GB2517981A

GB2517981A - A container flange

Info

Publication number: GB2517981A
Application number: GB1315981.9A
Authority: GB
Inventors: Samantha Moore
Original assignee: Colpac Ltd
Current assignee: Colpac Ltd
Priority date: 2013-09-06
Filing date: 2013-09-06
Publication date: 2015-03-11
Also published as: WO2015033164A1; GB201315981D0

Abstract

A container, such as a sandwich box, formed from a folded blank (101) of material comprises an opening and a flange surrounding the opening. The flange is formed from a plurality of inner flange panels 114, 116 and one or more outer flange panels 118, 120 wherein each outer flange 118, 120 panels overlies at least part of each inner flange panel 114, 116 to provide a flat surface that is continuous around the container opening. A separate closure means can be bonded to the flange. The flange may either be provided around the outside or inside of the container opening with each outer flange panel 118, 120 preferably being joined to the inner flange panels 114, 116 by a fold line. The invention also relates to a blank 101 for forming the container.

Description

A CONTAINER FLANGE

The invention relates to a container body comprising a flange for receiving a closure and particularly, but not exclusively, to the flange of a container formed from a folded blank. The invention also relates to a blank for forming such a container and particularly, but not exclusively, to the parts of the blank for forming the container flange.

It is known to produce containers and packaging from folded blanks of material, such as paperboard. For the purpose of this specification paperboard' is considered to encompass paper, cardboard and similar materials. These containers will often have flanges around their opening formed from outwardly folded panels of the blank to allow the container to be sealed by bonding a lid or other closure means to the, flange.

Commonly, one panel of the blank will provided a hinged lid to the finished container so that a single blank for forming the container body and lid will be formed in a single cutting step.

However, in certain situations it is preferable for a separately formed closure, such as a separate paperboard lid or sheet of film, to be applied to a container body. This can cause problems with folded paperboard container bodies because the flanges formed from the folded blank can have gaps or otherwise not present a uniform flat surface to ensure good bonding of the closure means.

It is an object of the present invention to provide a container body with a flange around its opening, wherein the flange provides a flat uniform surface to improve the bonding of closure means to said surface of the container flange.

According to the present invention there is provided a container body according to the appended claim 1. Further advantageous features of the container body are recited in the associated dependent claims. * -2-

The claimed container body is formed from a folded blank, so maintains all of the benefits of this construction, but the inclusion of at least one outer flange panel in addition to the inner flange panels (which correspond to the panels for forming the flange in known container bodies) advantageously ensures that a flat upper/outer surface is provided to the container flange to ensure the best possible bonding of a closure meaps.

The flange may be provided around either the inside or the outside of the container opening as desired.

The or each outer flange panel is preferably joined to an inner flange panel by a fold line, and may then be folded back over the inner flange panels to provide the outer surface of the flange.

This helps to simplify construction of the container body and reduce waste because there is no need to gut the or each outer flange panel separately. The integrity of the flange is also improved by virtue of the permanent connection of the or each outer flange panel to an inner flange panel.

Preferably, at least two outer flange panels are provided so as to minimise the size of each outer flange panel. Equal numbers of inner and outer flange panels may be provided such that each inner flange panel is joined to an outer flange panel.

Where more than one outer flange panel is provided it is beneficial if part of an outer flange panel joined to a first inner flange panel overlies at least part of a second inner flange panel.

This avoids edges of two adjacent outer flange panels coinciding with gaps that may exist between two adjacent inner flange panels and provides added strength and integrity to the finished flange. The edges of the outer flange panels preferably abut one another so that no gaps exist in the surface of the flange.

A large surface area and a uniform flat flange will be provided if said one or more outer flange panels completely overlies each inner flange panel.

The container body preferably comprises paperboard and/or a layer of plastics film, for example the container may be formed from a blank having a paperboard layer and a layer of plastics film providing a barrier to the ingress of liquids from the container contents. Any gaps that exist between adjacent inner flange panels are preferably spanned by areas of plastics film.

A further aspect of the present invention provides a blank for forming a container body according to the appended claim 14. Further advantageous features of the blank are recited in the associated dependent claims.

Preferably at least two outer flange panels are provided. In this case, it is preferable if at least one outer flange panel is shorter than the inner flange panel to which it is joined and at least one outer flange panel is larger than the inner flange panel to which it is joined, such that when a container is formed from the blank an area of an inner flange panel not covered by its respective shorter outer flange panel is covered by a part of a larger outer flange panel. The larger flange panels may have extensions provided at right angles to their length.

Equal numbers of wall panels and inner flange panels may be provided and equal numbers of inner and outer flange panels may also be provided such that each wall panel has an associated inner flange panel and each inner flange panel has an associated outer flange panel. By providing a plurality of outer flange panels the degree by which the size of the overall blank is increased is minimised, which is helpful in reducing waste of the blank material.

The wall panels and flange panels are preferably defined by cuts and fold lines in the blank material, which may be paperboard, and the blank may further comprise a plastics film layer spanning gaps between adjacent inner flange panels.

A better understanding of the present invention will be obtained from the following detailed description. The description is given by way of example only and makes reference to the accompanying drawings in which: Figure 1 is a plan view of the blank of a known sandwich container; Figure 2 is a perspective view of a known sandwich container body formed from the blank of Figure 1; Figure 3 is a perspective view of a sandwich container blank illustrating the present invention; Figures 4 to 6 are perspective views showing the forming of a sandwich container body fonned from the blankof Figure 3; Figures 7 and 8 are perspective view of a sandwich container body formed from the blank of Figure 3.

Figure 9 is a perspective view of an alternative sandwich container blank illustrating the present invention; Figure 10 is a perspective view of a part-formed sandwich container body formed from the blank of Figure 9; and Figure 11 is a perspective view of a sandwich container body formed from the blank of Figure 9.

The blank I used in the formation of a known sandwich container is illustrated in Figure 1. The blank 1 comprises two generally rectangular end wall panels 2 and two triangular side wall panels 4. Fold lines. 6 are provided between the end wall panels 2 and the side wall panels 4, and further fold lines 8 bisect the side wall panels 4, running from the mid-point of the longest edge of each panel 4 to an apex opposite said longest edge.

First and second tabs 10,12 are respectively provided at edges of one of said end wall panels 2 and one of said side wall panels 4, and tab fold lines 11 are provided between the tabs 10,12 and saidwallpanels2,4.

A short flange panel 14 is provided at a short edge of each end wall panel 2, and a long flange panel 16 is provided at the longest edge of each side wall panel 4. The further fold lines 8 continue through each long flange panel 16, Flange fold lines 15 provided between the wall panels 2,4 and the flange panels 14,16 allow the flange panels 14,16 to be folded relative to the wall panels 2,4.

Figure 2 shows a view into a container body 51 formed from the blank 1 of Figure 1. The interior of the container body 51 can be seen, with the tabs 10,12 bonded to a surface of the other of said end wall panels 2 to hold the container body 51 together. The flange panels 14,16 -have been folded outwardly relative to the wall panels 2,4 at flange fold lines 15 to provide an outwardly extending flange around the opening of the container body 51. Closure means, such as film andlor paperboard, can be bonded to the outwardly extending flange in order to close the container once filled.

As can be clearly seen in Figure 2, there are gaps in the flange at each corner of the opening between the long flange panels 16 and the short flange panels 14. These gaps can be problematic in ensuring that a good seal is provided between the container body and the closure means.

Figure 3 shows a blank 101 embodying the features of the present invention. The blank 101 is similar in many ways to the known blank 1 of Figure 1, and corresponding/equivalent parts of the two illustrated blanks 1,101 have been ascribed reference numerals differing by exactly one hundred.

The key difference between the blank 101 of Figure 3 and the known blank 1 of Figure 1 is that a further flange panel 118,120 is provided along the outer edge of each short and long flange panel 114,116 respectively. These further panels will hereafter be referred to as outer flange panels 118,120, while the panels 114,116 corresponding to the flange panels 14,16 of Figure 1 will be referred to as inner flange panels 114,116.

It will be noted that the long outer flange panels 120 are shorter than the long inner flange panels 116 to which they are connected such that a rectangular area 122 at each end of each long inner flange panel 116 does not adjoin a long outer flange panel 120. Tn contrast, the short outer flange panels 118 are larger than the short inner flange panels 114 and extend beyond the ends of the short inner flange panels 114 to which they are connected. A rectangular extension 124 is provided at right angles to each end of the short outer flange panel 118, in each case extending away from the short inner flange panel 114. A forty-five degree cut 126 provided at each end of the short outer flange panel 118 provides a space between the edges of the short outei flange panels 118 and an adjacent long inner flange panel 116 when the blank is marked and cut from a sheet of coated or film laminated paperboard.

Figure 4 shows the initial step of forming a container from the blank 101 of Figure 3. Tab 110 has been folded along its fold line 111 and the blank 101 has been folded at fold lines 108 so that the two end wall panels 102 sandwich tabs 110,112 between them, In this conflgufation, the tab 110, which remains connected by fold line 111 to. one end wall panel 102 is bonded, along with tab 112, to the other end wall panel 102.

Once bonded, the side walls 104 of the partially assembled container are flattened out by opening up fold lines 108 in each side wall 104 to form an open container body 151 as shown in Figure 5. The flange panels 114,116,118,120 are then folded outwardly from the opening of the container body 151 as shown in Figure 6.

Figure 6 shows a view, similar to that of Figure 2, looking into the container body 151 showing tabs 110,112 bonded to one end wall panel 102 to hold the container body 151 together. The side wall panels 104 are completely flat and the flange panels 114,116,118,120 are all folded outwardly around the opening of the container body 151.

The fmal step in forming the container body 151 shown in Figure 7 is to fold the outer flange panels 118,120 back inwardly such that they overlie the inner flange panels 114,116 and bonded in place. The rectangular areas 122 at the end of each long inner flange panel 116, which remain exposed when the outer long flange panels 120 are folded against the inner flange panels 116, are covered by the rectangular extensions 124 provided at each end of the short outer panels 118 such that a continuous flange, free of gaps, is provided around the opening of the container body 151.

As clearly shown in Figure 7, the rectangular extensions 124 abut the ends of the long outer flange panels 120. so that the outward facing surface of the resulting flange is completely flat, as illustrated in the side view of Figure 8. The forty-five degree cuts 126 ensure that sharp corners are avoided on the flange. . . -The provision of a continuous flange of paperboard with a completely flat outer face and no gaps greatly simplifies the bonding of a further closure of paperboard and/or film to close the container body once filled. The double thickness of the flange is also beneficial in providing extra strength and rigidity, minimising the chances of the flange or closure being inadvertently damaged during transportation and/or handling. This is especially relevant where a closure is formed of only film, because no additional strength is then provided by the closure.

An alternative blank 201 illustrating the inventive principles of the invention is shown in Figure 9. The blank 201 has a number of features in common with the blank 101 of Figure 3, and again is for the formation of a sandwich container body. The significant differences are outlined below.

The blank 201 of Figure 9 is intended for the formation of a container body suitable for so called modified atmosphere packaging'. Modified atmosphere packaging is a technique whereby the amount of Oxygen remaining in said sealed container is reduced, ideally to zero, in order to extend the shelf life of packaged food products. It can take the form of vacuum packaging, where the atmosphere within the packaging is removed; or gas flushed packaging, where the atmosphere within the packaging is forced out by the addition of a gas such as Nitrogen and/or Carbon Dioxide. In order for such techniques to be possible, it is important that the sealed container is as airtight as possible.

A number of features of the blank 201 of Figure 9 contribute to providing a substantially airtight container body, and these are described in detail in WO 20 12/080708.

Briefly, two panels 202a,202b are used to form one of the end walls 202 so that each corner of the container opening is provided at the end of a fold line between two panels. rather than at the end of a join between two panels. This has the result that one of the short inner flange panels 214 has been split into two parts 2*14a,214b, which are joined to panels 202a and 202b respectively, and that one short outer flange panel 218 has also been split into two parts 2l8a,218b which are joined to parts 214a and 2l4b respectively.

The blank 201 is also formed from a paperboard having a continuous film layer applied over its surface. This film layer spans the gaps between the inner flange panels 214,216 to form triangular areas 228 of unsupported film at the ends of the fold lines 206 which will form the corners of the container opening.

In contrast with the blank 101 of Figure 3, the outer flange panels 218,220 are also narrower than the corresponding inner flange panels 214,216.

Figure 10 shows a yiew, similar to that of Figure 6, of a part formed container body 251 formed from the blank 201 of Figure 9. The two parts 214a,214b are now adjacent each other to form one of the inner flange panels 214, and the two parts 21 8a,2 1 8b are also adjacent each other to fotrn the corresponding outer flange panel 218. The film areas 228 can be seen at all four corners of the opening, the film being stretched as the flange panels 214,216,218,220 are folded outwardly from the walls 202,204 of the container body 251.

The design of the blank 201 ensures that, when a container body 251 is formed as shown in Figure 10, the inner flange panel 214 formed from the two parts 214a,214b nonetheless presents a substantially flat surface, and thE film areas 228 ensure that the flange is free of any gaps.

However, the unsupported film areas 228 can still prove problematic when a separate closure * -means is applied over the opening. The film areas 228 lack the rigidity of the paperboard parts provided in the remainder of the flange so can cause difficulty especially when unsupported film is used to close the cOntainer opening. Furthermore, when heat sealing is employed to bond the closure to the flange the film areas 228 can be damaged by the high temperatures used, thereby compromising the container's integrity.

Figure 11 shows the outer flange panels 218,220 folded back to overlie the inner flange panels 214,216 in a similar manner to that described above. Once again, rectangular extensions 224 of the short outer flange panels cover rectangular areas 222 of the long inner flange panels 216 and abut the long outer flange panels 220. The outer flange panels 218,220, being narrower in this embodiment, do not completely cover the inner flange panels 214,216 so parts of these and of the film areas 228 remain visible in Figure 11. The outer flange panels 218,220 nonetheless provide a continuous and relatively rigid outer edge to the flange. The film areas 228 provide integrity and improved sealing at the corners of the container body, so it is less important that the outer flange panels 218,220 completely cover the inner flange panels 214,216 in this embodiment.

It should be appreciated that the invention is not considered to be limited to the configurations and materials described above. The configuration of the structure as well as the dimensidns and, to a certain extent, the material of the component parts would be dependent on a specific application.

In particular, the gtheral concept of the invention would be equally applioable to containers of other shapes and for other purposes. For example, the invention could be applied to generally rectangular trays and tubs for salads, noodles or ready meals, or to packs for bakery products.

The. shape of the outer flange panels could also vary from what is shown above. In particular, the rectangular extensions 128,228 could be made larger and the long outer flange panels 120,220 made correspondingly shorter or even omitted altogether. Alternatively, the outer flange panels could be provided with extensions similar to the rectangular extensions 128.228 shown and the short outer flange panels made shorter or omitted. It is even possible to provide. -10-

a single closed loop of blank material to serve as an outer flange panel. It should be borne in mind, however, that these alternatives would generally represent an inefficient use of the blank material.

Claims

CLAIMS1. A container body formed from a folded blank of material and having, at its opening, a flange formed from a plurality of inner flange panels and one or more outer flange panels, wherein said one or more outer flange panels overlies at least a part of each inner flange panel to provide a flat surface to the flange that is continuous around the container opening.
2. A container body according to claim 1, wherein the flange is provided around the outside of the container opening.
3. A container body according to claim 1, wherein the flange is provided around the inside of the container opening.
4. A container body according to any of the preceding claims, wherein the or each outer flange panel is joined to an inner flange panel by a fold line.
5. A container body according to claim 4, wherein the or each outer flange panel is folded back over the inner flange panels.
6. A container body according to claim 4 or 5, wherein at least two outer flange panels are provided.
7. A container body according to claim 6, wherein equal numbers of inner and outer flange panels are provided.
8. A container body according to claim 6 or 7, wherein part of an outer flange panel joined to a first inner flange panel overlies at least part of a second inner flange panel. -12-
9. A container body according to any of claims 6 to 8, wherein edges of the outer flange panels abut one another.
10. A container body according to any of the preceding claims, wherein said one or more outer flange panels completely overlies each inner flange paneL
11. A container body according to any of the preceding claims, wherein the container body comprises paperboard.
12. A container body according to any of the preceding claims, wherein the container body comprises a layer of plastics film.
13. A container body according to any of the preceding claims, wherein gaps between adjacent inner flange panels are spanned by the plastics film.
14. A blank of material for forming a container body, the blank comprising a plurality of wall panels, a plurality of inner flange panels, each being joined to a wall panel by a fold line, and one or more outer flange panels, wherein the or each outer flange panel is joined by a fold line to an inner flange panel and is foldable to overlie at least a part of at least one inner flange panel.
15, A blank according to claim 14, wherein at least two outer flange panels are provided.
16. A blank according to claim 15, wherein at least one outer flange panel is shorter than the inner flange panel to which it is joined and at least one outer flange panel is larger than the inner flange panel to which it is joined.
17. A blank according to any of claims 14 to 16, wherein equal numbers of wall panels and inner flange panels and provided.
18. A blank according to claim 17, wherein equal numbers of inner and outer flange panels are provided.
19. A blank according to any of claims 14 to 18, wherein the wall panels and flange panels are defmed by cuts and fold lines in the blank material.
20. A blank according to any of claims 14 to 19, wherein the blank thrther comprises a plastics film layer spanning gaps between adjacent inner flange panels.
21. A container body substantially as herein described with reference to the accompanying drawings.
22. A blank substantially as herein described with reference to the accompanying drawings.