Food tray

CA 02630367 2013-03-04

FOOD TRAY

BACKGROUND

[0001] Food trays for holding and heating a food product are well known. One type in common use has a single compartment. When a pasta or other low value product is heated for consumption in the single compartment, any sauce, which may contain meat and or vegetables, is layered on top or beside of the low value product. Heating of the food arranged in this manner causes the flavours to blend and textures to deteriorate. Another food tray has two compartments, one beside the other. Heating does not cause blending of flavour, but having to spoon sauce from one compartment to another for consumption by the customer is inconvenient.

[0002] In another food tray available in Europe from InterFrost GmbH, a smaller paperboard tray is nested snugly within a larger paperboard tray. The two trays fit tightly together. Sauce may be placed in the smaller tray, and pasta or rice in the larger tray. Upon heating of the InterFrost food tray, steam may build up in the lower tray, and may be released suddenly when the smaller tray is removed from the larger tray. In addition, due to the close tight fit of the smaller tray in the larger tray, the smaller tray tends to stick in the larger tray, and pulling on the smaller tray can result in a sudden release of the smaller tray, causing a risk of spilling hot food product from the smaller tray. The steam and heat generated from the lower tray may cause the upper tray to deconstruct, which increases the probability of spillage. Risk of steam release and hot food spill makes the food tray somewhat of a hazard to use.

SUMMARY

[0003] The food tray claimed here is intended to provide the advantages of separate heating of low and high value food products, while reducing the risk of spillage and steam release. In addition, the claimed food tray is convenient to use, and provides a pleasing aspect to the user.

(0004] Therefore, there is provided a food tray comprising a lower tray containing a first food product and an upper tray nested stably at least partly inside the lower tray, with the

CA 02630367 2013-03-04 upper tray containing a second food product. In one embodiment, an air permeable interface is provided between the upper tray and lower tray to allow venting of steam from the lower tray during cooking. In one embodiment, a cover is provided for one or both of the upper food tray and lower food tray. Each of the lower tray and the upper tray may be formed of a material that is suitable for use in a microwave oven. Various constructions may be used to create the air permeable interface, such as lugs, ledges and lips. The upper tray may sit above the lower tray, or may have an upper edge lower than the upper edge of the lower tray. The trays are preferably nested loosely for ease of removal of the upper tray from the lower tray. Various configurations of cover may be used such as a sleeve, carton, lid or plastic film. The upper tray may contain the higher value food product.

[0005] In other embodiments, the top of the upper tray may be level with or lower than the top of the lower tray, indents may be provided in either or both the upper tray or lower tray for ease of removal of the upper tray, the peripheral wall of the lower tray may be formed in upper and lower parts, the upper part angling outward at a greater angle with respect to a normal to the base than the lower part; and the upper tray may have a downward facing shoulder that rests on an upward facing shoulder of the lower tray.

[0006] There is also provided a method of cooking food products of different value, the method comprising the steps of providing a food tray comprising a first food product in a lower tray and a second food product in an upper tray nested loosely in the lower tray; and subjecting the food tray to food heating energy while permitting steam to escape from the lower tray.

BRIEF DESCRIPTION OF THE FIGURES

[0008] Embodiments of the food tray will now be described with reference to the figures, in which like reference characters denote like elements, by way of example, and in which:

Fig. 1 is a section through a food tray comprising an upper tray and lower tray according to an embodiment of the invention;

Fig. 2 is a top view of the food tray of Fig. 1 ;

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Fig. 3 shows the food tray of Fig. 1 with a cover;

Fig. 4 shows an embodiment of a food tray with a snap-on cover;

Fig. 5 is a section through a further embodiment of a food tray;

Fig. 6 is a section through a still further embodiment of a food tray;

Fig. 7 is a top view of the upper food tray shown in Fig. 6;

Fig. 8 is a side view of a further embodiment of a food tray comprising an upper tray and lower tray;

Fig. 9 is a side view of the food tray of Fig. 8 at right angles to the view of Fig. 8 with food product in the upper and lower trays;

Fig. 10 shows the food tray of Fig. 8 with a cover;

Fig. 11 is a top view of the food tray of Fig. 8;

Fig. 12 is a top view of the lower tray of Fig. 8;

Fig. 13 is a top view of the upper tray of Fig. 8;

Fig. 14 is a section through the upper tray of Fig. 8;

Fig. 15 is another section through the upper tray of Fig. 8;

Fig. 16 is a section through the lower tray of Fig. 8;

Fig. 17 is another section through the lower tray of Fig. 8;

Fig. 18 is a perspective drawing of the upper tray of Fig. 8;

Fig. 19 is a perspective drawing of the lower tray of Fig. 8; and

Fig. 20 shows a section through the food tray of Fig. 8 illustrating angles of side walls of the upper tray.

DETAILED DESCRIPTION

[0009] In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite article “a” before a claim feature does not exclude more than one of the feature being present. As shown in Figs. 1 and 2, a food tray is formed from a lower tray 10 and an upper tray 12 nested stably at least partly inside the lower tray 10. An air permeable interface 14 is provided between the upper tray 12 and lower tray 10 by outwardly extending lugs 16 at the corners of the upper tray 12. The lugs 16 rest on top of the upper edge 18 of the lower tray 10 with a gap 19 between the upper tray 12 and

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WO 2007/056866 PCT/CA2006/001894 lower tray 10. The gap 19 may extend around the perimeter of the lower tray 12. With a gap between the lower tray 10 and upper tray 12, when product in the lower tray 10 is heated, any steam produced can vent through the gap 19.

[0010] The lugs 16 and gap 19 permit the upper tray 12 to sit loosely on the lower tray 10. The only force retarding removal of the upper tray 12 from the lower tray 10 is the force of gravity on the upper tray 12 and its contents. Removal of the upper tray 12 from the lower tray 10 is therefore frictionless. The lugs 16 are at the corners of the upper tray 12 as shown, but may be anywhere around the periphery of the upper tray 12. Four lugs are convenient, and there should be a sufficient number of lugs suitably spaced around the periphery of the upper tray 12 so that the upper tray is stable, and is resistant against tipping. To assist stability, the lugs 16 should be near the top of the upper tray 12 so that the main mass of the upper tray 12 and its contents are below the lugs 16. Both the upper tray 12 and lower tray 10 include respective lips 32 and 30. The lips 32, 30 should be at least a few millimeters wide for example 3 mm wide for ease of sealing.

[0011] Each of the lower tray 10 and upper tray 12 may be made by injection moulding, thermoforming or any other suitable manufacturing process. The sidewalls 20 of the lower tray 10 and the sidewalls 22 of the upper tray 12 each may have the same nesting angle. The nesting angle of a tray is the angle between the sidewalls and a perpendicular to the plane defined by the upper edge of the tray. The upper tray 12 may be made in the same mould as the lower tray 10, but with an insert in the mould to reduce the volume. The upper tray 12 and the lower tray 10 may be formed of a material that is suitable for use in a microwave oven, and also may be formed of a material suitable for use in a conventional oven. Exemplary materials are polypropylene (microwave only) and dual use CPET (crystalline polyethylene terephthalate) available from a number of manufacturers. CPET is particularly suitable due to its wide temperature tolerance. The trays 10, 12 may be transparent or opaque. [0012] As shown in Fig. 3, the food tray may be provided with a cover 24, such as a sleeve. The sleeve may be a paperboard sleeve into which the combined trays 10 and 12. are inserted. The cover 24 could also be a carton that encloses both trays 10 and 12 completely.

[0013] As shown in Fig. 4, the cover may comprise a snap-on microwavable lid 26 for the upper tray 12. The lid 26 may extend over the lip 20 on the lower tray 10. The cover 24 may

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WO 2007/056866 PCT/CA2006/001894 also include a film that is heat sealed to the lip 32 on the upper tray 12. The film may be on the underside of a cardboard sleeve, or a stand alone cover heat sealed to the lip 32.

[0014] As shown in Fig. 5, the air permeable interface may be formed by a seat created by lugs or ledges 28 formed in the sidewalls 20 of the lower tray 10 and spaced around the periphery of the lower tray 10, with the upper tray 12 resting directly on the lugs or ledges 28. The lugs or ledges 28 may be discontinuous or provided with openings to allow the escape of steam during cooking. As shown in Fig. 6, the air permeable interface may be formed by the lip 32 resting directly on the upper edge 18 of the lower tray 10. In this case, as shown in Fig. 7, the lip 32 is preferably provided with protrusions 34 for allowing steam release. In each of these cases, the air permeable interface may support the upper tray 12 in the lower tray 10 so that the lip 32 of the upper tray 12 sits above the lower tray 10. In the example of Fig. 7, the outwardly extending lip 32 of the upper tray 12 sits loosely on the upper edge 18 of the lower tray 10 to form the air permeable interface with a gap 29 between the side walls 22 of the upper tray 12 and the sidewalls 20 of the lower tray 10. The upper tray 12 and lower tray 10 may also have fluted sides to allow venting of steam during cooking. In another embodiment, the upper tray 12 may sit entirely within the lower tray 10 on lugs or ledges, with a handle provided on the upper tray 12 to allow the upper tray 12 to be easily removed from the lower tray 10.

[0015] As shown in Figs. 8-20, a further embodiment of a food tray is formed from a lower tray 50 and an upper tray 52. Fig. 10 shows the food tray with a cover 56. The cover 56 may be any suitable cover such as a heat-sealed shrinkwrap, or a plastic snap-on lid, suitable for microwave use. In Figs. 8-17, the lower tray 50 is shown as having side walls perpendicular to the base of the tray, but this is for illustrative purposes only, and its side walls may be angled outward as shown in Figs. 19 and 20. Likewise, the side walls of the upper tray 52 may be angled outward and may extend parallel to the upper side wall 66 shown in Fig. 19. Fig. 9 shows a first food product 92 in the lower tray 50, and a second food product in the upper tray 52.

[0016] Various air channels 46, 48 and 54 may form an air permeable interface between the upper tray 52 and lower tray 50. The air channels may be formed of cooperating indentations on the upper tray 52 and lower tray 50. The upper tray 52 has a downward

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WO 2007/056866 PCT/CA2006/001894 facing shoulder 70 extending around the upper tray 52, which sits on a corresponding upward facing shoulder 68 extending around the lower tray 50. The shoulder 70 is not continuous, but is interrupted by parts forming the air channels 46, 48 and 54. Air channels 46 are formed from several indents 98 in the sidewall of the upper tray 52 that extend part of the way across the shoulder 70, the indents 98 cooperating with indents 100 formed in the sidewall of the lower tray 50. The indents 98 form cavities that open downward, while the indents 100 form cavities that open upward. The cooperating indents 98 and 100 together form air channels 46. [0017] Air channels 48 are formed from indents 58 and 60 in the lower tray 52 and upper tray 50 respectively. The indents 58 are formed in slanting upper sidewalls of the lower tray 58, and open upward. The indents 60 are sized to receive a person's finger, and open outward from the wall of the upper tray 52. The indents 58 and 60 cooperate to form the air channels 48. In addition, the indents 58 and 60, as well as the lip 62 of the upper tray 52, allow for easy removal of the upper tray 52 from the lower tray 50. This ease of removal is more specifically facilitated by the dome shape of the indent 58 on the lower tray 50, and the shape of the indent 60 on the upper tray 52, which are shaped to receive a person's finger.

[0018] The lower tray $0 has a side wall formed of a lower peripheral wall 64 and upper peripheral wall 66 connected by shoulder 68, upon which the upper shoulder 70 of the upper tray 52 stably rests. The upper shoulder 70 of the upper tray 52 is attached to the peripheral wall 72 of the upper tray 52. The lower shoulder 68 is attached to the upper peripheral wall 66 of the lower tray 50. Fig. 11 shows the contact area 74 between the upper shoulder 70 and the lower shoulder 68 of the upper tray 52 and lower tray 50 respectively.

[0019] Fig. 20 illustrates the outward slant of upper and lower parts of the side wall of the lower tray 50. Normals 82 and 84 are drawn perpendicular to the plane 96 created by the bottom of the lower tray 50. A projection 86 of the upper peripheral wall 66 of the lower tray 50 intersects line 84 at an angle 78. A projection 80 of the lower peripheral wall 64 of the lower tray 50 intersects line 82 at an angle 76 that is smaller than angle 78. Various angles may be selected for the angles 76 and 78.

[0020] Each of the lower tray 50 and the upper tray 52 have upper edges forming a flange or lip, that is preferably at least a few millimeters wide to accommodate sealing of the top to a cover. The top flange or lip 88 of the lower tray 50 and the top flange or lip 90 of the upper

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WO 2007/056866 PCT/CA2006/001894 tray 52 may be level with each other when the product is assembled. This allows both trays to be simultaneously sealed. This may be done with shrinkwrap or a plastic cover. Alternatively, the lip 90 of the upper tray may be lower than the lip 88 of the lower tray 50.

[0021] Both tray combinations 12, 10 and 52, 50 are used in the same manner. This description will make reference to upper tray 12 and lower tray 10, but the same description applies to upper tray 52 and lower tray 50. In use, food is placed in each of the upper tray 12 and lower tray 10. The food product 42 in the upper tray 12 may be a higher value food product in terms of cost per weight than the food product 40 in the lower tray 10. Thus the lower tray 10 may include pasta, rice or vegetable, which is usually the higher volume product. The upper tray 12 may include a sauce, such as cheese sauce, meat or seafood sauce, or vegetable sauce. The food may be pre-packaged and may be pre-cooked. The food may be stored in a frozen state until defrosted and cooked or re-heated by the user. Water may be added to the lower tray 10 to assist in cooking the food product in the lower tray 10. A gap 44 may be provided between the top of the food product 40 and the bottom 46 of the upper food tray 12 to avoid the food product 40 coming into contact with the bottom 46 of the upper food tray.

[0022] In one embodiment, chili may be placed in the lower tray 10 and a biscuit in the upper tray 12. For food product such as a biscuit that should have a crisp exterior texture when cooked, a susceptor board may be placed in the tray with the food product.

[0023] When sold, the food tray, including food, may be wrapped in shrink wrap, and the food may be frozen. For use, the customer removes the shrink wrap and deposits the food tray in an oven (conventional or microwave as appropriate for the materials), where the food tray is subject to food heating energy. If the upper tray 12 is sealed with a film, it may be removed or loosened prior to cooking depending on the cooking instructions. Due to the air permeable interface 14, the food tray permits steam to escape from the lower tray. Upon removal of the food tray from the oven, the higher value food product may be added to the lower value food product, simply by pouring the higher value food product into the lower tray. Due to the product being in separate trays, quicker more even heating is obtained. With the higher value product in the top tray, the aromas of the higher value product are easily available to the customer upon heating, and the higher value product also presents a pleasing

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WO 2007/056866 PCT/CA2006/001894 aspect to the customer. Either or both the cover 24 or the sidewalls 20, 22 may be provided with graphics illustrating the food product and providing instructions for use.

[0024] Immaterial modifications may be made to the embodiments described here without departing from what is claimed.