Patent Publication Number: US-7709035-B2

Title: Self-heating, self-hydrating pouch to simultaneously hydrate and heat completely or partially dehydrated food or beverage products in said pouch

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for Governmental purposes without payment of any royalties thereon or therefore. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is generally relates to self-heating, self-hydrating pouch that simultaneously hydrates and heats a partially or completely dehydrated food and beverage product in the pouch. 
     2. Description of the Related Art 
     Self-heating pouches or packages for the storage of foods and beverages are known in the art. Typically, such pouches are used by military personnel but are also used in recreational settings, e.g. mountain climbing, hiking, etc. One prior art method of heating prepackaged, shelf-stable foods is known as the Flameless Ration Heater. This technique is typically used by military personnel and is configured to heat prepackaged foods that are already hydrated. However, this method is inadequate for heating dehydrated food and beverage products. Another prior art product is known as the Trioxane Fuel Bar. This product has several disadvantages, namely, it emits a thermal signature, is time consuming, and requires the use of a metal cup that must be cleaned after each use. In a military situation, these disadvantages inhibit mobility on the battlefield. 
     Other prior art self-heating pouches use internal membrane filters that require a significant amount of time, e.g. several hours, to filter the water. Furthermore, even after the water was purified, the user would still have to heat food items and beverages, such as coffee and tea, for an additional 10-15 minutes. 
     A search of the prior art reveals several different types of self-heating pouches or packages configured for the storage of food and beverage products. U.S. Pat. No. 4,762,113 discloses a self-heating container having an inner container for holding a foodstuff. A primary water bag and an envelope containing an exothermic reaction agent are used to generate heat, and a secondary water bag provides continued hydration. U.S. Pat. No. 4,895,135 discloses a self-heating container that generates heat by hydration of an exothermic reaction agent. The container includes an outer shell, an envelope enclosing the exothermic reaction agent, a water bag filled with water for reaction with the agent, and a container body for containing a foodstuff. U.S. Pat. No. 5,117,809 discloses a flameless heater product for ready-to-heat meals. This invention comprises a heater pad that is adapted to be placed in a bag and contacted by water for heating food. A water-activated, exothermic heater material generates the heat. U.S. Pat. No. 5,220,909 discloses a self-heating individual meal module that comprises a tray having a top surface with a food receptacle tub formed therein for holding food to be heated by the module. The food is heated by an exothermic chemical heater pad. U.S. Pat. No. 5,465,707 discloses a self-heating individual meal package that comprises an outer pouch, a foodstuff pouch enclosed within much of the outer pouch, an exothermic pack located between the outer pouch and food stuff pouch and a solvent bag affixed to a trigger device (e.g. pull tab). U.S. Pat. No. 5,517,981 discloses a water-activated chemical heater with suppressed hydrogen. The chemical heater uses a chemical combination that generates heat for heating small portions of matter (e.g. consumable rations) without the simultaneous production of dihydrogen gas. U.S. Pat. No. 5,611,329 discloses a flameless heater that uses two non-woven polyester sheets that are thermally bonded together to form a number of components. Each pocket is filled with a powder mixture of a Mg—Fe alloy, NaCl, antifoaming agents, and inert fillers. U.S. Pat. No. 6,248,257 discloses a portable heat source for warming food or beverages. A solid heat-producing composition is activated by the addition of water or an aqueous solution. The heat producing composition contains an acidic anhydride, an acidic salt, a basic anhydride or a basic salt. U.S. Pat. No. 6,289,889 discloses a self-heating flexible package that generates heat by contact of a heat-producing composition, such as calcium oxide, and an activating solution. The heater has several compartments containing a heat-producing composition and activating solution. The heater is activated by application of hand pressure to rupture a frangible seal that allows the heater components to mix. U.S. Pat. No. 6,341,602 discloses a heater pouch that provides flameless caloric heat to a food product inside a product container. The pouch has a flexible cover having a gas-permeable portion and a liquid permeable portion. The cover forms a closed cavity. Tablets of exothermic material are located in the cavity. U.S. Pat. No. 6,644,383 discloses a self-heating, self-coding package that comprises a flexible temperature changing package that can heat or cool food in the package. The package includes a temperature changing element adjacent to the food item and an offset activation point that prevents damage to the food. 
     What is needed is a new and improved self-heating pouch that is also self-hydrating and which can quickly heat and hydrate partially or completely dehydrated food or beverage products. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a self-heating, self-hydrating pouch that can quickly heat and hydrate partially or completely dehydrated prepackaged foods and beverages stored therein. 
     It is another object of the present invention that the pouch is non-toxic and safe to use. 
     It is a further object of the present invention that the self-heating, self-hydrating pouch is easy to use. 
     It is yet another object of the present invention that the self-heating, self-hydrating pouch is reliable. 
     It is yet a further object of the present invention that the self-heating, self-hydrating pouch is lightweight. 
     Other objects and advantages of the present invention will be apparent from the ensuing description and the accompanying drawings. 
     Thus, in one aspect, the present invention is directed to a self-heating, self-hydrating pouch that is configured to quickly heat and hydrate shelf-stable, dehydrated, compressed and intermediate moisture food and beverage products that are prepackaged in the pouch. In a preferred embodiment, the pouch is fabricated from laminate materials that prevent the transmission of water, and gasses thereby preventing deterioration of the prepackaged food in the pouch. The interior of the pouch includes a membrane filter and flameless, ration-heating ingredients. In accordance with the invention, the user may add potable or non-potable water to the pouch. When the water contacts the flameless, ration-heating ingredients, an exothermic reaction occurs and heats the water above 200° F. The membrane filter filters the heated water so as to remove bacteria, pathogens and chemicals. The filtered, heated water contacts the dehydrated or intermediate-moisture foods or beverages and simultaneously heats and hydrates the food or beverage product. This simultaneous heating and hydration process provides a hot, fully reconstituted, high quality food or beverage product. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing features of the present invention will become more readily apparent and may be understood by referring to the following detailed description of an illustrative embodiment of the present invention, taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  is a front elevational view of the self-heating, self-hydrating pouch of the present invention; 
         FIG. 2  is a cross-sectional view taken along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is cross-sectional view taken along line  3 - 3  of  FIG. 1 ; and 
         FIG. 4  is a-cross-sectional view taken along line  4 - 4  of  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , there is shown self-heating, self-hydrating pouch  10  of the present invention. Pouch  10  is configured to safely and quickly heat and hydrate shelf-stable, dehydrated, compressed and intermediate moisture food and beverage products that are prepackaged in the interior of pouch  10 . Pouch  10  comprises water-receiving section  12  that has an interior  13  for receiving potable or non-potable water. Pouch  10  further includes water-heating section  14 , water-filtering section  16  and product storage section  18 . Product storage section  18  has an interior  19  for storing therein a dehydrated or semi-dry food or beverage product  30 . 
     Referring to  FIGS. 1-4 , in a preferred embodiment, pouch  10  is fabricated from laminate materials that prevent the transmission of water and gasses thereby preventing deterioration of food or beverage product  30 . In a preferred embodiment, pouch  10  comprises exterior layer  20  and inner layer  22 . In a preferred embodiment, exterior layer  20  is made from polyester and inner layer  22  is made from aluminum foil. Pouch  10  also includes food contact/sealant layer  24  that is within product storage section  18  and joined to the portion of inner layer  22  that is within product storage section  18 . In a preferred embodiment, food contact/sealant layer  24  is an ionomer or polyethylene film. Water-receiving section  12  includes re-sealable opening device  28  that allows a user to open water-receiving section  12  and add water to interior  13 , and then close the opening to water-receiving section  12 . In one embodiment, re-sealable opening device  28  is configured as a zip-loc that is known in the art and is commonly used on commercially available food storage bags. Thus, the user manipulates re-sealable opening device  28  to create access to interior  13  of water-receiving section  12  in order to pour water into interior  13 . Once water is added, the user then uses re-sealable opening device  28  to close access to interior  13 . Potable or non-potable water can be poured into interior  13 . Preferably, the water poured into interior  13  is cold or cool. 
     Referring to  FIGS. 1 and 4 , food or beverage product  30  (shown in phantom) is contained within product storage section  18 . Product  30  can be a food or beverage product that is in a fully or partially dehydrated state. If the product is a beverage product, the beverage product is in the form of a dry, powder. Tear-notches  32  enable a user to have access to food or beverage product  30  after it has been heated and hydrated. The use of tear-notches  32  is further explained in detail in the ensuing description. 
     Referring to  FIG. 1 , water-heating section  14  contains exothermic reaction agent  22 . A flameless, exothermic reaction is produced when the water contacts exothermic reaction agent  22 . In accordance with the invention, exothermic reaction agent  22  is comprised of reaction agents that provide an exothermic reaction that heats the water above 200° F. In a preferred embodiment, exothermic reaction agent  22  is in solid form, such as granules, pellets and/or powder, and comprises magnesium, a food grade iron powder and sodium. When water contacts the magnesium, magnesium hydroxide is produced thereby causing an exothermic oxidation-reduction reaction. The food-grade iron powder and sodium catalyze the exothermic reaction. In one embodiment, exothermic reaction agent  22  consists only of magnesium, the food-grade iron powder and sodium. Other exothermic reaction agents are possible. 
     Referring to  FIGS. 1-3 , water-filtering section  16  is in liquid communication with interior  13  of water-receiving section  12  and with water-heating section  14 . Water-filtering section  16  comprises membrane filter structure  26  that filters the water heated by water-heating section  14 . Membrane filter structure  26  has side edges  26 A and  26 B, front edge  26 C and rear edge  26 D. Each edge  26 A,  26 B,  26 C and  26 D comprises a sealant layer that is sealed to inner layer  22  so as to hold membrane filter structure  26  in place. In a preferred embodiment, the sealant layer is polyethylene. Membrane filter structure  26  comprises multiple membranes  27  that permit heated water to flow therethrough but restrict solutes such as exothermic reaction agents, exothermic reaction by-products, bacteria, viruses, pyrogens and ions. Thus, membrane filter structure  26  allows potable or non-potable water to be added into interior of water-receiving section  12 . Filtered, heated water then passes through membrane filter structure  26  and into product storage section  18  where it contacts dehydrated or intermediate-moisture food or beverage product  30 , and simultaneously heats and hydrates the food or beverage product  30 . The simultaneous heating and hydration of food or beverage product  30  provides a hot, fully reconstituted, high quality food or beverage product. Once the filtered, heated water passes through membrane filter structure  26 , membrane filter structure  26  blocks the heated, filtered water from flowing back into water-receiving section  12 . 
     In order to use the pouch  10 , the user opens water-receiving section  12  with re-sealable opening device  28  and pours either potable or non-potable water into interior  13 . The water enters water-heating section  14  and contacts exothermic reaction agents  22 . This results in an exothermic reaction that heats the water to at least 200° F. The heated water passes through filtering section  16  and is filtered by membrane filter structure  26 . The filtered, heated water passes into product storage compartment  18  where it simultaneously heats and hydrates food or beverage product  30 . The user waits for a predetermined amount of time that allows for completion of the exothermic reaction and the heating and hydration of food or beverage product  30 . This predetermined amount of time varies depending upon the food or beverage product. The particular features of pouch  10 , as described in the foregoing description, result in a waiting time between about 15 and 30 minutes. After this time period has elapsed, the user then holds pouch  10  upside down and tears open product storage section  18  with tear notches  32 . The user may then consume the completely heated and hydrated food or beverage product. 
     The particular structure and configuration of membrane filter structure  26  allows the use of potable and non-potable water to hydrate and heat the food or beverage product  30 . Thus, non-potable water containing pathogenic bacteria and foreign particles can be used with pouch  10 . The relatively high temperature, i.e. above 200° F., achieved by water-heating section  14  decreases the hydration rate and increases the filtration rate thereby providing a preparation time between 15-30 minutes. The result is a high quality, hot food or beverage product in one step. 
     The self-heating, self-hydrating pouch of the present invention can be used by a variety of users in different scenarios, e.g. military personnel, first responders, hikers, campers, mountain climbers and boaters. The present invention is also suitable for use by civilians during natural disasters. Pouch  10  is relatively light in weight can be easily carried and/or stored, and can be manufactured at reasonable costs. 
     In military situations, the present invention provides military personnel with the advantage of being able to heat and hydrate prepackaged food and beverage products while on the move by simply adding potable or non-potable water to water-receiving section  12 . The present invention provides a high quality, hot food or beverage product in significantly less time than prior art systems. The present invention substantially lessens the logistical burden of carrying large amounts of clean water on missions. Furthermore, pouch  10 , and the use thereof, does not generate any significant thermal signature. 
     The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description only. It is neither intended to be exhaustive nor to limit the invention to the precise form disclosed; and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.