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 fϊnished. 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 runnels 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. [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 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, 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 1239 A, then acts as a gap filler between the rim and the film, while also providing some degree of chemical repulsion with the meat juice. [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 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.