GB2380180A

GB2380180A - Resealable container

Info

Publication number: GB2380180A
Application number: GB0123397A
Authority: GB
Inventors: Andrew C Boardman
Original assignee: Redbridge Holdings Ltd
Current assignee: Redbridge Holdings Ltd
Priority date: 2001-09-28
Filing date: 2001-09-28
Publication date: 2003-04-02
Anticipated expiration: 2021-09-28
Also published as: US20050000965A1; EP1438238A1; GB2380180B; GB0123397D0; EP1438238B1; DE60217702D1; WO2003029100A1

Abstract

A resealable container comprises an at least semi rigid receptacle (1) with an opening, a lip (3) surrounding the opening, a closure (5) for closing the opening, and an adhesive (4) which provides a releasable and resealable bond between the closure and the lip (3), substantially all of the adhesive remaining on one of the closure (5) or the lip (3) when the bond is released. The receptacle (1) may be moulded from a flat sheet of food grade polypropylene, polyethylene, polyester or polystyrene and the closure (5) may be a laminated extrusion and may be micro-porous or macro-porous.

Description

Container The invention relates to a container such as a resealable container for soft fruit or other items.

The area of soft fruit retailing has many difficulties and it would be beneficial to producer, supplier and consumer to have a container to store soft fruit between field and table which would allow the consumer easy access and where the life of the fruit would be extended for as long as possible. The present invention provides such a container.

The present invention provides according to a first aspect a resealable container comprising : an at least semi rigid receptacle with an open side, and a lip surrounding its open side ; a closure closing the open side of the receptacle, and an adhesive which provides a releasable and resealable bond between the closure and the lip of the receptacle.

Preferably the adhesive is such that the bond can be broken and resealed several times.

Said adhesive preferentially attaches to either the lip or the closure.

Preferably the adhesive is applied using hot melt at, for example, ISOC.

Alternatively, the adhesive is applied as a cold liquid and allowed to dry.

Preferably, the lip includes a substantially flat portion

The lip may be between 2 mm and 6 mm wide.

A preferred embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a perspective view, partly cut away, of a punnet forming part of a container in accordance with the invention, Figure 2 is a perspective view of a closure to close the open side of the punnet of figure 1, the closure being shown upside down with respect to the orientation of the punnet of Figure 1, and Figures 3 to 5 are partial cross sections showing the engagement and disengagement of the closure with the punnet.

Figures 1 to 5 show a resealable container for soft fruit or other items The container comprises an open-topped, rigid or semi-rigid receptacle in the form of a so-called punnet 1 and a closure 5 for closing the open top 2.

The punnet is provided with a lip 3 surrounding the open top 2, said lip being substantially flat or including a substantially flat portion, the flat portion having a minimum width of 2 mm in order to form an effective seal. A lip width of up to 6 mm may be used, the wider lip allowing a stronger resealable attachment between the punnet 1 and the closure 5 but requiring more force to open (as will be apparent later) Within these parameters, the width of the lip may be determined in each application by, for instance, the necessity to allow a clip-on lid to be applied The punnet 1 is form-or blow-moulded from a flat sheet of standard, food grade polypropylene. This polypropylene may be biodegradable due to the incorporation of an additive. The dimensions of the punnet 1 will be determined by the contents of the container.

Figure 2 shows a closure 5 for closing the open top 2 of the punnet I made from a flat sheet of oriented polypropylene, which can be either a single, or laminated, extrusion and which may be micro-, macro-or non-porous. The sheet material will shear but not stretch in a particular direction due to the nature of oriented polypropylene.

The closure 5 may be manufactured as one of a series of closures in a strip 7 which may be then wound onto a reel for ease of handling during manufacture. Adhesive 4 is applied to the closure 5 (usually whilst it is still in a strip with other closures before winding up in a reel).

It is desired that the adhesive bonding and sealing the punnet 1 and the closure 5 together is of a type that provides a releasable and resealable bond thereby allowing the closure to be partially or completely removed from the punnet I and then resealed to it. This allows, for example, the removal of a single piece of fruit by the consumer and the resealing of the container to maintain the fruit left in the container in a fresh condition. Furthermore, we desire to arrange for the adhesive to remain bonded with one of the surfaces, (in this case, where the receptacle is a punnet for fruit, with the closure 5, but in other cases it may be with the lip of the receptacle), but releasable from the other surface.

One way of arranging this is with a hot-melt adhesive, which is applied to the closure 5 at a high temperature (140-180 C, typically substantially 180 C) so as to form a substantially permanent bond with the material of the closure 5. The adhesive is applied in a desired pattern, typically in the shape of a band 4 of overall shape and dimension matching the shape and dimension of the flat portion of the lip 3 of the punnet 1. The adhesive may be in the form of a continuous surface or may be broken up into a patch pattern.

Thus in the manufacture of the container, the moulded punnet I is filled with the desired fruit. The strip 7 comprising a plurality of closures 5 is aligned with the top of the punnet I with the side with the adhesive facing the lip and aligned therewith (see Figure 3). The closure 5 is engaged with the lip of the punnet (see Figure 4) and separated from the remainder of the strip 7.

The container may then be sold to a consumer.

In order to open the container, the closure 5 may be peeled back from the lip of the punnet (see Figure 5). The adhesive 4 remains substantially permanently bonded to the closure 5 but releases from the lip of the punnet I without leaving a measurable trace of adhesive. If the consumer wishes to keep some of the fruit in the punnet, the closure is then reengaged with the lip of the punnet and once again the adhesive forms a bond and seal. The process may be repeated several times so long as the lip remains clean.

If the container is to be used for a'living'product, such as soft fruit, the closure 5 will normally be porous, as this will allow an appropriate atmosphere to be maintained within the container, which can double the shelf life of the product Also, when the consumer opens and reseals the container after purchase, the life of the product left in the container will be extended much further than if the container remained open because the proper atmosphere within the container will be re-established In order to provide the desired porosity of the closure, the sheet material from which the closure is made includes perforations of a size, which may be, for micro-porous material, below 00 u. m, for macro-porous material above 100 u, m In an example, one or two lines of 40-80 n. m perforations may be created by an electrostatic or laser perforating machine along the length of the film material comprising the closure The closure may also carry printing (directly or on a separate carrier layer such as paper), which is used as a label detailing the contents of the container The closure may also incorporate a means by which the consumer can establish whether the contents satisfy their requirements as to freshness-i e, a'smell box', for the detection of odour.

The closure is dimensioned so that it overhangs 6 the lip 3 of the punnet I by 3 mm, (either all round the punnet or just at one edge or in one corner as appropriate), this overhang forming a means for the consumer to grip the closure for peeling the closure off the lip as is shown in Figure 5 to open the container and expose the contents.

An alternative means of attaching the closure to the punnet (without requiring expensive machinery to apply to the closure a predetermined pattern of adhesive matching the flat surface) would involve manufacturing the cover from two sheets of film attached across their width by the adhesive wherein the sheets can peel apart. The shape and dimensions of the lip of the punnet is then cut out from the bottom sheet and peeled away leaving the adhesive attached to the closure.

Where the punnet is for food use, the polypropylene used and the oriented polypropylene used for the closure, should meet the required specification.

The adhesive 4 is a food grade, commonly available, permanent adhesive meeting the requirements of FDA regulation CFR. 21. 175. 105'Adhesives'allowing for indirect food use which, when applied to a polypropylene surface using hot melt at 180'C, becomes preferentially attached to that surface and will form a non-permanent seal between it and the surface of the lip of the punnet.

Alternatively, in place of the hot-melt adhesive, one may use an adhesive which is applied cold and allowed to dry on the surface to which preferential attachment is required (i. e. the surface of the closure film), the adhesive forming a permanent bond with that surface and a releasable bond with the surface of the flat lip of the punnet..

Thus, using the materials identified here, the punnet 1, closure 5 and adhesive 4 form a resealable container wherein the adhesive 4 attaches preferentially to the closure 5 The invention is not limited to the above example. For example, in some circumstances it may be preferred to have the adhesive form a permanent bond with the receptacle and a resealable bond with the closure, or have the adhesive applied to the receptacle For non-food use, the adhesive (4) can be of a non-food grade standard.

Also, where stretching of the closure as the closure is pulled off the punnet is not a problem, other cheaper closure materials manufactured by a casting process may be used, such as polyester, polyethylene or other materials.

In addition, the punnet may also be made of other materials to suit a particular application (or cost) requirement and these may be polyester, polyethylene, polystyrene or other materials.

Claims

Claims.

1. A resealable container comprising: an at least semi rigid receptacle (1) with an open side (2), and a lip (3) surrounding its open side ; a closure (5) closing the open side of the receptacle, and an adhesive (4) which provides a releasable and resealable bond between the closure (5) and the lip (3) of the receptacle (1).

2. A container according to claim 1, wherein said adhesive is such that the bond can be broken and resealed several times.

3. A container according to claim 2, wherein said adhesive preferentially attaches to the receptacle.

4. A container according to claim 2, wherein said adhesive preferentially attaches to the closure.

5. A container according to claims 2 or 4, wherein the adhesive is applied to the closure.

6. A container according to claims 2 or 3, wherein the adhesive is applied to the receptacle.

7. A container according to any of claims 1 to 6, wherein the adhesive (4) is a food grade, permanent adhesive meeting the requirements for indirect food use.

8. A container according to any of claims 1 to 7, wherein the adhesive is applied using hot melt.

9. A container according to any of claims I to 7, wherein the adhesive is applied as a cold liquid and allowed to dry.

10. A container according to any of claims I to 9, wherein the lip (3) includes a substantially flat portion

11. A container according to claim 10, wherein the flat portion of the lip (3) is between 2 mm and 6 mm wide.

12 A container according to any of claims 1 to 11, wherein the closure (5) is made from a flat sheet of oriented polypropylene

13. A container according to any of claims 1 to 12, wherein the closure (5) overhangs (6) the lip (3) by 3 mm

14. A container according to any of claims I to 13, wherein the closure (5) is manufactured in a strip (7), then reeled up.

15. A container according to any of claims 1 to 14, wherein the closure (5) is partially covered by adhesive (4).

16. A container according to any of claims 1 to 15, wherein the closure (5) includes a label incorporating information as to the contents of the container

17. A container according to any of claims 1 to 15, wherein the closure (5) incorporates a"smell box".

18. A container according to any of claims 1 to 17, wherein the closure (5) is a single sheet.

19. A container according to any of claims 1 to 17, wherein the closure (5) is a laminated extrusion

20. A container according to any of claims 1 to 19, wherein the closure (5) is micro-porous, and includes perforations less than 100Am.

21. A container according to any of claims 1 to 19, wherein the closure (5) is macro-porous, and includes perforations greater than lokoum.

22. A container according to any of claims 1 to 19, wherein the closure (5) is non- porous.

23. A container according to claim 1, wherein the receptacle is form or blow moulded from a flat sheet of standard, food grade polypropylene

24. A container according to claim 23, wherein the polypropylene is biodegradable.

25. A container according to claim 1, wherein the receptacle is form or blow moulded from a flat sheet of standard, food grade polyethylene, polyester or polystyrene.