CA2813053A1 - Repositionable lidding film-seal activated - Google Patents

Abstract

The present document describes a package for distributing and storing produce comprising: a container for holding produce, the container comprising a peripheral edge defining an opening into the container; a film for being positioned onto the peripheral edge of the container to close the opening; and an adhesive material for providing an airtight seal between the film and the peripheral edge upon being activated once the film has been positioned to cover the opening; and wherein upon being activated, the adhesive material populates both the peripheral edge and the film, the film thereby being repositionable onto the peripheral edge to reclose the opening of the container once the airtight seal has been broken upon initial opening of the package.

Description

REPOSITIONABLE LIDDING FILM- SEAL ACTIVATED
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of US provisional patent application 61/278,284, filed October 6, 2009. For the US only, the foregoing US
provisional patent application is hereby incorporated by reference.
TECHNICAL FIELD

[0002] This description relates to packaging for food. More particularly, the present specification relates to lidding films, to methods of making such, and to packages sealed with lidding films.
BACKGROUND

[0003] Food products such as fresh cut produce, nuts, cookies, candies are typically packed in polyethylene terephthalate (PET) packages which are stackable, offer merchandising appeal, and protect the products during distribution. Such commercial (produce) packaging is typically made of a tub section such as a clear plastic tray, closed with a rigid, clear plastic lid.
A
plastic shrink band is placed around the lid and upper section of the tray to ensure package integrity. The production of such PET packages which involve the closing of the lid and the placement of the shrink band are however typically quite expensive, resource and labor intensive.

[0004] In addition, while the rigid lid can be reclosed after opening of the package, it cannot be resealed since the shrink band has to be cut out in order to open the package. The closing of the rigid lid onto the tray does not reseal the package.

[0005] Another limitation of these packages is that they do not provide for an enhancement of produce quality and shelf life via controlled respiration, which is desirable to be able to deliver fresher produce to the consumer, generate less waste by reducing spoiled produce, and in turn provide appreciable overall savings for the food industry. This is especially true for the distribution of fresh fruits and vegetables.
[0006] Produce quality and shelf life can be enhanced by sealingly enclosing the produce in a package that is capable of controlled respiration such that given levels of certain gases such as oxygen, carbon dioxide and water vapour (moisture) are maintained inside the package at least until opening of the package. Such a package is capable of modifying its interior atmosphere by providing a controlled ingress and egress of certain gases; generally referred to as Modified Atmosphere Packaging (MAP).

[0007] For example, without the controlled respiration offered by MAP, oxygen inside the package is quickly consumed by the produce stored therein, which creates an anaerobic atmosphere leading to accelerated produce degradation and limited shelf life.

[0008] There is therefore a need for an improved packaging which at least reduces the processing labor associated with the lidding of typical commercial produce trays, while providing an alternative to their rigid lids which is easily handled to open and close the package after purchase, and which has the option of being adapted to enhance produce quality and shelf life.
SUMMARY

[0009] The packaging solution herein disclosed proposes a lidding film which is seal activated and positionable over any typical PET tray, thereby removing the need for a lid and shrink band typically used in the prior art.

[0010] The present disclosure seeks to provide sealing of a package and lidding film which addresses one or more disadvantages associated with prior art packaging, or at least provides useful alternatives thereto. According to an embodiment, there is provided a package for distributing and storing produce comprising: a container for holding produce, the container comprising a peripheral edge defining an opening into the container; a film for being positioned onto the peripheral edge of the container to close the opening; and an adhesive material for providing an airtight seal between the film and the peripheral edge upon being activated once the film has been positioned to cover the opening; and wherein upon being activated, the adhesive material populates both the peripheral edge and the film, the film thereby being repositionable onto the peripheral edge to reclose the opening of the container once the airtight seal has been broken upon initial opening of the package.

[0011] According to another embodiment, there is provided a lidding film for installation over a peripheral edge of a container to be loaded with produce, to form a package, the lidding film comprising: a film for being positioned onto the peripheral edge, to close the container once loaded with the produce and to form an airtight seal with the peripheral edge upon an activation of an adhesive material, the adhesive material being provided between the film and the peripheral edge; and wherein the activation of the adhesive material populates both the peripheral edge and the film, the film thereby being repositionable onto the peripheral edge to allow the container to be reclosed once the airtight seal has been broken upon the package being initially opened..

[0012] In the present specification, the term "produce" is intended to refer to any perishable food, such as fresh fruits and vegetables, or any non-consumable produce which has a limited lifetime before degradation or decomposition, such as flowers. "Produce" is also intended to comprise non-perishable food such as cookies, candies, nuts, or any non-consumable produce that typically has an extended lifetime before degradation or decomposition; or at least longer than the time taken until final distribution or consumption for example. In any case, "produce" is intended to present a given respiration rate which is to be taken into consideration in designing a package in order to maximize produce shelf life.

[0013] In the present specification, "shelf life" is intended to refer to the time until the produce is no longer suitable for consumption and/or presentation to customers and shall be discarded. In one example, this is the time until the fresh produce presents fully-ripe or over-ripe characteristics, whichever the case may be.

[0014] In the present specification, "micro-perforations" refer to perforations having a well-defined area which allow a controlled transmission of gases through the package.

[0015] In the present specification, the expression "controlled respiration"
or "controlled respiration rate" is intended to refer to the control of the amount or type of gas that is allowed to pass through a material. For example, a sealed container made of such breathable material is able to control the amount of humidity (gaseous water particles), oxygen and, or carbon dioxide which is allowed to enter and escape from its interior volume, based on a produce respiration rate (i.e. the produce's consumption rate of Oxygen and production rate of Carbon Dioxide for example). Produce (also referred to as foodstuff) stored in an interior volume of such a container is thus able to breathe accordingly, the controlled respiration rate of the container being in accordance with the produce respiration rate. The controlled respiration provided by a gas permeable material is dependent on its specific design, and more particularly on the design of the micro-perforations in the material.
These micro-perforations are shaped, positioned and sized to allow such breathing to take place. Such a control on the gazes which are permitted to enter and escape the sealed container similarly provides for the control of the internal pressure and humidity level inside such containers. In some instances, the package is able to keep its interior gaseous environment different from the exterior gaseous environment (e.g., oxygen levels can be lower inside than outside the package; an amount of water molecules can also be kept higher inside the container; or any other gaseous combinations). A specifically designed breathable package is thus able to maintain an interior modified atmosphere (MA) suitable to slow aging and degradation of produce stored therein.
BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0017] Fig. 1 is a schematic side view of a package with a lidding film in accordance with an embodiment;

[0018] Fig. 2 is a schematic cross-sectional view of the lidding film of Fig.
1;

[0019] Fig. 3 is a method for sealing a container loaded with produce with a lidding film in accordance with an embodiment;

[0020] Fig. 4 is a picture of a package in accordance with an embodiment, with a lidding film sealed and not yet peeled off; and [0021] Fig. 5 is another picture of the package of Fig. 4 in accordance with an embodiment where the lidding film is partly peeled off.

[0022] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION

[0023] There is generally described below, with reference to Fig. 1, a produce package 10 comprising a container 12 for holding fresh produce 16. The container 12 has a peripheral edge 20 (also referred to as a lip, a land or a flange) defining an opening 14 usable to access an interior of the container 12=
to store the produce 16 therein.

[0024] The package 10 has a lidding film 18 (also known as lidding stock) positioned over the peripheral edge 20 of the container 12. An adhesive =
material (not shown) is also provided between the lidding film 18 and the peripheral edge 20.

[0025] In one embodiment, the adhesive is formulated to provide an airtight seal between the lidding film 18 and the peripheral edge 20 upon being activated once the produce 16 has been loaded therein and the lidding film 18 is positioned over the peripheral edge 20 accordingly. Such an airtight seal maintains an integrity of the produce 16 inside the package 10, at least during the distribution time and until the package 10 is initially opened by breaking the airtight seal.

[0026] In one embodiment, the adhesive material is already provided over either one or both of the lidding film 18 and the peripheral edge 20 of the container 12. The airtight seal is only formed upon initial positioning of the lidding film to close the container 12 and activating the adhesive properties of the adhesive material. This step is performed for example, during a distribution process, as later described. At the time of the initial application of the adhesive material between the film and the peripheral edge, the adhesive material has little or no adhesive properties.

[0027] In one embodiment, upon its activation, the adhesive material populates both the peripheral edge 20 and the lidding film 18. In this way, the lidding film is able to be repositioned onto the peripheral edge 20 to reclose the opening , 14 of the container 12 after the airtight seal has been broken at an initial opening of the package 10, via a first peeling off of at least a portion of the lidding film from the container 12.

[0028] In one embodiment, the package 10 is first opened by peeling at least a portion of the lidding film 18 off from the peripheral edge 20, breaking the airtight seal in order to be able to access the produce 16 via the opening 14 of the container 12. This is typically done by a consumer having purchased the produce package 10.

[0029] Since both of the interfacing surfaces of the lidding film 18 and the peripheral edge 20 are populated with the adhesive material, any minor misalignment of the lidding film 18 over the opening 14 of the container 12, or the presence of extraneous materials (not shown) between the two surfaces at the time of the reclosing of the package 10, does not result in a failure of the adhesive and sealing properties of the adhesive material, nor the capability of repositioning the lidding film 18 onto the peripheral edge 20 to reclose the package 10.

[0030] Although not shown in Fig. 1, in one embodiment, a coloured sticker or any other type of opening indicator is provided on the package 10. For example, a tab extending as a protruding portion of the lidding film 18 or of the container 12 (e.g. a pull tab section) may be provided to show a user how to open the package 10, and allow its opening via a grabbing and pulling of such a tab to peel the lidding film 18 away from the peripheral edge 20.

[0031] Additionally or alternatively, although not shown in the figures, a tamper evident colored sticker or other type of tamper evident indicator is positioned and sealed onto a portion of the container 12 once the package 10 sealed.
Such a tamper evident indicator (i.e., an indication) is intended to show that the package 10 has not yet been opened before. One example is an adhesive strip of about 3/8-1/2" wide x 2-3" long applied over a corner of the container 12 which also has the above-described tab. The strip, being sealed onto the lidding film 18 on the corner of the container 12, over the tab and down over the corner onto the container 12 below the edge. In one example, a printing is provided onto the strip so as to indicate its purpose.

[0032] Still referring to Fig. 1, the container 12 can take various forms, such as any recipient having an opening 14, typically an upper opening, a tub-like container, a box-like container, a can-like container, a tray, a plate, and the like. In one embodiment, the container 12 is shaped to be stackable onto other like container.

[0033] In one embodiment, the container 12 is a made of a clear rigid plastic, or any other translucent polymer material.

[0034] In one embodiment, the lidding film 18 is a film made of a transparent material such as a polymer, cellulose, corn or starch-based material. The lidding film 18 can however be made of various polymer structures, such as any number or combinations of specific polymer structures suitable for food contact: polypropylene, polyethylene or combination of polyethylene and polypropylene for example, or of a paper-base (i.e. such as cardboard or wax paper) and plastic combination for example. In one instance, the lidding film 18 has a thickness varying from about 25 to about 175 microns.

[0035] In one embodiment, only a portion of the lidding film 18 is peelable from the peripheral edge 20 of the container 12 in order to ensure that the lidding film 18 is not completely removed there from, thereby facilitating the reclosing and resealing of the package 10. This is provided, for example, by the package 10 comprising a non-breakable sealant (not shown) over a portion of the peripheral edge 20, in addition or alternatively to the adhesive material previously described. This non-breakable sealant section thereby prevents complete peeling of the lidding film 18.

[0036] The lidding film 18 is printable and thus has a printing (not shown) in one embodiment, on an interior or an exterior portion thereof. Such printing is, for example, to provide produce labelling information such as produce description, a producer, distributor or vendor identification, a price, or any other useful information.

[0037] Although not shown in Fig. 1, in one instance, the lidding film 18 is micro-perforated to provide a controlled respiration appropriate for the produce 16 stored inside the container 12. In this way, since the lidding film 18 is gas permeable and is airtight sealed to the peripheral edge 20, the overall package is capable of controlled respiration through the lidding film 18.

Characteristics of the micro perforations provide for the type and/or an amount of gas allowed to enter and to be released out of the package 10. For example, such micro-perforations are able to keep oxygen and carbon dioxide levels inside the package 10 at constant levels although the produce 16 consumes oxygen and generates carbon dioxide at a given rate.

[0038] As detailed above, since the initial seal provided by the activation of the adhesive material is airtight, the package 10 is able to maintain a defined controlled respiration rate, or has given barrier properties which are capable of controlling an environment of the produce inside the package. In one embodiment, the controlled respiration and the barrier properties offered by the package are designed in order to maximize shelf life of the produce 16.

[0039] Now referring to Fig. 2, which shows a cross-sectional schematic view of a specific embodiment of a lidding film 18 having a base layer 24, printing 28, an adhesive layer 26, micro-perforations 22, and additives 29. It is noted that the printing 28, the adhesive layer 26, the micro-perforations 22, and the additives 29 are all each optional.

[0040] In the illustrated example, the micro-perforations 22 have a diameter in the order of about 30 to about 150 microns. In another instance, the micro-perforations 22 have a diameter from about 30 to about 90 microns in size, whereas in yet another instance, the diameters range from about 30 to about 60 microns. In some instances, the distribution of the micro-perforations 22 is uniform over the entire surface of the lidding film 18, or only a given portion thereof, such as a center or middle-portion for example. In other instances, the micro-perforations 22 are grouped over a specific area.

[0041] As described above with reference to Fig. 1, in one embodiment, the size, position, and distribution of the micro-perforations 22 are dependent on the characteristics of the produce 16 and/or of the container 12. For example, a respiration rate of the produce 16 as well as a quantity of produce 16 in the container 12 is considered. Other characteristics which are known to have an incidence on a type and an amount of gas transfer(s) to be allowed and maintained by the lidding film 18 are optionally considered in order to provide an optimal conservation environment for the produce 16. Other non-limiting characteristics are optionally considered in designing the micro-perforations, such as: produce moisture retention, ideal moisture levels, a shape, size or weight of the produce, and the like.

[0042] Still referring to Fig. 2, the printing 28 is applied in one embodiment by simply printing onto the base layer 24 to represent printed text or an image.
An ink suitable for proper adherence to the base layer 24 is used, such as any suitable food-safe inks.

[0043] The base layer 24 is as the lidding film 18 described above in reference to Fig. 1. In one example, the base layer 24 is a single layer of film material. In another example, base layer 24 is formed by the co-extrusion of multiple films onto one another.

[0044] The adhesive layer 26 is provided on a surface of the base layer 24 intended to come into contact with the peripheral edge 20 (refer to Fig. 1).

[0045] It is noted that the printing 28 can be comprised between the base layer 24 and the adhesive 26 in another instance.

[0046] The adhesive layer comprises an adhesive material as desribed above in reference to Fig. 1. For example, such an adhesive material is suitable for food contact and ingestion and is formulated to allow removal and re- ' adherence as described above. It is noted that the adhesive layer 26 is optional and is provided, in one embodiment, on the container 12 instead;
e.g., at the peripheral edge 20 thereof (Fig. 1).

[0047] Non-limiting examples of seal-activated adhesive material which are used include either water or solvent based adhesives; acrylic or rubber emulsions such as soluble rubber; or any other non-permanent adhesives for example; any food-grade approved adhesive compositions, which are adapted to adhere to a variety of surfaces such as paper, corrugate, metals, glass, vinyl, foam, fabric, polystyrene, polypropylene, polyethylene, paper, or corrugate under any given activation conditions such as specific cold, hot (heat), damp or dry conditions, specific wavelength radiation and the like. In one embodiment, the adhesive material is chosen to be a transparent, non-tacky and flexible film composition, such as ethyl vinyl acetate (EVA), maleic anhydride (MAH), ethyl acetoacetate (EAA) and Ethylene methyl acetate (EMA), or any other acrylates.

[0048] Still in reference to Fig. 2, the additive compounds 29 are optionally added to the base layer 24. The additive compound 29 can additionally or alternatively be added to the adhesive layer 26. Such additive 29 is intended to be used for example, to provide a control of a ripening rate of the produce stored inside the container, or to improve translucence of the container by controlling a fogging effect occurring from the moisture level inside the container. Non-limiting examples of additives which are optionally used include food grade anti-fog agents, ripening agents such as food grade ethylene absorption additives, and any other agent for altering an interior environment composition of the package 10, so as to impact on either or both of the produce and the an overall visual aspect associated with the package 10.

[0049] Now referring to Fig. 3, there is shown a method 40 for sealing a lidding film onto a container in accordance with an embodiment.

[0050] In step 42, a container is provided and loaded with produce. The container has a peripheral edge forming an opening thereof, via which the produce is loaded and unloaded for example.

[0051] it is noted that the produce can be any produce, perishable food or non-perishable, such= as nuts, candies, cookies for example. A quantity and a type of the produce are typically used to establish adequate or optimal respiration =
rates according to which the produce is best kept.

[0052] In step 44, a lidding film is positioned over the opening and onto the peripheral edge of the container.

[0053] Either one of both of steps 42 and 44 involve providing a not yet activated adhesive material (i.e. the adhesive material does not present any, or very limited, adhesive property at this time), to the peripheral edge and the lidding film, respectively.

[0054] In step 46, the adhesive material present between the lidding film and the peripheral edge is now activated such that the adhesive properties are rendered operative to seal the lidding film to the peripheral edge and over the opening, effectively lidding the container with the produce loaded therein.
Upon such activation, an airtight seal is formed between the lidding film and the peripheral edge.

[0055] In addition, in step 46, the adhesive material, upon being activated, populates both the lidding film and the peripheral edge such that the lidding film is peelable and is subsequently repositionable to reclose the opening of the container after the breaking of the airtight seal at initial opening of the package.

[0056] In one embodiment, step 46 involves the use of an automatic tray sealer which automatically seals the lidding film onto the peripheral edge of the container.

[0057] In one embodiment, the adhesive material is formulated such that after initial opening of the package via an initial at least partial removal of the lidding film, the lidding film is re-sealed over the opening by applying a slight pressure thereto over the peripheral edge.

[0058] In some instances, the method 40 involves any further step and alternative which is suitable to arrive at a final package as described hereinabove in relation to Figs. 1 and 2.

[0059] Fig. 4 shows an example of an empty package 50, with the lidding film 18 sealed to the peripheral edge 20 of the container 12, and such that the empty package 50 has not yet been initially opened by initial peeling off of the lidding film 18 from the peripheral edge 20. The tab 52 is for being grabbed in order to pull at least a portion of the lidding film 18 away from the peripheral edge 20 of the container 12 to open the empty package 50, as shown in Fig. 5, where the lidding film 18 is has been partly peeled off from a portion of the peripheral edge 20.

[0060] Referring to Fig. 5, once the empty package 50 has been opened, the opening 14 defined by the container 12 allows access to the interior of the package 50. The tab 52 is also usable to reposition the lidding film 18 over the peripheral edge 20 for closing and resealing the container 12 by adherence with the peripheral edge 20. As both the peripheral edge 20 and the side of the lidding film 18 thereover are coated with an amount of adhesive (not shown), the lidding film 18 is repositionable onto the peripheral edge 20 without having to be exactly realigned as when initially sealed during the manufacturing process.

[0061] While Figs. 4 and 5 show an empty package 50 for exemplary purposes, it is understood that produce (not shown) are to be stored in such a package 50.

[0062] There has been described a packaging solution with reduces labor costs, increases packaging speeds, increases cost savings by eliminating the need for plastic lid, shrink band and individual labels, thereby reducing plastic or other material consumption. The lidding film herein described provides for the strong sealing of stackable container.

[0063] While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made therein without departing from the scope of this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.
=

Claims (24)

1. A package for distributing and storing produce comprising:
a container for holding produce, the container comprising a peripheral edge defining an opening into the container;
a film for being positioned onto the peripheral edge of the container to close the opening; and an adhesive material for providing an airtight seal between the film and the peripheral edge upon being activated once the film has been positioned to cover the opening; and wherein upon being activated, the adhesive material populates both the peripheral edge and the film, the film thereby being repositionable onto the peripheral edge to reclose the opening of the container once the airtight seal has been broken upon initial opening of the package.

2. The package of claim 1, wherein the peripheral edge of the container comprises the adhesive material to be activated.

3. The package of claim 1, wherein the adhesive material is for being activated via at least one of heat and radiation being applied thereto.

4. The package of claim 1, wherein the film comprises micro-perforations practiced there through for controllably transferring a gaseous substance into or out of the container, through the film, and according to a respiration rate of the produce.

5. The package of claim 4, wherein the micro-perforations each comprise a diameter from about 30 to about 60 microns.

6. The package of claim 1, wherein the film comprises at least one of a polymer-based film, a layer of translucent plastic, a layer of paper-based material a cellulose-based film, and a corn-based film.

7. The package of claim 1, wherein the container comprises one of: a tub-like container; a box-like container; a can-like container; and a tray.

8. The package of claim 1, wherein the container is made of a clear rigid plastic material.

9. The package of claim 1, wherein the film comprises an additive for altering an interior environment composition, to impact on at least one of: the produce;
and an overall visual aspect associated with the package.

10. The package of claim 1, wherein the film comprises a thickness from about 25 to about 175 microns.

11. The package of claim 1, wherein at least one of the film and the container comprises at least one of an opening indicator and a tamper evident indicator, thereby respectively providing for a breaking of the airtight seal upon the initial opening of the package and an indication of the package having been opened.

12. The package of claim 1, comprising a non-breakable sealant over a portion of the peripheral edge, for preventing a complete peeling of the film away from the peripheral edge upon the initial opening of the package.

13.A lidding film for installation over a peripheral edge of a container to be loaded with produce, to form a package, the lidding film comprising:
a film for being positioned onto the peripheral edge, to close the container once loaded with the produce and to form an airtight seal with the peripheral edge upon an activation of an adhesive material, the adhesive material being provided between the film and the peripheral edge; and wherein the activation of the adhesive material populates both the peripheral edge and the film, the film thereby being repositionable onto the peripheral edge to allow the container to be reclosed once the airtight seal has been broken upon the package being initially opened.

14.The lidding film of claim 13, wherein the film comprises micro-perforations practiced there through, the micro-perforations for controllably transferring a gaseous substance into or out of the package upon the airtight seal being formed, the controllably transferring being according to a respiration rate of the produce.

15. The lidding film of claim 14, wherein the micro-perforations have a diameter from about 30 to about 150 microns.

16. The lidding film of claim 14, wherein the diameter is from about 30 to about 90 microns.

17. The lidding film of claim 14, wherein the diameter is from about 30 to about 60 microns.

18. The lidding film of claim 14, wherein the micro-perforations are uniformly distributed over at least a portion of the film.

19. The lidding film of claim 13, wherein the film comprises at least one of a polymer-based film, a layer of translucent plastic, a layer of paper-based material a cellulose-based film, and a corn-based film.

20. The lidding film of claim 13, wherein the film comprises an additive, the additive comprising at least one of: an ethylene absorption agent for slowing a ripening rate of the produce to be packaged; and an anti-fog agent for improving a translucence of the package.

21. The lidding film of claim 13, comprising printing on at least a portion of the film, the printing for providing produce labeling information.

22. The lidding film of claim 13, wherein the film has a thickness from about 25 to about 175 microns.

23. The lidding film of claim 13, wherein the activation of the adhesive material is triggered via at least one of heat and radiation.

24.The lidding film of claim 13, wherein the film comprises a pull tab section for being pulled to break the airtight seal upon the package being initially opened.