GB2479703A

GB2479703A - Hermetically sealed container and blank

Info

Publication number: GB2479703A
Application number: GB0914696A
Authority: GB
Inventors: Edwin Wyn Owen; Neal Andrew Whipp
Original assignee: CARTON EDGE 2009 PENSION SCHEME TRUST
Current assignee: CARTON EDGE 2009 PENSION SCHEME TRUST
Priority date: 2009-08-21
Filing date: 2009-08-21
Publication date: 2011-10-26
Also published as: GB0914696D0

Abstract

A blank 10 for forming at least part of a substantially hermetically sealed container, comprises: a substrate having a first surface and a second surface. The substrate comprises adjacent wall panels 25, 26 and lip panels, 34, 35 and a connecting structure 29 between the first wall panel 25 and the second wall panel 26. A corner recess 37 is provided in the substrate, between the first lip panel 34 and the second lip panel 35, the recess being configured to allow the lip panels 34, 35 to overlap when the connecting structure is folded into a face contacting relationship with the first surface of one of the wall panels. Further wherein, the blank includes a heat sealable barrier layer provided over the first surface and additionally extending across the corner recess 37, between the first lip panel 25 and the second lip panel 26, and extending over the edge of the recess 37 to form a tab 52, such that, upon folding of the connecting structure into a face contacting relationship with the a surface of one of the wall panels, the first and second lip panels 34, 35 overlap, and the tab 52 can be brought into a face contacting relationship with the first surface of one of the lip panels 34, 35 (figure 5) to thereby form a corner structure capable of substantial hermetic sealing.

Description

A blank, a container, a method for forming a blank, and a method for forming a container The invention relates to a blank, a container, a method for forming a blank, and a method for forming a container. In particular, a blank for forming at least part of hermetically sealed container, a container with a corner capable of being hermetically sealed, and methods for producing said blank and said container.

It is desirable that packaging, and in particular food packaging, is produced, to the greatest extent possible, from sustainable resources, such as carton board, rather than plastics material. Many types of packaging, for example, sandwich containers, are now produced substantially from carton board rather than plastics material. Such containers generally include a laminate polymer layer which acts a barrier to prevent migration of liquid from the foodstuffs into the carton board.

For some foodstuffs, it is also desirable to pack them in a hermetically sealed manner, for example to prevent leakage or to enable the use of an inert atmosphere inside the packaging to aid preservation of the foodstuffs contained. Further it would be advantageous for the container to be ovenable. For example, a known ovenable, hermetically sealed container comprises a moulded plastic tray, with a planar top edge, and a plastic film lid heat sealed to the top edge of the tray. Until now, when trying to produce such a tray from carton board, it has not been possible to produce an arrangement in which the integrity of the seal between the tray and the lid is sufficient. The present invention seeks to overcome, or at least

mitigate, the problems of the prior art.

According to a first aspect of the present invention, there is provided a blank for forming at least part of a substantially hermetically sealed container, the blank comprising: a substrate having a first surface and a second surface and the substrate comprising a first wall panel, a first lip panel connected to the first wall panel, a second wall panel, a second lip panel connected to the second wall panel, and a connecting structure between the first wall panel and the second wall panel, wherein, a corner recess is provided in the substrate, between the first lip panel and the second lip panel, the recess being configured to allow the lip panels to overlap when the connecting structure is folded into a face contacting relationship with the first surface of one of the panels, and further wherein, the blank includes a heat sealable barrier layer provided over the first surface and additionally extending across the corner * *1 recess, between the first lip panel and the second lip panel, and extending over the edge of the recess which extends between the lip panels, to form a tab, such that, upon folding of the connecting structure into a face contacting relationship with the first surface of one of the wall panels, the first and second lip panels overlap, and the tab can be brought into a face contacting relationship with the first surface of one of the lip panels to thereby form a corner structure capable of substantial hermetic sealing.

The tab preferably extends from the sheet a distance greater than the minimum distance the first lip and the second lip extend from the respective main portions of the panels. In order that the corners of the assembled container are rounded, the edges of the lips are preferably tapered towards the wall panels. The extended tab, therefore, utilises the wider lip available at the point of sealing, thus promoting a better seal. The tab preferably extends from the sheet a distance smaller than the maximum distance the first lip and the second lip extend from the respective main portions of the panels. Therefore, on heat sealing, there will not be excess material from the tab overlapping the edge outer edges of the lips.

Preferably, the heat sealable barrier layer extends across the entire first surface of the sheet.

Therefore, the entire container, as well as the corner in the region of the lips, can be suitable for forming a structure capable of substantial hermetic sealing.

According to second aspect of the invention, there is provided a container with at least one corner structure capable of substantial hermetic sealing, the container formed from a blank, the blank comprising: a substrate having a first surface and a second surface and the substrate comprising a first wall panel connected to a first edge of the base panel, a first lip panel connected to the first wall panel, a second wall panel, a second lip panel connected to the second wall panel, and a connecting structure extending between the first wall panel and the second wall panel, wherein, a corner recess is provided in the substrate, between the first lip panel and the second lip panel, the recess being configured to allow the lip panel to overlap when the connecting structure is folded into a face contacting relationship with the first surface of one of the panels, and further wherein, the blank includes a heat sealable barrier layer provided over the first surface and additionally extending across the corner recess, between the first lip panel and the second lip panel, and extending over the edge of the recess which extends between the lip panels, to form a tab, such that, the connecting structure is folded into a face contacting relationship with the first surface of one of the wall panels, the first and second lip panels overlap, and the tab is in a face contacting relationship with the

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first surface of one of the lip panels, the corner being heat sealed to produce a corner structure may be substantially hermetically sealed.

The blank preferably includes a base panel, the first wall panel being connected to a first edge of the base panel, the second wall panel being connected to a second edge of the base panel.

The base panel may be rectangular and the blank may comprise wall panels, one wall panel extending from each side of the base panel, and the blank may further comprise a connecting structure between each adjacent pair of wall panels.

The container preferably further includes a lid, the heat sealable barrier layer extending across the lid such that the lid can be hermetically heat sealed to the lip. Therefore a container which is substantially hermetically sealed can be produced.

According to a third aspect of the present invention, there is provided a method of forming the blank according to the first aspect of the present invention, the method comprising the steps of (a) removing material from a master sheet of substrate so that the master sheet defines a recess of a width equal to that of the corner recess required in the blank, and of a depth at least equal to that required for the tab, the position of the recess corresponding to the desired position of the corner recess and the tab in the blank; (b) securing a heat sealable barrier layer to the first surface of the substrate master sheet; (c) cutting out the outer perimeter of the blank from the master sheet, so that the blank can be folded to form a container; wherein, step (b) precedes or succeeds steps (a) and (c), and step (c) succeeds step (a).

According to a fourth aspect of the present invention, there is provided a method of forming the container according to the second aspect of the present invention, the method comprising the steps of: forming a blank according to the third aspect of the present invention; then (ii) folding the connecting structure into a face contacting relationship with the first surface of one of the panels, such that the first and second lip panels overlap, and the tab is in a face contacting relationship with the first surface of one of the lip panels; and (iii) heat sealing the corner to produce a corner structure which is substantially hermetically sealed.

A blank and container, and a method of forming a blank and a container, in one embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Fig 1 shows a section of sheet with the printed area of two blanks indicated by dashed lines; Fig 2 shows the sheet and blanks of Fig 1, with the recesses created; Fig 3shows the sheet and blanks of Fig 2 with a laminate layer applied; Fig 4 shows a blank of Fig 4 after cutting from a sheet and fold lines and the perforated seam have been produced; Fig 5 shows in detail a corner of a tray in the process of being folded from a blank of Fig. 5, in order to assemble the blank into a tray; Fig 6 shows in detail the corner of Fig. 5, the corner being heat sealed; Fig 7 shows a tray assembled from a blank of Fig 4, such that the corners are substantially hermetically sealed, but without the lid being sealed on the container; and Fig 8 shows an assembled tray as shown in Fig. 7, with the lid sealed on the container to produce a substantially hermetically sealed container.

A blank 10 comprises a substrate 12, which in this embodiment is a sheet of carton board.

The substrate 12 comprises a rectangular base panel 14 with sides 16, 18, 20, 22, and with a wall panel extending from each side of the base panel, such that there are first, second, third, and fourth wall panels 24, 25, 26, 27. Each pair of adjacent wall panels 24, 25; 25, 26; 26, 27; 27, 24 is connected by a connecting structure, comprising a gusset panel 29. Each gusset panel 29 is an isosceles triangle with the two equal length sides connected to each of the adjacent wall panels and the corner 30 in between these two sides connected to the corner of the base panel between the two adjacent wall panels. Each wall panel 24, 25, 26, 27 is substantially trapezoidal, with the shorter of the parallel sides 31 of the trapezoid adjoining the base panel and the longer side 32 of the trapezoid forming the outer edge of the wall panel. The longer parallel side 32 of each side wall panel in fact tapers in a curved manner towards the gusset panel 29 for a small portion at either end.

A lip panel 33, 34, 35, 36 extends from each wall panel 24, 25, 26, 27, respectively. Each lip panel 33, 34, 35, 36 is substantially of uniform width except on the curved portions of the side 32 of the wall panels, where the lip panels taper inwards slightly towards the wall panels 24, 25, 26, 27, respectively. The lip panels 33, 35 which extend from the wall panels 24, 26 which themselves extend from the long sides 16, 20 of the base panel 14 slightly overlap the gusset panels 29 and are joined to the gusset panels. The lip panels 34, 36 which extend from the wall panels 18, 22 which themselves extend from the short sides 18, 22 of the base panel 14 stop short of the gusset panel 29, so that there is a portion of the wall panel 18, 22 at each end from which a lip panel does not extend. Therefore, a corner recess 37 is defined between each pair of adjacent lip panels, the corner recess 37 extending over most of the gusset panel 29 and also over a portion of the end of one of the adjacent wall panels 18, 22.

All parts of the tray are hingedly connected to each other via fold lines 38 in the carton board.

A lid 40 is connected to the straight portion of the lip panel 35. It is connected in a hinged manner via a perforated seam 42. The lid 40 is substantially rectangular in shape, with rounded corners 44. A window opening 46 is provided in the centre of the lid. The window opening 46 is substantially rectangular, with rounded corners 48.

The substrate 12 is laminated with a heat sealable layer 50. The heat sealable layer 50 comprises A PET (amorphous polyethylene terephthalate), and is in a range of 5 to 150.tm, typically 30 to 60 im thick. Dependent upon the ratio of thickness of substrate to heat sealable layer, it is possible for the resulting carton board container to be considered recyclable. The A PET layer 50 extends across each corner recess 37, and also protrudes from each corner recess 37, forming a tab 52 of heat sealable material. The A PET layer 50 also extends across the window opening 46, thus forming a window 54.

The blank 10 is formed by the following method, as illustrated in Figs 1 to 9. A sheet 60 of substrate material is printed with the indicia required for the finished containers using a suitable press. In Fig 1, two such blanks 10 are shown, however, in other embodiments blanks could be produced singly or in a greater number, for example on a continuously fed sheet. Portions of sheet material are then cut out of each blank to form recesses 62 to correspond to the desired area of each tab 52, i.e. an area with a width equal to that of the corner recess 36 and a depth equal to the that of the corner recess, plus the distance the tab 52 extends from the corner recess 36. A portion of substrate material is also removed to form the window opening 46 in the lid 40 and fold lines are also formed in the substrate. The substrate 12 is then laminated with an A PET layer 50, 50 that the A PET layer 50 covers the recesses 62 and the window opening 46. The outer edge of the blank 10 is then cut out so that the blank can be removed from the sheet 60, the outer edge of the blank 10 comprising the outer edges of the lip panels 33, 34, 35, 36, the outer edge of the lid 40, and the outer edges of the tabs 52. The perforated seam 42 is then created in between the lid 40 and the adjacent lip panel 35.

Once the blank 10 has been removed from the sheet 60, it can be folded using the fold lines 38 to form a tray 64. The creation of each corner 66, 68, 70, 72 of the tray 64 is shown in more detail in Figs 6 and 7. Figs 6 and 7 show in detail the corner 72 in between wall panels 24 and 27. The gusset panel 29 is brought into facing contact with the side 24, such that the lip panel 36 overlaps the lip panel 33 on the laminated side of the blank 10. The tab 52 is thereby folded over on itself. The lip panels 33, 36 are bent away from the laminated side of the blank 10, so that they are substantially parallel with the base panel 14. The folded tab 52 overlaps the lip panel 33. The corner is then heat sealed by applying heat and pressure in the vicinity of the gusset panel 29, so that the facing laminated surfaces of the gusset panel 29 and the wall panel 16 are welded together. The corner 72 can be further heat sealed by applying heat and pressure to the corner in the region of the lip panels 28, 34 and the folded tab 52. Thus, the edge of the gusset panel 29 and corners between the gusset panel 29 and the lip panels 33, 36 are hermetically sealed in relation to the inside of the tray 64 by the tab 52.

Thus, a tray 64 is formed to which the lid 40 can be heat sealed, to form a substantially hermetically sealed container, which is also ovenable. If the thickness of the heat barrier layer is sufficiently low, then the container can be considered recyclable carton board. Of course, the step of heat sealing the lid 40 to the tray 64 to form a substantially hermetically sealed container may be carried out in a different location, after the container has been filled.

The tab 50, instead of extending further than the edges of the lip panel, may extend across the corner recess sufficiently to cover the edge of the gusset panel and the corners at the bottom of the corner recess. Preferably, the tab extends at least 1mm from the substrate, more preferably at least 3 mm, and most preferably at least 5 mm.

The embodiment given here is an example, but there are a number of alternatives which could be used. Although the heat sealable barrier layer forms the tabs and covers the window in the above embodiment, it is feasible that separate heat sealable barrier layers could be applied only for the tabs and window, as long as these were still capable of creating a substantially hermetic seal.

A rectangular tray is described, but it is envisaged any shape of container with a lip could be created according to the invention, for example, a tray with a different number of corners or a triangular sandwich package.

In the above embodiment, the method of creating the blank involves removing substrate material before laminating the substrate material, in order to create the tabs and window.

However, it is envisaged that the substrate material could be removed after lamination, by peeling off the unwanted portions of substrate and leaving the laminate layer covering the resulting recess.

A carton board container laminated with A PET has been described, but the skilled man would contemplate using a number of suitable materials, preferably ovenable materials. For example, the substrate could be any suitable plastics material layer, or the heat sealable barrier layer could be a biopolymer such as PLA (polylactic acid). Further, it is feasible that the heat sealable barrier layer comprises a first layer and a second layer, the first layer providing barrier properties and the second layer providing heat sealing properties. Or, a laminated heat sealable barrier layer may be applied to form the tabs and the window, and an emulsion coating could be applied to at least a portion the remainder of the blank. Further, although lamination has been used, the heat sealable barrier layer could be fixed by other means, for example by gluing.

The tab in the above embodiment extends from the gusset panel and wall panels further than the ends of the lip panels, but any depth of tab could be used, as long as extended overlapped the gusset panel and extended across the recess.

In the above embodiment, the connecting structure is folded into facing contact with the side of the substrate which the heat sealable barrier layer overlies. However, the connecting structure could also be folded into facing contact with the other surface of the substrate.

Claims

Claims 1. A blank for forming at least part of a substantially hermetically sealed container, the blank comprising: a substrate having a first surface and a second surface and the substrate comprising a first wall panel, a first lip panel connected to the first wall panel, a second wall panel, a second lip panel connected to the second wall panel, and a connecting structure between the first wall panel and the second wall panel, wherein, a corner recess is provided in the substrate, between the first lip panel and the second lip panel, and further wherein, the blank includes a heat sealable barrier layer provided over a surface and additionally extending across the corner recess, between the first lip panel and the second lip panel, and extending over the edge of the recess which extends between the lip panels, to form a tab, such that, upon folding of the connecting structure into a face contacting relationship with a surface of one of the wall panels, the first and second lip panels overlap, and the tab can be brought into a face contacting relationship with the first surface of one of the lip panels to thereby form a corner structure capable of substantial hermetic sealing.
2. A blank according to claim 1, wherein the recess is configured to allow the lip panels to overlap when the connecting structure is folded into a face contacting relationship with a surface of one of the panels.
3. A blank according to claim 1 or claim 2, wherein the corner recess extends across at least a portion of the connecting structure.
4. A blank according to claim 1, claim 2, or claim 3, wherein the corner recess also extends between a portion of the first wall panel and a portion of the second wall panel.
5. A blank according to any preceding claim, wherein the first lip panel is hingedly connected to the first wall panel by means of a first hinging connection.
6. A blank according to any preceding claim, wherein the second lip panel is hingedly connected to the second wall panel by means of a second hinging connection.
7. A blank according to any preceding claim, wherein the blank includes a base panel, the first wall panel being connected to a first edge of the base panel, the second wall panel being connected to a second edge of the base panel.
8. A blank according to claim 7, wherein the first wall panel is hingedly connected to the base panel.
9. A blank according to claim 7 or claim 8, wherein the second wall panel is hingedly connected to the base panel.
10. A blank according to any preceding claim, wherein the blank further includes a further heat sealable barrier layer provided over the first surface.
11. A blank according to any preceding claim, wherein the blank further includes a barrier layer on the second surface.
12. A blank according to any preceding claim, wherein the connecting structure is a gusset panel which extends between the first and second wall panels.
13. A blank according to any preceding claim, wherein the tab extends from the sheet a distance greater than the distance the first and second lip panels extend from the respective wall panels.
14. A blank according to any preceding claim, wherein the plastics material layer extends across the entire first surface of the sheet.
15. A blank according to any of claims 7 to 14, wherein the base is rectangular and the blank comprises four wall panels, one wall panel extending from each side of the base, the blank further comprising a gusset panel between each adjacent pair of wall panels, such that the blank can be assembled to form a rectangular tray.
16. A blank according to claim 15, wherein the blank further includes a lid, the heat sealable barrier layer extending across the lid such, when the blank is assembled to form a tray, the lid can be heat sealed to the lip panels of the tray to form a substantially hermetically sealed container.
17. A blank according to claim 16 wherein the heat sealable barrier layer extends across the whole first surface of the lid.
18. A blank according to any preceding claim, wherein the substrate comprises carton board.
19. A blank according to any preceding claim, wherein the heat sealable barrier layer comprises plastics material.
20. A blank according to claim 19, wherein the plastics material is A PET.
21. A container with at least one corner structure capable of substantial hermetic sealing, the container formed from a blank, the blank comprising: a substrate having a first surface and a second surface and the substrate comprising a first wall panel connected to a first edge of the base panel, a first lip panel connected to the first wall panel, a second wall panel, a second lip panel connected to the second wall panel, and a connecting structure extending between the first wall panel and the second wall panel, wherein, a corner recess is provided in the substrate, between the first lip panel and the second lip panel, and further wherein, the blank includes a heat sealable barrier layer provided over a surface and additionally extending across the corner recess, between the first lip panel and the second lip panel, and extending over the edge of the recess which extends between the lip panels, to form a tab, such that, the connecting structure is folded into a face contacting relationship with a surface of one of the wall panels, the first and second lip panels overlap, and the tab is in a face contacting relationship with a surface of one of the lip panels, the corner being heat sealed to produce a corner structure may be substantially hermetically sealed.
22. A container according to claim 21, wherein the recess is configures to allow the lip panels to overlap when the connecting structure is folded into a face contacting relationship with a surface of one of the panels.
23. A container according to claim 21 or claim 22, wherein the corner recess extends across at least a portion of the connecting structure.
24. A container according to claim 21, claim 22, or claim 23, wherein the corner recess also extends between a portion of the first wall panel and a portion of the second wall panel.
25. A container according to any preceding claim, wherein the first lip panel is hingedly connected to the first wall panel by means of a first hinging connection.
26. A container according to any of claims 21 to 25, wherein the second lip panel is hingedly connected to the second wall panel by means of a second hinging connection.
27. A container according to any of claims 21 to 26, wherein the blank includes a base panel, the first wall panel being connected to a first edge of the base panel, the second wall panel being connected to a second edge of the base panel.
28. A container according to any of claims 21 to 27, wherein the first wall panel is hingedly connected to the base panel.
29. A container according to any of claims 21 to 28, wherein the second wall panel is hingedly connected to the base panel.
30. A blank according to any of claims 21 to 29, wherein the blank further includes a further heat sealable barrier layer provided over the first surface.
31. A container according to any of claims 21 to 30, wherein the connecting structure is a gusset panel which extends between the first and second wall panels. Il
32. A container according to any of claims 21 to 31 wherein the connecting structure is folded such that the first surface of the substrate is on the inside of the corner structure when the blank is folded to form a corner structure.
33. A container according to any of claims 21 to 32, wherein the heat sealable barrier layer, and the connecting structure are configured to be on the inside of the corner structure when the blank is folded to form a corner structure.
34. A container according to any of claims 21 to 33, wherein the blank further includes a barrier layer on the second surface.
35. A container according to any of claims 21 to 34, wherein the tab extends from the sheet a distance greater than the distance the first and second lip panels extend from the respective main portions of the panels.
36. A container according to any of claims 27 to 35, wherein the base panel is rectangular and the blank comprises four wall panels, one wall panel extending from each side of the base, the blank further comprising a gusset between each adjacent pair of wall panels, such that the blank can be assembled to form a rectangular tray.
37. A container according to any of claims 21 to 36, wherein the container further includes a lid, the heat sealable barrier layer extending across the lid such that the lid can be heat sealed to at least one lip panel to form a substantially hermetic seal.
38. A container according to claim 37, wherein the lid is heat sealed to the lip panels to form a substantially hermetically sealed container.
39. A container according to any of claims 21 to 38, wherein the heat sealable barrier layer extends across the entire first surface of the sheet.
40. A container according to any of claims 21 to 39, wherein the heat sealable barrier layer extends across the whole first surface of the lid.
41. A container according to any of claims 21 to 40, wherein the substrate comprises carton board.
42. A container according to any of claims 21 to 41, wherein the heat sealable barrier layer comprises plastics material.
43. A container according to claim 42, wherein the plastics material is A PET.
44. A container according to any of claims 21 to 43, wherein the lid an integral part of the container.
45. A method of forming a blank, the blank according to claims 1 to 20, the method comprising the steps of: (a) removing material from a master sheet of substrate so that the master sheet defines a recess of a width equal to that of the corner recess required in the blank, and of a depth at least equal to that required for the tab, the position of the recess corresponding to the desired position of the corner recess and the tab in the blank; (b) securing a heat sealable barrier layer to the first surface of the substrate master sheet; (c) cutting out the outer perimeter of the blank from the master sheet, so that the blank can be folded to form a container; wherein, step (b) precedes or succeeds steps (a) and (c), and step (c) succeeds step (a).
46. A method according to claim 45, wherein step (b) succeeds step (a) and precedes step (c).
47. A method according to claim 45 or claim 46, wherein the method further includes a step (d) of creating a recess in the sheet to correspond to a window opening of the blank.
48. A method according to claim 47, wherein the step (d) is carried out at the same point in the method as step (a).
49. A method according to any of claims 45 to 48, wherein the method further includes a step (e) of applying fold lines or perforations to the blank to aid in folding the blank.
50. A method according to claim 49, wherein the step (e) succeeds step (b).
51. A method according to any of claims 45 to 50, wherein the method includes a step (g) of printing a design on the sheet.
52. A method according to any of claims 45 to 51, wherein step (a) comprises removing material from a master sheet so that the master sheet defines four recesses of a width equal to that of four corner recesses required in the blank, and of a depth at least equal to that required for the four tabs, the positions of the recesses corresponding to the desired positions of the corner recesses and the tabs in the blank.
53. A niethod according to any of claims 45 to 51, wherein the heat sealable layer is plastics material.
54. A method according to claim 53, wherein the plastics material is A PET.
55. A method according to any of claims 45 to 54, wherein the sheet material is carton board.
56. A method of forming the container according to any of claims 21 to 44, the method comprising the steps of: (i) forming a blank according to any of claims 45 to 55; then (ii) folding the connecting panel into a face contacting relationship with the first surface of one of the wall panels, such that the first and second lip panels overlap, and the tab is in a face contacting relationship with the first surface of one of the lip panels; and (iii) heat sealing the corner to produce a corner structure which is substantially hermetically sealed.
57. A method according to claim 56, wherein, the container includes a lid, the heat sealable barrier layer extending across the lid such that the lid can be heat sealed to at least one lip panel to form a substantially hermetic seal container, the method further including, after step (iii), a step (iv) of heat sealing the lid to the at least one lip panel.
58. A method according to claim 57, wherein, in the container, the base panel is rectangular and the blank comprises four wall panels, one wall panel extending from each side of the base, the blank further comprising a gusset between each adjacent pair of wall panels, each adjacent pair of wall comprising a first wall panel and a second wall panel, such that the blank can be assembled to form a rectangular tray, the method comprising folding each connecting panel as in step (ii) and further wherein the step (iv) comprises heat sealing the lid to all four lip panels, to form a substantially hermetically sealed container.
59. A blank substantially as described herein andlor with reference to Fig. 4.
60. A container substantially as described herein and/or with reference to Figs. 5 to Fig. 8.
61. A method of forming a blank substantially as described herein.
62. A method of forming a container substantially as described herein.