AU2014200479A1 - Multi-walled container - Google Patents

Abstract

- 22 A container comprising an inner shell defining a containment zone for product to be retained therein, and an outer shell engaged to the inner shell to define at least one cavity between the inner shell and outer shell. x £ x ) 7

Description

Regulation 3.2 AUSTRALIA PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: ALTO PACKAGING LIMITED Actual Inventors: LONG, Steven Mark Address for service AJ PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT in Australia: 2601, Australia Invention Title: Multi-Walled Container The following statement is a full description of this invention, including the best method of performing it known to us.

- 2 The present invention relates to a multi-walled container and related methods of manufacture and in particular though not solely to a single container created from two interlocking formed component parts. Containers for storing, heating and/or serving food are known. For example containers in the form of disposable meat trays used to carry meat from the abattoir to the point of sale and taken home by the consumer, are well known. They are usually thermoformed and of a thin walled foamed material. They will carry a soaker pad at their base to help absorb exudates that may run from the meat. This ensures a well presented product is provided at point of sale. However the soaker pad may still be visible to a consumer at the point of sale and the fact that exudates have been absorbed by it can be visually apparent and unappealing. There is hence a desire to obscure drained exudates so that the consumer does not see such unappealing exudates. Containers for preparing food are also known. Such containers may be placed into a microwave oven to heat its content. For certain foods their cooking can benefit from a moist environment. Water is hence often added to such containers so that during cooking this water steams off to help the cooking process and/or enhance the flavour of the food so cooked. But for shallow containers for example transferring them from the tap at here water would typically be added to the microwave can result in such water being spilt. In addition over or underfilling the container with water can also be an issue. It is hence an object of the present invention to provide a multi walled container that addresses one of more of the above mentioned disadvantages and/or that will at least provide the public with a useful choice. Accordingly the present invention may broadly be said to be a container comprising: an inner shell defining a containment zone for product to be retained therein, and an outer shell engaged to the inner shell to define at least one cavity between the inner shell and outer shell. Preferably the outer shell is located substantially about the inner shell. Preferably the outer shell includes a base by which the container can be vertically supported on a support surface. Preferably a least one upwardly extending sidewall (outer shell sidewall) that extends from the base of the outer shell. Preferably the base is quadrilateral in plan view and there are four outer shell sidewalls each connected to an adjacent said sidewall. Preferably the inner shell includes a false base to support said product. Preferably the inner shell includes at least one upwardly extending side wall (inner shell side wall) that extends from the false base. Preferably the false base is quadrilateral in plan view and there are four inner shell sidewalls each connected to an adjacent said sidewall.

- 3 Preferably the inner and outer shells are connected to each other at an upper container rim region. Preferably the container rim region is located at the top of the outer shell sidewall and/or inner shell sidewall. Preferably the inners shell sidewall and outer shell sidewall are coterminous. Preferably the inner shell and outer shell are conterminous at the edge of the container rim. Preferably the inner and outer shells contact each other at the rim region. Preferably the inner and outer shells contact each other at discreet regions intermediate of the rim region. Preferably the base and false base contact each other at discreet regions. Preferably the container rim is defined at the upper regions of the inner and outer shells side walls. Preferably at the container rim the inner and outer shells are parallel each other. Preferably at the container rim the inner and outer shells are in contiguous each other. Preferably at the container rim the inner and outer shells are in at least partial (and preferably full) contact each other. Preferably at the container rim the inner and outer shells are coextensive each other. Preferably the inner shell defines, at the rim region, an inner shell rim that is continuous about the mouth opening of the container. Preferably the inner shell rim flares outwardly of the mouth opening of the container. Preferably the inners shell rim is shaped to have an undercut outwardly of the inner shell sidewall. Preferably the inner shell rim is shaped and configured to include an undercut outwardly of the inner shell sidewall. Preferably the undercut is located below the upper most region of the inner shell rim. Preferably the inner shell rim defines a channel that includes said undercut. Preferably the outer shell defines, at the rim region, a rim that is continuous about the mouth opening of the container. Preferably the rim of the outer shell flares outward of the mouth opening. Preferably the rim of the outer shell is shaped to have an undercut outwardly of the outer shell sidewall. Preferably the rim of the outer shell is shaped and configured to include an undercut outwardly of the outer shell sidewall.

-4 Preferably the undercut is located below the upper most region of the rim of the outer shell. Preferably the rim of the outer shell defines a channel. Preferably the undercut of the inner shell captures the outer shell. Preferably the outer shell nests in the channel of the rim of the inner shell. Preferably the outer shell has a rim that nests in the channel of the inner shell. Preferably the outer shell rim is shaped and configured to be able to be pushed into the channel of the inner shell rim. Preferably the inner shell channel has a downwardly facing opening. Preferably the outer shell rim region is shaped to gradually penetrate the inner shell rim, via the opening during the assembly of the containers. Preferably the outer shell rim has a nosing shaped upper rim region. Preferably the outer shell rim fits snugly into the channel of the inner shell rim. Preferably the interlocking of the rims of the inner shell and the outer shell is coextensive the inner and outer shell rims. Preferably the interlocking of the rims of the inner shell and the outer shell is intermittent the inner and/or outer shell rims. Preferably one or both of the inner and outer shells are made from a resiliently flexible material. Preferably one or both of the inner and outer shells are made from a flexible material having memory. Preferably the container is an insulated container. Preferably the container is an insulated container to isolate hot content in the container from the fingers and/or hands of a person holding the container. Preferably the container is a food cooking vessel, wherein food content in the container can be cooked in an oven (preferably a microwave oven). Preferably the food cooking vessel is able to receive water in the at least one cavity between the inner and out shell. Preferably the water is able to pass into and out of the at least one cavity via at least one aperture of the inner shell. Preferably the water is able to be added into the containment zone and drain through the inner shell into the at least one cavity. Preferably the apertures of the inner shell are located in the false base. Preferably the apertures are set down from food supporting upstands of the false base in order to elevate food thereon above the apertures. Preferably a plurality of upstands are provided at the false base. Preferably the plurality of upstands are provided equispaced at the false base. Preferably the plurality of upstands are nodes. Preferably the plurality of upstands are ridges.

- 5 Preferably the adjacent each upstand there are at least 4 apertures. Preferably the container is a meat tray. Preferably the container provides the at least one cavity for a space for any exudates from the meat to flow into. Preferably the inner shell includes a plurality of apertures to allow exudates to pass there through. Preferably the apertures of the inner shell are located in the false base. Preferably the apertures are set down from meat supporting upstands of the false base in order to elevate meat thereon above the apertures. Preferably a plurality of upstands are provided at the false base. Preferably the plurality of upstands are provided equispaced at the false base. Preferably the plurality of upstands are nodes. Preferably the plurality of upstands are ridges. Preferably the adjacent each upstand there are at least 4 apertures. Preferably the apertures are located in trough or dimple formations of the false base. Preferably the material or one of both of the inner and outer shell is able to be thermoformed. Preferably both shells are polypropylene (PP). Preferably one of or both shells are made from a material selected from one of: Polystyrene (PS) Polyvinyl Chloride (PVC) Low Density Polyethylene (LDPE) High Density Polyethylene (HDPE) Cellulose Acetate Polymethylmethacrylate (PMMA), and Acrylonitrile-Butadiene-Styrene (ABS). Preferably the inner shell defines at least two containment zone each in which product can be retained separated from each other. Preferably the inner shell comprises a partition that separates two product containment zones of said container. Preferably the partition is integrally formed as part of the remainder of the inner shell. Preferably the two containment zones each comprise of a false base of said container. Preferably the false base of each containment zone is of the same size. Preferably the false base of each containment zone is of different size. Preferably the false base of each containment zone is of the same shape and configuration.

- 6 Preferably the false base of each containment zone is of different shape and configuration. Preferably the false base of each containment zone is co-planar. Preferably the outer shell includes a base by which the container can be vertically supported on a support surface and the false base of a first containment zone is distal more the base than the at least one other false base. Preferably the inner shell and outer shell are conterminous at the edge of a container rim region and the partition extends from one part of the rim region to another part. Preferably the inner shell and outer shell are conterminous at the edge of a container rim region and the partition extends downwardly from a height proximate or at the rim region. Preferably at at least one of said containment regions, said inner shell includes a plurality of apertures to create a fluid connection for at least one containment region with said at least one cavity. Preferably at only one of said containment regions, said inner shell includes a plurality of apertures to create a fluid connection for said containment region with said at least one cavity Preferably at each said containment regions, said inner shell includes a plurality of apertures to create a fluid connection for each said containment regions with said at least one cavity. Preferably the apertures are provided at at least the sides of the containment region(s). Preferably the apertures are provided at at least the sides of the base of the containment region(s). Preferably a separate cavity exists for and adjacent each of said containment regions. Preferably said partition is multi-walled and provides a separate wall for each of said containment regions. Preferably at least one of said containment regions is not spaces apart from the other of said containment regions by a multi walled partition. In a further aspect the present invention may be said to be a pack comprising a container as herein before described with food content located in the containment region. In a further aspect the present invention may be said to a pack comprising a container as herein before described with a food content located in at least one of said containment regions. In yet a further aspect the present invention may be said to be a pack comprising a container as herein before described with a different food content located in each of said containment regions.

- 7 In yet a further aspect the present invention may be said to be a pack as wherein before described wherein the food content is over wrapped by a wrap also at least partially wrapping the container. In yet a further aspect the present invention may be said to be a pack as wherein before described wherein a lid is provided to cover the food content and enclose it with the container. In a further aspect the present invention may be said to be a method of forming a multi walled container comprising, taking an inner shell that has a base from which at least one upstanding sidewall extends to a resiliently flexible inner shell perimeter rim that includes a downwardly opening channel having an undercut, driving a perimeter rim of an outer shell to locate substantially about the inner shell, into the channel, the outer shell perimeter rim being shaped and configured to be captured by the undercut to interlock the inner and outer shells together. Preferably the inner and outer shells are formed from roll stock precursor sheet material. Preferably the inner and outer shells are thermoformed from the roll stock. Preferably said driving causes one or both of the inner and outer shell rims to be deformed, whereupon they revert back to their original shape to interlock togehter. Preferably the thermoformed roll stock has an outer shell precursor formed therein, whereupon it is perimeter trimmed at the rim region in a trim press. Preferably the trim press carries the outer shell after trimming, at its rim, whereupon thermoformed roll stock that has an inner shell precursor formed therein is introduced into the press. Preferably the same components of the press that trimmed the outer shell, trim the inner shell precursor. Preferably the trimming of the inner and outer shell precursor occurs at regions thereof so that they trimmed edges are coincident each other. Preferably the trim press, carrying the outer shell also drives the outer shell rim into the channel of the inner shell precursor, preferably prior to the inner shell precursor being trimmed. Preferably the outer shell includes a channel formation at its rim at where the trim press can carry the outer shell during it being driven. This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

-8 It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. As used herein the term "and/or" means "and" or "or", or both. As used herein "(s)" following a noun means the plural and/or singular forms of the noun. The term "comprising" as used in this specification means "consisting at least in part of". When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in the same manner. The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference. Preferred forms of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a container of the present invention being of a tray shape with a large open top, Figure 2 is a side view of a form of the container of the present invention, Figure 3 is a partial sectional view through the container illustrating the inner and outer shell and the preferred from in which the inner and outer shell are engaged with each other at the rim, Figure 4 is a top perspective view of a preferred form of the container, Figure 5 is a bottom perspective view of Figure 4, Figure 6 is a plan view of Figure 4, Figure 7 is a bottom view of Figure 4, Figure 8 is a view from the front or back of the container of Figure 4, Figure 9 is an end view of either of the ends of the container of Figure 4, Figure 10 is a sectional view through the container of Figure 4, Figure 11 is a sectional view through region A of Figure 10, Figure 12 is a view of region B of Figure 10, Figure 13 shows the formed components of the container and a trim too prior to trimming, -9 Figure 14 is a sectional view through one of the components of the container prior to trimming, Figure 15 shows more detail of region C of Figure 14, Figure 16A-161 illustrates the steps in the process for the trimming and assembling of the container of the present invention, Figure 18 is a top perspective view of another example of a container of the present invention showing two compartments formed by the inner shell, Figure 19 is a bottom perspective view of the container of figure 18, and Figure 20 is a perspective cut-away view of a container of figure 18 and wherein a lid is shown. With reference to Figure 1 there is shown a container 1. The container may generally consist of a base region 4 from which there extend upstanding side walls 5 that terminate at a rim 106. The container may be an open-topped container as shown in Figure 1 where the rim defines a mouth of the opening to the container. In the examples shown in the accompanying drawings the container is preferably of an open-topped tray shape. Contents can be placed in the containment region 7 and such content may preferably sit below the rim in the containment region. The content may for example be meat such as mince or steak or chicken or similar. It may alternatively be different products. In one form the container may be used for the shipping of meat from an abattoir and/or pack house to a point of sale where the container with its content is displayed for sale to the consumer. Meats may be contained in the container and an overwrap (not shown) may be placed at least partially on the container to close the mouth to the containment region 7 to thereby envelope the content together with the container. Alternative forms of container of the present invention may include a cup shape, bowl shape or other. The container may define two separate containment regions 7 A and 7 B as shown in figure 18. The container may also have a lid 210 associated or able to be associated with it as seen in figure 20. In some forms the container may be used for supporting and heating content in a microwave. For example the container may be a noodle bowl where noodles are placed into the containment region 7. And for preparation for cooking, water can be added to the containment region 7 wherein after it may be placed for example in a microwave to heat the water. The container preferably comprises of an inner shell 2 and an outer shell 3. In a substantial part of the container the inner shell 2 and the outer shell 3 are separated from each other to create a void or voids or cavity 8. This can for example be seen in Figure 3.

- 10 The inner shell 2 defines a false base 9 from which there extends side walls 10 that extend to the rim region 106 of the container. Preferably the inner shell 2 is preferably continuous from the rim region down the side walls and to the false base 9 although apertures may be provided through the shell to provide for fluid communication between the void(s) 8 and the containment region 7. The inner shell 2 defines at least in part the form of the containment region 7. At least one containment region may be provided. In figure 18 it can be see that the inner shell may be formed to define two containment regions 7A and 7B. These may be separated by a partition region 211 defined by the inner shell. The partition region 211 allow separation to be provided between the two containment regions so that different types of food can be retained in each. The container comprises also the outer shell 3. The outer shell 3 defines the outer form of the container. The outer shell 3 includes a base 11 such base for example being the base which will support the container when placed on a surface. The base 11 has extending upwardly there from side wall(s) 12 that extend to the rim region 106. The shape of the base 11 and side walls 12 of the outer shell 3 and the shape of the false base 9 and side walls 10 of the inner shell 2 are different. At the rim region 106 the shape of the outer shell 3 and the inner shell 2 are complimentary each other in a manner to become substantially contiguous each other thereat and as for example seen in Figure 3. At the rim region 106 a joining of the inner and outer shell occurs in order to ensure that the inner and outer shell remain paired. Such joining may also occur at other parts of the inner and outer shell but it is preferably at the rim 106 that such pairing of the inner and outer shell occurs. It can be seen that at the rim region 106 at least from the top flange 150 to the terminal edges 170 of the inner and outer shell, the inner and outer shell are substantially parallel each other. At the rim region 106 the inner and outer shell are preferably interlocked together although other forms of establishing a join to ensure pairing occurs may be provided such as in the form of heat sealing. In addition or alternatively to create sealing and/or connection between the inner and outer shell, a profile 108 may be provided by the container. This may be appropriately shaped beading region. The beading region 108 in the preferred form provides some resistance to any moisture entering in or leaving the space between the inner and outer shell. It creates a seal between the inner and outer shells. In the preferred form this beading 108 extends at the entire mouth region of the container and preferably below and/or adjacent the rim region 106 of the container. Preferably the side walls of both the inner and outer shell are outwardly inclined and seen extending away from their respective bases. They extend upwardly to the rim region 106 at where they are formed to have an undercut region 101. It may be that its - 11 only the inner shell that has the undercut. It is created at a channel formation at the rim region. The undercut 101 facilitates an interlocking of the inner and outer shells. The side walls 10 and 12 together with the undercut region ensure that once assembled it is difficult to remove the outer shell from the inner shell because of the interlocking at the rim 106. For example with reference to Figure 3 it can be seen that a pulling down of the outer shell relative to the inner shell would require for the inner shell at the undercut region to flare outwardly in order to be able to release the outer shell from the inner shell. In addition some resistance to such a pulling down would be encountered by virtue of the bead 108 in itself also a form of undercut providing resistance to the process of removing the inner shell from the outer shell. The process by which the inner shell and outer shell are formed and interlocked together will hereinafter be described. In a preferred form the materials used for the inner and outer shell are preferably resiliently flexible. In some forms it may be that it is only the inner shell that is resiliently flexible or that it is the outer shell that is resiliently flexible. In some forms it may be that such resilient flexibility differs between the inner and outer shell. The inner and outer shells may also be of a different material or may be of a different construction. For example materials that may be chosen may be gas and/or liquid impermeable or similar. Preferably the inner and outer shell terminate at the rim region at the terminal ends 170. Preferably the terminal ends of both the inner and outer shell are coincident. Preferably the terminal end of the outer shell is located below the terminal end of the inner shell. Preferably the terminal end of the outer shell is located proximate more the containment region than the terminal end of the inner shell. As can be seen with reference to Figures 10-12, the cavity 8 may be defined as a plurality of cavities 8 as a result of some contact occurring for example at region 25 between the inner and outer shells. In addition formations such as dimples 26 may be defined one or both of the inner and outer shells preferably at their base to help with any heat transfer requirements and/or base strengthening requirements and/or cavity volume increasing requirements or similar. In one form the container may be used for the purposes of draining/storing exudates from a product contained in the containment region 7. For the purposes of draining exudates away from the containment region 7 and into the cavity or cavities 8, the false base 9 of the inner shell 2 may include a plurality of apertures 27. These apertures may allow for exudates to drain therethrough. The apertures may be so shaped as to allow for flow from the containment region 7 into the cavity 8 but restrict or prevent flow out of the cavity 8 back into the containment region 7. Preferably for these - 12 purposes some one-way valved-like construction of the apertures 27 may be provided. A duckbill type design at the apertures may be provided. Where a plurality of containment regions are provided as seen in figure 18, the inner shell, as a unitary item preferably defining both containment regions, may be differently configured. As an example one containment region may have apertures for drainage at the base 9 whilst the other may not have any apertures. As an example, the base of one containment region may have apertures to allow drainage of meat exudates of meat contained thereat, whilst the other may have no apertures as it may contain a sauce or pasta for which there is no need to have drainage apertures. And may be undesirable to have apertures due to the risk of drained exudates coming into contact with the pasta. Apertures may also/instead be provided in the false base 9 and/or side walls of the inner shell where the container is used for heating foods. For example when cooking foods in a microwave it may be desirable to include some water in the cooking container. The present invention allows for such water to be added into the cavity or cavities 8. Preferably such water is added by pouring into the containment region 7 and for such water to then drain through the apertures 27 into the cavity 8. Food can then be cooked in the containment region without sitting in water yet steam created in the cavity by virtue of boiling water therein can pass through the apertures and into the containment region 7 to facilitate the cooking process. Preferably a plurality of apertures are provided such as seen in the rows and columns of apertures in Figure 4. Where the container includes a plurality of containment regions as seen in figure 18, the containment regions at their base and or sidewalls may be differently configured. This may be desirable if different food is contained in each region. For example a first type of food or foods may be contained is a first region that has apertures through to the cavity. The food contained herein being subjected to steaming in appropriate conditions. The second region may contain food that is not to be steamed and as a result no aperture are provided through to the cavity. Other examples may include where apertures are provided in only the base of one containment region and only in sidewalls of the other. Or in the base and side walls of one containment region and only in one of the base and side walls of the other. Or in the base and side walls of one containment region and none in the base and side walls of the other. In order to ensure or reduce the prospect of apertures being blocked by the product sitting in the containment region on the false base 9, the product may be supported by a plurality of nodules 28. These nodules 28 will support the product above the apertures 27 so that steam can still rise through the apertures below the product and pass out into the containment region. It will be appreciated that in the preferred form the entire rim regions functions to interlock the two shells together. However, it may be that at one edge, the inner and - 13 outer shells are integrally formed and by say a hinge line, the connection between the outer and inner shell is established. It may also be that interlocking formations of the inner and outer shell are not continuous and that discreet regions as say intervals on the rim region provide for such interlocking. The preferred process of making the container will now be described. In the preferred form both the inner and outer shell of the container are made of the same material. However, it will be appreciated that the materials may be dissimilar. They may also be similar but of a different gauge to each other. Where heat welding is used to join the shells as herein after described, the materials need to be compatible. Preferably the material is able to be thermoformed. Both shells are hence preferably polypropylene (PP). Materials such as the following may also be used. Polystyrene (PS) Polyvinyl Chloride (PVC) Low Density Polyethylene (LDPE) High Density Polyethylene (HDPE) Cellulose Acetate Polymethylmethacrylate (PMMA) Acrylonitrile-Butadiene-Styrene (ABS) Thermoforming is preferably used to to create the two shells from for example roll stock sheet of PP. Both the inner shell 2 and the outer shell 3 may be formed as one piece as shown in figure 13. Alternatively the two shells may be separately formed. Within standard thermoforming tooling, the outer shell is preferably formed with adequate perimeter undercut 101 and associated profile and to produce a smooth outer contour 100 and to a depth "d" to define the interlocking feature at the perimeter rim 106 of the outer shell 3. A pre-clamp region 102 is defined to hold the formed shell during the trimming and assembling process. In addition a lead-in slope region 104 is formed at the rim 106 at this stage, intend to be used in the second stage of the trimming process. Additional features such as a leak proof bead profile 108 can be incorporated to provide a seal between the two shells. Such a bead may provide for the interlocking of the two shells or provide for additional interlocking. To produce the finished article a two stage process may be employed using the trim press 110 as shown in figure 13. The trim press 110 includes a fixed bolster 112 supporting a fixed clamp frame 113 that together with a cutting die 114 allow for cutting of the thermoformed precursor. The press also includes a moving bolster 115 holding a cutting punch 116 and pre loaded moving clamp frame 117 and a locator/stretcher 118. The thermoformed blank may advance from the thermo former to trim press in a continuous process as illustrated in figure 13. The sequential introduction of the outer - 14 then inner shell has been catered for in the design of the process so that continuous operation is possible. During the trimming process, the outer shell precursor is first introduced into the trimmer 110 to be cut to its final from the thermoformed blank that at this stage is still peripheral thereto. As seen in figure 13 and 16 a, the outer shell pre cursor 2 is positioned between the upper and lower parts of the trimmer 110. With the outer shell positioned in the trimmer 110, and as the moving bolster 115 advances towards the fixed bolster 112, the fixed clamp frame 113 and pre-loaded moving clamp 117 move toward each other and engage on opposite surfaces of the pre clamp feature 102 of the outer shell precursor, thereby trapping it. This is seen in figure 16a. With the continued motion of the moving bolster 115, the cutting punch and locator/stretcher 118 start to move relative the moving clamp frame 117 and continue to advance toward the out shell precursor. The clamp frames 117 and 112 continue to hold the precursor. As the locator/stretcher 118 reaches the position of contact with the outer precursor, the lead-in region 104 is engaged by the locator/stretcher 118 as seen in figure 16b. With the outer precursor still clamped, continued advancement of the locator/stretcher 118 forces the material of the outer precursor to be stretched over profile of the locator/stretcher 118 as seen in figure 16c. The resiliently flexible nature of the material of the outer precursor allows for this deformation to occur. This forcing of the profile by the locator/stretcher 118 and its shape forces the undercut to open/flare outwards. The cutting punch 116, which may up to then also have been travelling with the locator/stretcher, is then advanced further. With the cutting punch 116 and die 114 nearing their intersecting cut point and the outer precursor has temporarily been deformed fully to the shape of the locator/stretcher 118, continued motion of the moving bolster stretches the near straightened undercut region section just prior to the cutting. Once the punch and die have engaged, the outer shell 2 is separated from the sheet material 120. As the punch & die disengage, the trimmed outer shell 2 is retained on / in the locator/stretcher by the elastic return force of the deformed undercut rim. With the outer shell 2 retained insitu on the locator/stretcher, the inner shell precursor 3 is then introduced to the trimming area as seen in figure 16 e. The Pre Clamp sequence is repeated. As the Locator/Stretcher with the Outer shell still in place, reaches the position of contact with the Inner shell, its Lead-In feature is engaged with a corresponding feature on the outer shell on the Locator. With the sheet trapped, continued advancement of the Locator force the material of the Inner shell to be stretched over profile of the Outer shell/Locator, forcing the undercut of the inner shell outwards by the nature of the resultant forces.

- 15 The inner shell precursor rim is deformed temporarily over the outer shell rim and locator, prior to cutting, then both item are ejected as one as seen in the steps of figures 16f - 16i. A light force is applied to eject. This force may be applied to the base of the Outer shell, enough just to release the fit on the Locator. The memory of the material is sufficent that the undercut is reinstated, producing the desire features of smooth interlocking inner and outer shell. The resultant cutline is under and within the outside extremities of the top flange 150 of the container. As the two shells leave the locator, the natural elasticity within the rims allow them to revert back to their preformed shape, locking the shells together at their rim. Heat welding of the shells to each other at the rim may also be done, either in the trimmer or subsequent thereto. However, the use of a suitably guaged inner and/or outer shell at their rims can ensure that the elastic nature of the material(s) keeps the two shells interlocked at their rim. Possible end uses of the container could be, but not limited to: Thermally insulated container, where an airgap or gaps exist between the outer and inner shell. In addition a regular pattern of air voids may be created between the two interlocking shells. The pattern of air gaps, reduce the temperature transfer of the hot or cold contents in the inner shell reaching the outside shell. Self-Absorbing container, where a void is created between the two interlocking shells at where exudates or other fluids may become captured. The inner shell has discrete penetration holes in the base to allow liquid to be drawn into the void. The penetration holes being such a profile as to allow flow one way and restrict the return flow of liquid. Microwave Steam container, where a void is created between the two interlocking shells. Water can be added into the void by pouring it into the inner shell. Discrete penetration holes in the inner shell will allow the water to drawn into the void. When placed in a microwave oven, the water boils and is released through the holes as steam, cooking the content of the container evenly.

Claims (94)

1. A container comprising: an inner shell defining a containment zone for product to be retained therein, and an outer shell engaged to the inner shell to define at least one cavity between the inner shell and outer shell.

2. A container as claimed in claim 1 wherein the outer shell is located substantially about the inner shell.

3. A container as claimed in claim 1 or 2 wherein the outer shell includes a base by which the container can be vertically supported on a support surface.

4. A container as claimed in claim 3 wherein there is a least one upwardly extending sidewall (herein after "outer shell sidewall") that extends from the base of the outer shell.

5. A container as claimed in claim 3 or 4 wherein the base is quadrilateral in plan view and there are four outer shell sidewalls each connected to an adjacent said sidewall.

6. A container as claimed in any one of claims 1 to 5 wherein the inner shell includes a false base to support said product.

7. A container as claimed in claim 6 wherein the inner shell includes at least one upwardly extending side wall (herein after "inner shell side wall") that extends from the false base.

8. A container as claimed in claim 6 or 7 wherein the false base is quadrilateral in plan view and there are four inner shell sidewalls each connected to an adjacent said sidewall.

9. A container as claimed in any one of claims 1 to 8 wherein the inner and outer shells are connected to each other at an upper container rim region.

10. A container as claimed in claim 9 wherein the container rim region is located at the top of the outer shell sidewall and/or inner shell sidewall.

11. A container as claimed in any one of claims 1 to 10 wherein the inner shell sidewall and outer shell sidewall are coterminous.

12. A container as claimed in claim 9 or 10 wherein the inner shell and outer shell are conterminous at the edge of the container rim region.

13. A container as claimed in any one of claims 9 or 10 or 12 wherein the inner and outer shells contact each other at the rim region.

14. A container as claimed in anyone of claims 9 or 10 or 12 or wherein the inner and outer shells contact each other at discreet regions intermediate of the rim region.

15. A container as claimed in any claim 6 when dependent on anyone of claim 3 to 5 wherein the base and false base contact each other at discreet regions.

16. A container as claimed in any one of claims 1 to 15 wherein a/the container rim is defined at the upper regions of the inner and outer shells side walls.

- 17 17. A container as claimed in claim 16 wherein at the container rim the inner and outer shells are parallel each other.

18. A container as claimed in any one of claims 16 to 17 wherein at the container rim the inner and outer shells are in contiguous each other.

19. A container as claimed in any one of claims 16 to 18 wherein at the container rim the inner and outer shells are in at least partial (and preferably full) contact each other.

20. A container as claimed in any one of claims 16 to 19 wherein at the container rim the inner and outer shells are coextensive each other.

21. A container as claimed in any one of claims 16 to 20 wherein the inner shell defines, at the rim region, an inner shell rim that is continuous about the mouth opening of the container.

22. A container as claimed in any one of claims 16 to 21 wherein the inner shell rim flares outwardly of the mouth opening of the container.

23. A container as claimed in any one of claims 16 to 22 wherein the inner shell rim is shaped to have an undercut outwardly of the inner shell sidewall.

24. A container as claimed in any one of claims 16 to 23 wherein the inner shell rim is shaped and configured to include an undercut outwardly of the inner shell sidewall.

25. A container as claimed in claim 24 wherein the undercut is located below the upper most region of the inner shell rim.

26. A container as claimed in claims 24 or 25 wherein the inner shell rim defines a channel that includes said undercut.

27. A container as claimed in any one of claims 16 to 26 wherein the outer shell defines, at the rim region, a rim that is continuous about the mouth opening of the container.

28. A container as claimed in claim 27 wherein the rim of the outer shell flares outward of the mouth opening.

29. A container as claimed in any one of claims 16 to 28 wherein the rim of the outer shell is shaped to have an undercut outwardly of the outer shell sidewall.

30. A container as claimed in any one of claims 16 to 29 wherein the rim of the outer shell is shaped and configured to include an undercut outwardly of the outer shell sidewall.

31. A container as claimed in claims 30 wherein the undercut is located below the upper most region of the rim of the outer shell.

32. A container as claimed in any one of claims 16 to 31 wherein the rim of the outer shell defines a channel.

33. A container as claimed in any one of claims 24 to 26 wherein the undercut of the inner shell captures the outer shell.

34. A container as claimed in any one of claims 16 to 33 wherein the outer shell nests in the channel of the rim of the inner shell. - 18

35. A container as claimed in claim 1 wherein the inner and outer shells each include an upper rim configured to interlock together,

36. A container as claimed in claim 35 wherein interlocking is coextensive the inner and outer shell rims.

37. A container as claimed in claim 35 wherein the interlocking of the rims of the inner shell and the outer shell is intermittent the inner and/or outer shell rims.

38. A container as claimed in any one of claims 1 to 37 wherein one or both of the inner and outer shells are made from a resiliently flexible material.

39. A container as claimed in any one of claims 1 to 38 wherein one or both of the inner and outer shells are made from a flexible material having memory.

40. A container as claimed in any one of claims 1 to 39 wherein the container is an insulated container.

41. A container as claimed in any one of claims 1 to 40 wherein the container is an insulated container to isolate hot content in the container from the fingers and/or hands of a person holding the container.

42. A container as claimed in any one of claims 1 to 41 wherein the container is a food cooking vessel, wherein food content in the container can be cooked in an oven (preferably a microwave oven).

43. A container as claimed claim 42 wherein the food cooking vessel is able to receive water in the at least one cavity between the inner and out shell.

44. A container as claimed in claim 43 wherein the water is able to pass into and out of the at least one cavity via at least one aperture of the inner shell.

45. A container as claimed in claim 43 or 44 wherein the water is able to be added into the containment zone and drain through the inner shell into the at least one cavity.

46. A container as claimed in claim 44 wherein the apertures of the inner shell are located in the false base.

47. A container as claimed in claim 46 wherein the apertures are set down from food supporting upstands of the false base in order to elevate food thereon above the apertures.

48. A container as claimed in claim 6 wherein a plurality of upstands are provided at the false base.

49. A container as claimed in claim 48 wherein the plurality of upstands are provided equispaced at the false base.

50. A container as claimed in claim 48 or 49 wherein the plurality of upstands are nodes.

51. A container as claimed in claim 48 or 49 wherein the plurality of upstands are ridges.

52. A container as claimed in any one of claims 48 to 51 wherein adjacent each upstand there are at least 4 apertures. - 19

53. A container as claimed in any one of claims 1 to 39 wherein the container is a meat tray.

54. A container as claimed in claim 53 wherein the container provides the at least one cavity for a space for any exudates from the meat to flow into.

55. A container as claimed in claim 53 or 54 wherein the inner shell includes a plurality of apertures to allow exudates to pass there through.

56. A container as claimed in claim 55 wherein the shell includes a false base and apertures of the inner are located in the false base.

57. A container as claimed in claim 56 wherein the apertures are set down from meat supporting upstands of the false base in order to elevate meat thereon above the apertures.

58. A container as claimed in any one of claims 1 to 57 wherein the material or one of both of the inner and outer shell is able to be thermoformed.

59. A container as claimed in any one of claims 1 to 57 wherein both shells are polypropylene (PP).

60. A container as claimed in any one of claims 1 to 70 wherein one of or both shells are made from a material selected from one of: Polystyrene (PS) Polyvinyl Chloride (PVC) Low Density Polyethylene (LDPE) High Density Polyethylene (HDPE) Cellulose Acetate Polymethylmethacrylate (PMMA), and Acrylonitrile-Butadiene-Styrene (ABS).

61. A container as claimed in claim 1 wherein the inner shell defines at least two containment zone each in which product can be retained separated from each other.

62. A container as claimed in claim 1 or 61 where the inner shell comprises a partition that separates two product containment zones of said container.

63. A container as claimed in claim 62 wherein the partition is integrally formed as part of the remainder of the inner shell.

64. A container as claimed in anyone of claims 61 or 62 wherein the two containment zones each comprise of a false base of said container.

65. A container as claimed in claim 64 wherein the false base of each containment zone is of the same size.

66. A container as claimed in claim 64 wherein the false base of each containment zone is of different size.

67. A container as claimed in claim 64 wherein the false base of each containment zone is of the same shape and configuration. - 20

68. A container as claimed in claim 64 wherein the false base of each containment zone is of different shape and configuration.

69. A container as claimed in anyone of claims 61 to 68 wherein the false base of each containment zone is co-planar.

70. A container as claimed in anyone of claims 61 to 68 wherein the outer shell includes a base by which the container can be vertically supported on a support surface and the false base of a first containment zone is distal more the base than the at least one other false base.

71. A container as claimed in claim 62 wherein the inner shell and outer shell are conterminous at the edge of a container rim region and the partition extends from one part of the rim region to another part.

72. A container as claimed in claim 64 wherein the inner shell and outer shell are conterminous at the edge of a container rim region and the partition extends downwardly from a height proximate or at the rim region.

73. A container as claimed in claim 61 wherein at at least one of said containment regions, said inner shell includes a plurality of apertures to create a fluid connection for at least one containment region with said at least one cavity.

74. A container as claimed in claim 61 wherein at only one of said containment regions, said inner shell includes a plurality of apertures to create a fluid connection for said containment region with said at least one cavity

75. A container as claimed in claim 61 wherein at each said containment regions, said inner shell includes a plurality of apertures to create a fluid connection for each said containment regions with said at least one cavity.

76. A container as claimed in anyone of claims 73 to 75 wherein the apertures are provided at at least the sides of the containment region(s).

77. A container as claimed in anyone of claims 73 to 75 wherein the apertures are provided at at least the sides of the base of the containment region(s).

78. A container as claimed in anyone of claims 61 to 77 wherein a separate cavity exists for and adjacent each of said containment regions.

79. A container as claimed in claim 62 wherein said partition is multi-walled and provides a separate wall for each of said containment regions.

80. A container as claimed in claim 61 wherein at least one of said containment regions is not spaces apart from the other of said containment regions by a multi walled partition.

81. A pack comprising a container as claimed in anyone of claims 1 to 60 with food content located in the containment region.

82. A pack comprising a container as claimed in anyone of claims 61 to 80 with a food content located in at least one of said containment regions. - 21

83. A pack comprising a container as claimed in anyone of claims 61 to 80 with a different food content located in each of said containment regions.

84. A pack comprising a container as claimed in claim 83 wherein the food content is over wrapped by a wrap also at least partially wrapping the container.

85. A method of forming a multi walled container comprising, taking an inner shell that has a base from which at least one upstanding sidewall extends to a resiliently flexible inner shell perimeter rim that includes a downwardly opening channel having an undercut, driving a perimeter rim of an outer shell to locate substantially about the inner shell, into the channel, the outer shell perimeter rim being shaped and configured to be captured by the undercut to interlock the inner and outer shells together.

86. A method of forming a multi walled container as claimed in claim 85 wherein the inner and outer shells are formed from roll stock precursor sheet material.

87. A method of forming a multi walled container as claimed in claim 85 or 86 wherein the inner and outer shells are thermoformed from the roll stock.

88. A method of forming a multi walled container as claimed in any one of claims 85 to 87 wherein said driving causes one or both of the inner and outer shell rims to be deformed, whereupon they revert back to their original shape to interlock together.

89. A method of forming a multi walled container as claimed in claim 87 wherein the thermoformed roll stock has an outer shell precursor formed therein, whereupon it is perimeter trimmed at the rim region in a trim press.

90. A method of forming a multi walled container as claimed in claim 89 wherein the trim press carries the outer shell after trimming, at its rim, whereupon thermoformed roll stock that has an inner shell precursor formed therein is introduced into the press.

91. A method of forming a multi walled container as claimed in any one of claims 89 to 90 wherein the same components of the press that trimmed the outer shell, trim the inner shell precursor.

92. A method of forming a multi walled container as claimed in any one of claims 89 to 91 wherein the trimming of the inner and outer shell precursor occurs at regions thereof so that they trimmed edges are coincident each other.

93. A method of forming a multi walled container as claimed in any one of claims 89 to 92 wherein the trim press, carrying the outer shell also drives the outer shell rim into the channel of the inner shell precursor, preferably prior to the inner shell precursor being trimmed.

94. A method of forming a multi walled container as claimed in any one of claims 89 to 93 wherein the outer shell includes a channel formation at its rim at where the trim press can carry the outer shell during it being driven.