GB2446795A

GB2446795A - Container with hinge of reduced resilience

Info

Publication number: GB2446795A
Application number: GB0703579A
Authority: GB
Inventors: Kevin Mccourt
Original assignee: PREGIS RIGID PACKAGING Ltd
Current assignee: PREGIS RIGID PACKAGING Ltd
Priority date: 2007-02-23
Filing date: 2007-02-23
Publication date: 2008-08-27
Anticipated expiration: 2027-02-23
Also published as: GB2446795B; GB0703579D0

Abstract

The invention provides an integral container 10 comprising a base portion 12, a lid portion 14 and a hinge portion 50 provided between the base portion 12 and the lid portion 14. The hinge portion 50 substantially resists separation of the lid and base portions. The lid portion 14 and the base portion 12 are moveable about the hinge portion 50 such that the lid portion 14 is arranged to be releasably closed over the base portion 12, and wherein at least a part of the hinge portion 50 is provided with a resilience reducing means 62, 64. The resilience reducing means 62, 64 can comprise at least one groove for reducing the amount of material coupling the lid portion 14 to the base portion 12. The at least one groove can be arranged in a transverse orientation across an area of the hinge portion 50 that is subject to bending forces such that transmission of bending forces across the groove(s) is substantially restricted. Alternatively the resilience reducing means may comprise one or more discontinuities in the hinge portion.

Description

"Container and Method" The present invention relates to a container and

a method of manufacturing the container. In particular, although not exclusively, the invention relates to containers for foodstuff.

Some known food packaging comprises a container portion which holds a food product and a lid which is provided to cover the container portion to prevent contamination and tampering with the food product stored within the container portion. The container portion and the lid can be separate parts or connected via a hinge. Typically, hinges are useful when the food packaging is used to contain snack products, which are often marketed and purchased as a convenience food. The hinge ensures that the lid and the container portion are not separated once the packaging has been opened. This allows, a user to hold the entire packaging in one hand while it is possible to access the contents of the container with the other hand. In contrast, a separate lid is less convenient as this must be stored while the contents of the packaging are being accessed.

*:*::* 20 Where the packaging is required to have greater strength, the packaging S... . . . is often manufactured using more material to increase the thickness of the packaging. However, thicker hinges offer greater resistance to folding and can result in a hinge having a tendency to spring into a certain position *5* once the packaging is opened. This can be disadvantageous on production lines and result in lids having to be securely clipped in the desired position. It can also prove inconvenient for users of the food packaging.

According to a first aspect of the invention, there is provided an integral container comprising a base portion, a lid portion and a hinge portion

I

provided between the base portion and the lid portion to substantially resist separation of the lid and base portions, wherein the lid and the base portion are moveable about the hinge portion such that the lid portion is arranged to be releasably closed over the base portion, and wherein at least a part of the hinge portion is provided with a resilience reducing means.

The resilience reducing means of the hinge portion substantially restricts the hinge portion from being urged towards a specific position under its own resilience so that relative movement of the lid and base portions is more easily controlled.

The resilience reducing means can comprise at least one groove (typically more than one) that is advantageously arranged in a transverse orientation across an area of the hinge portion that is subjected to bending forces, whereby the transmission of the bending forces across the groove(s) is restricted. The groove(s) typically reduce the amount of material coupling the lip portion to the base portion. Typically there are two or more groove(s) arranged parallel to one another. The groove(s) *:*::* 20 may include discontinuities in the hinge portions, for example cuts or slots. * . S...

Preferably, the base portion is shaped to define a recess. The recess can be suitable for storing the contents of the container.

Preferably, the lid portion and the base portion are moveable about the hinge portion between an open position in which the recess of the base portion can be accessed and a closed position in which the lid portion substantially restricts access to the recess of the base portion.

The lid portion and the base portion can be pivotable about the hinge portion between the open position and the closed position.

"Integral container" as used herein is intended to refer to a container that is formed as a one-piece item.

The hinge portion can have a hinge length, and the resilience reducing means can include at least one cut or slot such that the length of material coupling the lid portion and the base portion is less than the hinge length in the region of the at least one cut.

The hinge length of the hinge portion can be defined as the distance between two free edges of the hinge portion. The hinge length can be between 20 -400 mm. The hinge length can be between 50 -325 mm.

The hinge length can be at least 50 mm.

The at least one cut can have a greater length relative to its width.

The at least one cut can be aligned with a perimeter of at least one of the *:*::* 20 lid portion and the base portion. The at least one cut can be located *::::* tangentially or circumferentially relative to at least one of the lid portion and the base portion.

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The resilience reducing means can comprise at least two cuts. The at least two cuts can be cuts that are aligned with one another, and can, for example, be parallel to one another.

Thus, in the region of the resilience reducing means of the hinge portion there can be at least three attachment points (i.e. uncut parts of the hinge length) where the base portion and the lid portion remain attached to one another. Preferably, the hinge has at least one attachment point centrally disposed in the hinge portion.

The attachment points ensure that the hinge portion retains sufficient strength to withstand forces tending to separate the lid portion from the base portion of the container during normal use.

The length of each attachment point is preferably less than any of the channels or cuts.

The resilience reducing means for a given hinge length can include a greater proportion of cut length of the hinge portion than uncut length of the hinge portion.

The resilience reducing means for a given hinge length can include a ratio of cut length of the hinge portion relative to uncut length of the hinge portion of at least 5:1. Alternatively, this ratio of cut length of the hinge portion relative to uncut length of the hinge portion can be at least 8:1 Preferably, the ratio of cut length relative to uncut length can be at least *:*:: 20 10:1. *... * I I...

The resilience reducing means can be provided to reduce the resilience of *s*.

the hinge portion along two hinge lengths that are spaced relative to one S..

another. The two hinge lengths having reduced resilience can be substantially parallel to one another.

S

*S..SS * A reinforced part can be provided between the two hinge lengths having reduced resilience. The reinforced part can comprise a ridge member.

The hinge portion in the region of the resilience reducing means can be at least partially deformable.

The resilience reducing means can be provided in at least one U-shaped channel.

The resilience reducing means of the hinge portion typically reduces the tendency of the lid portion to spring over the base portion under the natural resilience of the hinge portion once the container has been formed.

Therefore, the resilience reducing means allows the container to be more easily manipulated on production lines and increases the convenience of accessing the recess of the base portion for a user.

The recess of the base portion can have an opening adapted to be selectively closed by the lid portion. The opening can provide access to the recess of the base portion. Optionally, the lid portion can be adapted to close the opening such that the lid portion provides a seal around the recess of the base portion.

*:::* 20 According to a second aspect of the invention, there is provided a method of manufacturing a container including the steps of: (a) integrally forming a container comprising a lid portion and a base portion with a hinge portion therebetween such that the lid and base portions are movable about the hinge portion and wherein the hinge portion substantially restricts separation of the lid portion and the base portion; and (b) reducing the resilience of at least a part of the hinge portion.

The method of step (a) can include thermoforming the integral container.

The method step (b) can include reducing the proportion of material in the hinge portion that connects the lid portion to the base portion.

The method step (b) can include forming (e.g. punching or cutting) at least one cut in the hinge portion and simultaneously punching out the integrally formed container following its formation in step (a).

Embodiments of the invention will now be described with reference to and as shown in the accompanying drawings, in which:-Figure 1 is a perspective view of a container according to the invention in a closed position; Figure 2 is a perspective view of the container of Fig. 1 in an open position; Figure 3 is a perspective view of part of a container during manufacture showing a hinge portion; Figure 4 is a perspective view of part of the container of Figure 2; Figure 5 is a plan view of the container of Figure 2; Figure 6 is a side view of the container of Figure 2; Figure 7 is a sectional view of part of the container of Figure 6. * ** * 20 * S.

A transparent plastic container is shown generally at 10 in Figure 1. The container 10 includes a base 12 that is substantially circular in section and *I*.

shaped to define a recess 26 that is useful for containing a foodstuff, such S..

* as salads, snacks and other prepared foods. The container 10 is also provided with a lid 14. The lid 14 is shown in a closed position in Fig 1, in which the lid 14 covers the base 12 to substantially contain the food within the recess 26 of the container 10. Fig. 2 shows the container 10 in an open position in which the lid 14 is not covering the base 12 and allows access to the recess 26. The lid 14 is coupled to the base 12 by means of a hinge 50. The lid 14 and the base 12 are pivotable about the hinge 50 to move the container 10 from the closed position (Fig. 1) to the open position (Fig. 2).

As shown in Fig. 2, the base 12 has a lower wall 241, which is intended to be the lowermost part of and support the container 10 in normal use. A sidewall 24s that is substantially circular in section extends upwardly and outwardly from the lower waIl 241 to define the recess 26. Towards an opening of the recess 26 there is provided a step 28 that is substantially parallel to the lower wall 241, such that the diameter between opposing parts of the sidewall 24s increases in a stepwise rather than a gradual manner. At an outer edge of the step 28 the sidewall continues to extend outwardly and upwardly for a short distance to a lip 22 that circumscribes the opening of the recess 26. A discontinuous arcuate rim 20 protrudes from the lip 22. The rim 20 is discontinuous in a region 22t for receiving a tab and in a region 22h of the lip that is proximate the hinge 50.

The lid 14 has a substantially planar circular region 46. An outer part of the central region 46 meets an annular protrusion 40 that projects from the plane of the region 46. The lid 14 has an outer edge 44 that adjoins the *:*:* 20 hinge 50 in a hinge region 44h. The edge 44 also has a tab 42 extending outwardly in the plane of the central region 46 and formed with ridges 42r to improve the strength. * S..

S *5S*

In the closed position, an outermost part of the edge 44 abuts an innermost part of the rim 20 and the annular protrusion 40 is arranged to cooperate with the step 28 of the base 12. In this position, the tab 42 is accommodated in the region 22t of the lip 22 and protrudes over an edge of the lip 22 such that the tab 42 can be accessed by a user and pulled upwardly to move the container 10 into an open position.

The resilience reducing means of the hinge 50 is shown in detail in Fig. 4.

The hinge 50 comprises a first substantially U-shaped channel 52 that borders the hinge region 22h of the lip 22 on one side and borders a ridge 58 on the other side. The ridge 58 also borders another substantially U-shaped channel 54 along its other side. The U-shaped channel 54 is provided adjacent the hinge edge 44h of the lid 14. In this arrangement, the U-shaped channels 52, 54 and the ridge 58 are parallel to one another. The U-shaped channel 52 comprises two aligned longitudinal cuts 62 along its length. This leaves three uncut portions 72 of the U-shaped channel 52. Two uncut portions 72 are provided at each end of the U-shaped channel and the remaining uncut portion 72 is provided in a central region between the cuts 62. The proportion of the cuts 62 relative to the uncut portions 72 is approximately 10 to 1. Similarly, the U- shaped channel 54 has parallel longitudinal cuts 64 and corresponding uncut portions 74.

The plastic material to be used in construction of the container is thermoformed into the required shape having a thickness of 500 microns.

The container 10 is then punched or cut out by making cuts around the *:*:* 20 outer part of the rim 22 and the edge 44. The longitudinal cuts 62, 72 are .. punched or cut simultaneously as the container 10 is cut out of the * *8s surrounding material. p...

Prior to use of the container 10, the recess 26 is filled with contents such : 25 as foodstuff, typically on production lines. Following filling of contents in the recess 26, the lid 14 is required to be moved into the closed position over the base 12, shown in Fig. 1. Once the container 10 has been closed, the lid 14 remains in this position due to the longitudinal cuts 62, 72 that substantially reduce the resilience of the hinge 50 to thereby prevent the lid 14 from being urged into the open position by the resilience of the hinge 50.

During filling of the container 10 on the production line and its subsequent use, it is desired that the lid 14 remains attached to the base 12 of the container 10 by means of the hinge 50. This is achieved by maintaining a requisite length of uncut portions 72, 74. Additionally, the ridge member 58 between the U-shaped channels 52, 54 and the ability of the resilience reducing member to substantially deform to absorb any separation force improves strength of the hinge 50 and substantially restricts separation of the base from the lid during normal use. Any force applied to the container 10 tending to separate the lid 14 from the base 12 encourages defamation of the U-shaped channel members 52, 54 and can increase the lateral separation of the longitudinal cuts 62, 64. However, the absolute length of the uncut parts 72, 74 is controlled to ensure that the separation force applied to the container 10 does not cause propagation of the longitudinal cuts 62, 64 such that the cut length is prone to increase into the uncut part 72, 74 thereby extending the length of the longitudinal cuts 62, 64. In the present case, the uncut parts 72, 74 between the longitudinal cuts 62, 64 is approximately 2.5 millimetres and the length of the uncut parts 72, 74 between ends of the longitudinal cuts 62, 64 and the edge of the U shaped channels 52, 54 is approximately 7 millimetres, : with a total hinge length of 72 millimteres. This length of uncut parts 72, 74 should ideally be above a pre-determined value such that on encountering a reasonable separation force during filling and use, the base 12 and the lid 14 of the container 10 do not become separated due * to disruption of the hinge 50. This value is dependent on the thickness of the material of the hinge 50, the length of the hinge 50 and the number of cuts 62, 64. The ridge 58 between the U-shaped channel members 52, 54 also reinforces the hinge 50 and tends to reduce the. tendency of the hinge to be disrupted.

Since resilience of the hinge 50 is reduced by the longitudinal cuts 62, 64, the container 10 represents an improvement over existing containers and packaging. For example, a person wishing to access the contents within the recess 26 can move the container 10 into the open position by engaging the tab 42 of the lid 14 and applying a force to the tab 42 in a direction away from the base 12 while maintaining a grip on the base 12.

Opening the container 10 allows the user to access the food stuff within the recess 26 without the resilience of the hinge 50 urging the lid 14 to re-cover the opening of the base 12. Therefore the longitudinal cuts 62, 64 cause the lid 14 to remain in the open position once the lid 14 has been moved into the open position. Since the hinge 50 retains sufficient strength, the lid 14 remains attached to the base 12 so that the lid 14 can be repositioned over the base 12 when the user requires the contents of the container 10 to be recovered.

Modifications and improvements can be made without departing from the scope of the invention. For example the invention is described with reference to the substantially circular-section container 10, although the invention is applicable to any shape of integral container. The above embodiment described two cuts to the hinge, but there may be three or more longitudinal cuts to in each of the U-shaped channels 52, 54.

Typically the resilience reducing means is useful for containers 10 that are * formed with a thickness of above around 400 microns, but the invention is * not restricted to use on such a container. Other factors which can have an impact on the resilience of the hinge are the total length of the hinge 50 and the weight of the lid 14. For example, a lighter lid can be more susceptible to hinge resilience. -11

Claims

1. An integral container comprising a base portion, a lid portion and a hinge portion provided between the base portion and the lid portion to substantially resist separation of the lid and base portions, wherein the lid and the base portion are moveable about the hinge portion such that the lid portion is arranged to be releasably closed over the base portion, and wherein at least a part of the hinge portion is provided with a resilience reducing means.

2. A container according to claim 1, wherein the resilience reducing means comprises at least one groove for reducing the amount of material coupling the lid portion to the base portion.

3. A container according to claim 2, wherein the at least one groove is arranged in a transverse orientation across an area of the hinge portion that is subject to bending forces such that transmission of bending forces across the groove(s) is substantially restricted.

4. A container according to any preceding claim, wherein the *..*** resilience reducing means comprises at least two groove(s).

5. A container according to claim 7, wherein the at least two grooves are aligned with one another in the same transverse orientation.

*..S..

* :

6. A container according to any preceding claim, wherein the **.** * resilience reducing means comprises one or more discontinuities in the hinge portion.

7. A container according to any preceding claim, wherein the resilience reducing means includes at least one cut such that the bending forces are not transferred across the hinge in the region of the cut.

8. A container according to claim 7, wherein the at least one cut has a greater length relative to its width.

9. A container according to claim 7 or claim 8, wherein the at least one cut is aligned alongside at least one of the lid portion and the base portion.

10. A container according to any one of claims 7 to 9, wherein the at least one cut is located tangentially relative to at least one of the lid portion and the base portion.

11. A container according to any one of claims 7 to9, wherein the at least one longitudinal cut is located circumferentially relative to at least one of the lid portion and the base portion.

12. A container according to any one of claims 7 to 11, wherein the resilience reducing means includes a greater proportion of cut length of the hinge portion than uncut length of the hinge portion along a particular transverse orientation along the hinge portion. S.

S

13. A container according to any one of claims 7 to 11, wherein the resilience reducing means for a given transverse orientation along the S. ***.

* hinge portion includes a ratio of cut length of the hinge portion relative to s*S*S * uncut length of the hinge portion of at least 5:1.

14. A container according to any one of claims 7 to 11, wherein the resilience reducing means for a given transverse orientation along the hinge portion includes a ratio of cut length of the hinge portion relative to uncut length of the hinge portion of 8:1.

15. A container according to any one of claims 7 to 11, wherein the resilience reducing means for a given transverse orientation along the hinge portion includes a ratio of cut length of the hinge portion relative to uncut length of the hinge portion of 10:1.

16. A container according to any preceding claim, wherein the resilience reducing means is provided to reduce the resilience of the hinge portion in two transverse orientations that are spaced relative to one another.

17. A container according to claim 16, wherein the two transverse orientations having resilience reducing means are substantially parallel to one another.

18. A container according to claim 16 or claim 17, wherein a reinforced part is provided between the two transverse orientations having reduced *:*::* 20 resilience. S... * S * .*S

19. A container according to claim 18, wherein the reinforced part **S.

comprises a ridge member. *S.

S

20. A container according to any preceding claim, wherein the hinge S.....

* portion in the region of the resilience reducing means is at least partially S.S.* * S deformable.

21. A container according to claim 20, wherein the resilience reducing means are provided in at least one U-shaped channel. a

22. A container according to any preceding claim, wherein the thickness of walls of the container is greater than around 400 microns.

23. A container according to any preceding claim, wherein the thickness of walls of the container is greater than around 500 microns.

24. A method of manufacturing a container including the steps of: (a) integrally forming a container comprising a lid portion and a base portion with a hinge portion therebetween such that the lid and base portions are movable about the hinge portion and wherein the hinge portion substantially restricts separation of the lid portion and the base portion; and (b) reducing the resilience of at least a part of the hinge portion.

25. A method according to claim 24, wherein step (b) includes reducing the proportion of material in the hinge portion that connects the lid portion to the base portion.

*:*::* 20

26. A method according to claim 24 or claim 25, wherein step (b) includes punching at least one cut in the hinge portion and simultaneously punching out the integrally formed container following its formation in step (a).

27. A container as substantially hereinbefore described with reference *..* * to and as shown in Figures 1, 2 and 4 to 7. *..*S * S