GB2482491A

GB2482491A - Sandwich Carton with Frangible Opening

Info

Publication number: GB2482491A
Application number: GB201013013A
Authority: GB
Inventors: Frank Mills; Philip Wright
Original assignee: Colpac Ltd
Current assignee: Colpac Ltd
Priority date: 2010-08-02
Filing date: 2010-08-02
Publication date: 2012-02-08
Anticipated expiration: 2030-08-02
Also published as: GB2482491B; GB201013013D0

Abstract

A container and blank 1 therefore for food e.g. sandwiches having an opening, a lid 10 for closing the opening and a flange14 to which the lid is bonded to close the container, the flange and container each having lines of weakness or score lines 16, 18 provided by partial cuts to create a frangible portion for opening the container. A cut line 20 in the lid may be provided between the line of scoring and the edge of the lid, the cut line aligning with a discontinuity in the flange and providing a start point for tearing (Figure 5). The line of scoring in the lid may be offset but parallel to the line of scoring in the flange. The container may be paperboard, the lid being integral with the container. The line of scoring may be provided in a surface of the flange opposite to that to which the lid is bonded. The lid and flange may be covered with a liquid impermeable, film layer susceptible to heat sealing which is not penetrated by the score lines.

Description

A CONTAINER

The invention relates to a container, and particularly, but not exclusively to a food product container with a frangible opening.

There is an ongoing desire in the field of food packaging, in particular sandwich packaging, to improve the seal of food product containers to prolong the shelf life and optimum freshness of the product contained therein. There is also a continuing desire to continue using paperboard (which, in the context of the application is taken to mean paper, cardboard and similar materials) because of environmental concerns and because of the benefits this material provides for providing printed graphics on the exterior of the packaging.

A number of techniques have been employed to improve the seal of a container, including using continuous laminated films as an interior layer of the container and employing modified atmosphere packaging techniques. Providing improved layouts for paperboard blanks from which the containers are made has also been an area of development, leading to the incorporation of a number of features such as webbing portions between wall panels which all serve to improve the integrity of the finished container.

A problem arises when the improved packs come to be opened. By virtue of their improved seal, a customer can experience difficulty in separating the lid of a container from a body portion where the food product is held. The problem is particularly significant in film laminated packs where the lid is heat sealed into a closed position.

It is an object of the present invention to provide a container with a closure which can be easily opened by a user without compromising the integrity of the sealed container.

According to the present invention there is provided a container as defined in the appended claim 1.

The container according to the present invention retains its integrity when sealed, but also comprises first and second lines of weakness (score lines) to provide a frangible portion which simplifies opening of the container.

Further preferable features of the container of the present invention are defined in the dependent claims 2 to 19.

The container is preferably a food product container, in particular a sandwich box. The container may be formed from paperboard, in particular from a paperboard blank, in which case a liquid impermeable coating is preferably provided on at least its interior surface to prevent the ingress of liquids into the paperboard. The lid is preferably formed integrally with the body of the container, but may alternatively be provided as a separate component.

The first surfaces of the flange and lid, which are to be bonded together to close the container, preferably comprise a coating that is susceptible to heat sealing to allow for robust and reliable sealing of the finished container. The coating may also form the liquid impermeable coating referred to above, and is preferably provided as a layer of film, for example a plastics film, although other types of coating may be used. Where film is used, it can further improve integrity if the film also forms windows over apertures formed in the substrate of the blank.

The first line of scoring is preferably provided in a second surface of the container flange and the second line of scoring is preferably provided on the first surface of the container lid, preferably in a portion thereof that overlies a portion of the flange when the container is closed and sealed. In this way, no lines of scoring are provided on the interior of the finished container, which improves the integrity of the sealed container.

A full cut line is preferably provided through the container lid between an edge of the lid and the second line of scoring. The cut line preferably aligns with a discontinuity provided in the flange to provide a start point for a tear running through the frangible portion when the container is opened.

The flange of the container may be formed in a plurality of sections, more than one of which may comprise a first line of scoring. Preferably, all portions of the flange comprise a first line of scoring.

There is no need for the lines of scoring in the lid and flange to align when the container is closed. Tn particular, the second line of scoring may be parallel with, but offset from, the or each first line of scoring such that an area of the lid is bonded to an area of the flange between the two lines of scoring.

If the container is formed from a blank, the blank preferably comprises a paperboard substrate and a film layer laminated to the paperboard substrate.

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 a blank suitable for forming a container according to the present invention; Figure 2 is a plan view showing an alternative blank during production; Figures 3a to 3c show the folding of a blank into a container according to the present invention; Figure 4 is a perspective view of a sealed container according to the present invention; and Figure 5 shows a user opening a container according to the present invention.

Figure 1 shows a plan view of a blank 1 suitable for forming a container according to the present invention. The blank 1 has a paperboard substrate which is cut from a single piece of paperboard using a conventional technique such as die-cutting.

The blank 1 shown in Figure 1 is for a sandwich container and, once folded, provides a container with a generally triangular profile for receiving diagonally cut sandwiches. The surface of the blank 1 shown in Figure 1 (the second surface) will form the outside of the finished container. The first surface of the blank 1, opposite to the second surface, will form the inside of the finished container and comprises a laminated plastics film. The film serves as both a moisture impermeable barrier and as a heat sealable medium for sealing the finished container and, in some cases, also for bonding the container walls together.

The blank 1 comprises a generally rectangular central panel 2 which forms the apex of the finished pack and is connected by fold lines to a pair of generally triangular side wall panels 4 and a pair of generally rectangular end wall panels 6. In the particular embodiment shown, the sides of the end wall panels 6 taper away from the central panel 2 such that the finished container has an opening that is wider than the apex of the pack to aid insertion of the cut sandwiches, but this is not essential.

Webbing portions 8 are provided between each side wall panel 4 and end wall panel 6 to improve the integrity of the finished container. As shown, each webbing portion 8 comprises a larger webbing panel 8a and a smaller webbing panel 8b with a fold line in between. When forming the container, as seen in Figures 3a to 3c, each webbing portion 8 is folded like a concertina such that the larger webbing panel 8a and a side wall panel 4 sandwich the smaller webbing panel 8b. The webbing portions 8 are then bonded to the wall panels 4 to form the body of the container. By virtue of the larger size of larger webbing panel 8b, the entire webbing portion 8 can be bonded to the side wall panel 4 by common bonding means, for example heat sealing.

The blank 1 also comprises a generally rectangular lid panel 10 joined by a fold line along one of its long edges to the outside edge of one of the side wall panels 4. A window 12 is provided in the lid panel 10 to allow a customer to view the contents of the container once it is sealed. In the illustrated embodiment the window 12 is provided as an aperture in the paperboard substrate which is covered by the continuous laminated film layer. This helps to maintain an optimum seal by avoiding discontinuities in the finished lid panel 10. However, it is also possible for the window 12 to be covered by a separate piece of film if the coating of the paperboard is achieved by alternative means, such as by spraying.

The outside edge of the remaining side wall panel 4 is joined by a fold line to a large flange forming panel 14a and the outside edges of the end wall panels 6 are joined by fold lines to small flange forming panels 1 4b.

Figure 1 also shows a first score line 16 provided in the outer, or second, surface of each of the flange forming panels 1 4a, 1 4b. The first score lines 16 run along substantially the entire length of each of the flange forming panels 14a,14b, but a short length of the blank remains un-scored at each end of each first score line 16. Each first score line 16 is provided as a partial cut through the paperboard substrate making up the blank 1. Significantly, none of the first score lines 16 penetrates the film layer forming the first surface of the blank.

Each first score line 16 is spaced from the edge of the flange forming panel I 4a,1 4b in which it is formed and from the fold line joining said flange forming panel 14a,l4b to a wall panel 4,6.

In the illustrated embodiment, the width of the large flange forming panel 14a, measured from the fold line where it joins the side wall panel 4 to its outside edge, is 15mm. The width of each small flange forming panels I 4b is 10mm. Each first score line 16 is spaced from the adjacent fold line by 4mm, meaning that the large flange forming panel 1 4a has a first score line 16 located 11mm from its edge, and each small flange forming panel has a first score line 16 located 6mm from its edge.

A further, second, score line 18 is provided in the lid panel 10. The second score line 18 is a continuous partial cut having three straight sections, each running parallel to a side of the lid panel 10 that is not joined to the side wall panel 4. The sections of the second score line 18 running parallel to the short sides of the lid panel 10 stop short of the edge of the lid panel so that every part of the second score line 18 is spaced from the edge of the lid panel. Unlike the first score lines 16 in the flange forming panels 14, the second score line 18 is provided in the first surface of the lid panel 10 of the blank 1. As such, the partial cut that forms the second score line 18 is through the film layer, but does not fully penetrate the paperboard substrate.

The second score line 18 in the lid panel 10 is spaced from the long edge of the lid panel 10 by 15mm and from each short edge of the lid panel 10 by 9.5mm. A small cut 20 is provided through the entire thickness of the lid panel 10 from one of the short edges of the lid panel 10 to the second score line 18 that runs parallel to that edge. The cut 20 is spaced 18mm from the long edge of the lid panel 10 so does not align with the second score line 18 that is parallel with thelongedge.

The location of the score lines 16,18 and the cut 20 ensures that an area of weakness is provided to simplify opening of the sealed container without there being any exposed cut lines on the interior of the finished container. The first score lines 16 provided on the flange forming panels 14a,14b are provided in the second surface of the blank 1 and are spaced from the fold line between the flange forming panels 14a,l4b and the wall panels 4,6 to which they are connected.

The second score line 18 in the lid panel is also not exposed to the interior of the finished container, as will become clear later.

Although not shown in Figure 1, it is preferable if the film layer on the first surface of the blank 1 extends beyond the edge of the paperboard substrate in at least some locations. One way of achieving this is described in relation to Figure 2, which shows a blank 1' similar to that of Figure 1, but with a further window 22 provided in one of the end wall panels 6. The outline shape of the blank 1' shown in Figure 2 is identical to that of the blank 1 shown in Figure 1, -7..

with fold lines provided between various panels as before. However, a number of additional lines are shown around the blank 1' in Figure 2 to illustrate the manufacturing steps.

Starting with a single sheet of paperboard, a first cutting process or pass produces apertures to form window portions 12,22. In the same pass, fold lines are created between the flange forming panels 14a,14b and the remainder of the blank I', and further apertures 23 are cut outside the area of the finished blank 1', specifically adjacent to each of the webbing portions 8.

These further apertures 23 encompass regions 24 and 26 shown in Figure 2. Once the apertures 12,22,23 have been cut, a layer of film is laminated to the entire sheet of paperboard to form a first surface of the blank I and cover each aperture 12,22,23. A second cutting pass then cuts out the outline shape of the finished blank 1'. Significantly, this second pass cuts through each of the additional apertures 23 at the line indicated at 25 such that a small amount of film 26 remains attached to the finished blank 1', while the remaining film 24 covering aperture 23 is discarded. The remaining fold lines of the blank 1' are also provided during the second pass.

The benefit of providing a small amount of surplus film in this way is that when the container is formed from the blank, the surplus film 26 provided will overlie and seal the cut edges of the paperboard at the edge of each webbing portion 8. This further improves the integrity of the container. It is clear from Figure 2 that the amount of film provided at the edge of each webbing section 8 is not uniform. However, it is also possible for a uniform amount of film to be provided by simply modifying the shape of each additional section 24 and/or by cutting along a different line 25 in the second pass. A similar technique can also be used to provide an excess of film around substantially all or the perimeter of the blank 1', or in further or alternative key areas as required.

The blank 1' of Figure 2 is shown at a stage in the production process before the score lines 16,18 in the flange forming panels 14a,l4b and lid panel 10 have been formed. However, various fold lines similar to those in the blank I of Figure 1 are shown between the panels of the blank 1'. The various fold lines can be formed as score lines similar to score lines 16,18, or as creases. Where score lines are used, it is important in maintaining integrity of the finished container that the score line is made in the second surface of the blank 1' and does not penetrate the film layer forming the first surface of the blank 1. In this regard, it can be beneficial to make the partial cut lines before the film layer is applied to the first surface of the paperboard, although this is not essential. It is also possible for a fold line to be formed as a combination of creases and score lines. For example, in Figure 1 the fold line between the lid panel 10 and the side wall panel 4 to which it is joined comprises a score line with a short section of creasing at either end.

Figures 3a to 3c show the folding of the blank 1,1' to form a finished container. The process of forming the container is essentially conventional, and will not be discussed in any great detail.

As mentioned in respect of Figure 1, the webbing portions 8 concertina as the side wall panels 4 and end wall panels 6 are brought together, and are then bonded to the side wall panels 4 by heat sealing to form the finished container of Figure 3c. The small amount of surplus film (not shown) at the edge of each webbing portion overlies and seals the otherwise exposed cut edges 28 adjacent the opening of the container. Figure 3c also shows the flange forming panels 1 4a, I 4b folded outwardly from the opening of the container to provide a flange 14 around three sides of the opening, with the lid panel 10 hinged to the other side. Discontinuities 30 are provided in the flange 14 at the point where the large flange forming panel 14a meets each of the small flange forming panels I 4b.

The container 32 shown in Figure 3c is ready to receive a sandwich. Once the container 32 has been filled the lid 10 is closed and heat sealed to seal the flange 14 of the container 32.

Modified atmosphere packaging techniques, for example vacuum packaging or flushing the container with an inert gas, can be used as required.

A closed and sealed container 32 is shown In Figure 4. When the lid panel 10 is sealed to the flange 14 of the container 32 there is typically an overlap such that the edges of the lid panel 10 extend beyond the edges of the flange 14. As such, and as a result of the location of the score lines 16,18 defined in relation to Figure 1, the second score line 18 is positioned closer to the edge of the flange 14 than the first score lines 16 provided in the flange 14 itself. As such, the score lines 16,18 are offset by a few millimetres (typically 1 to 3mm) when the container is sealed closed, and the second score line 18 overlies the flange 14 so as to avoid the presence of exposed cuts in the interior of the container 32. Every exposed paperboard edge 28 or score line 18 provided in the film layer of the blank I is, therefore, covered when the container 32 is closed and sealed. As a result, the integrity of the finished container is not compromised by any exposed edges of paperboard or by the second score line 18 or any other feature of the frangible opening.

Figure 4 also shows cut 20 in the lid panel 10 of the container 32. Cut 20 is aligned with one of the discontinuities 30 in the flange 14 of the container 32 to provide a start point for a user to tear the lid panel 10 away from the remainder of the container 32. The location of the cut 20 may differ from that shown in Figure 4. For example, the cut 20 could be provided at the opposite end of the lid 10 or at any other location where a tear is to be initiated.

Figure 5 shows a container 32 being torn open by a user. The tear initiates at the base of the cut line 20, and is then encouraged to follow the score lines 16,18. The offset nature of the score lines 16,18 means that a user is not required to tear through both the lid 10 and flange 14 of the container simultaneously, and that there is only a very small strip 34 of heat sealed material between the score lines 16,18 that needs to be de-bonded to open the container 32. This greatly simplifies the opening process.

As shown in Figure 5, the long flange forming panel 14a generally tears along the first score line 16 provided therein and the lid 10 also tends to tear along the long side of the second score line 18. This means that a strip of material 36 comprising a part of the flange 14 and a part of the lid 10 is torn away from the remainder of the container. The tear then tends to follow the second score line 18 in the lid 10 such that when it reaches the short flange forming panel 1 4b distal from the cut line 20 the lid is separated from this panel I 4b. The lid panel 10 may delaminate as a result of the second score line 18, or the short flange forming panel I 4b may be torn away at the first score line 16 provided therein. In either case, the spacing of the first and second score lined 16,18 ensures that it is only necessary to overcome a small width of the heat -10-seal in order to separate the lid 10 and the flange 14. The lid 10 is then separated from the flange 14 along two sides of the opening of the container 32, but one short edge of the lid 10 remains bonded to a short flange forming panel 1 4b.

To separate the lid 10 from the remaining short flange forming panel 1 4b and fully open the container 32, a user simply needs to pull on one of the open sides of the remaining part of the lid 10. Once again, the separation of the lid 10 can either be through delamination of the lid 10 at the second score line 18, or tearing of the short flange forming panel 14b at the first score line 16.

The frangible opening described above greatly simplifies the opening of the heat sealed sandwich container 32. The first and second score lines 16,18 provide a reliable opening via one of two mechanisms, and the second score line 18 in particular assists in guiding a tear around the opening of the container 32. Furthermore, the two-stage opening process can be beneficial in ensuring that sandwiches do not spill from the container 32 in the event that it is dropped during the opening process.

The invention is not considered to be limited to the configurations and materials described above. While the description is limited to a container formed from a paperboard blank, the principles of the invention would also be applicable to similar containers made by other means.

Furthermore, the shape of the container and the blank from which it can be formed may vary from that described as may the dimensions and, to a certain extent, the materials used.

Claims

CLAIMS1. A container comprising a body with an opening for receiving a food product and a lid for closing the opening, the body of the container comprising a flange which extends along at least part of a perimeter of said opening and having a first surface to which a first surface of the lid is bonded to close the container, wherein at least a portion of the flange is provided with a first line of scoring and the lid is provided with a second line of scoring, and wherein both lines of scoring are provided as partial cuts in the material forming the container to create a frangible portion for opening the container.
2. A container according to claim 1, wherein the lid is formed integrally with the body of the container.
3. A container according to claim 1 or 2, wherein the material forming the container comprises paperboard.
4. A container according to claim 3, wherein the inside surface of the container body and the first surface of the lid comprise a coating that is liquid impermeable.
5. A container according to any of the preceding claims, wherein the first surfaces of the flange and lid comprise a coating that is susceptible to heat sealing.
6. A container according to claim 4 or 5, wherein the coating comprises a layer of film.
7. A container according to any of the preceding claims, wherein the first line of scoring is provided in a second surface of the container flange opposite to the first surface of the container flange.
8. A container according to any of the preceding claims, wherein the second line of scoring is provided on the first surface of the container lid.

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9. A container according to claim 8, wherein, when the container is closed, the second line of scoring overlies a portion of the flange.
10. A container according to any of the preceding claims, wherein a full cut line is provided through the container lid between an edge of the lid and the second line of scoring.
11. A container according to claim 10, wherein, when the container is closed, the cut line aligns with a discontinuity provided in the flange.
12. A container according to any of the preceding claims, wherein the flange is formed in a plurality of sections and a first line of scoring is provided in more than one of the sections.
13. A container according to any of the preceding claims, wherein, when the container is closed, the second line of scoring is parallel with, but offset from, the or each first line of scoring.
14. A container according to claim 13, wherein a region of the flange is bonded to a region of the lid between the first and second lines of scoring.
15. A container according to any of the preceding claims, wherein the container is formed from a blank.
16. A food product container according to any of the preceding claims.
17. A blank for forming a container according to any of the preceding claims.
18. A blank according to claim 17, wherein the blank comprises a paperboard substrate and a film layer laminated to the paperboard substrate.-13 -
19. A container substantially as herein described with reference to the accompanying figures.