DOUBLE-WALLED CONTAINER

Abstract

A single piece container (200) made from cardboard, paperboard or other lightweight foldable sheet material is provided. The container (200) includes an outer shell and an inner shell. The outer shell has first and second ends (202, 204), and includes a plurality of outer shell sidewall panels (3, 5, 7, 9) hingedly connected to one other about respective outer shell sidewall foldlines. The outer shell sidewall panels (3, 5, 7, 9) extend between the first and second ends (202, 204) of the outer shell. At least the second end of the outer shell is a closed end. The inner shell includes a plurality of inner shell sidewall panels hingedly connected to one other about respective inner shell sidewall foldlines. The inner shell is integrally connected to the outer shell along a foldline. Each one of the inner shell sidewall panels is in face-to-face contact with the inner surface of a respective one of the outer shell sidewall panels (3, 5, 7, 9).

Claims

1. A single piece container made from cardboard, paperboard or other lightweight foldable sheet material, the container comprising: an outer shell having a first end and a second end, and comprising a plurality of outer shell sidewall panels hingedly connected to one other about respective outer shell sidewall foldlines, the outer shell sidewall panels extending between the first end and the second end of the outer shell, wherein at least the second end of the outer shell is a closed end; an inner shell comprising a plurality of inner shell sidewall panels hingedly connected to one other about respective inner shell sidewall foldlines, wherein the inner shell is integrally connected to the outer shell along a foldline; wherein each one of the inner shell sidewall panels is in face-to-face contact with the inner surface of a respective one of the outer shell sidewall panels.

2. The container of claim 1 wherein one of the outer shell sidewall panels is connected on one side along a foldline to an adjacent one of the outer shell sidewall panels, and comprises a flap connected thereto along a foldline along its opposite side, wherein the flap is bonded to one of the inner shell sidewall panels.

3. The container of claim 2 wherein the flap is a glue flap.

4. The container of claim 2 or claim 3 wherein the flap is sandwiched between the outer shell sidewall panel to which it is connected along a foldline and the inner shell sidewall which is in face-to-face contact with that outer shell sidewall panel.

5. The container of any preceding claim wherein only some of the pairs of inner and outer shell sidewall panels which are in face-to-face contact with one another are bonded to one another.

6. The container of any preceding claim wherein a one of the inner shell sidewall panels adjacent the one of the inner shell sidewall panels which is connected along a foldline to one of the outer shell sidewall panels extends over only a portion of the width of the outer shell sidewall panel with which it is in face-to-face contact.

7. The container of any preceding claim wherein the outer shell comprises first, second, third and fourth outer shell sidewall panels, wherein the first and second outer shell sidewall panels and the third and fourth outer shell sidewall panels form opposed pairs of outer shell sidewall panels.

8. The container of claim 7 wherein the inner shell comprises first, second, third and fourth inner shell sidewall panels, wherein the first inner shell sidewall panel is in face-to-face contact with the first outer shell sidewall panel, the second inner shell sidewall panel is in face-to-face contact with the second outer shell sidewall panel, and the third inner shell sidewall panel is in face-to-face contact with the third outer shell sidewall panel, and the fourth inner shell sidewall panel is in face-to-face contact with the fourth outer shell sidewall panel.

9. The container of any preceding claim wherein one or more of the outer shell sidewall panels comprise a base flap connected to a second end thereof along a foldline for use in providing a closed base at the second end of the outer shell, and wherein one or more of the inner shell sidewall panels comprises a reinforcement flap connected to a second end thereof along a foldline, which reinforcement flap is arranged to underlie one of the base flaps of the outer shell to reinforce the outer shell base flap.

10. The container of claim 9 wherein the outer shell comprises first, second, third and fourth outer shell sidewall panels, and each one of the first, second, third and fourth outer shell sidewall panels comprises a base flap connected to the second end thereof along a foldline to provide a set of base flaps, the base flaps including; a first base flap connected along a foldline to one of the sidewalls; second and third opposed base flaps connected along respective foldlines to respective ones of the sidewalls adjacent the sidewall to which the first base flap is connected on either side thereof, wherein the second and third base flaps are folded over the first base flap; and a fourth base flap connected along a foldline to a sidewall opposite the sidewall to which the first base flap is connected, wherein the fourth base flap is folded over the second and third base flaps; wherein the fourth base flap comprises a base panel portion which forms part of the exterior of the base and a locking tab portion connected to a distal end of the base panel portion, wherein the locking tab portion of the fourth base flap is inserted through a slot defined by the first, second and third base flaps into the interior of the container to retain the base in a closed configuration; and wherein a reinforcement flap is provided in respect of at least the first and fourth base flaps.

11. A container made from cardboard, paperboard or other lightweight foldable sheet material, the container comprising: first, second, third and fourth sidewall panels hingedly connected to one other about respective foldlines, the sidewall panels extending between first and second ends of the container, wherein each one of the first, second, third and fourth sidewall panels comprises a base flap connected to the second end thereof along a foldline to provide a set of base flaps, the base flaps including; a first base flap connected along a foldline to one of the sidewalls; second and third opposed base flaps connected along respective foldlines to respective ones of the sidewalls adjacent the sidewall to which the first base flap is connected on either side thereof, wherein the second and third base flaps are folded over the first base flap; and a fourth base flap connected along a foldline to a sidewall opposite the sidewall to which the first base flap is connected, wherein the fourth base flap is folded over the second and third base flaps; wherein the fourth base flap comprises a base panel portion which forms part of the exterior of the base and a locking tab portion connected to a distal end of the base panel portion, wherein the locking tab portion of the fourth base flap is inserted through a slot defined by the first, second and third base flaps into the interior of the container to retain the base in a closed configuration; wherein the container comprises a reinforcement flap in respect of each of one or more of the base flaps, the reinforcement flap being arranged to underlie a respective one of the base flaps to reinforce the base flap.

12. The container of claim 11 wherein the first, second, third and fourth sidewalls form an outer shell of the container, and the container further comprises an inner shell comprising a plurality of sidewall panels hingedly connected to one another along respective foldlines, and the reinforcement flaps are connected along foldlines to the second ends of respective ones of the sidewall panels of the inner shell.

13. The container of any one of claims 9 to 12 wherein each reinforcement flap extends over only a portion of the area of the base flap which it reinforces.

14. The container of any one of claims 9 to 13 wherein each reinforcement flap is unsecured to the base flap which it reinforces.

15. The container of any one of claims 9 to 14 wherein each reinforcement flap is in face-to-face contact with the base flap which it reinforces.

16. A single piece blank erectable to provide a container in accordance with any preceding claim.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0111] Some preferred embodiments of the invention will now be described by way of example only and with reference to the followings drawings, of which;

[0112] FIG. 1 shows a blank in the flat for forming a container in accordance with a first embodiment of the present invention;

[0113] FIG. 2A illustrates the blank of FIG. 1 after an initial folding and gluing step in a flat configuration;

[0114] FIG. 2B illustrates the blank of FIG. 2A after a first folding and gluing step in a flat configuration;

[0115] FIG. 2C illustrates the blank of FIG. 2B after a second folding and gluing step in a flat configuration;

[0116] FIG. 2D illustrates the blank of FIG. 2C after a third folding and gluing step in a flat configuration;

[0117] FIG. 2E illustrates the blank of FIG. 2D after a fourth folding and gluing step in a flat configuration;

[0118] FIG. 2F illustrates the blank of FIG. 2E after a fifth folding and gluing step in a flat configuration;

[0119] FIG. 2G illustrates the blank of FIG. 2F after a sixth step to erect the blank into a 3-dimensional state, with both ends in an open configuration′

[0120] FIG. 2H illustrates a container obtained after a seventh step to close the first and second ends of the erected blank of FIG. 2G;

[0121] FIG. 3A illustrates a first step in the closure of the base of the container of the erected blank of FIG. 2G in accordance with one embodiment for obtaining the container of FIG. 2H;

[0122] FIG. 3B illustrates a second step in the closure of the base of the container of the erected blank of FIG. 2G in accordance with one embodiment for obtaining the container of FIG. 2H;

[0123] FIG. 3C illustrates a third step in the closure of the base of the container of the erected blank of FIG. 2G in accordance with one embodiment for obtaining the container of FIG. 2H;

[0124] FIG. 4A is a view of the interior of the erected blank of FIG. 2G taken from the second, bottom end prior to closing of the first and second ends of the container;

[0125] and FIG. 4B is a view of the interior of the erected blank of FIG. 2G taken from the first, top end prior to closing of the first and second ends of the container.

DETAILED DESCRIPTION

[0126] With reference to FIG. 1, a blank for providing a container in accordance with a first embodiment of the invention will now be described.

[0127] FIG. 1 shows the blank in the flat from above, from the side which will provide portions of the exterior surface of the erected container.

[0128] The blank has a first end 4 which provides a first end of the container when erected, and a second end 6 which provides a second end of the container when erected. The second end of the container is a base of the container.

[0129] The blank 1 includes an outer shell sub-assembly 72 for providing an outer shell and associated components of the container, and an inner sub-assembly 74 for providing an inner shell and associated components of the container.

[0130] The outer shell sub-assembly 72 includes a first outer shell sidewall panel 3, a second outer shell sidewall panel 5, a third outer shell sidewall panel 7, and a fourth outer shell sidewall panel 9. The first and fourth outer shell sidewall panels 3, 9 are connected by a foldline 25. The second and fourth outer shell sidewall panels 5, 9 are connected by a foldline 27. The second and third outer shell sidewall panels are connected by a foldline 29.

[0131] A glue flap 35 is connected along a foldline 38 to the first outer shell sidewall panel 3.

[0132] An array of flaps 70 is connected to the first ends of the first, second, third and fourth outer shell sidewall panels 3, 5, 7, 9 for forming a closed lid structure at the first end of the container erected from the blank. The flaps include a first lid flap 55 connected along a foldline 58 to the second outer shell sidewall panel 5, second and third lid flaps 72, 52 connected to the third and fourth outer shell sidewalls 7, 9 respectively along foldlines 74, 54, and a product support flap 40 connected along a foldline 50 to the first end of the first outer shell sidewall panel 3.

[0133] The first lid flap 55 includes a lid panel 56 and first and second side flaps 60, 68 connected along respective foldlines 62, 70 to the side edges of the lid flap 56. A closure flap 64 is connected along a foldline 66 to the distal end of the lid panel 56.

[0134] The product support flap 40 includes a proximal portion 46 and a distal portion 42 connected along a foldline 48 thereto. The proximal portion 46 is connected along a foldline 50 to the first end of the first outer shell sidewall panel 3. The distal portion 42 of the product support flap 40 includes an opening 44.

[0135] A first base flap 55, is connected to the second end of the second outer shell sidewall panel 5 along a foldline 80. The distal end of the first base flap 55 defines a recess. The proximal end of the recess is provided by an edge 56. The first base flap 55 has distal portions defining hooks 93, 95 on either side of the recess.

[0136] A second base flap 57 is connected to the second end of the third outer shell sidewall panel 7 along a foldline 82. A third base flap 59 is connected to the second end of the fourth outer shell sidewall panel 9 along a foldline 84, and a fourth outer shell base flap 53 is connected along a foldline 86 to the second end of the first outer shell sidewall panel 3. These base flaps may be used to provide an envelope type base closure. It will be seen that the distal portions of the second and third base flaps 57, 59 define hooks 58, 60 respectively. The fourth base flap 53 has a distal end portion 91.

[0137] As described below, in the closed base, the hooks 58, 60 of the second and third base flaps 57, 59 engage behind the edge 56, and the distal portions of the second and third base flaps 57, 59 and the edge 56 define a slot through which the distal end portion 91 of the fourth base flap 53 is inserted into the interior of the container. The fourth base flap 53 defines a base panel portion 62 and a locking tab portion 64. The base panel portion 62 forms part of the exterior of the base in the erected container, while the locking tab portion 64 is located to the interior of the base. The base panel portion is denoted in hatched lines. However, this is merely to facilitate understanding of the arrangement. It will be appreciated that there is preferably no foldline or other feature distinguishing the portions of the fourth base flap 53 from one another.

[0138] The inner shell sub-assembly 74 includes a first inner sidewall panel 11, which is connected to the third outer shell sidewall panel 7 along a foldline 31.

[0139] The inner shell sub-assembly 74 also includes a fourth inner shell sidewall panel 17 connected to the first inner shell sidewall panel 11 along the foldline 22, a second inner shell sidewall panel 13 connected to the fourth inner shell sidewall panel 17 along a foldline 34, and a third inner shell sidewall panel 15 connected to the second inner shell sidewall panel 13 along a foldline 37.

[0140] The foldlines 33, 34, 37 connecting the sidewalls of the inner shell may comprise one or more, e.g. a plurality of cutlines along their length to facilitate folding of the inner shell. This may help the inner shell panels to lie close to the outer shell panels.

[0141] A first base reinforcement flap 63 is connected to the second end of the second inner shell sidewall panel 13 along a foldline 88, and lies inside the first base flap 55 to reinforce the base flap 55 when the base is closed. The first base reinforcement flap 63 has a smaller area than the first base flap 55, so as to fit within the outer contour of the portion of the first base flap proximal to the recess of the first base flap 55.

[0142] A second base reinforcement flap 61 is connected to the second end of the first inner shell sidewall panel 11 along a foldline 97, and lies inside the fourth base flap 53 to reinforce the base flap 53 when the base is closed. The second base reinforcement flap 61 has the same shape as the fourth base flap 53, but a smaller area, so as to lie within the outer contour of the fourth base flap 53.

[0143] One way in which the blank 1 may be used to provide a container will now be described by reference to FIGS. 2A-H and 3A-C.

[0144] FIG. 2A illustrates the blank in the flat from above, with the surface which will be located to the interior of the container uppermost i.e. the opposite surface to that which is uppermost in FIG. 1.

[0145] In a first step, glue is applied to the interior surface of the glue flap 35 and to the interior surfaces of the first and second lid side flaps 60, 68. In the embodiment illustrated a glue line is applied to the surface of each flap 35, 60, 68. However, any suitable glue pattern may be used. The glue flap 35 is folded in the direction of the arrow A shown in FIG. 2A along the foldline 38 connecting the flap 35 to the first outer shell sidewall panel 3. The lid side flaps 60, 68 are folded along the foldlines 62, 70 connecting them to the lid panel 56 in the direction of the arrows B in FIG. 2A. This provides a folded blank as shown in FIG. 2B. The glue flap 35 is adhered to the inner surface of the first outer shell sidewall panel 3, and the lid side flaps 60, 68 are adhered to the inner surface of the lid panel 56. In this way, the lid side flaps 60, 68 reinforce the lid panel 56.

[0146] In step 2, the blank is folded in the direction of the arrow C about foldline 37 so as to fold the third inner shell sidewall panel 15 onto the inner surface of the second inner shell sidewall panel 13. This provides the folded blank shown in FIG. 2C.

[0147] In step 3 glue is applied to the outer surface of the third inner shell sidewall panel 15. In the illustrated embodiment a pair of parallel glue lines is used. This may result in improved strength in the resulting container. However, other glue patterns e.g. a single central glue line may be used. The blank is then folded in the direction of arrow D about the foldline 33 between the fourth inner shell sidewall panel and the first inner shell sidewall panel 11 to provide a folded blank as shown in FIG. 2D.

[0148] In step 4, glue is applied to the outer surface of the fourth inner shell sidewall panel 17. In the illustrated embodiment a pair of parallel glue lines is used. This may result in improved strength in the resulting container. However, other glue patterns e.g. a single central glue line may be used. The blank is then folded in the direction of the arrow E about the foldline 29 connecting the second and third outer shell sidewall panels to provide the folded blank shown in FIG. 2E.

[0149] In step 5, glue is applied to the uppermost surface of the glue flap 35. The blank is then folded about the foldline 25 connecting the first and fourth outer shell sidewall panels 3, 9 to provide the folded blank shown in FIG. 2F. The glue flap 35 is adhered to the outer surface of the first outer shell sidewall panel 3.

[0150] In step 6, the folded and glued blank is caused to change from the flat configuration shown in FIG. 2F to a 3-dimensional configuration as shown in FIG. 2G. The erected container is referred to as 200. This may occur at a different time and place to steps 2A-F if required. Thus, the folded, glued blank may be supplied in the form shown in FIG. 2F for final erection. Conversion of the flat folded and glued blank shown in FIG. 2F to the configuration shown in FIG. 2G may be achieved by applying suction to the surface lying uppermost in FIG. 2F, or by urging the sides of the folded blank inwardly, or in any suitable manner.

[0151] After step 2G, the first and second ends of the container 202, 204, provided by the first and second ends 4, 6 of the blank respectively are open.

[0152] In a final step 7, the first and second ends of the container are closed to provide the container 200 with closed first and second ends as shown in FIG. 2H. The manner in which the base flaps associated with the second end of the container are used to close the base will be described in more detail below by reference to FIGS. 3A-C. The lid and base may be closed in any order, sequentially or simultaneously. A product is inserted in the container before both ends are closed. Typically the base is closed, the product inserted, and the first end then closed, although other options may be envisaged.

[0153] The first end of the container is closed in by folding the product support flap into the interior of the container, and bending the product support flap about the foldline 48, such that the proximal portion 46 extends along the interior of the first outer shell sidewall panel 3, and the distal portion 42 extends substantially perpendicular thereto toward the second inner shell sidewall panel 13. The opening 44 may then be used to support the neck of a bottle located in the container in use. The second and third lid flaps 72, 52 are then rotated 90 degrees from the position shown in FIG. 2G toward the interior of the container, and the reinforced lid panel 56 is folded thereover, with the closure flap 64 tucked between the proximal portion 46 of the first lid flap 40 and the side edges of the second and third lid flaps 72, 52.

[0154] The configuration of the lid structure at the first end of the container illustrated is merely exemplary. Different configurations of lid may be used, depending e.g. upon the nature and configuration of a product to be included in the container. For example, the product support flap 40 may be omitted. The side flaps extending from the lid panel 56 may be omitted, in which case the shape of the second and third lid flaps 52, 72 may be altered. In yet other embodiments, the first end of the container may be left open, and not include a lid structure. Rather than providing a releasable and refastenable closure as shown, the lid may be bonded in a closed configuration.

[0155] One way in which the base may be closed will now be described by reference to FIGS. 3A-C. The first end is shown as open in these exemplary figures. However, the first and second ends of the container may be closed in any order, sequentially or simultaneously.

[0156] In a first step the first base flap 55 associated with the second end of the second outer shell sidewall panel 5 is rotated through 90 degrees (in the direction of arrow G in FIG. 2G) about foldline 80 from the position shown in FIG. 2G to the position shown in FIG. 3A. This causes the first base reinforcement flap 63 connected to the first inner sidewall panel 11, and which underlies the first base flap 55, to simultaneously be rotated around foldline 88.

[0157] In a second step, the second and third base flaps 57, 59 associated with the second ends of the third and fourth outer shell sidewall panels 7, 9 respectively are rotated through 90 degrees about the foldlines 82, 84 (in the direction of arrows H in FIG. 3A) to the position shown in FIG. 3B so as to overlie the first base flap 55.

[0158] In a third step the fourth base flap 53 connected to the first outer shell sidewall panel 3 is folded about the foldline 86 (in the direction of arrow K in FIG. 3B) and its distal end portion pushed toward the interior of the container to the position. This causes the second base reinforcement flap 61 connected to the first inner sidewall panel 11, and which underlies the first base flap 55, to simultaneously be rotated around foldline 97, with the distal end portion of the base reinforcement flap 61 being pushed with the distal end portion of the fourth base flap 53 into the interior of the container.

[0159] The movement of the fourth base flap 53 and the underlying second base reinforcement flap 61 into the interior of the container pushes the hooks 58, 60 of the distal portions of the second and third base flaps 57, 59 behind the edge 56 defined by the recess at the distal end of the first base flap 55, with the locking tab portion 64 of the fourth base flap 53 (and the distal end portion of the underlying second base reinforcement flap 61) being inserted through a slot thus defined by the edge 56 and the distal portions of the second and third base flaps 57, 59. The distal end 91 of the fourth base flap 53 (and the distal end portion of the underlying second base reinforcement flap 61) is disposed in the interior of the container in the closed base, while the base panel portion 62 forms part of the exterior of the base. In the closed base, the hooks 58, 60 help to prevent movement of the locking tab portion 64 of the fourth base flap 53 (or the distal end portion of the second base reinforcement flap 61) out of the slot once more, and thus helps to avoid the base undesirably coming open when an outwardly directed force is exerted on the interior thereof by a product located in the container.

[0160] The resulting closed base resembles the reverse of an envelope, and may be referred to as an “envelope base” closure.

[0161] It will be seen that in the embodiment illustrated, the base reinforcement flaps 63, 61 underlie the first and fourth base flaps 55, 53 respectively, providing additional strength to the base.

[0162] It will be appreciated that the locking tab portion 62 of the fourth base flap 53 extends through a slot as described in the closed base. The slot may not necessarily exist prior to insertion of the fourth base flap into the interior of the container e.g. if the second and third base flaps comprise distal ends which hook behind the edge 56 of the first base flap 55.

[0163] Of course, the closure of the base need not be performed in exactly the manner above-described. For example, the hooks of the second and third base flaps 57, 59 may be engaged behind the edge 56 of the first base panel 55 in a separate step, prior to pushing the distal end portion of the fourth base flap 53 toward the interior of the container. Likewise, the steps of folding and gluing the blank need not be performed as illustrated with respect to FIGS. 2A-G. For example, the order of steps, and/or the lines along which folding occurs may differ. Any suitable methods may be used which result in a container as shown in FIG. 2H, and described further by reference to FIGS. 4A and B.

[0164] The shape of the first, second, third and fourth base flaps 53, 55, 57, 59 need not be as shown. For example, the distal portions of the second and third base flaps 57, 59 need not define hooks. The distal portions of the second and third base flaps may include straight side edges which extend along the edge 56 of the first base flap 55 to define the slot through which the distal end portion 91 of the fourth base flap 53 is inserted. Such an arrangement may be provided where the side edge of the distal portion of the base flap extends substantially perpendicular to the end edge of the flap. However, the use of hooks may provide a stronger base construction. Alternatively or additionally, the distal portions 93, 95 of the first base flap 55 need not necessarily define hooks. The opposed inner side edges of the distal portions which provide side edges of the recess in the distal end of the first base flap 55 may be extend parallel to one another. However, the use of hooks may again provide a stronger base construction, helping to retain the second and third base flaps 57, 59 in position in the closed base.

[0165] The shapes of the first and second base reinforcement flaps 63, 61 may differ from that shown. For example, the shape of the first base reinforcement flap may correspond to that of the first base flap 55 i.e. including a recess, with the first base reinforcement flap being of smaller area than the first base flap 55 to ensure that it fits within the contour thereof, in a similar manner to the first base reinforcement flap 61 and the fourth base flap 53.

[0166] Where hooks are provided on any or all of the second, third or first base flaps, the configuration of the hooks, e.g. the steepness of the angle defined at the distal end thereof, and/or the length of the hooks may be varied as desired. The shape of any of the base flaps may be varied as desired e.g. to provide a base closure of required strength for a given application, provided that the flaps may interact in the manner described.

[0167] The first and second base reinforcement flaps 63, 61 may be omitted if desired e.g. if a stronger base construction is not required.

[0168] Finally, although an envelope base closure has been described, any suitable method of providing a closed base may be used, which may or may not involve the use of adhesive or other bonding to retain the base in its closed configuration.

[0169] In the erected container 200 e.g. as shown in FIG. 2H, the sidewall panels of the inner shell cooperate with respective ones of the outer shell sidewall panels to reinforce the walls of the container. The first, second third and fourth inner shell sidewall panels 11, 13, 15, 17 are in face-to-face contact with the first, second, third and fourth outer shell sidewall panels 3, 5, 7, 9 respectively. In the embodiment illustrated, the inner shell sidewall panels each extend over substantially the entire height of the outer shell sidewall panels. However in other embodiments, it is envisaged that at least some of the panels may extend over less than the full height of the outer shell sidewall panels. In the illustrated embodiment, the first, second and fourth inner shell sidewall panels 11, 13, 17 extend over the full width of the outer shell sidewall panels with which they are in contact. However, the third inner shell sidewall panel 15, which provides a glue panel, extends over less than the full width of the third outer shell sidewall panel 7. In the illustrated embodiment, the panel extends over approximately 90% of the width of the outer shell sidewall panel. In other embodiments, the third inner shell sidewall panel 15 might extend over a different proportion of the width of the third outer shell sidewall panel 7, e.g. up to the full width, and preferably at least 60% of the width to provide effective reinforcement.

[0170] The present invention provides a method of strengthening the walls of the container, to provide a double thickness wall, which may be achieved by folding and gluing a single piece blank, and without the need laminate sheets of material together to provide the blank initially, which may undesirably complicate manufacture and assembly.

[0171] Certain features of the erected container 200 will now be described by reference to FIGS. 4A and B. FIG. 4A is a view into the interior of the container through the second end (with the base structure open for the purposes of illustration). FIG. 4B is a view into the interior of the container through the first end (with the lid structure open for the purposes of illustration).

[0172] It may be seen that the first inner shell sidewall panel 11 is in face-to-face contact with (and adhered to) the inner surface of the first outer shell sidewall panel 3. The glue flap 35 is sandwiched between the first inner shell sidewall panel 11 and the first outer shell sidewall panel 3. In this way, the presence of a visible raw edge of material is avoided. The user is instead presented with a folded edge. This may be advantageous in providing improved appearance of the container. The outer surface of the outer shell may have a more uniform appearance. For example, where the material of the blank from which the container is erected has a decorative finish e.g. colouring or printing at least on the surface which provides the outer surface of the sidewall panels of the outer shell, the folded edge may then have the same appearance as the remainder of the visible exterior surfaces of the outer shell of the container, e.g. the same colouring etc., rather than being a raw edge. The sandwiching of the glue flap may also provide a neater overall appearance of the container.

[0173] The third inner shell sidewall panel 15 is in face-to-face contact with (and adhered to) the third outer shell sidewall panel 7. The second inner shell sidewall panel 13 is in face-to-face contact with (and not adhered to) the inner surface of the second outer shell sidewall panel 5, and the fourth inner shell sidewall panel 17 is in face-to-face contact with (and not adhered to) the fourth outer shell sidewall panel 9. Of course, in other embodiments, the second and fourth inner sidewall panels might be adhered to the second and fourth outer shell sidewall panels respectively.

[0174] FIG. 4B shows the way in which the base flaps and base reinforcement flaps interlock to provide the closed base structure. It may be seen that the distal ends of the fourth base flap 53 and the second base reinforcement flap 61 extend through a slot provided by the distal edge regions of the distal portions of the second and third base flaps 57, 59 and the proximal edge 56 of the recess in the first base flap and of the recess in the distal end of the corresponding underlying first base reinforcement flap 63. The distal ends of the fourth base flap 53 and the underlying second reinforcement flap, which are located within the container, provide locking tab portions (the locking tab portion of the fourth base flap 53 being denoted 64). The bases of these locking tab portions are sandwiched between the hooks 58, 60 associated with the second and third base flaps and the region of the first reinforcement flap 63, proximal to the slot defining edge therein. The distal portions 93, 95 of the first base flap 55 and the first reinforcement flap 63 underlie (and are in face-to-face contact with) the second and third base flaps when the base is viewed from the interior as in FIG. 4B, to help secure the second and third base flaps in place, and hence to help inhibit movement of the distal end of the fourth base flap and the second reinforcement flap out of the slot e.g. when a force is applied by a product located in the container, to urge the base outwardly in use.

[0175] The first and second reinforcement flaps are in face-to-face contact with their respective base flaps, and are unsecured thereto.

[0176] It is envisaged that a reinforcement flap may only be provided in respect of one of the first and fourth base flaps.

[0177] This arrangement provides an envelope type base structure, but in which certain flaps i.e. the first and fourth base flaps, are reinforced. Thus, reinforcement is provided for flaps which are particularly important in avoiding failure of the base.

[0178] It has thus been recognised that the flaps 61 and 63 connected to the ends of the first inner shell sidewall panel 11 and the second inner shell sidewall panel 13 may be used to reinforce the outer base flaps 53, 55 associated with the second and first outer shell sidewall panels 9, 3. These flaps may be cut from areas of the sheet from which the blank is produced which would otherwise be wasted. This may be achieved without the need to laminate sheets together when forming the blank.

[0179] It is envisaged that the reinforcement of base flaps forming part of an envelope base may be of utility in respect of containers other than those of the type illustrated having inner and outer shells of the type described, provided that some suitable arrangement is provided to result in the reinforcement flaps being located appropriately with respect to the base flaps. For example, the container might be formed of multiple pieces, or have some other form of inner shell structure.

[0180] While the bonding of various components to one another has been described in relation to an adhesive connection, other bonding technologies may be used e.g. heat sealing etc. An adhesive connection referred to herein may, unless the context demands otherwise, in general be any bonded connection, not limited to adhesive.

[0181] It is envisaged that the number of inner and outer shell side wall panels may vary from that illustrated.

[0182] All of the assembly steps described by reference to FIGS. 2A-H and 3A-C, including all gluing and folding steps, may be performed in a fully automated manner by a machine.

[0183] The containers described herein may be used with any desired product, but are particularly useful in the context of fragile products, such as bottles e.g. drinks bottles. The construction may provide a relatively stronger container for such products, in embodiments, with reduced risk of base failure.

[0184] It will be understood that the above description is of a number of exemplary embodiments only and that modifications may be made to the embodiments without departing from the scope of the invention.