Abstract:
A food transportation container which will maintain food in a fresh, hot and undeteriorated condition during delivery of the food from its point of origin to its destination, while being disposable, lightweight, thin, and easy to use and store. The container will not impart undesirable taste to its contents.

Description:
BACKGROUND  
         [0001]    It is customary for pizzas to be prepared for take-out by customers, or for delivery to the houses of persons who place orders for pizzas by telephone. One format for packaging pizzas in such circumstances is to place the pizza in a single-walled, paper-board box that folds up from a flat paperboard blank. Such boxes customarily enclose the pizza with a lid. The conventional means of packaging Chinese food, bakery products, or the like, other than pizza, for take out or for home delivery are also a cardboard box of square or rectangular shape.  
           [0002]    Boxes of this type provide only a moderate degree of heat retention for the pizza during delivery. If the boxes are unvented, an extended delivery period can result in a pizza/food that is both cool and soggy.  
           [0003]    The standard cardboard pizza box also has a number of drawbacks. For one thing, cardboard containers have a low insulation coefficient. Furthermore, during transportation, the pizza crust loses the rigid, crispy texture it had only 30 minutes earlier. The explanation for this is simple. As the steamy hot pizza is removed from the oven and placed in the box, it continues to give off moisture and heat until it has cooled. The standard cardboard box, though not perfectly airtight, retains substantially all of the moisture given off by the pizza. In essence, the pizza sits in a steam sauna during delivery. The final result is that the driest portion of the pizza (the crust) absorbs moisture and becomes limp.  
           [0004]    Pizza/food loses heat by radiation, conduction, convection and current pizza boxes provide essentially no barrier to radiated heat loss and convection (hot air) loss.  
           [0005]    Companies which provide home food delivery services are constantly seeking ways to improve the service, food quality and taste due to the competitive nature of the business. Insulated food and pizza delivery bags have been used for many years whereby warmed foods will retain a certain temperature level during delivery, depending on the transportation time and delivery route length, primarily by blocking conduction of heat through the use of a bulky thick insulating barrier.  
           [0006]    Yet, despite the proliferation of so-called “delivery” and “take out” items and services, mechanisms for effectively transporting the prepared food from one location to another have changed little over the past several decades. Referring to a familiar example, this lack of innovation in the food transportation industry is readily apparent.  
           [0007]    No item of food is delivered to more American homes in greater quantities than the pizza. As the business of pushing pizzas exceeds the 32 billion dollar mark annually in the United States alone, multitudes of both multi-national and local establishments vie for their “slice” of the action.  
           [0008]    At it&#39;s very best, though, a pizza delivered to your door pales in comparison to the same pizza served at a pizzeria. Apart from the ambiance of the red-checkered tablecloth and the spectacle of dough-tossing, pizzeria pizza is far superior because it has not suffered delivery deterioration. (e.g. cold and soggy)  
           [0009]    The industry standard delivery time, pizza-to-door, is 30 minutes. The journey begins when the fresh, crisp-crusted, bubbling-cheese delicacy is removed from the oven and placed flat in the bottom of a box. Typically, the box is of the square, brown cardboard variety and may have a circular piece of reinforcing cardboard under the pizza to bolster its bottom. Then, the pizza is cut with a circular or “wheel” cutter. The box is closed, stacked on other pizza boxes and, when delivered by pizzeria personnel, is sometimes placed in a reusable cumbersome insulating bag. The delivery driver tosses the bag into a delivery vehicle and makes the appointed rounds. It is during this journey that delivery deterioration occurs. The deterioration may be worse when a customer self transports the pizza, since the customer will not have the benefit of an insulating bag which is bulky, unyielding, and not easily stored when not in use.  
           [0010]    While previous devices are advantageous under certain circumstances, the need for a simple, inexpensive delivery/ transportation container for retaining a certain temperature level during delivery remains. From the foregoing it is apparent that a food packaging system is required that is low in cost yet ensures that food, after the time delay required for delivery, are still warm (or cold), without having become substantially soggy. Accordingly, there is a need for a food transportation container which will maintain the food in a freshly-cooked state (or a refrigerated state) during delivery of the food from its point of origin to its destination, or simply over an elapsed time period that will effectively maintain heat, that is lightweight, and can be effectively used by restaurants and consumers alike.  
         SUMMARY  
         [0011]    A lightweight, disposable, and sealable food transportation container having a radiant barrier and a convection barrier, comprising a reflective material and an airtight material for slowing the heat transfer of an object placed within the container by minimizing heat lost by radiation and convection.  
           [0012]    A system for maintaining the heat of a take-out food item, the system includes a disposable and sealable food transportation container having a radiant barrier and a convection barrier, the container includes a reflective material and an airtight material for slowing the heat transfer of an object placed within the container by minimizing heat lost by radiation and convection.  
           [0013]    A system for maintaining the heat of a take-out food item, the system includes a disposable and sealable food transportation container having an integral radiant barrier and a convection barrier, the container includes a reflective material and an airtight material for slowing the heat transfer of an object placed within the container by minimizing heat lost by radiation and convection.  
           [0014]    A system for maintaining the heat of a take-out food item, the system includes a disposable and sealable food transportation container and an enclosure for surrounding the food item, the disposable container having a radiant barrier and a convection barrier, the container includes a reflective material and an airtight material for slowing the heat transfer of an object placed within the container by minimizing heat lost by radiation and convection.  
           [0015]    In addition, the material used for the container should also be flexible, thin, and light so that it can be easily folded up when desired. Lastly, it is preferred that the material be inexpensive so that it is disposable.  
           [0016]    A lightweight disposable container for blocking convection and radiation losses of an item placed within the container.  
           [0017]    The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a perspective view of an exemplary embodiment of a food container having its lid in the open position to reveal the heated food product;  
         [0019]    [0019]FIG. 2 is a perspective view of the food container seen in FIG. 3 having its lid closed and joined to the body portion of the food container;  
         [0020]    [0020]FIG. 3 is top plan view of a food container before assembly showing phantom fold lines;  
         [0021]    FIGS.  4 - 7  illustrate an alternative embodiment of the present invention;  
         [0022]    [0022]FIG. 8 illustrates another alternative embodiment of the present invention;  
         [0023]    [0023]FIGS. 9 and 10 illustrate yet another alternative embodiment of the present invention; and  
         [0024]    [0024]FIG. 11 is a cross-sectional view of an alternative embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0025]    This disclosure relates to packages, and is more particularly directed to packages for take out and/or delivery of pizzas, Chinese food, fast food hamburgers, dessert pies, and the like. The disclosure is more particularly concerned with a thermally insulated disposable container for pizzas or other food items to be served hot (or cold), the container being configured with a radiant barrier, and a convection barrier.  
         [0026]    Referring to FIGS. 1 and 2, food container  20  includes a rectangular body portion  24  provided with a hinged lid  28 , both of which are made of cardboard. The body portion  24  of the food container  20  includes a rectangular base section  30  integrally formed with upstanding front and rear walls  32  and  34 , respectively, and a pair of laterally spaced upstanding side walls  38  and  40 . The lid  28  has a rectangular top section  42  integrally formed with a pair downward depending laterally spaced side walls  44  and  46  and a front wall  48 . A centrally located tab  50  is optionally cut out of the front wall  48  and is used to facilitate opening and closing of the lid  28 . In addition, the lid  28  is hingedly connected to the rear wall  34  of the body portion  24  of the food container  20  at a score line  52  extending the length of the rear wall  34 . Accordingly, the lid  28  is adapted to be folded downwardly about the score line  52  to a closed position wherein the side walls  44  and  46  and the front wall  48  of the lid  28  are located, as seen in FIG. 2, within the confines of the body portion  24  adjacent the side walls  38  and  40  and front wall  32 . Food containers of this type are typically used for accommodating a heated pizza  54  as shown in FIG. 1. Once the lid  28  is closed, the hot pizza  54  is located in a closed rectangular chamber  56 , the inner air of which becomes heated due to the heat loss of the pizza  54 . The insulating properties of the cardboard, although limited to some extent, serve to prevent the heat in the chamber  56  from being rapidly dissipated. Various pizza companies as well as various “Mom and Pop” stores utilize food containers of the above-described type for holding a heated pizza.  
         [0027]    In an exemplary embodiment, a radiant barrier  60  is attached to at least an inside or outside portion  62  of rectangular top section  42  for reflecting heat in chamber  56  back towards the pizza  54 , thus helping to retain the temperature level of the pizza and reduce dissipation of the heat from the rectangular top section  42  of food container  20 .  
         [0028]    Radiant barrier  60  provides a thin, integrated reflection/insulator that is integrated into the box. In one embodiment, barrier  60  is Aluminum.  
         [0029]    Radiant barrier  60  works by reducing the heat transfer by thermal radiation across the air space in chamber  56  between the top of pizza  54  and the inside portion  62  of rectangular top section  42 . Radiant barrier  60  has a reflective surface that faces the open air in chamber  56  and the top of pizza  54 .  
         [0030]    Heat travels from a warm area to a cool area by a combination of conduction, convection, and radiation. Heat flows by conduction from a hotter material to a colder material when the two materials touch. Heat transfer by convection occurs when a liquid or gas is heated, becomes less dense, and rises. Radiant heat travels in a straight line away from the hot surface and heats anything solid as the wave of energy hits the solid. Since most of the heat transfer from pizza  54  is emitted from the top where the sauce and cheese are not insulated by the crust, an exemplary embodiment comprises radiant barrier  60  depending from at least an inside portion  62  of rectangular top section  42  that is directly above pizza  54 .  
         [0031]    Conventional insulation traps still air within the insulation, and hence also reduces the heat transfer by air movement (convection). The insulation fibers or particles also block radiation heat transfer through the space occupied by the insulation; however, having insulation on top of a pizza is undesirable for obvious reasons.  
         [0032]    Radiant barrier  60  comprises a thin sheet or coating of a highly reflective material applied to a substrate (i.e., the cardboard that makes up rectangular top section  42  in FIG. 1.  
         [0033]    In an exemplary embodiment, radiant barrier  60  is a metallized polymer applied to a portion of the inner or outer surface of container  20 . In an alternative embodiment, radiant barrier is applied to substantially the entire inside or outside portion  62  of food container  20 .  
         [0034]    In yet another alternative radiant barrier is integrated into the box or the box is formed from a metalized cardboard. In this embodiment the metalized cardboard is preferably {fraction (24/1000)} of an inch. Of course, and as applications may require the metalized cardboard can be greater or less than {fraction (24/1000)} of an inch.  
         [0035]    In practicing the present disclosure and using the pizza  54  as an example of a food product, the pizza  54  is initially baked and removed from the oven and placed on a cutting board. While on the cutting board, the pizza  54  is at a temperature of approximately 200 degrees Fahrenheit. The pizza  54  is then pre-cut into pie-shaped pieces and immediately placed within the food container  20  as seen in FIG. 1 after which the lid  28  is closed. Once the lid  28  is closed, some of the heat from the hot pizza will be transferred to the air within the chamber  56  and as well as to the food container  20  in its entirety by a combination of convection and conduction. Most of the heat from the pizza  54  radiates from the top of a pizza in a straight line away from the hot sauce surface because the sauce topping has a higher emissivity than the surrounding crust and therefore a greater emitted radiation. The emitted radiation contacts the radiant barrier  60  lining the lid  42  and radiates the heat back towards the pizza topping, thus aiding in heat retention.  
         [0036]    Referring now to FIG. 3, an alternative embodiment of a food container  20  is shown before assembly into a box structure. In an exemplary embodiment, the radiant barrier  60  is applied to substantially the entire inside or outside portion of food container  20 . The above-described embodiments are also suitable for packaging hamburgers, hot grinders, and the like when the food container is configured to contain such foods.  
         [0037]    Turning now to FIGS.  4 - 7 , another exemplary embodiment of a food container  100  is shown. FIG. 4 depicts a disassembled food container  100  having a radiant barrier sheet  102  comprising of a thin rectangular sheet of metalized oriented polyethylene. In an exemplary embodiment, the metalized oriented polyethylene has a thickness of about 0.00125 inches or 1.5 mm. Of course, is contemplated that the thickness of sheet  102  may be greater than or smaller than 0.00125 inches. Sheet  102  has the metalized layer on one side of sheet  102  while the other side is the polymer material from which sheet  102  is formed.  
         [0038]    As an alternative, sheet  102  is a metalized polyethylene of approximately 1.25 mm or 0.00125. Of course, this thickness may also vary. As yet another alternative, sheet  102  is polypropylene or polyethylene material with sufficient optical densities to act as potent reflective and convection barriers.  
         [0039]    Container  100  provides a light-weight disposable container that has sufficient optical and reflective densities that will retain the heat and/or cold qualities of a food product inserted therein.  
         [0040]    In one embodiment, container  100  is constructed out a thin polymer material that has an integral convection and reflective barrier (e.g. metalized oriented polyethylene). The thin and light-weight material of container  100  makes it ideal for use as a disposable food container. As will be discussed herein, container provides an air-tight enclosure with optimum heat retention characteristics and is convenient for disposable usage. In addition, and when the container is no longer needed the user simply tears the container to open it as it is constructed out of a thin material.  
         [0041]    Moreover, and since the container is used for food products it is desirable to have it be disposable.  
         [0042]    It is noted that in one embodiment radiant barrier  102  is provided with a non-metalized periphery  104  to aid in the assembly of container  100 . Alternatively, the entire sheet  102  can have a metalized layer or coating. During assembly sheet  102  is folded about line  106  and the non-metalized periphery is sealed at sides  108  and  110  to define the enclosure illustrated in FIG. 5.  
         [0043]    [0043]FIG. 5 shows a completed food container  100  that has seams  112  and  114  sealed and an opening  116  to provide a bag or envelope to place food in for delivery. Seams  112  and  114  are formed by the melting of the non-metalized portions of the polymer sheet or alternatively by an adhesive attachment of the same.  
         [0044]    A flap portion  118 , as in an envelope, for closing the food container is formed by folding sheet  102  at an asymmetrical folding line such as line  106  in FIG. 4. Thus, one half of folded sheet  102  is longer than the other half.  
         [0045]    More specifically, flap portion  118  is a length that one half of sheet  102  that exceeds the other half when sheet  102  is folded about line  120 . Flap portion  118  further includes an adhesive strip  122  with a peel off covering (e.g., peel off type used on envelopes) for adhering flap portion  118  to a portion of container  100  after an item has been inserted into container  100 . Flap portion  118  is sufficiently long enough to provide enough material to seal container  100  after an item such as a pizza box has been inserted inside.  
         [0046]    Due to its light-weight configuration container  100 , through the use of flap portion  118  and its complimentary adhesive strip allows the sealed configuration of container  100  to be varied. For example, and in the case when a small item is placed in container  100  (e.g. a single slice of pizza) the user simply folds container  100  until the enclosed item is snugly encased and then the covering of the adhesive strip is removed and the container is sealed.  
         [0047]    [0047]FIGS. 6 and 7 illustrate container  100  in an assembled state and being configured to accommodate a box carton in opening  116 . In exemplary embodiment, container  100  has the following dimensions (24″×24″) in order to accommodate a standard size pizza box. Of course, the dimensions of container  100  may vary to accommodate objects of varying sizes.  
         [0048]    Opening  116  is configured for easy placement of a complementary configured box (e.g., a pizza box) within food container  100 . Due to the flexible nature of sheet  102 , container  100  is easily folded and provides a flat configuration for storage. Thus, numerous containers can be easily stored for use in restaurant applications.  
         [0049]    Current “pizza bags”, (e.g., delivery bags) are primarily insulators and by necessity, they must be thick and cumbersome. In accordance with an exemplary embodiment of the present invention and by blocking convection and radiation losses the materials for the bags or container  100  can be constructed out of much thinner, lighter, and less costly materials which are disposable.  
         [0050]    In a quantitative test utilizing a pizza bag (i.g., food container  100 ) constructed in accordance with an exemplary embodiment of the present invention, one boxed pizza using a standard pizza box was placed within the sealed container  100  and another boxed pizza was left standing alone, both in a room at room temperature, after  17  minutes elapsed, the temperature of the pizza placed in the pizza bag was 142.5° Fahrenheit and the unbagged pizza was 123.4° Fahrenheit. Container  100  provided a pizza that was 15.5% hotter. In addition, four blinded subjects accurately picked the bagged pizza as hotter compared to the un-bagged pizza.  
         [0051]    In addition, while the pizza is placed within container  100  moisture from the steaming pizza as well as moisture from the standard cardboard box is condensated onto the outside of the box. This important feature allows the moisture to vent out of the inside of pizza box  150  and harmlessly condensate on the exterior surface of the pizza box preventing the pizza from becoming soggy.  
         [0052]    For example, and referring now to FIGS. 6 and 7, a conventional pizza box  150 , with the pizza  54  in place, is inserted into container  100 . The container  100  is configured and dimensioned so as to contain a complementary sized pizza box  150  as well as expand (FIG. 6) due to heat from pizza  54 . After insertion of pizza box  150  into container  100 , pizza box  150  is then sealed within container  100  through the use of flap  118  and adhesive  122 .  
         [0053]    In this configuration, openings  154  provide a ventilation outlet or outlets to permit escape of moisture that dissipates from the heated pizza  54 , thus diminishing the tendency of such pizzas to become soggy, while providing a radiant barrier to reflect heat energy back towards the pizza  54 . In such a configuration, the heat retention by the pizza is enhanced while the amount of moisture dissipated onto the pizza is limited. Accordingly, the likelihood of a soggy pizza due to moisture is reduced and/or negated, whilst simultaneously maintaining the heat of the pizza/food.  
         [0054]    Accordingly, and through the use of container  100 , the heated air travels from the internal cavity of pizza box  150  travels through vent openings  154  and is entrained within the cavity defined by container  100 . In addition, and through this airflow moisture from pizza  54  as well as the moisture of the cardboard material comprising box  150  is harmlessly vented out of pizza box  150  and ultimately condensated on the exterior surface of the same.  
         [0055]    In yet another alternative, container  100  is used in combination with the embodiment of FIGS.  1 - 3  further enhancing the heat retention qualities of the present invention.  
         [0056]    Further combinations are also contemplated including but not limited to pizza box  150  being constructed with radiant barrier  60  on either the inside or outside portion of the pizza box. In addition, it is also contemplated that radiant barrier  60  may be positioned on both the inner and outer portions of the pizza box which is then inserted within container  100 , effectively maximizing heat retention utilizing a bag and box system.  
         [0057]    In addition, a pizza box construction in accordance the embodiments of FIGS.  1 - 3  is contemplated for use with container  100 .  
         [0058]    Referring now to FIG. 8, yet another alternative embodiment is illustrated, here sheet  102  is provided with a thin layer of insulative material  130  configured and dimensioned to be about half the size of sheet  102 . Insulative material  130  is disposed on a first half  132  of radiant sheet  102 .  
         [0059]    The other half of sheet  102  is folded over insulative material  130  at fold  132  and the two sides are sealed essentially providing a three-ply sheet material. This three-ply sheet material is then folded as illustrated in FIG. 4 to provide container  100 .  
         [0060]    Alternatively, and referring now to FIGS.  4 - 8  and  11 , sheet  102  is folded over itself once and then again and the two sides are sealed essentially providing a three-ply sheet material  140 , comprising a metal reflective layer  142  as a radiant barrier facing the food, a middle convection barrier  144  an insulating layer, and an outer metal reflective layer  146  facing the outside environment that can be water resistant to protect the food from outside elements (e.g., rain) and contain the food in the food container in the event of a the food spill. For example, and when sheet  102  is folded over itself layers  142  and  146  are provided by the metalized polymer of sheet  102  and insulative layer  144  is provided by the air entrained between sheet  102  as it is folder over on itself.  
         [0061]    Thus, and referring now to FIG. 11 a Trilaminar design including an inner reflective, a middle layer or convection barrier and an outer layer (reflective) provide the material for container  100 .  
         [0062]    In yet another alternative, the surface of sheet  102  comprising layer  146  is configured to have a higher concentration of metalized polymer.  
         [0063]    In addition, the material used for the container should also be flexible, thin, and light so that it can be easily folded up when desired. Lastly, it is preferred that the material be inexpensive so that it is disposable.  
         [0064]    Additionally, the material for container is also contemplated to be capable of having indicia printed thereon. The indicia may included advertising materials or trademarks, etc.  
         [0065]    Referring now to FIG. 9, an alternative embodiment  300  of container  100  is shown with a drawstring closure  304  that considerably reduces the rate of heat loss from a packaged pizza, Chinese takeout, or the like, stored therein by (reducing the size of the opening from which the heat energy of the packaged food can escape to a lower-temperature outside environment) mechanisms previously described (radiating heat and blocking convection currents).  
         [0066]    [0066]FIG. 10 illustrates another alternative embodiment of a food container shown generally at  400  for considerably reducing the heat energy absorbed by a cold food stored therein by reducing the amount of heat energy from a higher-temperature outside environment from reaching the cold food stored within bag  400  (i.e., cold soda can). One embodiment of bag  400  is bag  300  turned inside out, wherein the reflective layer is facing the higher-temperature outside environment providing a radiant barrier for the higher-temperature heat energy and thereby reducing the emissivity of bag  400  to emit the heat energy to the cold food stored therein. In quantitative tests with bag  400 , two cold soda beverage cans were taken from a refrigerator at 45° Fahrenheit. One soda can was placed in bag  400  and closed via drawstring  404 , the other soda can was left alone in the same room at room temperature. After 45 minutes elapsed, the bagged soda can was at a 48° Fahrenheit and the unbagged soda can was at a temperature of 51.6° Fahrenheit. It will be appreciated that in a warmer outside climate, the differential is significantly larger.  
         [0067]    Current “pizza bags”, (e.g., delivery bags) are primarily insulators and by necessity, they must be thick and cumbersome. In accordance with an exemplary embodiment of the present invention and by blocking convection and radiation losses the materials for the bags or container  100  can be constructed out of much thinner, lighter, and less costly materials which are disposable.  
         [0068]    As a result of the present disclosure, an economical and disposable heat maintaining food delivery container is provided. Through its combination of components, embodiments described herein meet both the customer&#39;s desire to receive delivered pizzas/food which are still highly palatable, in terms of warmth and crispness, and the pizza supplier&#39;s desire to minimize packaging costs. On the basis of the foregoing it will be seen that this disclosure has been described which will allow pizza to be delivered to consumers in a low cost format, while providing for the preservation of the quality of the product up to the time of delivery. Likewise, an economical and disposable bag is provided for keeping food cold longer.  
         [0069]    While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.