 14 that are complementary to the underside profile of bottom portion 15 which includes a number of recesses 16 that can accommodate projections 14 to facilitate stacking of alike containers 5.

The recesses 16 open onto a side of the container to form positioning slots 18, which can accommodate forklift tynes to facilitate unidirectional stacking of alike containers (see Figure 8).

The external side wall of bottom portion 15 includes a concave rib 19 that increases the rigidity of the container 5 to improve mechanical strength. The internal base profile of the bottom portion 15 includes a number of convex ribs 22 to channel material from the flexible bag towards the outlet 50 during the draining process (see Figure 7).

In the embodiment illustrated in Figure 7, the material collects in region 24 which is the lowest point in the container. A siphon 26 is positioned within the flexible bag in region 24 to drain the material collected via outlet 50. The siphon 26 is connected to a ball valve 34 which leads to outlet 150 using adaptor 36. Adaptor 36 includes two O- rings 38 which provide secondary containment of the material in the container 5. In this respect, the O-rings 38 reduce the likelihood of any material that has leaked into the container body from the flexible bag, for example, if the flexible bag is punctured, from exiting the container 5.

In some embodiments, the flexible bag includes a cap 33 which is positioned at region 24 to protect the flexible bag from damage by the siphon 26 (see Figure 9).

In an embodiment of the present invention, the container 5 may be enclosed or encapsulated in any suitable exoskeleton when it is in the expanded configuration. For example, the exoskeleton may be a metal frame (such as that shown in Figures 11 A and 11B) and the metal frame may be detachable from the container. The type of metal may be that type known in the industry as a "Goodpac" which may act as both a modular intermodal device as well as providing supporting strength to the container.

Advantageously, the present invention provides a container that is collapsible such that its volume is reduced for efficient storage and transport, but allows for easy and quick expansion to provide a strong and durable container for containing material - particularly hazardous fluids.

In a further embodiment, the container may be profiled on the top and bottom portions. The profiling may serve to engage corresponding containers when placed one upon the other. In particular Figure 10A shows the bottom portion of a container 70 having longitudinal recesses 75 which correspond to longitudinal projections on the top portions. The longitudinal recesses may also act to receive tynes from a forklift or other transport device. To ensure lateral movement of stacked containers, the longitudinal recesses 75 may have enlarged zones 80 and 90 for receiving corresponding enlarged projections in the top portion. Having enlarged portions may act to both resist shear forces, as well as preventing movement along several lateral axes. If the enlarged zones 80 and 90 were not enlarged, movement parallel to the longitudinal recesses may not be sufficiently prevented.

A centrally located recess 85 within the longitudinal recess 75 includes a deeper recess, such that the central recess 85 is not co-planar with the remainder of the longitudinal recess 75. This may provide several advantages including strengthening the bottom portion, as well as providing a separation between the enlarged zones 80, 90. It is conceivable that a tyne insert into the longitudinal recess 75 may adhere along its length hindering removal. With the deeper recess 85, the tyne is not in surface contact along the full length and so breaking an adhesion that may occur. Further still, by having the deeper recess 85 in the central position, the weight of the container is distributed to the tynes at the edge regions of the bottom portion and so away from the potentially weaker planar region. As previously stated, Figures 11A and 11B show containers placed within metal, or rigid polymer, intermodal devices. Whilst the containers may be used within conventional intermodal devices, the devices 115 of Figure 11A and 11B are particularly adapted for use with containers according to the present invention.

The intermodal devices 115 include detachable walls 125 to aid in access to the containers 95. End walls 100 include selectively openable panels 105 to gain access to the tap 110 of the container 95. The devices 115 may be open as shown in Figures 11 A and 1 IB, soa s to gain access to the inlet 120 of the container 95. Alternatively, a lid (not shown) may be fitted to the device to seal the container fully within the device 115.

The device 115 further includes recesses 130 for receiving tynes for ease of transport.

In the transport of the containers, engagement between the top and bottom portions of stacked containers is arranged to prevent lateral movement of the containers. Figures 12A to 12C shown further adaptations to prevent vertical movement. Included in the top and bottom portions are apertures arranged to receive rods linking the containers together and so increasing the required applied force need to shift the containers. Effectively, the bottom container 145 acts as an anchor for the top container 135. The apertures on the top and bottom portions are positioned so that on stacking the containers, the apertures align so as to allow the rods to penetrate each aperture, and consequently engage the stacked containers.

Figures 12A and 12B show an embodiment whereby the rods 140, 150 are applied parallel to the shortest dimension, with Figure 12C showing the arrangement whereby the rods 155 are placed parallel to the longest dimension. Whilst there has been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.