INTEGRATED HEATER FOR FOOD PACKAGING

Abstract

The invention relates to a portable package and method for preparing a meal. A warm meal is prepared by taking dehydrated food within a package and combining it with non-boiling water. The mixture is then heated by an electrical, portable power source, such as a battery or vehicle power system. This allows a warm meal to be prepared almost anywhere, even without access to boiling water.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and incorporates by reference in its entirety U.S. Provisional Application No. 60,696,521, filed Jul. 6, 2005, titled “INTEGRATED HEATER FOR FOOD PACKAGING”.

TECHNICAL FIELD

The following relates to an apparatus and method for providing heating within food packaging.

BACKGROUND

For many applications, quick-prepared food kits are necessary for nourishment when traditional cooking supplies are not accessible. As examples, military soldiers, astronauts, and recreational campers often must rely upon food rations that will provide nourishing and filling meals without requiring a significant amount of time, effort, or supplies to prepare for consumption. For some applications, the food kits are known as “MREs”, or “meals ready to eat”.

One type of quick-prepared food kit consists of freeze-dried food within sealed packaging. The freeze-dried food may include meat that already has been cooked before having been dehydrated for long-term storage and portability without refrigeration. To prepare the food, the consumer opens the package and pours approximately 1-2 cups of boiling water inside. The food is hot once again in just a few minutes. The packaging contains the food to enable the consumer to consume the meal directly from the pouch. Typically, the serving size, calories, carbohydrates, sugars, and protein are pre-measured to ensure that a complete meal is included in the package.

While such food kits are portable and can be prepared very quickly with a minimum of tools and other supplies, it is still necessary to have a source of hot or boiling water to pour into the bag and re-hydrate the food. For campers or hikers, the only source of hot water may be from a campfire. Military soldiers and astronauts may need to rely upon other sources for hot water, which may be inconvenient or rarely accessible. In some circumstances, this may significantly impact the usefulness of the product.

Since access to heated water is often limited, one known mechanism for heating MREs is to use a chemical heater pack to provide “self-heating.” Water is added to the packaging and the heater is placed next to the packaging. The heater includes magnesium metal, which when mixed with water, forms magnesium hydroxide, hydrogen, and heat. Typically, the meal is ready to be consumed within approximately 15 minutes.

SUMMARY

BRIEF DESCRIPTION OF THE DRAWINGS

Additional embodiments will be more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

FIG. 1 is an illustration of packaging for a quick-prepared food kit;

FIG. 2 is a perspective view of packaging for a quick-prepared food kit;

FIG. 3 is an illustration of a heater integrated within packaging for a quick-prepared food kit in accordance with an embodiment of the present invention;

FIG. 4 is an illustration of electrode contacts and steam vents integrated within packaging for a quick-prepared food kit in accordance with an embodiment of the present invention;

FIG. 5 is a schematic representation illustrating power source options and other circuitry for integrating a heater within packaging for a quick-prepared food kit in accordance with an embodiment of the present invention;

FIG. 6 is a chart providing power, current, and resistance requirements for a 250 ml quick-prepared food kit package, in accordance with an embodiment of the present invention;

FIG. 7 is a chart providing power, current, and resistance requirements for a 350 ml quick-prepared food kit package, in accordance with an embodiment of the present invention;

FIG. 8 is a chart providing heater calculations for a 12 V DC power supply; and

FIG. 9 is a chart providing heater calculations for a 28 V DC power supply.

DETAILED DESCRIPTION

The following discloses a heater assembly is integrated within packaging of a quick-prepared food kit. Preferably, the heating assembly uses one or more flexible, semiconductive, electrically resistive heating elements powered by a source of electrical power. This embodiment's heater assembly withstands the stresses that can break and disconnect an electrical wire-based heater and efficiently provides quick heating capability with reduced power requirements. The integrated heater is designed to be disposable once the meal within the packaging is consumed.

FIGS. 1 and 2 illustrate exemplary quick-prepared food kits, or “MREs” that may be adapted to incorporate the integrated heating system in accordance with the present invention. The packaging consists of a flexible foil 20 that is designed to keep the food sealed from external elements. The packaging is lightweight, easily portable, compressible, and durable to impact. The exterior laminate(s) may use common materials such as nylon, polyethylene, polypropylene, polyester, or metal film, along with printed layers for branding and instructions. In some embodiments, to unseal the packaging, a tear portion 10 is included to enable consumers to easily tear open the packet without requiring any tools.

FIG. 3 illustrates an integrated heating system that may be used in accordance with an embodiment of the present invention. Although the outside packaging 34 appears as a standard, quick-prepared food kit, the interior of the packaging 32 includes a semiconductive heating element 30, preferably in a serpentine configuration. The inner laminate within the packaging may be made of any of nylon, polyethylene, polypropylene, polyester, metal film, or other common materials in the packaging industry.

The heating element is flexible to bend along with the packaging 34. Metallic contacts 33a and 33b connect to a power source to provide an electrical circuit to turn on the heater and start warming the package once water is added. In some embodiments, water is already added such that all that is needed is heating provided by the heating assembly.

The resistive heating element may include, for example, but is not limited to a graphite or carbon foil, or it may be a felt or fabric encased within the packaging. The heating element is designed for the intended power source, such as a 12 V DC automobile or a 28 V DC military system.

In one example, the metallic contacts 33a and 33b can be connected to a military vehicle, using on-board power device clamps. As another example, the contacts can be connected to a vehicle power adapter, such as through a cigarette lighter. As further examples, the contacts also may be connected to a rechargeable power device or to vehicle battery terminals.

FIG. 4 illustrates an optional protective label cover for the exterior of the packaging, in accordance with a further exemplary embodiment of the invention. Flexible packaging 40 includes a protective label cover 43, which peels back to expose a terminal 42 and a micro-perforated steam vent 44. This protects the vent and terminal during transport and storage while enabling easy access during heating. When the protective label is fully removed from the packaging 45, both terminals 46 and 47 are exposed, along with the vent 48. The micro perforations in the vent allow steam to vent but impede liquid water from exiting, for proper heating in some circumstances.

FIG. 5 illustrates a schematic with several possible power sources and other circuitry that may be associated with the heating system. Particularly, the heater 50 can connect through contacts 51a and 51b to a car adaptor 52a, vehicle battery terminals 52b, an in-vehicle connection 52c, a rechargeable device 52d, or other power sources. The spacing of the contacts 51b and 51a can be determined to easily connect the packaging to battery terminals having the same geometry. A 12 V DC power source is acceptable, although 28 V DC is preferred to minimize heating time. The heater element geometry varies according to the voltage and power requirements, as will be described further below.

As also shown in FIG. 5, the packaging may also optionally include an over-current fuse 54 to prevent damage to the input power source.

Significantly, as an optional embodiment, the heating element can additionally include a thermal fuse 53 designed to create an open circuit when the food and water have received a determined amount of heat energy. This is useful to prevent overcooking or undercooking. A thermal fuse indicator, such as an LED, can be included to inform the consumer that the meal in the food kit has been prepared appropriately.

FIG. 6 is a chart providing power, current and resistance requirements for a 250 ml quick-prepared food kit package, in accordance with an embodiment of the present invention. As can be seen, assuming a package that can contain 250 ml of water, with an initial temperature of 20° C. and a desired final temperature of 95° C., charts are provided that indicate the power, current, and resistance for given times and time, current, and resistance for given power to temperature. Similarly, FIG. 7 is a chart providing power, current, and resistance and time, current, and resistance for an integrated heater used in a 350 ml package. The package can be made in other sizes as well. Various pre-proportioned quantities of food can be packaged with instructions for the appropriate amount of water to add.

FIG. 8 is a chart providing heater calculations for a 12 V DC power supply. Particularly, for a 12 V supply, as power is varied, the current, resistance, and length to width ratio is provided. As the length is varied, the width and area are provided as well.

Lastly, FIG. 9 is a chart providing heater calculations for a 28 V DC power. Similar to FIG. 8, as power is varied, the current, resistance, and length to width ratio is provided. As the length is varied, the width and area are provided as well.

From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

Claims

1. A portable food packaging assembly comprising:

a handheld bag for enclosing a food product;

a heater element in direct contact with the bag; and

first and second electrical terminals in electrical contact with the heater element,

wherein when power is supplied to the terminals the heater element generates heat to warm food within the bag.

2. The food packaging assembly of claim 1, further comprising a tear strip seal portion for opening the assembly to consume the food product.

3. The food packaging assembly of claim 1, wherein the heater element is semiconductive foil.

4. The food packaging assembly of claim 1, wherein the heater element is graphite foil.

5. The food packaging assembly of claim 1, wherein the heater element is semiconductive felt or semiconductive fabric.

6. The food packaging assembly of claim 1, wherein the bag is made from material selected from the group consisting of nylon, polyethylene, polypropylene, polyester, and metal film.

7. The food packaging assembly of claim 1, wherein the bag further comprises a micro-perforated vent.

8. The food packaging assembly of claim 1 further comprising a fuse.

9. The food packaging assembly of claim 8, wherein the fuse further comprises an indicator for indicating when food is appropriately prepared.

10. The food packaging assembly of claim 1, wherein said power is supplied from a source selected from the group consisting of 12 V DC, 28 V DC, one or more batteries, one or more fuel cells, and one or more rechargeable batteries.

11. The food packaging assembly of claim 1, wherein said power is selected from the group consisting of a vehicle accessory jack, an in vehicle connection, direct battery contacts, and a rechargeable device.

12. The food packaging assembly of claim 1, wherein the micro-perforated vent has openings sized such that steam may exit said self-contained food preparation apparatus and said openings sized such that liquid water may not exit said self-contained food preparation apparatus.

13. A portable food preparation apparatus comprising:

a flexible container comprising an interior area and a food holding area;

a flexible heating element positioned within the interior area;

a first electrical contact; and

a second electrical contact,

wherein the flexible heating element is electrically in series with said first electrical contact and said second electrical contact.

14. The portable food preparation apparatus of claim 13, wherein the flexible container includes a seal that can be opened by hand.

15. The portable food preparation apparatus of claim 13, wherein the flexible heating element is a semiconductor.

16. The portable food preparation apparatus of claim 13, wherein the flexible container further comprises a vent having a plurality of openings sized such that steam may pass through the openings but liquid water is impeded from passing therethrough.

17. A food packaging apparatus comprising

a food holding area;

a heater element;

a micro-perforated vent; and

first and second electrical terminals,

wherein the first and second electrical terminals are electrically connected to the heater element, and

wherein when power is supplied to the first and second electrical terminals the heater element generates heat.

18. The food packaging apparatus of claim 17, wherein the micro-perforated vent has a plurality of openings sized such that steam may pass through the opening but liquid water is impeded from passing therethrough.

19. The food packaging apparatus of claim 17, wherein the heater element is a semiconductor.

20. The food packaging apparatus of claim 17, wherein the heater element is graphite foil.

21. The food packaging apparatus of claim 17 further comprising a removable protective cover that covers the micro-perforated vent and the first and second electrical terminals.