Insulated packaging

Abstract

A flat pattern (200, 200') for folding into a thermally insulated container (204, 204'), the flat pattern (200, 200') formed by a planar sheet (202) of insulating packaging material (3) having: a first panel (218a); a second panel (218b) coupled to the first panel (218a) by a first panel fold line (216a); a third panel (218c) coupled to the second panel (218b) by a second panel fold line (216b) extending parallel to and spaced from the first panel fold line (216a); a fourth panel (218d) coupled to the third panel (218c) by a third fold panel line (216c) extending parallel to and spaced from the second panel fold line (216b); and a tab portion (228a-d, 236a-d) extending from at least some of the panels (218a-d), wherein: the tab portions (228a-d, 236a-d) are coupled to the respective panels (218a-d) by tab fold lines (230a-d, 242a-d) formed along a first side of each panel (218a-d), perpendicular to the panel fold lines (216ac), the tab portions (228a-d, 236a-d) are separated from each other by cuts (232a-c, 240a-c) through the sheet (202) of insulating packaging material (3) extending parallel to and out from the panel fold lines (216a-c), and the tab fold lines (230a-d, 242a-d) on adjacent panels (218a-d) are offset from each other in a direction along the panel fold lines (216a-c) and cuts (232a-c, 240a-c).

Description

The present disclosure relates to a flat pattern for folding into a thermally insulated container, an insulated container formed from the flat pattern, a method for forming the flat pattern and a die for forming the flat pattern. Boxes for storage and transport of items are often made as flat patterns that can be folded to form the boxes. The flat patterns can be bulk manufactured and shipped to an end point of use, where they are assembled. The European Federation of Corrugated Board Manufacturers (FEFCO). FEFCO specifies various standard patterns, that are each assigned a code. Many products require thermal insulation during delivery to maintain a suitable temperature and avoid spoiling of the product. For example, delivery of food, pharmaceuticals or other medical products, construction materials and the like may require temperature controlled packaging. Materials currently used for thermal insulation in packaging include polystyrene, polyester, wool and denim. These are typically not kerbside recyclable, and can be costly and complex to make. In addition at least some of these material are not made of recycled materials themselves, as well as not being recyclable. GB 2 611 286 illustrates an example of an insulating material made of cardboard. However, this material is typically used to make an insulating liner that is fitted into an external container. The external container is based on a FEFCO defined product, but the liner is not. The use of a separate liner requires multiple parts for production and assembly, which is inefficient and time consuming. Even when the material of GB 2 611 286 is used as for forming the external container, without a liner, the flat pattern is complex to assemble, and not in line with FEFCO standards. According to a first aspect of the invention, there is provided a flat pattern for folding into a thermally insulated container, the flat pattern formed by a planar sheet of insulating packaging material having: a first panel; a second panel coupled to the first panel by a first panel fold line; a third panel coupled to the second panel by a second panel fold line extending parallel to and spaced from the first panel fold line; a fourth panel coupled to the third panel by a third fold panel line extending parallel to and spaced from the second panel fold line; and a tab portion extending from at least some of the panels, wherein: the tab portions are coupled to the respective panels by tab fold lines formed along a first side of each panel, perpendicular to the panel fold lines, the tab portions are separated from each other by cuts through the sheet of insulating packaging material extending parallel to and out from the panel fold lines, and the tab fold lines on adjacent panels are offset from each other in a direction along the panel fold lines and cuts. The tab fold lines on alternate panels may extend along the same direction. On the panels having a shorter length along the first side, the tab fold lines may be offset into the panel compared to the tab fold lines of panels having a longer length. At least some of the panels may have: further tab portions coupled to the respective panels by further tab fold lines formed along a second side of each panel, the second side parallel to the first side and spaced from the first side by the panel fold lines. The further tab portions may be separated from each other by further cuts through the sheet of insulating packaging material extending parallel to and out from the panel fold lines. The further tab fold lines on adjacent panels may be offset from each other in a direction along the panel fold lines and cuts. The further tab fold lines on alternate panels may extend along the same direction. On the panels having a shorter length along the first side, the tab fold lines may be offset towards the first side compared to the tab fold lines of panels having a longer length. The planar sheet of insulating packaging material may be at least 4mm in thickness. The planar sheet of insulating packaging material may be formed of a laminated structure. The planar sheet of insulating packaging material may be formed of cardboard. The planar sheet of insulating packaging material may include three or more corrugated layers extending parallel to each other; and between each of the three or more corrugated layers, a substantially planar intermediate layer, the intermediate layers being parallel to each other. The planar sheet of insulating packaging material may be formed of cardboard. The planar sheet of insulating packaging material may include: four or more corrugated layers extending parallel to each other; and between each of the four or more corrugated layers, a substantially planar intermediate layer, the intermediate layers being parallel to each other. The offset of the tab fold lines may be the same or substantially the same as the thickness of the planar sheet of insulating packaging material. The fold lines may be die cut though a portion of the thickness of the planar sheet of insulating packaging material, the cut extending from a first face, partway towards an opposing second face. The die cut formed by the fold line may narrow away from the first face. The flat pattern may comprise an assembly tab formed on a one of the first panel or fourth panel, the adhesion tab extending parallel to and spaced from the panel fold lines. The flat pattern may be folded around the tab fold lines to secure the assembly tab to the other of the first panel or fourth panel at an end of the panel parallel to and spaced from the panel fold lines. According to a second aspect of the invention, there is provided an insulated container formed of the flat pattern of the first aspect, wherein: the flat pattern is folded about the panel fold lines to form sides of the container; and the flat pattern is folded about the tab fold lines to form a base of the container. The flat pattern may be folded about the further tab fold lines to form a lid of the container. The insulated container may be made by the single planar sheet of insulating packaging material forming the flat pattern. The container may be formed according to any FEFCO code. According to a third aspect of the invention, there is provided a method of forming the flat pattern of the first aspect, the method comprising: cutting through the full thickness of a stock sheet of insulating packaging material to form the shape of the flat pattern; cutting through the full thickness of the shape to form the cut lines separating the tabs; and cutting through a portion of the thickness to form the fold lines. At least some of the cutting steps may be performed by die cutting. The method may comprise folding the sheet of insulating packaging material about the panel fold lines and securing the assembly tab. According to a fourth aspect of the invention, there is provided a die for forming the flat pattern of any of the first aspect, comprising: a platen; one or more first blades arranged to cut through the full thickness of the sheet of insulating packaging material to form cut lines and edges of the flat pattern; and one or more second blades arranged to cut partway through the thickness of the sheet of insulating packaging material to form fold lines. Typically, when the container is assembled, the panels form the four sides, and the tab portions co-operate together to form the base (and optionally the lid). The offset of the fold lines about which the tab portions are connected to the side panels allows thicker packaging materials to be used in making the container, while still using patterns similar to the patterns defined by FEFCO codes. This means the container can be formed by a thermally insulative material, without requiring a separate liner, coating or other packaging material. Corrugated cardboard provides similar insulation performance as other commonly used material, thickness for thickness. The stacking of multiple corrugated layers prevents conduction of energy. The energy is diverted into the cavities formed by the corrugations, and then passes along channels formed. The thermal insulating material is easy to make and easy to incorporate into existing packaging systems. Furthermore, the system can be at least partially made of recycled materials and can also be recycled after use. Embodiments of the invention will now be described, by way of the example only, with reference to the accompanying drawings, in which: Figure 1A illustrates a sheet of thermal insulating material according to an embodiment of the invention; Figure IB illustrates a close up of the edge of the sheet of Figure 1A; Figure 2 illustrates a flow chart showing the process of making the sheet of Figure 1A; and Figure 3A illustrates the first step of making a sheet of thermal insulating material; Figure 3B illustrates an intermediate product formed in the step shown in Figure 4A; Figure 3C illustrates a first example of making the top layer of a sheet of the thermal insulating material; Figure 3D illustrates a second example of making the top layer of a sheet of the thermal insulating material; Figure 4A illustrates a first example of a flat pattern made using the thermal insulating material; Figure 4B illustrates the container made by assembling the flat pattern of Figure 4A; Figure 5A illustrates a second example of a flat pattern made using the thermal insulating material; Figure 5B illustrates the container made by assembling the flat pattern of Figure 5A; Figure 6 illustrates a flow chart showing the process of making the flat patterns of Figures 4A and 5A; and Figure 7 illustrates a die for forming the flat pattern of Figure 4A in a single step. Figures 1A and IB illustrates a sheet 1 of thermal insulating material 3. Figure 1A shows a part of the sheet 1 with opposing edges 5a, 5b and an end 7a extending between the edges 5a, 5b. Figure IB shows the near edge 5a in more detail. As best shown in Figure IB, the material 3 is made of a stack 9 of layers 11, 13, 15a, 15b, 15c, 17a, 17b, 17c, 17d formed between a first face 11 of the sheet 1 (referred to as the outer layer 11) and a second face 13 of the sheet 1 (referred to as the inner layer 13). Each of the outer layer 11 and inner layer 13 extend parallel to each other in parallel planes. The outer layer 11 and inner layer 13 are spaced from each other along a direction perpendicular to the planes (and perpendicular to the edges 5a, 5b and end 7a of the sheet 1), defining a thickness of the material 3. A plurality of intermediate layers 15a, 15b, 15c are provided between the outer layer 11 and inner layer 13. The intermediate layers 15, 15b, 15c extend parallel to the inner layer 11 and outer layer 13, spaced from each other and the inner layer 11 and outer layer 13. In the spaces formed between the intermediate layers 15a, 15b, 15c, the space between the outer layer 11 and a first intermediate layer 15a, and the space between the final intermediate layer 15c and the inner layer 13, parallel corrugated (or fluted) layers 17a, 17b, 17c, 17d are provided. Any shape corrugation (or fluting) may be used. For example, the fluting may be ‘A’ flute, ‘B’ flute, ‘C’ flute, ‘E’ flute, ‘F’ flute, ‘N’ flute, ‘O’ flute. The different corrugated layers 17a, 17b, 17c, 17d may have the same or different fluting design. Furthermore, the pitch of the corrugated layers 17a, 17b, 7c, 17d (the spacing between adjacent ridges 19) may be any suitable spacing, and may be constant or varied between layers 17a, 17b,. 17c, 17d. A single corrugated layer 17a, 17b, 17c, 17d is provided in each space. In other words the stack 9 is formed of a number of stacked corrugated layers 17a, 17b, 17c, 17d, separated by intermediate layers 15a, 15b, 15c, sandwiched between the outer layer 11 and inner layer 13. As best illustrated in Figure 3A, which will be discussed below, the corrugated layers 17a, 17b, 17c, 17d comprise a plurality of parallel ridges 19 and valleys 21 extending parallel to the ends 7a, 7b and perpendicular to the sides 5a, 5b and thickness. The tops of the ridges 19 may define a plane that is parallel to the outer layer 11, inner layer 13 and intermediate layers 15a, 15b, 15c. Whilst the corrugated layers 17a, 17b, 17c, 17d are undulating (having ridges 19 and valleys 21), the outer layer 11, inner layer 13 and intermediate layers 15a, 15b, 15c may be flat sheets. However, it will be appreciated that these layers may not be completely flat, and may include some deviation from flat. Nonetheless, compared to the corrugated layers 17a, 17b, 17c, 17d, the outer layer 11, inner layer 13 and intermediate layers 15a, 15b, 15c are substantially planar. In the example shown, the stack 9 has four corrugated layers 17a, 17b, 17c, 17d. however, it will be appreciated that the stack 9 may include more than four corrugated layers 17a, 17b, 17c, 1 7d. For example, the stack may have up to 40 corrugated layers. For example, the material may have 5, 6, 10, 15, 20, 25, 30 or 40 corrugated layers. In one example, the thickness of a corrugated layer 17a, 17b, 17c, 17d combined with an intermediate layer 15a, 15b, 15c, 15d may be approximately 3mm. Therefore, a stack 9 having four corrugated layers 17a, 17b, 17c, 17d will have a thickness of approximately 12mm. A stack 9 having 40 corrugated layers 17a, 17b, 17c, 17d will have a thickness of approximately 120mm. However, it will be appreciated that this is by way of example only. In other examples, the corrugated layers 17a, 17b, 17c, 17d and intermediate layers 15a, 15b, 15c may have any thickness. Furthermore, in some examples, all corrugated layers 17a, 17b, 17c, 17d in the stack 9 may have the same thickness and all intermediate layers 15a, 15b, 15c in the stack 9 may have the same thickness. However, in other examples, the thickness of the layers 15a, 15b, 15c, 17a, 17b, 17c, 17d may vary through the stack 9. In the example shown, the outer layer 11 and inner layer 13 are formed by sheets of material. However, it will be appreciated that this is by way of example only. One or both of the inner layer 11 and outer layer 13, forming the faces of the sheet, may instead be provided by a corrugated layer. In the examples shown above, adjacent intermediate layers 15a, 15b, 15c are separated by corrugated layers 17a, 17b, 17c, 17d, such that the stack is comprised of alternating corrugated layers 17a, 17b, 17c, 17d and intermediate layers 15a, 15b, 15c, with an optional outer layer 11 and an optional inner layer 13. It will be appreciated that in some examples there may be two or more intermediate layers separating some or all of the corrugated layers. A method 100 of making the thermal insulated material 3 will now be discussed with reference to Figures 2 and 3A-D. It will be appreciated that this method is given by way of example only, and any suitable method for making the material 3 may be used. For simplicity, the method will only be illustrated for making material with four corrugated layers 17a, 17b, 17c, 17d, however the method is readily scalable to any number of corrugated layers 17a, 17b, 17c, 17d. In this example, the stack 9 of the material 3 is built up by stacking sheets 23a, 23b, 23c, 23d of single face corrugated cardboard. As shown in Figure 3A, single face corrugated cardboard comprise a composite sheet, including a base sheet 25 and a corrugated sheet 27. The single face corrugated cardboard may be provided, preformed, as a sheet or on a roll. In a first step 102, a first sheet of single face corrugated cardboard 23a is provided. This comprises a first base sheet 25 and a first corrugated sheet 27. These layers 25, 27 can be joined by any suitable adhesive. This may be a polyvinyl acetate (PVA) based adhesive, an organic starch adhesive, or any other adhesive. At this stage, the first base layer 25 forms a lower surface and the first corrugated layer 27 an upper surface. In the completed product, the first base sheet will form one of the surfaces 29, 31 of the material 3 (the surface forming the inner or outer face layers 11, 13). In a second step 104, adhesive 33 is applied to the tops of the ridges 19 of the first corrugated layer 27. In one example, the adhesive used may be a polyvinyl acetate based adhesive. In other examples, the adhesive may be an organic starch based adhesive, for simpler recycling of the product, once used. Any other adhesive may also be used. The adhesive may be the same or different to the adhesive used to join the layers 25, 27 in the single face corrugated cardboard 23a. In a third step 106, as shown in Figure 3A, a second sheet 23b of single faced cardboard is fixed on top of the first sheet 23a. The base sheet 25 of the second single faced cardboard sheet is fixed to the ridges 19 on the first sheet 23a. This results in the intermediate structure shown in Figure 3B. The corrugated layer of the second sheet 23b of single faced cardboard is now the upper surface. In one example, this process is repeated until sufficient corrugated layers are built up and then a top layer forming the second surface 31 is provided in step 108. Figure 3C shows a first example for applying the top layer 31. In this example, adhesive 33 is applied to the ridges on the upper surface, and a single sheet 35 forming the top layer 31 is fixed. In a second example, shown in Figure 3D, the final corrugated layer is provided as part of a composite layer include the corrugated layer 17d sandwiched between two sheets (referred to as single wall cardboard). Thus the top layer 31 is provided at the same time as the final corrugated layer 17d. Once the top layer 31 is provided, the material is cured in step 110. In one example, curing is by application of pressure in a direction through the thickness of the material 3. Pressure may be applied by straps, pneumatic or hydraulic devices or any other suitable means. In this example, no heat is applied, and the curing is done at ambient temperature. However, in other examples, heat may be used to cure the adhesive instead of or as well as pressure. The stack 9 may be built up either starting at the outer face layer 11 (such that the final layer added forms the inner face layer 13) or the inner face layer 13 (such that the final layer added forms the outer face layer 11). Alternatively, the stack may be built up from the middle, so that layers are added on either side of the first layer. In some examples, two composite layers 23a, 23b may be provided back to back (so that the base sheets 25 are fixed to each other. Further composite layers 23a, 23b may then be added on either side of this to build the stack 9. In the example discussed above, preformed single face cardboard is used to build up the layers. This may be provided in either rolls or sheets. However, it will be appreciated that in other examples, the layers may be built up separately. In other words, the sequence of building up the layers may start with a sheet, and then alternate between corrugated layers and flat sheets, until a final flat sheet is added. In this case, the adhesive may be applied to the flat sheet to align with the valleys 21 in the corrugate sheet. The corrugated sheets may be preformed, and provided in a roll or sheet, or may be taken directly from a creasing machine. Alternatively, the single face corrugated cardboard 23a, 23b may be formed in a preceding step, at a separate device, and fed directly to the method 100 discussed above. Any suitable cardboard may be used to form the thermal insulating material 3. The table below shows the thermal insulating properties for various materials at the same thickness. Material K-value R-value Polystyrene foam 0.033-0.0035 3.61 Fibreglass 0.05-0.052 3.52 Corrugated card 0.037 3.45 Wool 0.037 3.61 This table shows the following: K-value, which denotes the effective thermal conductivity of the material, which is a measure of the time rate of steady heat flow through a unit area of a material induced by a unit temperature gradient. The k-Value is expressed as 1 W / mK. The lower the K-value the better an insulator the material is; and R-value, which denotes materials thermal resistance. The higher the R-value, the better an insulator the material is. In some examples, the entire stack may be made of recycled cardboard. It will be appreciated that as cardboard is recycled, the length of fibres in the material is reduced. With shorter fibres, the material is more absorbent. Absorbing moisture at the inner face 13 of a container reduces the thermally insulative properties. Therefore, in some cases, the sheet forming the inner face layer 13, is made of material comprising longer fibres than the other layers. This may be either virgin (unrecycled) cardboard or cardboard that has been recycled less times than the other layers. This ensures reduced absorbance of moisture or condensation. In some examples, only the inner face layer 11 may be made of the longer fibre material. In other examples, a set of layers near the inner face layer 11 may be made of the longer fibre material. It may also be that the length of fibres reduces away from the inner face layer 11. This may be layer by layer (i.e. each layer has successively reducing fibre length) or in blocks of layers. Alternatively, a lining such as a polyethylene, acrylic or wax may be used. It will be appreciated that where either of the inner face 11 or outer face 13 is formed by a corrugated layer, the step 108 of adding the top layer may be omitted. Where both faces 11, 13 are formed by corrugated layers, a single corrugated layer or composite structure may be added as the top layer. Figures 4A and 5A illustrate two examples of flat patterns 200, 200’ formed from a single sheet 202 of the thermal insulating material 3 discussed above. Figures 4B and 5B respectively show the containers 204, 204’ formed by folding the flat patterns 200, 200’ as will be discussed below. The two flat patterns 200, 200’ are the same unless explained otherwise, and where parts of the two flat patterns 200, 200’ are the same, the same reference numbers are used. Figure 4A shows the flat pattern 200 for making a 204 without a lid. In the example shown in Figure 4A, the sheet 202 has a rectangular central section 206 having a pair of sides 212a, 212b running parallel to each other and defining a length 210 of the central section. A pair of ends 214a, 214b extend perpendicular to and between the sides 212a, 212b, defining a width of the central section 206. The width 208 of the central section 206 corresponds to the intended height of the assembled container 204, and the length 210 corresponds to the outer perimeter of the assembled container 204, around the sides 220a, 220b, 20c, 220d. Three fold lines 216a, 216b, 216c (referred to as panel fold lines) are formed extending across the width 208 of the central section 206, spaced along the length 210 of the central section 206. The panel fold lines 2 16a-c divide the central section 206 into four panels 218a, 218b, 218c, 218d, which form the sides 220a-d of the assembled container 204. Each panel 218a-f has spaced edges extending parallel to the ends 214a,b of the central section 206. In the first panel 218a, a first edge is formed by the first end 214a of the central section and the second edge is formed by the first panel fold line 216a. In the fourth panel 218d, a first edge is formed by the third panel fold line 216c and the second edge is formed by the second end 214b of the central section 206, opposite the first end 214a. In the second and third panels 218b,d both edges are formed by panel fold lines 216a, b,c. To form a rectangular container 204, the first and third panels 218a,c are the same length as each other, and the second and fourth panels 218b,d are the same length as each other. To form a square container 204, all four panels 218a-d are the same length. At the first end 214a of the central section 206, a rectangular assembly tab 222 is formed. The assembly tab 222 extends from the first edge of the first panel 218a, and extends for substantially the full width of the central section 206. The length of the assembly tab 222 (along the sides 212a,b of the central section) is only a portion of the length of any of the panels 218a-d. A fold line 224 is formed at the first edge of the first panel 218a, about which the assembly tab 222 may fold. The assembly tab 222 is only coupled to the central section 206 by the single fold line 222. The other three sides of the assembly tab 222 are free. The base 226 of the container 204 is formed by base tabs 228a, 228b, 228c, 228d extending from the second side 212b of the central section 206. Each base tab 228a-d is substantially rectangular in shape, having a length extending for substantially the length of the panel 218a-d to which it is coupled. The base tabs 224a-d have a width extending approximately half the width of the base 226. The base tabs 228a-d are separated from each other along the length 210 of the central section 206 by cuts 232a, 232b, 232c that extend along the same direction as the panel fold lines 216a-c Each base tab 228a-d is coupled to the central section 206 by a respective fold line 230a, 230b, 230c, 230d, about which the base tab 228a-d can be folded (referred to as base tab fold lines). The base tab fold lines 230-d extend parallel to the sides 212a,b f the central section. Each base tabs 228a-d is only connected to the central section 206 by a single fold line 230a-d such that the other three sides of the base tabs 228a-d are free. On the first and third panels 218a,c, the base tab fold line 230a,c are substantially along the second side 212b of the central section 206, and aligned with a lower side 234b of the assembly tab 222. The base tab fold line 232b,d of the second and fourth panels 218b,d is offset from the second side 212b of the central section 206 into the panel 218a,c (i.e., towards the first side 212a). The base tab fold lines 232b,d of the second and fourth panels 218b,d are along the same line as each other. The assembled container 204 is formed by folding the central section 206 around the panel fold lines 216a-c to fix the assembly tab 222 to the fourth panel 218d. The base tabs 228a-d are then folded about the base tab fold lines 230a-d to close the base 226 of the container 204. The base tabs 228a-d may be secured together to ensure the container 204 holds its shape. The offset of base tab fold lines 230a-d on alternating panels 218a-d ensures that even with the increased thickness of the thermal insulating material 3, the edges of the container 204 can be formed without the sides 220a-d or base tabs 228a-d interfering with each other. Therefore, the size of the offset is the same or approximately the same as the thickness of the thermal insulating material 3. In the assembled container 204, the length of the first and third panels 218a,c forms the length of the container 204, and the length of the second and fourth panels 218b,d forms the width of the container 204. In the base 226 of the assembled container 204, the first and third base tabs 228a,c fold towards each other to meet at a centre line extending along the length of the container 204. Similarly, the second and fourth base tabs 228b,d fold towards, but are spaced from each other along the length of the container 204. The first and third base tabs 228a,c will overlie the second and fourth base tabs 228b,d or vice versa. Any suitable means may be used to secure the assembly tab 222 to the fourth panel 218d and to secure the base 226. This may include adhesive, staples, stitching, tape, and the like. Different fixing means can be used for the assembly tab 222 and the base 226. In some examples, the assembly tab 222 may be secured to the fourth panel 218d as part of the manufacture process, to provide a flat element. A large number of these flat elements can be stacked and shipped (for example on a pallet) to a point of use, and the final folding (and securing of the base 226) can take place at the point of use. The flat pattern 200’ in Figure 5A is the same as the flat pattern 200 in Figure 4A. However, in addition to the base tabs 228a-d, lid tabs 236a-d are provided to form a lid 238 of the assembled container 204’. The lid tabs 236a-d are formed in a similar manner to the base tabs 228a-d, but extend from the first side 212a of the central section 216. Like the base tabs, 228a-d, the lid tabs 236a-d are separated from each other along the length of the central section 206 by cuts 240a-c extending from the panel fold lines 216a-c, and are coupled to the central section 206 by a single lid tab fold line 242a-d. As with the base tabs 228a-d, the fold lines 242a,c of the lid tabs 236a,c on the first and third panels 218a,c are along the first side 212a of the central section 206, and the fold lines 242b,d of the lid tabs 236b,d on the second and fourth panels 218b,d are offset into the panel (i.e. towards the second side 112b). The lid tabs 236a-d are rectangular in shape, having a length substantially the same as the length of the panels 218a-d and a width of substantially half he width of the lid 238. The container 204’ made from the second flat pattern 200’ is assembled in the same manner as the container 204 made from the first flat pattern 200. The lid 238 is assembled in the same manner as the base 226 and may be secured once the contents are provided in the container 204’. Figure 6 shows the method 300 for forming the flat patterns 200, 200’ discussed above. In a first step 302, a sheet 202 of the thermal insulating material 3 is provided. This may be by the method 100 of Figure 2 or any other method. The sheet is built up to the desired thickness of corrugated layers 17a, 17b, 17c, 17d. A first trimming step 304 is then performed, to cut the sheet 1 to the correct size and shape. At a next step 306, the fold lines 216a-c, 224, 230a-d, 242a-d are formed. A second trimming step 308 is then performed to form the cuts 232a-c, 240a-c separating the base and lid tabs 228a-d, 236a-d. Trimming the edges of the sheet 202, and forming the cuts 232a-c, 240a-c separating the base and lid tabs 228a-d, 236a-d requires cutting through the full thickness of the sheet 202, whilst forming the fold lines 216a-c, 224, 230a-d, 242a-d requires cutting partway through the thickness. In a next step 310, the assembly tab 222 is then fixed to the fourth panel 218d , and the container 204, 204' may then optionally be assembled. The trimming steps 304, 308 and formation of the fold lines 306 may be performed by a die cutter. It will be appreciated that all the cuts and fold lines may be made in a single step, using a single die. In this case, there is no separate first trimming step, second trimming step, and step of forming the fold lines. Alternatively, multiple steps using multiple dies may be used to perform the different cuts. Further steps may be provided to, for example, trim a larger sheet to the approximate size required and the like. Various features such as handles may also be cut out by die cutting. This may be incorporated in the single step or in multiple steps. Typically, die cutting is performed by applying pressure to press a die against the blank sheet to be cut. The die includes blades for forming the cuts. The different depth of cuts may be achieved by having blades of a different depth, or by applying different pressure to different areas of the die, or different dies. Furthermore, the blades may be shaped to form different cross-sectional shape cuts. For example, the edges and cuts 232a-c, 240a-c separating the base and lid tabs 228a-d, 236a-d may be straight edged through the thickness of the sheet 202, whilst the fold lines 216a-c, 224, 230a-d, 242a-d may taper inwards. Figure 7 illustrates an examples of a die 400 for cutting flat pattern 200 shown in Figure 4A in a single step. The die 400 has a platen 402 in the form of a plate. First blades 404 (shown by double lines) are provided to cut the outer edges of the sheet 202, second blades 406 (shown by thick solid lines) are provided to form the cuts 232a-c, 240a-c separating the base and lid tabs 228a-d, 236a-d and third blades 408 (shown by dashed lines) are provided to form the fold lines 216a-c, 224, 230a-d, 242a-d. The platen 402 as a front face 410 from which the blades 404, 406, 408 project, and an opposing rear face (not shown). In use, one face 11, 13 of the blank sheet 202 of thermal insulating material 3 is aligned over the first face 410 of the platen 402. Pressure is then applied to the rear face of the platen 402 and / or the other face 11. 13 of the blank sheet 202 of thermal insulating material 3 to cause the cutting action. In the example shown, the platen 402 is a flat plate. However, it will be realised that a cylindrical platen, or any other suitable platen may be used. Dies for forming other flat patterns 100’ will be apparent to the person skilled in the art. When the assembled container 204. 204’ is in use, heat energy is diverted into the cavities formed by the corrugated layers 17a, 17b, 17c, 17d rather than passing through the material. The captured heat passes along channels formed by the valleys 21. In one example, the ends of the corrugated layers 17a, 17b, 17c, 17d may be open, such that the heat does eventually escape. In another example, a score or crimp line (not shown) may be formed adjacent the edges of the sheet 202. The score or crimp line extends perpendicular to the ridges 19 and valleys 21 of the corrugated material. The score or crimp line closes the cavities formed by the corrugated layers 17a, 17b, 17c, 17d, further trapping heat and further improving the insulating properties of the material 3. It will be appreciated that in some examples, the score or crimp line is formed adjacent to but not at the edges. In order to ensure the sheet 202 retains the strength to support itself when folded, the score or crimp lines may be spaced from the edge. For example, the score or crimp lines may be at least 25mm from the edge. The score or crimp line may be formed by suitable application of pressure applied to one or both of the surface of the sheet 202. The score or crimp line will not break the layers, but compresses them. The indent formed by the score or crimp line will be narrower than the fold lines. The step of forming the score or crimp line may be part of the method 100 of making the stack 9 of material 3 or the method 300 of making the flat pattern 200, 200'. In some examples, multiple score or crimp lines may be provided along the length of the ridges 19 and valleys 21 to create isolated pockets to further trap air. The step of forming score or crimp line may be applied during die cutting by a blunt blade that applies pressure, rather than cutting the material. The closing ofthe cavities formed in the corrugated layers 17a, 17b, 17c, 17d is optional and may be omitted. Furthermore, the use of a score line or crimp line is by way of example, and any suitable closing method may be used. For example, a sealing membrane, or additional sheet may be provided over the ends of the ridges 19 and valleys 21. The use of die cutting to form the fold lines 216a-c, 224, 230a-d, 242a-d and the shape of the flat pattern is by way of example only. It will be appreciated that any suitable method may be used. For example, a box maker machine may be used instead of diecutting and folding. In the above examples, the flat patterns 200, 200’ are formed from a single sheet 202 of the thermal insulating material 3 discussed in relation to Figures 1A, IB, 2 and 3A-D. This sheet 202 has four or more corrugated layers 17a, 17b, 17c, 17d separated by planar layers 15a. 15b. 15c. This is by way of example only. The sheet may have only three corrugated layers 17a, 17b, 17c. Alternatively, any other type of insulated sheet may be used. For example a sheet formed of a plurality of n-flute layers may be used. The sheet 202 may have a thickness of 4mm or more. Where the thermal insulating material is formed by the method 100 shown in Figure 2, it may be that the material is passed straight to the method 300 of Figure 6. Alternatively, the material may be stored as rolls or sheets after it has been made, for later processing to form the flat pattern 200, 200’. The flat patterns 200, 200’ discussed above correspond to the flat patterns defined in FEFCO codes 0200 and 0201, modified to be used with thicker insulating material. It will be appreciated that by modifying the relative lengths and widths of the panels 218a-d and tabs 228a-d, 236a-d, modified patterns corresponding to different FEFCO codes may also be made (for example FEFCO codes 0202 to 0206). Furthermore, the size and shapes of the panels 218a-d and tabs 228a-d, 236a-d can be modified to make different size and shape containers. The overlaps at the base 226 and lid 238 may also be changed as desired. In some examples, tabs for the base 226 and / or lid 238 may not be coupled to every panel (for example where the base 226 and / or lid 238 is formed without an overlap. Furthermore, as shown by the two example discussed above, the lid 238 may be omitted altogether. The offsets given above are by way of example only. In the example discussed above, the panels 218a-d with a shorter length have the base tab fold lines 230a-d offset into the panels 218a-d, making these panels narrower as well as shorter. This is by way of example only, and the panels 218a-d with the longer length may be offset. The offset may be into the panels 218a-d as discussed above, or out of the panels 218a-d. In the examples discussed above, the base and lid tab fold lines 230a-d, 242a-d are offset towards each other in panels 218a-d. In other examples, one of the base tab fold lines 230a-d and lid tab fold lines 242a-d may be offset into the panels 218a-d and the other may be offset out of the panels 218a-d. In the example discussed above, alternating panels have the base tab fold lines 230a-d aligned with each other and lid tab fold lines, 242a-d aligned with each other. This is by way of example only. It may be that the two panels with fold lines 230a-d, 240a-d offset from the side 212a,b of the first section 206 may have different offsets. Alternatively, three or even four of the base tab fold lines 230a-d and / or lid tab fold lines 240a-d may be offset from the sides 212a,b of the first section 206. In the examples shown above, the sides of the assembly tab 222 are aligned with the sides of the first section, this need not necessarily be the case, and the assembly tab may be narrower than the first section 206, and may be offset at one or both sides 212a,b. Furthermore, multiple assembly tabs 222 may be provided across the width of the first section. The assembly tabs may extend from one or both of the first and fourth panels 218a,d. In one example, the sheet 202 of thermal insulating material 3 is arranged such that the ridges 19 and valleys 21 in the corrugated layers 17a, 17b, 17c, 17d extend vertically in the sides 33a, 33b, 33c, 33d of the container 204, 204’. However, this is by way of example only, and the ridges 19 and valleys 21 in the corrugated layers 17a, 17b, 17c, 17d may extend in any direction. Various different fold lines are referred to in the above description. The sheet 202 of insulating material 3 can be folded around the fold lines such that portions / tabs / panels on either side of the fold lines can rotate relative to each other. The amount of rotation can be between 0 degrees (in the flat pattern) to whatever angle is required by the assembled container 204, 204’ (90 degrees if rectangular). Further rotation may be allowed, for example to allow the assembly tab 222 to be fixed and to still allow stacking and shipping as a flat element. The fold line may be any suitable living hinge or other folding mechanism. The allowed rotation around the fold lines is determined by the depth and / or width of the cut forming the fold line. The face 11, 13 of the sheet 202 arranged to form the outside of the container 204, 204’ may be printed or have labels affixed to provide information on the container 204, 204’ or its contents.

Claims

1. A flat pattern for folding into a thermally insulated container, the flat pattern formed by a planar sheet of insulating packaging material having:a first panel;a second panel coupled to the first panel by a first panel fold line;a third panel coupled to the second panel by a second panel fold line extending parallel to and spaced from the first panel fold line;a fourth panel coupled to the third panel by a third fold panel line extending parallel to and spaced from the second panel fold line; and a tab portion extending from at least some of the panels, wherein:the tab portions are coupled to the respective panels by tab fold lines formed along a first side of each panel, perpendicular to the panel fold lines,the tab portions are separated from each other by cuts through the sheet of insulating packaging material extending parallel to and out from the panel fold lines, andthe tab fold lines on adjacent panels are offset from each other in a direction along the panel fold lines and cuts.

2. The flat pattern of claim 1, wherein the tab fold lines on alternate panels extend along the same direction.

3. The flat pattern of claim 1 or claim 2, wherein:on the panels having a shorter length along the first side, the tab fold lines are offset into the panel compared to the tab fold lines of panels having a longer length.

4. The flat pattern of any preceding claim, at least some of the panels having: further tab portions coupled to the respective panels by further tab fold lines formed along a second side of each panel, the second side parallel to the first side and spaced from the first side by the panel fold lines,wherein the further tab portions are separated from each other by further cuts through the sheet of insulating packaging material extending parallel to and out from the panel fold lines, andthe further tab fold lines on adjacent panels are offset from each other in a direction along the panel fold lines and cuts.

5. The flat pattern of claim 4, wherein the further tab fold lines on alternate panels extend along the same direction.

6. The flat pattern of claim 4 or claim 5, wherein:on the panels having a shorter length along the first side, the tab fold lines are offset towards the first side compared to the tab fold lines of panels having a longer length.

7. The flat pattern of any preceding claim, wherein the planar sheet of insulatingpackaging material is at least 4mm in thickness.

8. The flat pattern of any preceding claim, wherein the planar sheet of insulating packaging material is formed of a laminated structure.

9. The flat pattern of claim 8, wherein the planar sheet of insulating packaging material is formed of cardboard and includes:three or more corrugated layers extending parallel to each other; and between each of the three or more corrugated layers, a substantially planar intermediate layer, the intermediate layers being parallel to each other.

10. The flat pattern of claim 9, wherein the planar sheet of insulating packaging material is formed of cardboard and includes:four or more corrugated layers extending parallel to each other; and between each of the four or more corrugated layers, a substantially planar intermediate layer, the intermediate layers being parallel to each other.

11. The flat pattern of any of claims 7 to 10, wherein the offset of the tab fold lines is the same or substantially the same as the thickness of the planar sheet of insulating packaging material.

12. The flat pattern of any preceding claim, wherein the fold lines are die cut though a portion of the thickness of the planar sheet of insulating packaging material, the cut extending from a first face, partway towards an opposing second face.

13. The flat pattern of claim 12, wherein the die cut formed by the fold line narrows away from the first face.

14. The flat pattern of any preceding claim, comprising an assembly tab formed on a one of the first panel or fourth panel, the adhesion tab extending parallel to and spaced from the panel fold lines.

15. The flat pattern of claim 14, wherein the flat pattern is folded around the tab fold lines to secure the assembly tab to the other of the first panel or fourth panel at an end of the panel parallel to and spaced from the panel fold lines.

16. An insulated container formed of the flat pattern of any preceding claim, wherein:the flat pattern is folded about the panel fold lines to form sides of the container; andthe flat pattern is folded about the tab fold lines to form a base of the container.

17. The insulated container as claimed in claim 16, when the flat pattern is as claimed in any of claims 4 to 6, or any claim dependent thereon, wherein the flat pattern is folded about the further tab fold lines to form a lid of the container.

18. The insulated container as claimed in claim 16 or claim 17, wherein the insulated container is made by the single planar sheet of insulating packaging material forming the flat pattern.

19. The insulated container of any preceding claim, wherein the container is formed according to any FEFCO code.

20. A method of forming the flat pattern of any of clams 1 to 15, the method comprising:cutting through the full thickness of a stock sheet of insulating packaging material to form the shape of the flat pattern;cutting through the full thickness of the shape to form the cut lines separating the tabs; andcutting through a portion of the thickness to form the fold lines.

21. A method as claimed in claim 20, wherein at least some of the cutting steps a performed by die cutting.

22. The method as claimed in claim 19 or claim 20, wherein the flat pattern is as claimed in claim 15, the method comprising:folding the sheet of insulating packaging material about the panel fold lines and securing the assembly tab.

23. A die for forming the flat pattern of any of claims 1 to 15, comprising:a platen;one or more first blades arranged to cut through the full thickness of the sheet of insulating packaging material to form cut lines and edges of the flat pattern; andone or more second blades arranged to cut partway through the thickness of the sheet of insulating packaging material to form fold lines.

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