HRP20040949A2 - Ovenable stackable and nestable trays and industrial catering method using these trays - Google Patents

Description

The subject invention relates to a process intended for convenient and hygienic packaging, transport to a food supply point and serving of food products in industrial food supply, using a set of containers that are inserted into one another, each set of containers being preheated in an oven before the distribution of food products, and then it should be possible to stack the empty containers inside each other, so that they take up less space.

A number of procedures are already known in the food supply industry to facilitate the packaging and transportation of food products from a place of full or partial production to a food supply place where said products may undergo final preparation.

In air food service, food products are traditionally delivered to the aircraft on metal containers that are inserted, so that they can slide, into metal container insertion boxes, which boxes can be securely closed, for transport and boarding the aircraft. The food supplier should handle the food by placing the food in the containers. These container insert boxes usually fit in the galley in the airplane cabin. Once it is time to serve the consumer, the boxes with the inserted containers are opened, then the containers are individually removed and inserted, so that they can slide, into the cavity of one of the ovens which is provided with receiving supports, which supports accept each individual container. The carrying means in the oven cavities are spaced at a sufficient vertical distance to allow hot air to circulate between the containers. When heating is achieved, the individual packages of food are individually transferred to baskets or some suitable serving container, for delivery to the passengers around the container. The containers are then, when emptied, re-inserted into the container insertion boxes, which boxes are again placed in the galleys until the plane lands.

This traditional process requires too much handling and time, both for the caterer and the in-flight staff. Furthermore, too much space in the food supply cabin must be determined for these boxes to insert the containers, even after they have been emptied of food. These tank insertion boxes are therefore heavy and can usually only be inserted at floor level in the galley of the aircraft. Finally, air circulation around the container cannot be optimal if the means of carrying may not be optimally placed in the oven, which depends on the nature and size of the food product to be reheated.

US Patent No. 4,269,169 discloses a process in which containers, which are closed with a lid in such a way as to be securely closed, can be stacked one above the other in a container which is open on one side and which has openings which allow hot air to circulate in the spaces between of the tank, these openings are obtained by inserting the feet that are located at the bottom and rest on the lid of the tank that lies below it. These tanks and containers are usually pentagonal in shape so that the volume of a conventional oven with a rectangular base plate cannot be used optimally, which creates a disadvantage when reheating before consumption is carried out in a confined space, such as in serving areas food on the plane. These containers are in fact intended to be inserted into a special circular oven, which is disclosed in US Patent No. 4,625,867, such ovens also having the disadvantage of requiring more space than conventional ovens. It should also be noted that the secure closure of each individual container, which is necessary so that the containers can be stacked on top of each other, and since the container is not hermetically sealed at all, contributes to increasing the cost of the final product.

In US Patent No. 4,384,191, which was filed by the same author after the aforementioned patent, the container is also provided with openings, which are conventionally cube-shaped, with rails or with shelves that allow the normally securely closed containers to be located so that they do not touch each other , wherein one or more hot air generators are placed between the containers after they are inserted into the heating chamber.

This process has essentially the same disadvantages as the previous one, except that it requires individual safe closure of the container and special heating installations.

It may be noted that the above methods allow the containers to be inserted into each other after use, but do not allow them to be stacked on top of each other when heated, without additional means being used.

Within the field of palletizing, there are a large number of devices, all of which are based on the same principle, for taking finished or semi-finished products from the place of production to the place of delivery or sale, without the said products having to undergo any changes on the existing pallets, and they allow pallets to be stacked on top of each other when they contain products and to be stacked inside each other when they are empty. In accordance with this principle, all pallets, or likewise all containers, have the same shape with walls that extend downwards and allow them to be stacked on top of each other, and have two opposite sides with complementary shapes that allow them to be stack on top of each other, so that the head comes to the tail, which leaves free space for placing the product. For example, US Patent Nos. 4,522,301 and 5,896,992 may be cited.

US Patent No. 4,522,301 discloses a process consisting of making raw croissant dough in open cells of plastic containers, where they are frozen, the containers being stacked head to tail, and packed in cardboard boxes for delivery, to for example, in bakeries where frozen raw croissants are emptied and placed on the oven shelves to be prepared, and all the containers are then rotated in the same direction to be inserted into each other.

For transporting confectionary or bakery products, US Patent No. 5,896,992 discloses flat-bottomed rectangular boxes whose sides have a complex complementary shape that allows them to be stacked one on top of the other when placed head to tail and nested inside each other when all set in the same direction.

The subject invention therefore relates to a process which, with minimal handling, enables food products, which are placed in a set of containers that are stacked on top of each other, to be suitably and hygienically packed and transported from the place of production, where the products are prepared or pre-prepared , and preferably frozen, to the food supply point, where said containers are placed in a suitable oven to reheat the products before distribution.

The invention also relates to the containers themselves, the shape of which was designed to allow them to be easily stacked on top of each other and inserted into each other, in order to allow food products, which may have the same or slightly different dimensions, to be uniform again to heat up, and to allow the products in the containers to be easily removed for distribution after they have been heated.

The method according to the present invention is therefore characterized by the fact that the containers can withstand heat and can be stacked on top of each other to create at least one complex stack of containers whose shape and dimensions are such that one complex stack, or more , can be placed in the oven at the food service location, and that the stacked stack of containers leaves space between each container to maintain hot air circulation around the food products, and that the containers are kept stacked in the outer package for transportation to the food supply point, which outer package can maintain the integrity of a complex stack of containers.

The protective packaging, which is preferably a cardboard box or shrink-wrapped plastic film, is removed before introducing the stacked stack of containers into the oven.

For air food service applications, the outer carton is preferred, as it allows for easy palletizing from the point of production and eliminates handling at the food service provider, apart from the sheer logistics of acceptance, storage and on-boarding, and reduces in-flight handling to an absolute bare minimum. .

The protective packaging may further include easy-opening means to assist in unpacking the stack of stacked containers from the outer package. These leg means should also be arranged so as to facilitate placing a complex stack of containers in the oven, since they involve as few handling procedures as possible. For example, the easy opening means may be derived from at least one tear line, which marks at least one part of the opening on the carton that is sufficient to remove the stacked stack of containers contained in a single block. In a particularly advantageous aspect, the easy opening means comprises a tear area on the front and rear of the carton panel which is of sufficient size to allow the entire stacked stack of containers to be slid into the oven after a simple push thereof.

It should be noted that these containers can be made of a material that allows them to be reused, for example, aluminum. however, according to a preferred embodiment, said containers are made of disposable or recyclable material, such as plastic material or oven-safe paper, which can withstand temperatures of up to 230°C. This provides the further advantages of obtaining a lightweight product that is open to different design variations, to the choice of colors used for the material, or to the addition of stamps or logos to the sides of the container, such stamps representing the product contained in the container, the manufacturer or the like similar to. These containers can be made of thermoplastic materials that are thermally molded by injection molding. Suitable plastic materials used in the food industry are those that can withstand temperatures up to 230°C for at least 30 minutes, preferably 1 hour, during which time they generally maintain good mechanical properties. Preferred plastic materials can be selected from the group of heat-resistant polymers or copolymers that can be used in food and which consist of syndiotactic polystyrene (SPS), crystalline polyethylene terephthalate (CPET), polycarbonate, polyetherimide, polyimide, polyetherketone (PEEK), fluoropolymer, polyphthalamide, polyphenylene sulfide, polyether sulfone, polyaryl sulfone, polypropylene and a mixture of co-polymers of these thermoplastic materials. The material can also be made of thermostable polymers, such as polyester or epoxy resin.

Preferred plastic materials for containers are those having a glass transition temperature preferably higher than 60°C, and even more preferably higher than 95°C, and a melting point above 200°C, and even more preferably above 225°C. At oven temperatures above the transition temperature, the container may be slightly flexible but still hold its shape. In a preferred example, the containers contain a matrix of syndiotactic polystyrene (SPS) and a mechanical filler, preferably of a reinforced material, such as glass or the like. SPS is a crystalline polymer that has a glass transition temperature of about 100°C and a melting point of about 270°C. The container can be cast from such material with a thickness of less than 3 mm, preferably less than 2 mm, even more preferably of about 1..5 mm, while still retaining high mechanical properties, and especially excellent bending strength. Within the range of these thicknesses, containers made of these materials achieve sufficient strength, can be stacked after use with reduced volume, can be intended for only one use, and can be destroyed by burning after use.

The mechanical filler is advantageous for further increasing the bending strength of the containers in conditions when they are heated, especially at temperatures higher than the glass transition temperature. The SPS matrix and mechanical filler are preferably used together in a ratio of 99:1 in mass % to 60:40, and more preferably 90:10 to 70:30.

This invention also relates to a food container comprising:

- the lower surface for food parts on which it is placed,

- supporting means which are complementary shaped on the opposite sides, which means enable that one container can be stacked on top of another similar container, oriented so that they are directed 180 degrees in relation to each other, and that one container can be inserted into the other the same container when the containers are empty and all the containers are pointing in the same direction, so as to reduce the storage space, and

- means for ventilation to circulate air inside the tank.

It is preferable that the means for ventilation contain openings located on the sides of the container and/or serrations made on at least one side of the container, which means encourage horizontal air circulation inside the container. The means for ventilation can additionally contain openings located at the bottom of the tank to encourage vertical air circulation inside the tank.

Preferably, the container can be made of a material that can withstand high temperatures, and even more preferably, it is made of a disposable cast material with a high melting temperature and a high glass transition temperature, as previously stated.

Other characteristics and advantages of the subject invention will be more clearly seen after reading the following description of an advantageous embodiment, whereby this description is made with reference to the attached drawings, in which:

- figure 1 is a schematic diagram showing the different stages of the process, which process is in accordance with the present invention;

- Figure 2 shows the first realization of a complex stack of containers that are properly filled with individual portions of food and packed in a cardboard box;

- picture 3 shows in perspective one separated container from the pile from picture 2;

- Figure 4 is a top view of the tank shown in Figure 3;

- Figure 5 and Figure 6 show in perspective and side view two containers that are stacked on top of each other;

- Figure 7 and Figure 8 show in perspective and side view two containers that are inserted into each other;

- figure 9 shows a container containing two small portions of food products;

- picture 10 shows the easy placing of the container in the oven;

- Figure 11 shows another embodiment of a stacked stack of containers in accordance with the present invention, i

- picture 12 shows in perspective one separated container from the set in picture 11.

The diagram in Figure 1 schematically describes the stages of the process in accordance with the present invention. Products 1 for the production of food products are delivered to the preparation unit 2, which is located outside the food supply site 7, in which the food is cooked or pre-cooked. These can be, for example, food products for breakfast (hot dogs, Danish cakes, croissants, etc.), for breakfast or for lunch (calconi, pizza, quiche, etc.), or dough or bread products, or baked or fried products that freeze and regenerate well in a conventional oven or in an oven using heat transfer from air or steam by convection. After preparation, in the following stage 3, the products can be individually wrapped with wrapping tape or placed in oven paper bags, and then placed in containers, and then they can be deep frozen in stage 4; the products can also be first deep frozen and then placed in containers. Alternatively, food products can be directly placed in containers without individual packaging.

Deep freezing can be carried out by any suitable means, such as rapid cooling to the required temperature, i.e. from minus 18 to minus 49°C, in a spiral freezer or in a freezing tunnel, which tunnel has liquid nitrogen nozzles, or by any other suitable freezing technology. In all cases, the cold chain should be maintained all the way from the preparation of the food to the delivery to the food supply point, with the storage of packages in freezers in such a way as to ensure safe and hygienic conditions.

In the next stage 5, the containers are stacked on top of each other, so that the head is above the tail, and packed in bundles, for example, in cardboard boxes that can contain 5 to 10 containers, the bundles are then sealed to keep the stacked stacks of containers tightly in his position. The cartons are then brought to the food service station 6 located at the food supply site 7, where the stacked containers are removed from their packages and heated in a convection oven, then separated from each other to be distributed at the food supply site 7, for example, to passengers on a plane. Containers can be handled either directly with the help of heat-protective gloves, where the containers are used directly as passenger trays, or alternatively, the containers are inserted into larger insulated baskets that are prepared to contain the containers. When the containers are empty, they are inserted into each other to take up minimum space and are then discarded 8, or reused 9, after the preparation unit 2.

This procedure enables hot or warm food products to be served in a suitable and hygienic manner, especially in places where there is limited space for preparation and storage after use.

In order to make this process even more efficient, the shape of the tank was optimized, as explained in the further description.

Fig. 2 shows a cardboard box 10 in which seven containers 20 are stacked, with portions of food properly placed therein, the cardboard box having a front panel 10a which can be closed, for example, by means of adhesive tapes or by means of glue, which is not shown. The dimensions of the cardboard box depend on the dimensions of the container and the dimensions of the heating oven. The dimensions and shape of the cardboard box are determined in such a way as to provide a narrow confined space around the stacked stack of containers which keeps the stacked stack in place even in turbulent transport conditions. It is desirable that the box is sufficiently closed with as few holes or openings as possible, although this is not an absolute requirement, to ensure the highest degree of hygiene and to maintain an effective barrier of thermal insulation. For example, the cardboard box 10 may have dimensions that are, for example, 40x40x25 cm (that is, a height of 40 cm, a depth of 40 cm and a width of 25 cm), with a thickness between 1 and 20 mm, which allows the box to be easily handles, although other types of packaging with a smaller or larger number of containers can be imagined.

It is desirable that the carton may contain a means to facilitate placing the stacked stack of containers into the oven and require as little handling as possible. Preferably, both the front and back panels 10a, 10d have a tear-off section or perforated line 10b so that after tearing, a wide enough section of the carton can be removed to allow the stacked stack of containers to slide smoothly through one opening when pushing is done. to a stacked stack. The tear line may advantageously be combined with the first engagement zone 10c, which is advantageously located near the edge of the carton or near the periphery of the tear line.

As shown in Figure 10, when the operator needs to load a stacked stack of containers into the oven, he (or she) tears the tear areas on the front and back panels. The cardboard box can be placed in front of the cavity 51 of the oven 50, so that they are on the same flat surface 52, and the back of the cardboard box faces the oven cavity. The user can then push the entire stacked stack of containers in the A direction, so that the stack slides straight into the oven. The cardboard box is then discarded.

Containers and their complementary means of support are preferably designed, sized and shaped so that the desired number of containers can be placed in a stacked stack, so that the final stacked stack of containers is adapted, in the best case, to the available space in the oven cavity. Of course, depending on the oven, its cavity can accommodate only one stacked stack of containers, or alternatively two or more stacked stacks of containers placed in parallel.

Preferably, the stacked stack of containers is sized to fit into the oven cavity in such a way as to leave a predetermined space between the container and the oven walls to maintain sufficient air velocity along the walls to maintain convection heating. If the distance between the container and the oven cavity is too small, air cannot easily circulate from one container to another when the containers are filled with food. Conversely, if the gap is too large, the speed drops and the heating characteristics decrease accordingly. It was found desirable that the air velocity measured along the walls of the oven should be greater than 1 meter/second for convection heating, more preferably around 2 to 3 meters per second, in order to achieve rapid heating of the food in the containers. For conventional convection ovens as used, the required air velocity can be obtained with total clearance values of less than 15 mm, preferably around 4-8 mm (total clearance is measured at the "opening edge" of each container , when the container is pushed against one side wall for measurement).

It is also possible, for example, to keep containers stacked by wrapping them with plastic film or shrink-wrap, either alone or in combination with an outer carton, especially if the food portions in the container are not individually wrapped in the wrapper into which they are inserted. .

Containers can, in fact, be made with shapes that allow them to be produced economically, for example, by hot forming a plastic material, such as syndiotactic polystyrene (SPS), crystalline polyethylene terephthalate (CPET), polyamide, polyimide, PEEK or others suitable heat-resistant polymers or copolymers, or by forming an oven-safe cardboard that can withstand temperatures up to 230°C. It is preferable that the plastic is reinforced with a mechanical filler, such as glass, ceramic, carbon and the like. Depending on the choice of polymer or copolymer for the containers, the molding process can be performed by injection molding.

Referring to Figures 3 and 4, which show the preferred embodiment, it can be seen that the container 20 has the shape of a rectangular box containing two small sides 21, 22, two large sides 23, 24 and a bottom 25.

Also referring to Figures 5 to 7, it can be seen that the two small sides 21, 22 of the container 20 have a complementary support means or shape, which allows the containers to be stacked one above the other, as shown in Figure 5, when oriented in relation to each other so that their head comes above the tail, or they are stacked inside each other, as shown in Figure 7, when they are all oriented in the same direction.

On the inner surface of the container, along the edges connecting the large sides 23, 24, the small side 21 has two small flat protrusions 11, which are separated by a space 13, to form on the outside of the small side 21 two depressions 15 that have a complementary shape in relation to the small flat protrusions 11, where these recesses 15 are bounded at the bottom 25 with a support zone 17. The opposite small side 22 has, in a complementary manner, on its inner surface, which is close to its edges, which join the large sides 23 and 24, two recesses 14 which are generally complementary in shape with respect to the shape of this small flat protrusion 11, these recesses 14 being connected by a narrow band 18 having substantially the same shape as the support zone 17 at the base of the small side 21. The recesses on the small side 22 are closed on the underside to form legs 12 which will abut the small flat projections 11 of the small sides 21 when the containers are stacked head to tail, and the support zone 17 then abuts the abutment zone 18, as shown in Figures 5 and 6 for the two containers 20a, 20b. Conversely, as shown in Figures 7 and 8, when the containers point in the same direction, they stack into each other. For the small side 22, the legs 12 are engaged in the recesses 14 and the inner shape which is bounded by the supporting narrow strip 18 is engaged in the slot 16. The same happens with the small side 21 for the complementary shapes 11/15 and 13/17. The shape, size and dimensions of the complementary support means may vary widely without departing from the spirit of the present invention. In particular, these features can be determined to optimize the volume available for the food contained in the container, as long as they are not detrimental to the stability of the stack.

If we return to Figures 3 and 4, it can be seen that the bottom 25 is made by means of a series of slightly beveled regions 26, which are connected to each other by means of almost vertical narrow strips 27, wherein these beveled regions 26, or narrow strips 27, provided with venting means 36 and 37. In the same way openings 31 and 32 are provided on the small sides 21, 22. It can also be seen that the large sides 23, 24 have upper and lower edges of a series of serrations 28a, 28b, which edges have a profile that is generally equal to or similar to that of the bottom, with bevelled portions 29, 19, which are generally joined by vertical portions 28.

As can be seen in Figures 5 and 6, when the two containers 20a 20b are stacked, the edges of the large sides 23, 24 delimit the openings 38 between the regions 19, 28 and 29.

The serrations 28a, 28b of the upper and lower edges occupy such a position that when the containers are correctly stacked in a head-to-tail configuration, the serrations are generally positioned vertically, leaving side openings 38 which should be sufficient in number and cross-section for circulation of air on the upper surface of each set of food portions. Furthermore, the cross-section of the side openings 38, such as is obtained in the arrangement when the containers are stacked, which cross-section progressively widens from the bottom of the beveled areas towards the top of the beveled areas, therefore ensures homogeneous air circulation along the entire upper surface of the food portions.

Furthermore, the support means are positioned so that when the two containers are placed together on top of each other, the large openings 31 of the small sides 21, 22 are largely uncovered so as to allow air to circulate easily through these small sides.

All the openings 31, 32, 36, 37 and 38, which are provided on these containers, thus enable the hot air to circulate very easily between the small portions of food 30a, 30b and so on, which are placed on the bottom 25, and circulate at least around the four outer sides, if the small portions are in the shape of rectangular sticks, as shown in Figure 9. It can also be seen that this configuration allows the portions of food, preferably such portions that form hand-held snacks 30a, 30b, which have mostly of different lengths, be arranged, which makes it possible to obtain a reduced selection of containers that need to be had for a wide area of food products that need to be heated.

The number of means for ventilation and their distribution on the surfaces of the container can be determined as a function of the size of the food portions, which portions should be placed in the containers in such a way as to achieve rapid and uniform heating of the food portions, and to prevent the formation of cold, or vice versa, hot places, and especially the number of ventilation openings should be sufficient, so that each individual portion of food, which is placed on the container, is properly ventilated. Preferably, the food bearing surface to surface area ratio for each individual container is preferably within the range of 3:1 to 1:10, and more preferably 2:1 to 1:5.

The ventilation of the container is also regulated to create vertical and horizontal air paths, which provide a kind of network configuration that allows for a uniform increase in temperature of a number of vertical layers of individually placed portions of food that are distributed in containers that are stacked. Such efficient air circulation enables the temperature of the food to rise from a negative temperature, or the temperature of the frozen state, to a minimum temperature of around 60°C, even more preferably at least 70°C, in the core of individual portions of food, in less than 30 minutes, it is even desirable in less than 20 minutes.

Figures 11 and 12 show another embodiment of a set of containers in accordance with the present invention, which containers differ from the first embodiment described above in that stacking/stacking is achieved by means of a two-part device. . As shown in Fig. 11, the containers 40 are stacked, for example, in a type 10 "A" carton, but they are spaced from each other by a spacer 45, which is in the shape of an inverted U and is made , for example, from cardboard. These separating means having the shape of an inverted letter U have side walls which engage the bottom of the large sides 43, 44 of the lower tank 40 in a stacked stack, which sides extend upwards beyond the level of the circumferential edges of the tank, so as to form a tunnel 49 for the circulation of hot air in the direction of the small sides 41, 42. The separating means 45 form the surface of the upper flat support which provides support for the upper container in the folded stack. If desired, the top and sides of the U-shaped separating means can be provided with openings 46, 48. In this way, when the containers 40 are removed from the oven, the U-shaped separating means are folded and discarded, and when the containers 40 are empty, these containers can be placed inside each other regardless of their orientation. As in the first embodiment, the bottom of the container 40 can be provided with bevelled areas and/or with openings located in a row. The separation means may also be formed with four to six sides so that the elongated box has uniformly spaced vents. Preferably, the separation means is made of a low-cost, single-use material, preferably a material such as cardboard or hard paper that can withstand heating in an oven.

A preferred material for the container is a syndiotactic polymer reinforced with 15 to 40% glass by weight, preferably 20 to 30% glass by weight. Suitable syndiotactic materials are polystyrene polymers (SPS). Among the important properties of SPS, compared to polymers traditionally used for food needs, SPS have a lower coefficient of linear thermal expansion which makes them suitable since they are easier to cast, more stable and less subject to deformation in the configuration in which the containers are located which are stacked and when heated in the oven. These materials exhibit low melt viscosity, good thermal properties, but cool quickly after removal of the heating source, have relatively high impact resistance, little water absorption, relatively high glass transition temperature, and relatively high elongation before fracture. As a result of these properties, containers are created that can be produced with a relatively small thickness, preferably less than 3 mm, with a significantly lower price, while still showing excellent operating characteristics that do not vary significantly in the range of temperatures and relative humidity encountered during heating and serving. Furthermore, the container can be burned without causing problems for the surrounding area. Syndiotactic polystyrene, sold under the trade name Questra® by Dow Chemical Company, is a poly-crystalline thermoplastic polymer. However, in contrast to the disordered atactic configuration of general purpose amorphous polystyrene, syndiotactic polystyrene comprises styrene monomer units arranged in a highly ordered alternating configuration along the polymer chain. This ordered structure allows the polymer chain to crystallize. Crystallization improves material strength and heat resistance near and above the glass transition temperature. Since the material absorbs very little moisture (less than 0.1% after 24 hours of immersion according to ISO 62), the glass transition does not depend on moisture. The glass transition temperature of a plastic material is the temperature at which the amorphous phase of the material undergoes a transition from the glass state to a flexible state including the movement of long segments in the polymer chain. The glass transition for different materials is shown in the following table:

[image]

Therefore, due to improved heat resistance, strength properties and cost, syndiotactic polystyrene is preferred for tanks.

The invention is not limited to hand-held meals, but encompasses the ability to provide heated meals of food on individual plates or containers. For this reason, it is desirable that the containers have an enclosed space that is designed to accommodate a large number of frozen dishes on plates or in containers. The beveled portion of the bottom of each container suitable for hand-held meals can preferably be replaced with a flat bottom that can accommodate open plates, such as "plats á sabot" and the like. Large vents or inlets, as previously stated, are still required to ensure proper convection heating of meals in their bowls. Preferably, the food container does not have a lid on it which would reduce heat transfer to the upper part of the meal, although the lid could be used to prevent liquid food, such as soup or sauce, from spilling out of the container.

This invention provides numerous advantages, such as:

a) Procedure for better and more hygienic delivery of food to locations for serving food without direct handling of the food itself until serving the consumers themselves.

b) A more efficient, less clumsy, easy-to-serve and preferably single-use food delivery system that provides greater convenience to operators when boarding an airplane, carrying food around to passengers, and cleaning the food service cabin before landing.

c) Arrangement of food in the container, which enables optimization of space and optimization of vents for hot air circulation, depending on the nature and dimensions of the food portion that needs to be renewed by heating in the oven.

d) More secure packaging that can pass through airport security checkpoints, especially metal detectors, easier packaging compared to conventional metal boxes for inserting containers, since the packaging can be made of material that is intended for single use and that allows X -rays and is intended to be opened only once and only when it is loaded onto the plane, when the food is ready to be reheated in the oven.

e) Improved accommodation for trolleys used in aircraft and for elevated containers in the aircraft galley when the containers are packed in an outer carton, and better use of the allocated space in standard aircraft ovens with respect to product size/dimensions and heating characteristics.

Examples:

Example 1

Seven containers of the type described and shown in Figures 3 through 9 were filled with a frozen meal of the chalcone type. Each container contained an average of 9 meals with about 3 meals in a row. The individual weights of the meals ranged from 70 to 80 grams. The containers were placed as a stack of containers in an aircraft convection oven of the type commercially offered by B/E Aerospace. The medium temperature in the preheated oven, controlled by a thermostat, was set at 190°C, 180°C and 170°C. It took 18, 20 and 22 minutes for each of them to restore the meal in the core to serving temperature, to a minimum value of around 70°C. All meals were heated in the same way in containers within the medium temperature range of +/-8 to +/-10°C. The meals did not show any cold spots.

Example 2

A stacked stack of 240 mm wide Atlas size containers placed in an Atlas size oven, which has an internal width of 245 mm, resulted in a clearance of 5 mm when measured at the "opening edge" of the container. With the cross-sectional profile of the containers, the actual air space was 15 mm to 21 mm in width when the containers were pushed against one side wall of the oven. An air flow of 2-3 meters per second was measured at the front perimeter of the oven with these containers filled and in place, when the drive was maintained in the conventional manner and the heating time to the temperature of the center of the product was 70°C is 20 +/-2 minutes.

When these Atlas-sized containers were placed in a wider KSSU-sized oven (261 mm inside), the increased air space between the container and the side wall of the oven resulted in reduced air velocity at all locations to less than 1 meter/second, in convection heating method, the heating time was more than 33 minutes to reach a core temperature of 70°C.

Claims (22)

1. A method for convenient and hygienic provision of portions of food at a food service point, with reduced handling, which method provides a packaged set of containers for a plurality of individual containers, which containers are adapted to receive a number of portions of food, characterized in that the containers are suitable for ovens and can be stacked on top of each other to form at least one stacked stack of containers of a predetermined size and predetermined shape, which stacked stack is suitable for placement in at least one portion of the oven cavity at the food supply location, the stacked stack of containers having spaces between of each container, in order to support the circulation of hot air, which is in the oven, between each container, through the containers and inside the container. 2. The method according to patent claim 1, characterized in that the stacked stack of containers is packed in an outer protective package, which maintains the integrity of the stacked containers for transport to the food supply site. 3. The method according to claim 2, characterized in that the set of containers is removed from its outer protective package for heating in the oven. 4. A method according to any one of the preceding claims, characterized in that the individual containers are removed from the stacked stack of containers, after heating in the oven, in order to serve meals from the containers. 5. A method according to any of the preceding claims, characterized in that the empty containers are available to be placed together one inside the other in such a stacking arrangement as to reduce space after the meals from the containers have been served. 6. A method according to any of the preceding claims, characterized in that the food portions are individually frozen meals or handheld food. 7. A method according to any one of the preceding claims, characterized in that the stacked stack of containers has a predetermined distance to the walls of the oven, which distance successfully maintains an air velocity greater than 1 meter per second, by convection, when the stacked stack of containers is placed into the oven for heating. 8. A packaged set of food containers suitable for transporting, reheating and serving reheated food meals at a food service point includes: -a number of portions of food, - a larger number of individual containers that have a bottom adapted to accept a number of food portions, characterized in that the containers are suitable for ovens and are stackable to form at least one stack of stacked containers having a predetermined size and a predetermined shape and suitable for placement in at least a portion of the cavity of the oven at the food supply point, wherein the stacked stack of containers has spaces between each container, to support the circulation of the hot air in the oven between each container, through the containers and within the containers, and as necessary - an outer protective packaging that can be removed, and which maintains the integrity of the containers in the position when they are stacked, for transport to the food supply site. 9. A packaged set of food containers according to claim 8, characterized in that the containers have on opposite sides complementary shaped support means which enable the containers to be stacked on top of each other and are oriented so that they are rotated 180 degrees to each other relative to each other, and thus create enough space for food portions and for air circulation, and to stack one inside the other when the containers are empty, and all orient in the same direction to reduce storage space. 10. A packaged set of food containers according to claim 8, characterized in that the containers are stacked one above the other by means of spacers inserted between them, which means can be removed and which are placed so as to leave a path for air circulation between of each container. 11. A packaged set of food containers according to claim 8 or 9, characterized in that the containers, when in the folded position, leave large air inlets on the sides of the container which maintain the circulation of hot air within the container. 12. A packaged set of food containers according to patent claim 11, characterized in that the large entrance openings are made by means of openings that are carried through the supporting means or through the sides of the container and/or by means of serrations that are made on the upper edge of at least one side container. 13. A packaged set of food containers according to any one of claims 8 to 12, characterized in that the bottom of the container has ventilation means which additionally support air circulation in a vertical direction. 14. A packaged set of food containers according to any one of claims 8 to 13, wherein each individual container has beveled means to aid in the distribution of the food portions in the container and in the convenient handling of the food portions by the consumer. 15. A packaged set of food containers according to any one of claims 8 to 14, characterized in that the containers are made of plastic material intended for single use, or of plastic material that can be recycled, or of cardboard material that withstand heating in the oven. 16. A packaged set of food containers according to claim 15, characterized in that the containers are made of a polymer or copolymer that withstands heating at temperatures up to 250°C for at least 30 minutes. 17. A packaged set of food containers according to claim 16, characterized in that the plastic material is syndiotactic polystyrene (SPS), crystalline polyethylene terephthalate (CPET), polycarbonate, polyetherimide, polyimide polyetherketone (PEEK), fluoropolymers, polyphthalamide, polyphenylene sulfide , polyether sulfone, polyaryl sulfone, polypropylene and mixtures and copolymers of these thermoplastic materials. 18. A packaged set of food containers according to any one of claims 8 to 17, characterized in that the outer packaging is a cardboard box having a device for easy opening, which device includes at least one tear line, which line delimits at least one sufficient the area of the opening on the carton to facilitate the removal of a complex stack of containers in one block. 19. A packaged set of food containers according to claim 18, wherein the easy opening device comprises tear-off portions on the front panel and on the rear panel of the carton, which are large enough to allow the entire stack of containers to slide into the oven. after a simple stack push is performed. 20. A food container that is particularly intended for a process that is in accordance with any of patent claims 1 to 7, characterized in that it contains: the lower surface for portions of food on which it is placed, supporting means which are complementary shaped on opposite sides, which means enable the container to be stacked one above another of the same container, which are oriented so that they are oriented 180 degrees relative to each other, and which can be inserted into each other , the same container, when the containers are empty and all pointed in the same direction, in order to reduce the storage space, means for ventilation to circulate air inside the tank. 21. Food container according to patent claim 20, characterized in that the means for ventilation includes openings, which are arranged through the sides of the container and/or through the serrations made on at least one side of the container, which openings support the horizontal circulation of air inside the container . 22. Food container according to patent claim 21 or 22, characterized in that the means for ventilation comprises openings which are arranged at the bottom of the container and which support the vertical circulation of air inside the container.