THERMAL INSULATING PANELS AND CONTAINERS FORMED THEREFROM
FIELD OF THE INVENTION The present invention relates to panels useful in thermal insulation, and particularly to such panels when used in the construction of containers for the transportation of perishable articles.
BACKGROUND TO THE INVENTION
It is often necessary to transport temperature-labile articles suc as foods, medicines, vaccines, chemicals, biological samples and th like. The most common material used in packaging perishable articles for transport is polystyrene, which is a petroleum-based plastic made from the styrene monomer. Polystyrene is a light-weight material, with useful insulation properties. However, while an effective insulator the use of polystyrene presents a number of problems.
For example, the styrene monomer poses substantial risks to workers preparing the polymer. Acute health effects of styrene are generally irritation of the skin, eyes, and upper respiratory tract, and gastrointestinal effects. Chronic exposure affects the central nervous system showing symptoms such as depression, headache, fatigue, and weakness, and can cause minor effects on kidney function and blood. Styrene is classified as a possible human carcinogen by the United States Environmental Protection Agency (EPA) and by the International Agency for Research on Cancer (lARG),
Although some polystyrene manufacturers claim that their products to be "ozone-friendly" or substantially free of CFCs, there is still environmental detriment in the use. Some polystyrene is now manufactured with HCFC-22, which, although less destructive than related compounds CFC-11 and CFC-12, is still a greenhouse gas and harmful to the ozone layer. According to a study by the Institute for Energy and Environmental Research, HCFCs are three to five times more destructive to the ozone layer than previously believed. Indeed, many countries and localities have banned polystyrene foam, including Taiwan Portland, (OR), and Orange Count, (CA). A further problem of polystyrene foam packaging is the cost to transport the empty packaging to the user is high. While the empty foam packaging container is light, freight charges typicall include a volume component
Another problem is that polystyrene foam is not mechanically strong, with packaging being easily damaged during transit. This can lead to a substantial decrease in insulating ability as well as damage to the contents. A major problem of polystyrene is the difficulty in recycling used or contaminated materials. The above mentioned problem of transport costs also makes the reverse logistics of recovering used material cost prohibitive. As a consequence polystyrene typically exists for at least fifty years in landfill, being incapable bio degrading or composting. It is an aspect of the present invention to provide an insulating material suitable for use in the construction of transport packaging that is less environmentally damaging and/or stronger than prior art materials sueh as polystyrene. It is a further aspect to provide an alternative to insulation materials of the prior art. The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.
SUMMARY OF THE INVENTION
In a first aspect the present invention provides a thermal insulation panel, the panel comprising; (i) two opposing faces, and (ii) a plurality of baffles disposed between the opposing faces, wherein the baffles are configured to limit movement of air inside the panel.
In one embodiment, the opposing faces are substantially parallel to each other.
In one embodiment, at least one baffle is a wail extending between the two opposing faces. The at least one wall may be disposed substantially orthogonal to one or both of the opposing faces.
In one embodiment the baffles define at least one closed eel! which may be substantially hexagonal.
In one embodiment the opposing faces and/or baffles are fabricated from a substantially recyclable material, including a cellulose-based material such as a cardboard or a paper.
In one embodiment, the baffles are glued to one or both of the opposing faces.
In one embodiment one or both of the opposing faces is of muitilayered construction.
In one embodiment the thermal insulation panel is substantially compression resistant. The resistance to compression may be measured by application of a force directed at 90 degrees to one or both opposing faces. In one embodiment, the panel has a thickness of between about 10 mm and about 25 mm, or between about 25 mm and about 50 mm.
In one embodiment at least one of the opposing faces is laminated with a polymer which is substantially water impermeable and/or reflective.
In a second aspect the present invention provides a transport container comprising a cavity, and a thermal insulation panel as described herein.
In one embodiment, the cavity is lined with thermal insulation panels as described herein. The walls, and/or floor, and/or lid of the vessel may comprise insulation panels as described herein.
In one embodiment, the panels are disposed such that an edge of a first panel abuts the face of a second panel.
In yet a further aspect there is provided a blank capable of forming a transport container, the blank comprising a backing material having a series of fold lines, the blank comprising one or more panels as described herein affixed to the backing material. The one or more panels are arranged on th backing material such that upon assembly the edge of a first panel abuts the face of a second panel.
In one embodiment the blank comprises five panels such that upon assembly an open transport container is formed. Alternatively, the blank may comprise at least six panels to define four walls and one floor such that upon assembly a transport container having one or more hinged lid(s) is formed. The blank may be configured such that upon assembly, the container is substantially self-supporting.
In one embodiment the backing materia! of the blank is fabricated from a substantially recyclable material, including a cellulose-based material such as a cardboard or a paper. The backing material may be laminated on one or both sides with a polymer which is optionally substantially water impermeable.
Yet a further aspect of the present invention provides a lid for a transport container comprising a thermal insulation pane! as described herein. The lid may comprise a perimeter edge structure adapted to prevent the ltd from falling into a cavity of a transport container.
A further aspect of the present invention provides a standard bulk transport container comprising a thermal insulation panel as described herein.
In one embodiment, the standard bulk transport container is an air freight unit load device, and may be selected from the group consisting of AAP/AA2, AAF, AKH, ALF, DOF, AAX, PRA, PEB, PAG, AAU, A E, AMP, PMC, PGA, PAG, PMC, AAA, AAD, AAF, AAP, AAY, AAZ, AGA, A C, AKH, AKW, AKN, ALB, ALD, ALF, ALP, A A, A J, AMU, AVY, AWC, AYY, YX, DPE, DPN, DGF, FLA, FQA, P1 P, PAD, PLA, QKE, RAP, RAU, RKN, RWB, SAA, SAX, VRA, XAW, XKC, LD1 , LD2, LD3, LD3-45, LD6, LD8, LD11 , LD8, LD11 , and LD7.
In another embodiment, the standard bulk transport container is a standard shipping container or a Hi Cube shipping container. The present invention further provides is another aspect a method of transporting a perishable article, the method comprising the step of placing the article proximal to one or more panels as described herein, or surrounding the article with panels as described herein, or placing the article in the transport container as described herein, or placing the article in the standard bulk transport container as described herein. The method may further comprise the step of fitting a lid as described herein
In a further aspect the present invention provides use of a thermal insulation panel as described herein in the construction of a transport container, including a bulk transport container.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective diagrammatic representation of a thermal insulating panel of the present invention. The upper layer is shown partially removed to demonstrate the geometry and arrangement of the underlying cells. Fig. 2A is an anterior view of a blank that may be assembled into a transport container. The blank comprises 5 thermal insulation panels.
Fig. 2B is a posterior view of a lid suitable for enclosing a transport container of the present invention, as formed by the assembly of the blank shown in Fig. 2A. The lid comprises two thermal insulation panels.
Fig. 3 is a graphical representation of the data of Table 1 , being a time course experiment to assess the insulating capabilities of a prior art polystyrene containe (grey circle data points) to a container of the present invention (black circle data points). Ambient temperature is shown by the open circle date points,
DETAILED DESCRIPTION OF THE INVENTION
After considering this description if will be apparent to one skilled in the art how the invention is implemented in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention, Furthermore, statements of advantages or other aspects apply to specific exemplary embodiments, and not necessarily to all embodiments covered by the claims.
Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.
Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "i one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may.
The present invention is predicated at least in part on Applicant's finding that reducing the ability of air surrounding a temperature-labile article to form convection currents may dramatically interfere with heat transfer from the environment to the article (or vice versa). Accordingly, in a first broad aspect (although not necessarily the broadest aspect) the present invention provides a thermal insulation panel, the panel comprising: (i) two opposing faces, and (ii) a plurality of baffles disposed between the opposing faces, wherein the baffles are configured to limit movement of air inside the panel. The function of the baffles is to prevent (or to at least inhibit) the convection- ased movement of air within the panel. Without wishing to be limited b theory in any way it is proposed that limiting convection currents is effective in inhibiting heat transfer across the panel.
An alternative or additional function of the baffles is to limit the transfer of heat across the panel by conduction. Limiting heat transfer by conduction may be potentiated where the baffles are fabricated from a material of low thermal conductivity and/or by limiting the degree of contact between baffles and the opposing faces.
The opposing faces may be any structures capable of enclosing a volume of air. It is not necessary that the faces form an air tight chamber. Typically, the faces are substantially planar sheet-like structures of fixed thickness, but in some embodiments may be undulating, or of varying thickness. In one embodiment, the opposing faces are substantially parallel to each other thereby defining an air chamber of substantially fixed thickness, The baffles may be of any shape, material, dimension or structure capable of limiting movement of any air disposed between the opposing faces. Typically, the baffles are configured to interrupt movement of air in a direction substantially parallel to one or both opposing faces. This configuration has the effect of limiting the movement of air along a long or short axis of the panel, or along a diagonal axis of the panel,
The baffles may not completely inhibit the movement of air, and in some embodiments simply form a tortuous path for air to follow. In this form of the invention, the baffles may act to induce eddy currents, thereby substantially disrupting the normal convection current flows that would be established in the absence of baffles.
Air movement is preferably limited where the baffles are in the form of walls, preferably extending between the two opposing faces. By this arrangement, the flow of air is prevented flowing along the internal surfaces of the opposing faces. In one embodiment, the baffles form a series of ceils disposed throughout the air space between the two opposed faces. Preferably, the ceils are formed by walls extending between the opposing surfaces. The ceils may have an dimensions or geometry as required for a given application, in terms of geometry the cells may have a set geometry and may be substantially triangular, square, rectangular, pentagonal, hexagonal, septagonal, octagonal, nonagonal. or decagonal in other embodiments, the cells are substantially circular or ovoid, in these circumstances it wiil be appreciated that even where the circular or ovoid ceils abut, space wilt remain between the ceils. In that regard, the spaces between the circular or ovoid cells may be considered as cells in themselves, albeit of a non-circuiar or non-ovoid geometry.
In some embodiments of the panel the cells have mixed geometries. In other embodiments the cells have no set geometry, and may result from the random disposition of walls within the cavity formed by the two opposing faces.
Preferably the cells are arranged such that adjacent cells share at least one wall, in some embodiments, the cells are formed by disposing gas filled balloons betwee the opposing faces.
As discussed in the Background Section, it is a problem in the art that insulating materials may be fragile and easily damaged. Damage in the insulating material can in turn expose any underlying material to damage. For example, where the panel forms part of a transport container, damage can be occasioned on the contained article. It is therefore advantageous for the baffles and opposing faces to be configured to provide at least some mechanical resistance to a compressive force applied to the panel, in that regard, it is preferable that the baffles have a fixed geometry which is repeated across the panel to provide resistance to compression. Furthermore, the baffle waii(s) are preferably substantiall orthogonal to the plane of one or both opposing faces. Moreover, the opposing faces are preferably substantially parallel,
Where the baffles are cells, the cells preferably have a set geometry, and more preferably a repeating geometry to provide for substantially uniform compression resistance across the panel. Higher levels of compression resistance may be provided where the cells are at least pentagonal, and preferably at least hexagonal.
Compressive strength of the present panels may be assessed by way of a test directed to establish the compressive force required to mechanically compromise the panel, Useful tests include those which apply an increasing force over a set area until mechanical failure of the panel occurs. Compressive strength may be measured by plotting applied force against deformation (typically irreversible deformation) in a testing machine. Some materials fracture at their compressive strength limit; others deform irreversibly, so a given amount of deformation may be considered as the limit for compressive load. Compressive strength is often measured on a universal testing machine. Compressive strength (and other mechanical properties) may be measured according to various prescribed standards, such as the following Australian Standards: AS 2582.2 Pre conditioning; AS 2582.3 Stacking and compression test; AS 2582.4 Vertical impact test by dropping: and AS 1301.411s-2004 Cobb water absorption. Some embodiments of the panels (or the transport containers described elsewhere herein) are compliant with any 1 , 2 or 3 of the aforementioned standards. In a preferred embodiment the panels or transport containers are compliant with all four standards, thereby allowing for certification to the Australian Seafood Air Transport Regulations (2006; Revision 10,)
In some embodiments, the compressive strength of the panel is at least about 0.5, 0.6, 0.7, 0,8, 0.9, 1.0, 1.2, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 , 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2,9, 3.0, 3.1 , 3.2, 3,3, 3.4, 3.5, 3.6, 3,7, 3.8, 3.9, 4.0, 4,1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 30, 35, 40, 45 or 50 kg/cm2. It will be appreciated that each incremental increase in compressive strength provides a discrete and demonstrable advantage over prior art panels.
Also relevant to use of the present panels as components of transport containers is density. When fabricated from light weight materials such as paper-based materials an insulating panel capable of lowering freight costs (when measured by weight) is the result. In some embodiments, the panel has a gsm rating (grams per square meter) of less than about 1000,
900, 800, 700, 600, 500, 490, 480, 470, 460, 450, 440, 430, 420, 410, 400, 390, 380, 370, 380, 350, 340, 330, 320, 310, 300, 290, 280, 270, 260, 250, 240, 230, 220, 210, 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, 60 or 50. It will be appreciated that each incremental decrease in gsm rating provides a discrete and demonstrable advantage over prior a rt pane I s .
The panei may be fabricated from any suitable materia!(s) known to the skilled artisan. In one embodiment the opposing faces and/or baffies are fabricated from a celiulose-based material such as paper or cardboard. Even relatively flexible materials may be configured in the context of the panel to provide substantial compression resistance.
One or both of the opposing faces or the baffies may be of multilayer construction, including multiple layers of bonded papers or cardboard. In some embodiments the opposing faces or baffles are a laminated paper or cardboard. Typically, lamination is chosen to limit water or vapour permeability of exposed faces of the panel, and/or to provide a reflective surface to limit heat transfer. The lamination may be a polymer or a foil, or a metalised polyester. Suitable polymers include thermoplastic po!ymers including ethylene-based polymers such as high density polyethylene and low density polyethylene, and polyethylene terephthalate. Naturally derived polymers such as those from corn starch or sugarcane biomass are also suitable in some embodiments. As an alternative to polymer-based lamination, simple waxes may be used to confer at least some resistance to moisture and vapour permeation.
Advantageously, the baffles may be fabricated from wholly or partly recycled (or recyclable) material(s). Furthermore, the opposing face(s) may be fabricated from wholly or partly recycled (or recyclable) materials). It will be appreciated that compliance with any relevant food safety law may dictate that virgin materials are used where either opposing face or a baffle has contact with or proximity to food.
In terms of construction, the baffles may be secured to one or both opposing faces using an adhesive. Water-based adhesives (such as polyvinyl acetates) are preferred, and adhesives based on natural substances such as starch and gelatine are highly preferred.
Panel thickness may be selected by having regard to a number of parameters such as the level of insulation required, level of compression resistance required, weight and the like. The thickness (i.e. the minimum distance between the exterior surfaces of the two opposing faces) may be at least about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22,
23, 24, 25, 28, 27, 28, 29 or 30 mm. it will be appreciated that each incremental increase in thickness provides a discrete and demonstrable advantage over prior art panels.
Preferably, the panel thickness is between about 15 mm and about 25 mm. It has been found that performance comparable with prior art polystyrene containers is provided where a thickness of about 15 mm is implemented.
In one embodiment, the panel contains substantially no polystyrene. In other embodiments the panel contains less than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 , 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2 or 0% (w/w) of a synthetic polymer. It will be appreciated that each incremental decrease in synthetic polymer content rating provides a discrete and demonstrable advantage over prior art panels.
In a highly preferred embodiment the panel is substantially devoid of a synthetic polymer.
In one embodiment, the panel has thermal insulation characteristics substantially that of a polystyrene panel of similar thickness.
To improve performance, the panef may comprise a radiant barrier configured to reflect radiant heat back into a cavity of a container formed from the panel (thereby keeping the container contents warm, or reflect heat awa from the cavity (thereby keeping the container contents cool).
The radiant barrier may comprise any of the materials well known to reflect thermal radiation, such as foil and foil laminates, foil-faced poiyurethane or foil-faced polyisocyanurate panels, foil-faced expanded polystyrene, foil-backed bubble pack, aluminium foil with kraft paper backing, and the like.
Conveniently, the radiant barrier may be applied to the panel in the form of a coating configured to reflect radiation in the infra red part of the eiectromagnetic spectrum, which may be sprayed, painted or otherwise applied to the panel. Such coatings may comprise pigments that reflect infra-red radiation, and/or hollow silica/ceramic microsphere additives that reflect longer wavelength radiation. Suitable hollow microspheres may be found in thermally reflective paint products such as Insulad Inc. (TX), Hy-Tech Thermal Solutions' Inc and S.M inc..
As one example, the EC-100 Dirtguard M Silicone Modified Paint (Astec Paints Australasia Pty Ltd, South Australia) may be a suitable coating. This paint reflects predominantly in the spectrum at wavelengths over about 600 nm. In a further aspect the present invention provides a transport container comprising a cavity, and a thermal insulation panel as described herein. As used herein, the term "transport container' includes any construction capable of holding one or more articles in a manner suitable for transport by road, air, rail or sea. in one embodiment the cavity (which is preferably configured to receive the articie(s).) is lined on at least 1, 2, 3, 4, 5 or 6 sides with a panel as described herein. In a highly preferred form of the container the cavity is substantially cuboid or is substantially a rectangular prism, and is lined on a!l 8 sides with a panel as described herein. This embodiment provides higher levels of thermal insulation.
Where multiple thermal insulation panels are used in the construction of the transport container, it is preferred that the panels are disposed such that the edge of a first panel abuts the face of a second panel, in this way, the edges of the panels (which may expose the baffles) are protected from damage (mechanical and otherwise). It is a further advantage that this abutting arrangement provides for higher levels of thermal insulation to the cavity. Without abutment (for example where only the interior surfaces of the opposing faces meet) there exists a path with minimal or no insulation characteristics thereby compromising the overall insulating ability of the container.
As used herein, the term "abut" (or variations thereof) is not intended to be construed in a narrow sense to mean that the entire edge of a first panel contacts the face of a second panel. In some embodiments, only a proportion of the depth of first panel edge contacts the second panel face; and/or only a proportion of the length of first panel edge contacts the second panel face. Furthermore, the term "edge" is intended to include an edge face.
In one embodiment, substantially all of the first panel edge contacts the second panel face. This arrangement limits the opportunity for heat transfer where two panels intersect (for example where the first panel is a wad and the second panel is a floor of a container.
The container may be substantially open to allow deposit of the articles into the cavity, with a Sid being used to secure the articles before transport. In one embodiment, the lid comprises or consists of a thermal insulation panel as described herein.
The container may be of unitary construction and may comprise an integral hinged lid. Alternatively, the container may be configured to accept a separate iid.
Where the possibility exists for the contained articles or any coolant (such as ice) to leak, or conversely for moisture to enter the container, the container may be fitted with a waterproof liner bag or similar contrivance.
The transport container may be constructed such that the interna! or external walls, and/or floor, and/or lid of the vessel are insulation panels as described herein. The panels may completely form any of the walls, floor or lid or may be disposed interna! to dedicated walls, floor or lid.
The panels or containers of the present invention are preferably configured for use in the transport of articles by way of regular government postal services (such as those provided by the United States Postal Service and Royal Mail) or by private courier services such as Fedex™ and DHL™. Such services have preferred parcel sizes, with the present containers being dimensioned accordingly in some embodiments. In some embodiments, the total volume of a packaging container of the present invention is less than about 1 rrr 0.9 m3, 0.8 m3, 0.7 m3 0,6 m3, 0.5 m3, 0,4 m3, 0.3 m3, 0.2 m3 0.1 m3, 0.0S m3, 0.08 m3, 0.07 m3, 0.0S m3, 0.05 m3, 0.04 ms, 0.03 m3, 0.02 m3 or 0.01 m3.
In terms of geometry, the containers are preferably of a regular shape to facilitate close packaging with other containers. Suitable geometries include cubic, rectangular prismatic, and cylind ical,
The panels or transport containers of the present invention may be configured to be useful in bulk transport of goods. For example, the container may be configured for use in air freight, road freight, rail freight or sea freight, it is common for transport systems to utilize bulk containers of standard geometries and dimensions to allow for the time and space efficient loading of cargo holds. Such containers may be completely or partially enclosed, or may simply be a pallet of sorts upon which goods are disposed (although typically with some type of retaining means to secure the goods to the pallet). The present invention includes such standard containers, whereby the present panels are used to line a wall, a floor or a ceiling of a partially or completely enclosed container. Where the container is a pallet, the present panels may be used to form a wai! or a ceiling. Generally, and in accordance with the general teachings of this specification, the goods are substantially completely surrounded by panels to prevent the transfer of heat energy into or out of the standard container, it is
preferred that the panels form butt joints such that the transfer of heat energy is inhibited even at the regions where panels intersect panels.
For bulk transport applications, the panels may be relatively thick (as compared to postage and courier applications) and typically have a thickness of between about 20 mm and about 50 mm. It is contemplated that panels having a thickness of between about 20 mm and about 30 mm will be useful for many bulk transport applications.
Furthermore, any bulk container of the present invention may comprise means for elevating the container off the ground thereby facilitating mechanical handling. For example, the container may comprise feet which allow lifting by a fork lift or pallet jack.
As an example of the containers having standard geometries, freight may be uplifted onto a freighter aircraft or passenger aircraft using various standard-containers and/or pallets, typically termed Unit Load Devices (ULDs). ULDs are designed to allow efficient handling whilst making maximum use of available space in an aircraft.
The present panels or containers may be configured to be useful in the context of a lower deck ULD selected from the group consisting of AAP/AA2, AAF, AKH, ALF, DQF, AAX, PRA, PEB, PAG, AAU, AKE, AMP, PMC, PGA, PAG, PMCS AAA, AAD, AAF, AAP, AAY, AAZ, AGA, AKC, AKH, A W, AKN, ALB, ALD, ALF, ALP, AMA, AM J, AMU, AVY, AWC, AYY, AYX, DPE, DPN, DQF, FLA, FQA, PI P, PAD, PLA, QKE, RAP, RAU, RKN, RWB, SAA, SAX, VRA, XAW and XKC. The present panels or containers may be configured to be useful in the context of a main deck ULD, and may be selected from the group consisting of LD1 , LD2, LD3, LD3-45, LD6, LD8. LD11 , LD8, LD11, and LD7.
Panels and containers useful in bulk transport will typically be of larger dimension than those useful in the context of postal and courier services, and may have heights and or widths about those of any of the above referenced ULDs. In some embodiments, the panel or container be dimensioned such that a predetermined number of panels or containers fit substantially exactly into or onto the ULD with little to no wastage of space. For example, where the ULD is a PMC (having a base dimension of 2438 mm x 3175 mm, and a height dimension of 1626 mm), a container may have a base dimension of 812 mm 1058 mm and a height dimension of 813 mm. In this embodiment, the PMC holds 9 containers on a first layer, and 9 containers on a second layer.
As will be readily appreciated, the dimensiGns of all containers held by the ULD are not necessarily equal. However space wit! be optimized where the added dimensions of all containers are substantially that of the ULD concerned,
For bulk transport applications, a number of panels may be arranged so as to substantially enclose any goods for transport. The panels may be substantially self-supporting, and optionally interlocking to form a substantially continuous enclosure about the goods. One manner in which that may be accomplished is where the base panel is a tray-iike panel having a recess about the perimeter. Side panels are configured to insert into the recesses to create the walls, with a second tray-like panel (again having a perimeter recess) being placed on top of the walls to form a substantially enclosed arrangement.
Where the ULD is a pallet type ULD, the base panel may be placed directly onto the pallet, and the goods then placed onto the base panel, The walls may then be assembled around the goods, with the recess of the to panel then inserted onto the walls to substantially enclose the goods. By this arrangement, the base panel is always supported by the pallet and therefore has no need to be strong enough to bear the weight of the goods. Alternatively, the panels may be prefabricated into a container, the container (with goods) then being loaded into or onto the ULD. By this arrangement, the base panel may be required to bear the load of all contained goods and therefore configured as such.
In a further aspect, the present invention provides a unit load device for use in air freight, the unit load device carrying or containing a thermal insulation panel as described herein, or a transport container as described herein.
As another example, the standard container may be what is typically termed a "dry box" in the shipping industry to denote a non-refrigerated standard shipping container, or a "Hi Cube" shipping container. The internal faces of the container (floor ceiling, walls, and door) may be lined or tiled with panels of the present invention to substantially inhibit heat transfer.
As discussed in the Background Section herein, the transport of empty polystyrene containers to end users for use in packaging articles can be expensive. To overcome that problem, the present invention provides a blank capable of forming a transport container, the blank comprising a backing material (such as a backing sheet) having a series of fold lines, the blank comprising one or more panels as described herein affixed to the backing material.
It will be appreciated that the blank (being thin, and in some cases less than 20 mm thick) is stackab!e such that very little "dead space" is included where a number of blanks is freighted to an end user. By contrast, a consignment of empty polystyrene container contains a significant volume of dead space, thereby adding to costs.
Depending on the ultimate dimensions of the container it may be possible to ship up to four or five times the number of flat packed blanks per pallet, than the equivalent container fabricated from polystyrene. This provides significant benefits with regard to decreasing road use, emissions by transport vehicles, less materials handling for the purchaser, and less storage area needed by the user.
To facilitate assembly, the blank comprises a series of fold lines of the type well known to the skilled artisan and used in prior art packaging blanks. The blank may comprise any number of thermal insulation panels, and arranged in any suitable manner on the backing material, however the blank typically comprises five panels to define 4 walls and 1 floor such thai upon assembly an open transport container is formed.
In one embodiment, the blank comprises at least six panels such that upon assembly a transport container having an incorporated hinged lid is formed.
In some embodiments the blank comprise six panels, to define four walls, and one floor such that upon assembly a transport container is formed a hinged Sid, It is contemplated that a blank may comprise more than six panels.
Advantageously, the backing material and panels are dimensioned and/or arranged such that the assembled container is substantially self-supporting. By relying on frictional engagement between the various faces, walls, floor, edges and other structures in some embodiments there may be no necessity to include any other means to ensure the container maintains its shape over time. Minimising or removing the need to fortify the container with tapes, adhesive, fasteners, staples and the like leads to cost savings and also time saving in assembly.
The blank may include an incorporated hinged lid, or may be configured to accept a separate lid.
Accordingly, a further aspect of the present invention provides a !id for a transport container comprising a thermal insulation panel as described herein. The lid may consist only of the panel, in some embodiments adapted to rest on the iip of the transport container, or on a ledge incorporated into the internal faces of the container. Typically, some means of securing the lid by way of tape, strap, adhesive and the like is used.
In one embodiment, the lid comprises a perimeter edge structure adapted to prevent the lid from failing into a cavity of a transport container. Conveniently, this edge structure ma be formed by affixing a backing material of larger dimension to the pane) such that a perimeter portion of the backing material extends outside the edges of the panel. Alternatively, simple tabs could extend from the exterior face of the panel to prevent the panel from completely entering the cavity.
The lid may comprise two insulation panels fastened together, the first panel dimensioned to fit snugly in the container cavity, with the second of greater dimensions to allow the perimeter to sit on the rim of the container. The use of two panels in the formation of the lid is proposed to provide greater thermal insulation.
The panel configured to fit snugly within the cavity may have tapered edges to allow for a tighter fit. This embodiment greatly limits the ability for air to pass into and out of the cavity, thereby decreasing the opportunity for heat transfer.
In another aspect the present invention provides a method of transporting a perishable article, the method comprising the step of placing the article proximal to one or more thermal insulation panels as described herein, or surrounding the article with panels as described herein. For example, the article may be surrounded by the panels in any suitable manner (such as taped about the article) and placed into a standard cardboard box for transport.
Also provided in a further aspect is a method of transporting a perishable article, the method comprising the step of placing the article into a transport container as described herein. After placing the article, a lid is typically fitted and preferably a lid as described herein.
The present invention further provides use of a thermal insulation panel according in the construction of a transport container. The skilled artisan having the benefit of the present specification will be enabled to conceive of many other ways in which the presently described thermal insulation panels may be utilised to facilitate the packaging and transport of temperature labile articles.
The present invention will now be more fuiiy described by reference to the following non- limiting embodiments.
PREFERRED EMBODIMENTS OF THE INVENTION
Fig 1 shows a perspective diagrammatic view of a thermal insulation panel of the present invention having opposing faces 2 and 4 enclosing a plurality of hexagonal cells 6, The cells are formed by walls (baffles) 8, with each cell enclosing an air space. The opposing spaces are a multilayered paper card, as shown with one layer 12 adhered to the walls 8 with the remaining layers 14 shown peeled back from the panel. Fig 2A shows a blank for folding into a transport container according to the present invention. The container comprises a number of thermal insulation panels 40 42 44 48 50 having a construction as shown in Fig. 1 , the panels glued to a backing sheet 52. The edges 43 and 49 of the panels 42 and 48 respectively have coverings to protect the interior cells. The edges 82 and 84 of the panels 40 and 44 respectively have coverings to protect the interior cells. A plurality of fold lines 54, 56, 58, 60, 62 are pre-formed in the backing material 52 to facilitate assembly of the container. The fold lines in some instances define narrow channels 70 of backing material running between insulation panels. These channels 70 allow for the edges 43 and 49 of panels 42 and 48 respectively to abut the face of adjacent panel 50 (when assembled), thereby improving the insulation characteristics of the container as a whole. It will be apparent that widths of the channels 70 are approximately equal to the thickness of the panel 50. A second type of narrow channel 72 has a protective function when folded over the edges 41 and 45 of panels 40 and 44 respectively. These edges form the upper lip of the container, and the cells of panels 40 and 44 would otherwise be exposed to damage.
Assembly of the blank into a transport container is achieved by firstiy folding panels 42 and 48 along fold lines 54 such that edges 43 and 49 abut the face of panel 50. In the folding of panels 42 and 48, folds begin forming in fold lines 54 56 and 62. The areas 80 of backing material 52 are then folded upwards to 90 degrees by folding along fold lines 56. This action induces further folding of fold lines 62. The areas 90 of the backing material are pushed so as to abut the areas 80 of the backing material. Subsequently, panels 40 and 4 are rotated upwardly to 90 degrees such that the edges 41 and 45 abut the channels 72, The panels 40
and 44 are then further rotated inwardly such that the edges 82 and 84 abut the face of panel 50 to form an open rectangular container. The components of the blank are dimensioned such that sufficient frictionai engagement exists upon assembly such that no adhesive or fastener is required For the container to be substantially self-supporting.
Fig. 2B shows a lid for closing the open end of the assembled container resulting from folding the blank of Fig, 2A. The lid comprises a first thermal insuiation panel 100 to which is fastened a second thermal insulation panel 102 of construction shown in Fig. 1. The panel 102 is dimensioned to sit snugly within the opening of the assembled container, with the perimeter face 106 of the panel 100 dimensioned to abut the rim of the assembled container.
Fig. 3 shows an alternative construction for a blank, numbered generally consistently with the features of Fig. 2A. While sharing features with the blank shown in Fig. 2A, this embodiment has areas 52 allowing for panels 42 and 48 to rotate inwardly such that the face of panels 42 and 48 abuts the adjacent area 52. This embodiment further comprises areas 92 which fold over the edges 82 and 84 to provide protection to those edges.
CQWiPARATfVE EXAMPLE
The aim of this Example was to com are the insuiation capability of a transport container of the present invention with that of a standard polystyrene foam container. The experimental transport container was lined with thermal insulations panels having a construction as shown in Fig, 1 herein. The test container was assembled from a blank substantially similar to that shown in Fig. 2A. The backing sheet was constructed from standard "C" flute corrugated cardboard with a polymer based water impermeable coating. The fold lines followed those of the blank of Fig 2A.
The lid used in this Example was similar to that of a shoe box lid, having a single insulating panel abutting the rim of the container, with the backing sheet extending downwardly along the external faces of the container.
The panels were of thickness 18mm (as measured from the external faces of the opposing faces). The cells were hexagonal of diameter approximately 15mm.
The test container was constructed so that it had identical internal dimensions to the comparative polystyrene container. This ensured that the same internal volume of air was
enclosed by both containers, thereby allowing for the same mass of product in each container.
The comparative polystyrene container was purchased new from Frontier Industries (Clayton, Victoria, Australia, model no F101 B008). if was of the type HDPE which is the preferred densit and weight for most seafood transport applications. This HDPE also has a higher thermal rating than the standard LDPE often used by non seafood producers. This container was chosen as it is certified under the Seafood Air Transport Regulations {2006, Revision 10), having the approval number 10kg-02,
Testing was conducted at Vipac Laboratories (Port Melbourne, Victoria, Australia). Vipac is a testing facility accredited by the Australian National Association of Testing Laboratories ( ATA), Testing was undertaken in a controlled environmental chamber, the test and comparative containers were placed in the chamber so as to be shielded from any direct airflow. Each container was raised off the floor of the chamber so air could flow freely around the entire container. An equal mass (6 kg) of substantialiy identical fresh meat product was placed into each container and three calibrated thermocouple devices were inserted to a depth of 100mm into each product. This enabled recording of changes in the core temperature of product in each of the test containers. The products in each test container were identical in mass, volume and density. Products were pre-conditioned at minus 2 degrees for 24 hours prior to commencement of the testing. A fourth thermocouple device in each container measured the ambient air temperature inside the container.
The ambient temperature of the environmental test chamber was altered hourly according to a predetermined time / temperature curve. The curve was substantially that published by the International Safe Transit Association (ISTA). The curve chosen was the recommended summer profile, and represents the more extreme environments that temperature sensitive products may encounter in "out of cold-chain custody" during a typical 24 hour transit to a customer. This is profile is used by most pharmaceutical and biotechnology companies to pre-qualify freight providers.
Two more calibrated thermocouple devices were placed in the chamber to measure the ambient tennp of the chamber over the 24 hours. Each thermocouple returned a reading every 2 minutes over the test period. The raw data is presented in Table 1 , below. Table 1 : 24 hour time course experiment comparing insulating performance of polystyrene container with experimental container.
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These data are shown graphical!y in Fig. 4. it wiil be noted that temperature within the experimental container remained very similar to that of the prior art polystyrene container for the duration of the experiment. Even where ambient temperature was in excess of 30 degrees Celsius (at 7 hours) the contents of the experimental container remained cool. The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art.