Note: Descriptions are shown in the official language in which they were submitted.
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ANTI-LEAK MEAT PACK,
FOOD PACKAGING TRAY THEREFORE, AND
ASSOCIATED METHODS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of United States provisional
application no.
61/118,896, filed December 01, 2008 by applicant, the contents of which are
hereby
incorporated by reference.
FIELD
[0002] The instant specification relates to food packaging, and more
specifically discloses
a meat pack having an anti-leak seal for preventing meat liquids from leaking
out.
BACKGROUND
[0003] Traditional meat packs which were known in grocery stores typically
included a
tray made of a material such as expanded polystyrene (EPS), having a flat,
recessed bottom
surrounded by an upwardly and outwardly extending border. The meat was laid
onto the
recessed bottom of the tray, with, in some cases, a liquid-absorbing material
therebetween.
Both the tray and the meat were then wrapped with a see-through film.
[0004] Although satisfactory to a certain extent, such traditional meat packs
suffered from
several insufficiencies. For instance, it was common for liquids generated by
the meat to leak
from the packaging during handling thereof, either by the butcher or the
consumer, by
passing between the film and the border of the tray. This was undesired and
inconvenient for
many reasons, including aesthetic and sanitary aspects.
[0005] In particular, meat fluid leaks were unappreciated by consumers who
felt a
displeasing sensation when feeling the wet and sticky meat fluid as they took
meat pack with
their hands, and a lingering unclean hand sensation which followed until the
next occasion
the consumer had to clean his hands, which typically did not occur until the
grocery was
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finished. Any germs or bacteria which could have been collected when initially
manipulating
the wet meat pack thus had subsequent occasions to spread to other consumers,
such as via
manipulation of other grocery items, or during payment, for example. For
sanitary purposes,
at the time of placing the grocery into bags, it was common practice to place
meat packs into
additional separate plastic bags, to prevent their contact with other grocery
items in the main
bags. Even with these insufficiencies, the absence of a suitable and
commercially viable
solution resulted in the continued use of the above-described meat packs.
Hence, although the
use of liquid-absorbing material underneath the meat in the tray contributed
to reduce the
amount of leaking fluids, there remained room for improvement.
SUMMARY
[0006] The anti-leak meat pack described herein can overcome at least some of
the
insufficiencies of the prior art by providing a cost-effective means of
wrapping meat on a tray
with an anti-leak seal being formed all around the tray, between the tray and
the film, by
activation of an adhesive therebetween after the tray and meat have been
wrapped by the
film. The use of a heat-activatable adhesive can be very convenient for
example in
applications where appropriate heating means were already being used for other
reasons, such
as heat tunnels which were used for shrinkage of wrapping film, for example.
Applying the
adhesive around the tray on an outward-facing rim surface thereof can allow
achieving an
effective seal even in cases where the meat is thick and protrudes upwardly
from the tray.
[0007] In accordance with one aspect, there is provided an anti-leak meat pack
comprising
a tray having an outward-facing rim surface at the upper end thereof, meat
laying on the tray,
and a film covering the meat, wrapped around the tray, and sealed against the
outward-facing
surface all around the tray, an anti-leak seal thereby being formed
surrounding the meat.
[0008] In accordance with another aspect, there is provided a method of
packaging food,
the method comprising placing the food in a tray having outward-facing
surface; wrapping a
film over the food and around the tray, the film thence covering the outward-
facing surface
all around the tray; and sealing the film against the outward-facing rim
surface.
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[0009] In accordance with another aspect, there is provided a food packaging
tray
comprising a tray body having an outward-facing surface, and one of an
adhesive and a wax
covering the entire periphery of the outward-facing surface of the tray body.
[0010] In accordance with another aspect, there is provided a method of making
anti-leak
trays for food packaging, the trays having an outward-facing surface, the
method comprising
simultaneously applying one of an adhesive and a gap-filling wax on the
outward facing
surface of a plurality of trays in a stack, all around the trays.
DESCRIPTION OF THE FIGURES
[0011] In the appended figures,
[0012] Fig. 1 is a perspective view showing an example of a meat pack;
[0013] Fig. 2 is a perspective view showing a tray for use in the meat pack
shown in Fig. 1;
and
[0014] Fig. 3 is a schematic view showing spraying of an adhesive or wax on an
outward-
facing surface of a plurality of stacked trays.
DETAILED DESCRIPTION
[0015] In Fig. 1, an example of a meat pack 10 is shown. The meat pack 10
generally
includes a tray 12 in which is placed a piece of meat 14. The meat 14 in the
tray 12 is covered
by a wrapping film 16.
[0016] Turning also to Fig. 2, the tray 12 is generally rectangular with
rounded corners 18,
and has a recessed bottom 20 onto which the meat 14 is laid, and a surrounding
border 22
which extends both upwardly and outwardly from the recessed bottom 20. At an
upper
portion thereof 24, the border 22 has an outwardly extending rim 26 with an
outward-facing
rim surface 28 adjacent a flat upper surface 30 and surrounding the tray 12.
The outward-
facing rim surface 28 is generally flat and may be slightly rounded, and is
generally
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perpendicular to both the flat upper surface 30 and flat recessed bottom 20.
In particular, in
one embodiment, the upper edge of the outward-facing rim surface 28, leading
to the flat
upper surface 30, is slightly rounded. Also noted here, in this embodiment,
the outward-
facing rim surface 28 slightly protrudes from the remainder of the border 22,
this is optional
and in alternate embodiments, the outward-facing rim surface can be flat with
the adjacent
portion of the outer wall of the border.
[0017] In this embodiment, a food-grade adhesive 32 is applied on the outward-
facing rim
surface 28, and is activated during the packaging operation to form a seamless
anti-leak seal
34 around the meat 14 (Fig. 1). Positioning the adhesive on an outward-facing
rim surface of
the tray can allow achieving an adequate seal even in an application where the
meat is thicker
than the tray and protrudes upwardly therefrom.
[0018] It will be understood that various alternate embodiments may be
realized, the
details given below are thus provided solely for illustrative purposes with a
view of providing
a full description of the illustrated embodiment. In the illustrated
embodiment, the tray is
made of expanded polystyrene (EPS) but can alternately be made of another leak
proof
material such as other plastics or bioplastic, foamed or not, or a material
made of molded
fibers, molded pulp, or pressed paperboard which can be treated with a
waterproofing
treatment, to name a few examples. The wrapping film can be any suitable food-
grade
wrapping material. In the embodiment demonstrated in Fig. 1, the meat pack is
particularly
adapted for the packaging of thick and elongated pieces of meat, such as roast
beef. It will be
understood that the pack can be adapted or used as such with other types of
meat than beef,
such as marinated meat, poultry, fish, or pork for example, and with other
fresh, frozen or
cooked foods or even other goods which are susceptible to release liquids.
[0019] Turning to Fig. 2, the tray 12 is shown alone, prior to packaging of
the meat. To
prevent the activatable adhesive 35 which is used on the outward-facing rim
surface 28 at the
upper end 24 of the tray 12 from collecting dust or other particles prior to
its use, the
activatable adhesive 35 can be selected in a manner to be normally in an
unactivated state,
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but being activatable to form the seal 34 with the wrapping film 16 (Fig. 1)
at a
predetermined packaging step. For example, a heat-activatable adhesive can be
used. In this
case, the tray prior to use is kept, for example, at room temperature, and is
therefore not
subjected to heat sufficient to activate the adhesive. This helps prevent the
collection of dust
or other particles by the adhesive prior to its use. When the meat is placed
in the tray and the
tray is wrapped with a film, the meat pack can thus be subjected to heat in
order to activate
the adhesive and form the seal around the meat. In one embodiment, this
heating step can be
performed by placing the meat pack in a heat tunnel, such as known in the art
for use in
shrinking films, for example. In an alternate embodiment, the heat activated
adhesive can be
activated by heat directed specifically at the adhesive, such as by a heat gun
for instance, or
under the tray, to limit exposure of the meat to the heat. In yet another
embodiment, the
adhesive can be activatable by exposure to ultraviolet light, for instance, in
which case the
wrapped pack can be subjected to ultraviolet light to activate the adhesive
and form the seal.
The adhesive could also be activated by ultrasonic welding, in which case the
presence of the
adhesive can be optional.
[0020] The selected adhesive should be approved for a contact with food, i.e.
food-grade.
A low heat activation temperature (preferably below 300F) to reduce the
likelihood of heat
related damage to the food or other good packaged. A fast setting time should
also be favored
to speed up sealing time and further prevent heat damage.
[0021] Good bonding and sealing were obtained with an EVA-based hot melt
adhesive,
such as Technical Adhesive no. 1512A manufactured by Technical Adhesives
Limited,
Mississauga, Ontario, Canada, activated in a heat tunnel set to 280F and a
residence time of 5
seconds. Similar results are also possible with PUR water-based adhesives.
Water-based
adhesives can be favored with trays made of molded pulp or similar materials,
for instance. In
another embodiment, fair sealing can be obtained without a strong adhesion
using refined
waxes rather than an adhesive. The waxes, such as IGI 1239A, then acts as a
gap filler
between the rim and the film, while also providing some degree of chemical
repulsion with
the meat juice.
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[0022] As shown in the figures, applying the adhesive 35 on an outwardly-
facing rim
surface 28 can serve two purposes. First, compared to an adhesive 35 which
would be applied
to an upwardly-oriented surface, it can allow an effective seal to be
maintained even in the
case where the packaged goods are thicker than the tray 12, because the forces
applied onto
the film by the goods are then substantially oriented in a direction favoring
adherence of the
film 16 to the tray 12, i.e. for the film to squeeze the rim 26 of the tray 12
(see Fig. 1),
including the upper edge of the outward-facing rim surface 28 which leads to
the upper
surface 30 if slightly rounded. Using a heat shrinkable film and activating
the adhesive with
heat positioned below the tray can favor the squeezing of the adhesive between
the film and
the rim. Secondly, it can allow obtaining an anti-leak seal relatively close
to the source of the
liquid, thereby impeding the occurrence of liquid pockets which could result
from the seal
being located further away from the goods, such as outside and below the upper
end 24 of the
border 22.
[0023] The methods of applying the adhesive to the outward-facing rim surface
28 of the
tray 12 can represent an important element in obtaining a commercially viable
fabrication
method. For instance, if the adhesive is to be applied on the outward-facing
rim surface 28 of
the tray 12 with a sprayer, it can be advantageous to apply the adhesive to a
stack of trays all
at the same time. Stackable trays can thus be favored. In the illustrated
embodiment, the tray
12 is made stackable by having a border which extends both upwardly and
outwardly and by
having a shape which allows the recessed bottom to receive the underside of
the recessed
bottom of an other identical tray. The stack of trays can then be turned and
moved under the
sprayer as it simultaneously sprays adhesive on all the trays in the stack, in
order to
completely cover the entire periphery of the trays in the stack. In this
manner, a sufficient
amount of activatable adhesive can be applied to the desired portion of the
outward-facing
rim surface 28, which can include the upper edge thereof. Other adhesive
application
methods can include applying the adhesive on a stack of trays with rollers, or
applying the
adhesive one tray at a time either using a gun or a roller. In such alternate
embodiments, the
trays can be non-stackable and can have a border which extends upwardly from
the recessed
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bottom. In order to obtain a satisfactory seal, the adhesive should make a
continuous path on
the outward-facing rim surface 28 all around the tray and cover the rounded
upper edge
thereof where applicable. When using heat-activatable adhesive, any suitable
heat source can
be used to activate the adhesive such as a heat tunnel, a heat gun, a heated
panel, or another
heat source.
[0024] It will be understood that in alternate embodiments, the tray can have
a shape other
than rectangular and can alternately have non rounded corners, for instance.
In meat
packaging applications, rectangular trays with rounded corners having sides of
a length
between around 3 inches and 24 inches are most commonly used.
[0025] Various alternate embodiments to the ones described above are possible.
The scope
is thus indicated by the appended claims.
