WO1993003978A1

WO1993003978A1 - Disposable food packaging

Info

Publication number: WO1993003978A1
Application number: PCT/AU1992/000444
Authority: WO
Inventors: Frank Andrew Ward
Original assignee: Frank Andrew Ward
Priority date: 1991-08-21
Filing date: 1992-08-21
Publication date: 1993-03-04

Abstract

Disposable packaging (2) for hot food (16) served on a plate (14), the packaging including a container (4) having a mass of particulate material (20) located in a heatproof bag (18) in the bottom of the container, the particulate material is heated to a high temperature and the plate is placed thereon so as to keep the food warm during transport.

Description

DISPOSABLE FOOD PACKAGING

This invention relates to food packaging.

This invention relates to food packaging particularly arranged for keeping takeaway food hot.

Various arrangements are known for packaging of food in order to keep it warm during transportation. For instance pizzas are frequently placed in papier mache or cardboard boxes which have an insulating effect and keep the pizza warm for a limited period. Sometimes the containers are themselves placed inside a thermally insulated flexible bag in order to increase the insulation. Whilst these arrangements have some usefulness, they do not really keep the food warm for long periods. Further, they are not particularly suitable for transport of higher quality meals such as a restaurant prepared meal or the like. There have been some attempts to overcome these shortcomings. U.S. Patent Nos. 3,721,803 and 4,816,646 disclose arrangements which include an electric heating element to assist in the warming. U.S. Patent No.

4,182,405 discloses a food holder arrangement which includes a flat tray having a heat retaining element extending over a portion of the area of the tray. Whilst these arrangements would offer some improvement over the use of a simple cardboard box or container, they are relatively complicated and would be comparatively expensive to produce.

The object of the present invention is to provide a disposable food container for keeping takeaway food hot. A further object is to provide a container which enhances the presentation of takeaway food.

According to the present invention there is provided disposable packaging for hot food, said packaging comprising a container, a heatproof bag, a mass of solid particulate material located within the bag, the arrangement being such that the bag and the material can be heated to a predetermined temperature and located in the container whereby food on a plate or the like can be placed in the container so as to be kept warm by heat transfer from material in the bag.

Preferably the material comprises stones, aggregate, gravel, sand or crushed rock. Preferably the particle size is in the range from about 1mm to 10mm.

Preferably the weight of the particulate material is approximately equal to the food to be kept warm.

Preferably further, the bag comprises a bag of plastics material capable of withstanding temperatures in the range 50°C to 150°C. Commercially available oven cooking bags such as GLAD bags made by Union Carbide are quite suitable for this purpose. Australian Patent specification No. 567,242 discloses various high temperature containers which would be suitable for use with the invention.

Preferably further the bag is opaque.

Preferably the container is made from corrugated cardboard and is folded into the shape of a box with a lid in a manner known per se.

Preferably further, a sheet of cardboard is placed upon the bag and the particulate material so as to provide a flat base upon which the plate for the food can be placed.

The plate itself preferably comprises a disposable plastic plate so that the whole of the packaging can be disposed of after the food has been consumed.

The invention will now be further described with reference to the accompanying drawings in which: Figure 1 is a perspective view of food packaging of the invention; and

Figure 2 is a sectional view through food packaging of the invention. The disposable food packaging 2 illustrated in the drawings comprises a cardboard box 4 having sidewalls 6, base 8 and hinged lid 10. The structure of the box 4 can be of conventional form and therefore need not be described in detail. The lid is preferably formed with inwardly directed flaps 12 which assist in insulating the interior of the box when the lid is closed.

As seen in Figure 1, a disposable plate 14 is located in the box, the plate having food 16 placed thereon. As will be described hereinafter, means is provided in the base of the box so as to keep the food 16 hot or warm over relatively prolonged periods.

Figure 2 shows a cross-section through the container. Located in the bottom of the container is a bag 18 which contains a mass of particulate material 20. The particulate material may comprise stones, crushed rock, aggregate, gravel, sand or a mixture of these materials. These materials are chosen because they are inert, non- toxic, cheap and can be readily heated so as to elevate their temperature. Located above the bag of particulate material is a perforated barrier 22 which may be formed from a sheet of cardboard material having perforations 24 formed therein. The barrier 22 is optional and forms a neat and stable base upon which the plate 14 rests. It is preferred that the dimension of the plate 14 coincides with the sidewalls of the box so that the plate 14 cannot move laterally once it is resting on the barrier plate 22.

Perforations 24 in the barrier 22 enhance heat transfer from the particulate material 20 to the plate and hence to the food 16 on the plate.

It is preferred that the bag 18 is made from plastic sheet material which may be transparent or opaque. An opaque bag is preferred to aesthetic reasons. The bag is selected so as to be capable of withstanding quite high temperatures. It has been found that oven bags designed for cooking food in ovens is quite suitable for this purpose. The mass of particulate material is introduced into the bag and the bag is sealed by conventional means such as a tie wire or the like. 00444

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The particulate material may vary in size. For example, the individual particles may be of the order of 1mm to 15mm in their maximum dimension. As to the quantity of the particulate material, it is envisaged that about one third to half of the volume of the box would be occupied by the particulate material but this would of course depend upon the amount of heating effect which is required. It is also thought that approximately the same weight of particulate material as the weight of food 16 would also be appropriate measure of the quantity of particulate material required.

The box 4 can be made of cardboard, papier mache, foamed polystyrene or other inexpensive thermally insulating material. The size of the container can be varied as required for instance from a small container suitable for holding a single hamburger such as a 100mm cubic shape. A larger common size would be 255mm x 255mm base with a height of 75mm which is suitable for use with readily available disposable plastic plates. A larger size would also be possible say 500mm x 500mm base and 100mm high. With the larger sizes, a number of the bags of particulate material could be provided rather than having a single larger bag.

In use, the bag of particulate material 20 could be heated in an oven to a predetermined temperature say in the range 50°C to 150°C and preferably 80°C to 100°C and then placed in the base of the box 4. The temperature is selected having regard to the type of food to be kept warm and the time for which the food is to be warmed. Some foods, such as steaks, can tolerate high temperatures whereas others, such as foods in cream sauce, cannot tolerate high temperatures. The barrier 22, if used, is then placed in the box and the particulate material is spread generally evenly over the base. The plate 14 with the food 16 is inserted in the box and the lid 10 is then closed. The packaged food is then ready for transport and depending on the number of parameters, the food will remain relatively hot for a prolonged period, say 30 minutes or more.

In an alternative arrangement, the container 4 having the bag 20 of particulate material and the barrier 22 may be placed in an oven for heating as a single assembly. When heated sufficiently, the plate 14 of food can be placed in the box in readiness for transportation. For transportation of some food such as pizza the plate 14 and/or barrier 22 could be omitted.

Prototypes of the invention have been prepared and found to function exceptionally well. Preliminary tests show that a high quality meal, such as steak and vegetables, can be presented on a plastic plate and transported for transport times of up to say 30 minutes and the food arrives hot and well presented. The packaging is completely disposable and moreover the cost is insignificant when compared to the cost of the meal itself.

Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims

CLAIMS:

1. Disposable packaging (2) for hot food (16), said packaging comprising a container (4), a heatproof bag (18), a mass of solid particulate material (20) located within the bag, the arrangement being such that the bag and the material can be heated to a predetermined temperature and located in the container whereby food on a plate (14) or the like can be placed in the container so as to be kept warm by heat transfer from material in the bag.

^~2. Disposable packaging as claimed in claim 1 wherein the material comprises stones, aggregate, gravel, sand or crushed rock.

3. Disposable packaging as claimed in claim 2 wherein the particle size is in the range 1mm to 10mm.

4. Disposable packaging as claimed in claim 1, 2 or 3 wherein the bag comprises plastics material.

5. Disposable packaging as claimed in claim 4 wherein the bag is made from film which is capable of withstanding temperatures in the range 50°C to 150°C.

6. Disposable packaging as claimed in claim 5 wherein the bag comprises an oven cooking bag.

7. Disposable packaging as claimed in claim 5 wherein the film is opaque.

8. Disposable packaging as claimed in claim 1 including a barrier layer (22) spanning the container and located above said bag.

9. Disposable packaging as claimed in claim 8 wherein the barrier layer (22) includes perforations (24).

10. Packaged hot food comprising food (16) on a plate (14) and disposable packaging (2) as claimed in any one of claims 1 to 9.

11. Packaged food as claimed in claim 10 wherein the dimensions of the plate are such that it substantially cannot move laterally within the container.

12. Packaged food as claimed in claim 10 or 11 wherein the quantity of particulate material is such that it occupies about one third to one half the volume of the container.

13. Packaged food as claimed in claim 10, 11, 12 or 13 wherein the temperature of the particulate material is in the range 50°C to 150°C.

14. A method of transporting a hot meal comprising the steps of: heating a disposable mass of solid particulate material (20) located in a heatproof bag to a temperature in the range 50°C to 150°C; placing the bag in disposable container (4) so that the particulate material occupies the lower third to half the volume of the container; placing a meal (16) in thermal contact with the material in the bag; closing the container; and transporting the meal.

15. A method as claimed in claim 14 wherein the particulate material (20) is heated in an oven prior to being placed in the container.

16. A method as claimed in claim 15 wherein the meal (16) is cooked, placed on a disposable plate (14) and then the disposable plate is placed on the bag so as to establish the thermal contact between the meal and the material in the bag.

17. A method as claimed in claim 16 wherein the relative dimensions of the plate (14) and container (4) are selected so that there is substantially no lateral movement of the plate within the container.