Note: Descriptions are shown in the official language in which they were submitted.
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GAS PERMEABLE POLYMER LABEL FOR CONTROLLED RESPIRATION
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of US provisional patent application
61/212,120, filed April 8, 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 labels, methods of making such, and the
labelling of containers, to provide gas permeable packaging solutions.
BACKGROUND
[0003] The quality and shelf life of fresh produce is enhanced by enclosing
them in packaging that is capable of controlling levels of certain gases such
as
oxygen, carbon dioxide and water vapour (moisture) in the environment of the
produce.
[0004] Such packaging is generally referred to as "Modified Atmosphere
Packaging" (MAP). Fresher products to the consumer, less waste from spoiled
produce, better inventory control, and appreciable overall savings for the
food
industry are only some of the resulting benefits of MAP.
[0005] Typically available produce containers are however not suitable for
achieving Modified Atmosphere (MA). For example, typical lid closable trays
made out of rigid plastic material, and which are subsequently wrapped by a
shrink band placed around the lid and tray in order to ensure a hermetic
sealing of the overall package, do not allow for appropriate gas permeability.
Oxygen inside such packaged trays is quickly consumed by the produce
stored therein, which leads to accelerated produce degradation and limited
shelf life.
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(0006] Typical containers, such as the above-noted tray and lid example, are
also typically incapable of providing MA. By Modified Atmosphere (MA), it is
intended to refer to the packages ability to modify its interior atmosphere
via a
controlling of ingress and egress of certain gases.
[0007] As produce are known to have characteristic respiration rates under
non-packaged conditions (i.e. the produce's consumption rate of Oxygen and
production rate of Carbon Dioxide for example), some gas permeable
packages are specifically designed to be able to provide an optimal MA meant
to slow aging and degradation of a specific produce. Such specifically
engineered containers are however designed for specific types of produce.
[0008] As many vendors and/or distributors typically supply a wide variety of
produce such as fruits, vegetables and meats for example, and thus require a
number of differently engineered MA containers, there is need for a packaging
solution which offers easy and rapid market penetration; a packaging solution
which is adaptable to packaging processes which are already in place
throughout the industry.
SUMMARY
[0009] The packaging solution herein disclosed proposes an improved label
which is gas permeable and capable of MA.
[0010] The present disclosure seeks to provide an improved label that
addresses one or more disadvantages associated with prior art produce
packaging and/or labeling, or at least provides useful alternatives thereto.
[0011] According to an embodiment, there is provided a label for installation
over an opening of a container to be loaded with produce, the label
comprising: a thin layer of material; and micro-perforations through the
label,
whereby upon the label being sealingly installed over the opening of the
container, the micro-perforations controllably transfer a gaseous substance
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into or out of the container, through the label, and according to a
respiration
rate of the produce to be loaded in the container.
[0012] According to another embodiment, there is provided a gas permeable
package comprising: a container for holding produce, the container defining an
opening to an interior space of the container; a label sealingly affixed to
the
container to cover the opening; the label comprising a thin layer of material;
and micro-perforations practiced therethrough for controllably transferring a
gaseous substance into or out of the container, through the label, and
according to a respiration rate of the produce to be loaded in the container.
[0013] According to another embodiment, there is provided a method for
labeling a container loaded with produce, the method comprising: forming an
opening within a container to be loaded with produce; loading the produce into
the container, the produce having a given respiration rate; sealingly
installing a
label to the container, the label comprising: micro-perforations positioned
over
the opening once the label adhered to the container, the micro-perforations
for
controllably transferring a gaseous substance into and out of the container
according to the respiration rate of the produce therein.
[0014] In the present specification, the term "produce" is intended to refer
to
fresh fruits and vegetables, flowers, or any other type of produce that
presents
various respiration rates which are to be taken into consideration in order to
maximize their shelf life.
[0015] 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
produce presents fully-ripe or over-ripe characteristics, whichever the case
may be.
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[0016] In the present specification, "micro-perforations" refer to
perforations
having a well-defined area which allow a controlled transmission of gases
through the package.
[0017] In the present specification, the expression "controlled respiration"
or
"controlled respiration rate" is intended to refer to the control of the
amount of
gas that is allowed to pass through a material. A sealed container made of
such breathable material is able to control the amount of humidity which is
allowed to enter and escape from the interior volume of the container, while
permitting oxygen and carbon dioxide to pass through adequately. Produce
(also referred to as foodstuff) stored in an interior volume of such a
container
is able to breathe according to a controlled respiration rate; the rate being
dependent on a specific design of the micro-perforations in the material and
which allow such breathing to take place. Such a control on the type and the
amount of 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. The gaseous environment inside the package may
therefore be kept different compared to an 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, and the like).
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] 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:
[0019] Fig. 1 is a schematic front elevation view of a labeled package (e.g.,
a
bag), in accordance with an embodiment;
[0020] Fig. 2 is a schematic cross-sectional view of the label of Fig. 1;
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[0021] Fig. 3a is a method for fabricating the labeled package of Fig. 1, in
accordance with an embodiment;
[0022] Fig. 3b is a method for labeling a container loaded with produce to
produce the labeled package of Fig. 1, in accordance with an embodiment;
and
[0023] Fig. 4 is a photograph of the labeled package of Fig. 1, with a printed
label, in accordance with an embodiment.
[0024] It will be noted that throughout the appended drawings, like features
are
identified by like reference numerals.
DETAILED DESCRIPTION
[0025] There is generally described below, with reference to the appended
drawings a labeled package 10 comprising a container 12, here in the form of
a reclosable bag, for holding fresh produce 16. The bag 12 is labeled with a
label 18 in accordance with embodiment as described herein.
[0026] As seen in the embodiment shown in Fig. 1, the bag 12 takes the form
of a closeable recipient which is optionally made of a translucent polymer
material. The label 18 is in turn made of a polymer material, such as
polyester,
and is micro-perforated to provide a controlled respiration rate for the
produce
16 stored inside the bag 12. The micro-perforations of the label are such that
the label itself is gas permeable and capable of controlling a respiration
through its membrane by way of controlling a type and/or an amount of gas
passing there through. In this way, for example, a moisture level inside the
bag
12 is kept constant, while further maintaining an optimal respiration rate for
the
produce 16.
[0027] In the illustrated embodiment of Fig. 1, the bag 12 has an opening 14
defining an opening periphery at a location where the label 18 is to be
positioned. The size of the opening 14 is variable and dependent on an overall
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size of the bag 12 and/or a size of the label 18 to be installed, affixed or
adhered. The label 18 is then positioned over the opening 14 such that its
adhesive under-coating (not shown) adheres to the periphery (also referred to
as one or more edges) of the opening 14. The label 18 is made to adhere to
the container so as to create and airtight, sealed package 10 which is able of
gas permeability via the label 18 alone.
[0028] The label is printable over its exterior or upper surface area 20,
although may remain unprinted as desired. In one instance, the area 20 has
printed information pertaining to the produce 16, a producer, a vendor, a
price,
or any other useful information.
[0029] The label 18 is 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. In one embodiment, the label 18 is made of a
combination of a paper coated with a plastic layer. The label 18 has a
thickness varying from about 25 to about 175 microns.
[0030] Now referring to Fig. 2, which shows a cross-sectional schematic view
of a specific embodiment of a label 18 with micro-perforations 22.
[0031] 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 label 18, or an area thereof such as a
center or middle-portion. In other instances, the micro-perforations are
grouped over a specific area of the label.
[0032] Referring to Fig. 1 and Fig. 2, in one embodiment, the size, position,
and distribution of the micro-perforations 22 are dependent on the
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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 label 18 are optionally considered in order to provide an
optimal conservation environment for the produce 16. In this way, the
produce's shelf life is extended.
[0033] Other non-limiting characteristics which are optionally considered in
designing the micro-perforations include: produce moisture retention, ideal
moisture levels, a shape or size of the produce, the container, or a
combination thereof. For example, size of one or more micro-perforations 22 is
chosen based on a moisture level to be kept inside the container 12, so as to
retain or to allow an escape of water molecules.
[0034] Still in reference to Fig. 2, the label 18 in accordance to the
illustrated
example has a base layer 24 (also referred to herein as a thin layer of
material), an optional adhesive layer 26 and an optional print layer 28. The
print layer can be replaced simply by printing (i.e., printed text or image).
[0035] As described above, the base layer 24 is made of a combination of
polymers or paper-type materials, such as cardboard or wax paper, coated
with polymer. Materials for the base layer 24 can also include translucent
plastics, cellulose-based films and corn-based films alone or in combination.
[0036] In the illustrated embodiment, the adhesive layer 26 is provided as an
under-coating, or on a reverse side of the label 18 intended to be adhered to
a
container. In one embodiment, the adhesive layer is of a permanent type,
although kept suitable for food contact and ingestion. In another embodiment,
the adhesive layer is non-permanent to allow removal and re-adherence. Such
a label is usable to open the container via the opening to access the produce
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therein. In such an embodiment the label 18 in fact could replace the lid (or
cover) entirely.
[0037] It is noted that the adhesive layer 26 is optional when the adhesive is
provided on the container 12 instead; e.g., in the periphery of opening 14.
[0038] In addition, in a particular example, the adhesive layer 26 of the
label 18
is provided adjacent the print layer 28, both applied on a same side of the
base layer 24. This embodiment is used in cases where the label is affixed to
the container via adherence on an interior wall of the container, as later
described.
[0039] Non-limiting examples of adhesives which can be used include either
water or solvent based adhesives; acrylic or rubber emulsions such as soluble
rubber or maleic anhydride (MAH) adhesives for example, which are
permanent or not; or any food-grade approved adhesive compositions, glues
or epoxies 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 whichever conditions such as cold,
hot, damp or dry conditions. In one embodiment for example, the adhesive
layer is a transparent, non-tacky and flexible film composition such as a
vinyl
acetate-maleate copolymer resin available on the market as a blend of
isopropyl acetate and toluene.
[0040] Other means of installing the label are also contemplated. Examples
include any type of airtight seal. Examples of such airtight seals include the
zipper lock type closures which are commonly found on plastic food bag. Of
course, a combination of any of the installation schemes described herein
would also be feasible.
[0041] The print layer 28 is present when the label 18 is printed with a layer
of
ink suitable for proper adherence to the upper or front side of the label 18
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opposite the adhesive layer 26. Any inks which are suitable for printing on a
polymer-based material such as any suitable food-safe inks are used.
[0042] In one embodiment, the label 18 is a self-adhesive permanent label 18
in that the adhesive layer 26 does not require the application of extra
moisture
in order to obtain an adhesive effect of the layer. In one example, once
applied, such an adhesive layer 26 is protected with a backing paper (not
shown) until it is removed prior to sticking the label 18 on the container 12.
[0043] Still in reference to Fig. 2, it is noted that an additive compound 29
is
optionally added to the base layer 24. The additive compound 29 can
additionally or alternatively be added to the adhesive layer 26. Such an
additive compound 29 is intended to be used for example, to provide a control
on a ripening rate of the produce stored in the container, or to improve
translucence of the container by controlling any 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 and ripening
agents such as food grade ethylene absorption additives.
[0044] The label 18 is fabricated according to any type of suitable
manufacturing method such as one illustrated in Fig. 3a. In this example, the
method 30 involves the following steps:
[0045] In step 32, an adhesive layer is applied over a thin layer of material
in
order to form a label substrate. This step is accomplished in one example by
coating at least one side of a sheet of film material forming the base layer
with
a layer of adhesive substance. The other side or the same side is optionally
printed by way of applying a print layer.
[0046] Then, in step 34, at least a portion of the label substrate is micro-
perforated to provide micro-perforations through the label substrate, which
includes the base layer, the adhesive layer and the print layer when applied
in
step 32. The micro-perforations are designed in size and distribution over the
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label substrate so as to controllably transfer on ore more given gaseous
substances through the label substrate, and based on the respiration rate of
the fresh produce to be contained in the container. For example, the micro-
perforations have a size which is able to allow the ingress of oxygen while
venting out carbon dioxide and retaining moisture inside in accordance to the
produce's needs for longer shelf life.
[0047] In one embodiment of step 34, the label substrate is micro-perforated
according to a pre-established design, by subjecting the label substrate to a
number of small high voltage electric discharges (intense energetic sparks)
which vaporize the substrate at their application location. In another
example,
a laser is used to produce the micro-perforations.
[0048] In step 36, the label substrate is cut to form one or more gas
permeable
labels in accordance with a final size and shape. While this step is
optionally
done prior to step 32 and/or 34, in this embodiment, the label substrate is
cut
to provide one or more finished self-adhesive labels. Alternatively, cut lines
are
created in order to supply sheets of multiple pre-formed labels and allow
produce distributors to themselves cut and separate the labels from one
another.
[0049] Alternatively, the above method 30 is varied such that the base layer
is
micro-perforated (step 34) prior to the coating of the adhesive and optional
print layer (step 32). In such a variation, the layering technique used to
apply
the adhesive layer and the optional print layer on the base layer does not
reclose the micro-perforations. For example, the type of adhesive and the ink
used are composed of small enough particles which eliminate any risks of
clogging micro-perforations.
[0050] Additionally or alternatively, in one embodiment, the adhesive layer is
applied over a given area of the label, while the micro-perforated area
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occupies another area of the label different than the given area used by the
adhesive layer.
[0051] In a similar fashion, in one instance where both the adhesive layer and
the print layer are applied over a same side of the base layer in step 32, the
adhesive layer is applied over a given area of the label which is different
than
the area occupied by the print label. For example, the adhesive layer is
positioned along a periphery of the label, while the print layer is at a
middle-
portion of the label.
[0052] In the above method 30, it is noted that the application of the
adhesive
layer in step 32 is optional when for example the adhesive is to be instead
applied on the container prior or during the affixing the label thereon.
[0053] In addition, in some cases, the final cutting step 36 is performed
prior to
the printing of the label (application of the optional print layer).
[0054] The final label is capable of maintaining a given respiration rate in
accordance to the sizes and shapes of the micro-perforations.
[0055] Now referring to Fig. 3b, there is shown a method 40 for labeling a
container which is to be or is previously loaded with produce.
[0056] In step 42, an opening is formed within a container (or a lid portion
thereof) which is to be loaded with produce.
[0057] In step 44, the produce is loaded into the container. The produce can
be
any produce which has a given pre-established respiration rate, or range of
thereof, as known from the type of quantity of produce stored in the
container.
[0058] In step 46, the gas permeable label is fixedly and sealingly positioned
onto the container, over the opening. The gas permeable label has an
adhesive film which is meant to adhere along the periphery of the opening in
order to provide for an airtight seal with the container. In this way, the
overall
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package respires from the label. This is possible since the micro-perforations
are provided through the adhesive film at a location on the film which is in-
line
or at least corresponding to a location of the opening once the gas permeable
label is positioned onto the container.
[0059] In one embodiment, the adhesive film of the label is such that in step
46, a slight pressure is applied on the label to affix it to the container.
[0060] The micro-perforations allow for the label to controllably transfer one
or
more gaseous substances into and out of the container in order to maintain a
given gaseous environment inside the container, as provided from the
respiration rate of the produce.
[0061] In an example, the label has an adhesive layer for allowing the label
to
be adhered along a periphery of the opening.
[0062] Fig. 4 is a photograph of the package 10 of Fig. 1, with the label 18
being printed with package information such as: a description of the produce
16 inside the container 12; a purchasing price; a vendor's name; a bar code
associated to the package; and the like.
[0063] In this example, the produce 16 comprises a mix of cut and washed
vegetables including carrots and baby tomatoes. Any other produce can
however be packaged, such as any vegetable, fruit, meat, fish, nuts, baked
goods, and the like.
[0064] The gas permeable, micro-perforated label 18 as per the above
description is positioned over the opening 14, which is here circular and
formed on a top surface of the container 12. In one embodiment, the size of
the opening 14 is such as to create an opening area between about 150 mm2
and 600 mm2. In another embodiment, the size of the opening 14 has an
opening area between about 600 mm2 and 1000 mm2. The size of the opening
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14 is however adjustable and dependent on the container's shape and size, as
well as the quantity and/or type of produce 16 therein.
[0065] In one embodiment, the label 18 is affixed from an interior side of the
container 12. For example, the container 12 in the picture of Fig. 4 has a lid
50
onto which is located the opening 14. The label 18 is affixed from the
interior
side of the lid 50 using adhesive located between the label and the periphery
of the opening 14. In this way, the container is loadable with produce after
the
installation of the label thereto, but prior to the closing of the lid 50.
[0066] Although shown as a rigid clam shell tray container with the foldable
lid
50, the container 12 can be any type of container such as a bag made of
plastic-type material or a differently shaped container such as a bottle, a
box,
or any other hollow interior recipient for storing produce, not necessarily re-
closable or re-sealable.
[0067] 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.
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