Abstract:
An improved method and apparatus for packaging perishable goods comprises an inner insulating container that is quickly and easily formed from a flat sheet of metalized bubble pack material to a finished state that very closely approximates the size and dimensions of the carton. The constructed inner container can be quickly collapsed and reconstructed to improve the stackability and diminish the amount of space required to store the containers prior to use.

Description:
[0001]     This application is a Continuation-in-Part (CIP) of Ser. No. 09/074,670, filed on May 8, 1998, the disclosure of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to thermally insulating packaging. More particularly, the present invention relates to an improved method and apparatus for a packaging system with improved insulating, storage and cost effectiveness characteristics for transporting perishables and the like.  
         [0003]     Over the last few years, the demand for edible perishables has dramatically increased. The well publicized health benefits of fresh edibles has fueled even greater growth in the demand for such products. Due to the nature of these fresh food products and the desire for off-season supply among consumers, it is frequently necessary to ship such products from remote locations to virtually every corner of the world.  
         [0004]     The shipment or transport of perishable goods frequently requires that such materials remain at a stable temperature, which is either elevated or decreased with respect to ambient temperatures to which the packaging is exposed. Because of long transport times for perishable items and the sensitivity of certain of these items due to slight temperature fluctuations, considerable efforts have been made to provide shipping containers with improved insulating characteristics. Despite the at times satisfactory results of these prior art devices, they have likewise presented a number of drawbacks.  
         [0005]     By far the most common material utilized in corrugated containers as an insulating packaging material has been expanded polystyrene (EPS) foam, which is commonly referred to as “styrofoam®“. Although EPS has proven to possess acceptable insulating characteristics as a liner inside a corrugated box, for the shipment of perishable goods, use of this material has also required a number of compromises. To begin with, most packaging systems that use EPS liners have required a relatively thick liner of approximately 1 inch. Due to the thickness and density of the EPS materials they add weight to the packaging and increase freight costs while their cushioning effect in the overall packaging system is limited. The EPS liner therefore consumes a significant amount of space that could otherwise be utilized to ship a greater quantity of product.  
         [0006]     Leakage from such a container is highly undesirable and can lead to degradation of the container material, weakening of its structural integrity and damage to the transporting aircraft or surface vehicle. Therefore, it is necessary that the EPS liner be formed in such a manner that the chances of such leakage occurring would be minimized. The joining of flat panels of polystyrene by gluing or other means has proven to be relatively ineffective and subject to separation upon jarring of the container. Molding of the EPS to a single piece liner again introduces additional cost, is not very flexible in terms of varying the size or thickness of the EPS liner. Such molding further requires substantial capital expenditure for each die mold needed to form EPS liners.  
         [0007]     In addition, whether stored as flat panels or a molded container, the EPS liners require significant amounts of storage space. Since these liners are generally placed in corrugated type cartons, the user is left with a situation where the corrugated boxes are completely collapsible and can be stored flat and in large numbers without taking up much space, whereas the opposite is true for the EPS liners.  
         [0008]     Due to the drawbacks presented by the EPS packaging system, substantial efforts have been directed to providing thermally insulated packaging without the use of an EPS liner. U.S. Pat. No. 4,889,252 to Rockom et al discloses the bonding of bubble-type insulation to an inner surface of a corrugated paper box. Because of the direct contact of the bubble-type insulation with the box, much of the potential thermal containment ability of the insulation is subject to being undermined by the conduction of temperatures through the insulation to or from the box and subsequently to or from the ambient atmosphere. Additionally, the box of Rockom is not fully collapsible once the insulation is bonded thereto. Many other recent efforts have been directed at attempting to substitute alternative packaging systems for the EPS liner.  
         [0009]     While some of these systems provide arguably comparable insulating results, they frequently are cumbersome, costly, increase the weight of the overall package and decrease the volume of materials that can be transported in a given container. For example, U.S. Pat. No. 5,314,087 to Shea discloses a thermal reflective packaging system that requires at least one spacer insert between an outer and inner container, as well as a spacer tray. Additionally, the pouch of Shea requires a layer of single or double-bubble radiant barrier material to be sealed within a vinyl pouch in an expensive and time consuming procedure.  
         [0010]     A number of other known designs have attempted to utilize a bag constructed to nest inside a corresponding corrugated or other outer container. Such bag type constructions have generally not followed the contours of the outer container and have frequently had poor insulating characteristics. As a result, they have generally been either too large or too small for the usually rectangular container that they have been put inside of. As a result, they have often ended up bunched up at the bottom or area location with unwanted excess material at each end wasting productive packing space and adding packaging weight and thereby increasing shipping costs. Likewise, if the bags are significantly smaller than the outer container that they are in, significant packing space is again wasted.  
         [0011]     Attempting to consistently vary the size of such bags to match their contents is again another costly and cumbersome experience. In addition, the performance of any insulating container degrades in direct proportion to how tight the container is sealed. Prior art bags have had problems particularly when a liquid was inside of the bag in providing an adequate moisture-proof seal and preventing spillage. Damage to the outer container and/or the material inside the bags frequently resulted. Furthermore, many prior art designs have been designed to perform optimally only when they are not fully loaded with perishable items.  
         [0012]     It is therefore apparent that there exists a need in the art for an improved packaging method and apparatus for perishable materials that provides a highly insulative packaging structure that is light weight, less costly for storage and shipping purposes, easily conforms to the shape of an outer shipping container fully collapsible and has thermal characteristics at least as good as EPS in most applications.  
       SUMMARY OF THE INVENTION  
       [0013]     With the foregoing in mind, it is an object of the present invention to provide a packaging system with improved insulating and thermal containment characteristics.  
         [0014]     It is a further object of the present invention to provide a packaging which can be retrofitted to an existing transport container to improve the insulating characteristics thereof.  
         [0015]     It is another object of the present invention to provide improved insulating packaging that can be constructed of a flat sheet of material to the exact specifications of the outer container that it will be used with in an easy, simple and cost-effective manner.  
         [0016]     Yet another object of the present invention is to provide a simple and cost effective method for manufacturing such packaging systems.  
         [0017]     It is a further object of the invention to provide effective insulating packaging means for preserving perishable goods which are easy to assemble, light weight, can be shipped and stored flat and unassembled.  
         [0018]     It is a still further object of the present invention to provide an insulating container that can be stored in finished condition, flat and can be easily and readily expanded to take the exact shape of the outer container that it is going to be used in conjunction with.  
         [0019]     In order to implement these and other objects of the present invention, which will become more readily apparent as the description proceeds, a preferred embodiment of the present invention provides a method and apparatus for a fully collapsible inner container assembly, designed to be removably inserted into an outer container consisting essentially of a bottom, opposing first and second sidewalls and front and back walls, each constructed of a flexible insulating material having one metalized surface that closely follows the dimensions of the outer container, the first and second sidewalls and the front and back walls forming an integral moisture proof seal with the bottom and each other, an integral first foldable side extending above the first sidewall and having opposing edges, an integral foldable second side flap extending above the second sidewall and having opposing edges, an integral foldable front flap extending above the front end, an integral foldable back flap extending above the back end, a tape strip along one of the ends, and a top formed by folding the first and second side flaps toward each other and folding the front and back flaps toward each other until two of each of their edges become gusseted. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     The foregoing and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments as illustrated in the accompanying drawings, wherein like reference numbers referred to the same parts throughout the various views.  
         [0021]      FIG. 1  is a schematic view of one embodiment of the present invention.  
         [0022]      FIG. 2  is a cross-sectional view of material utilized by the present invention according to a first embodiment.  
         [0023]      FIG. 3  is a cross-sectional view of material utilized by the present invention according to a second embodiment.  
         [0024]      FIG. 4  is an assembled perspective view of  FIG. 1 .  
         [0025]      FIG. 5  is a schematic top view illustrating all the folds that are made in a flat sheet of material in order to form the present invention.  
         [0026]      FIG. 6  is a top view of the first step required in forming the present invention out of a flat sheet of material.  
         [0027]      FIG. 7  illustrates the next step of forming the present invention out of a flat sheet of material.  
         [0028]      FIG. 8  illustrates the next step of forming the present invention out of a flat sheet of material.  
         [0029]      FIG. 9  illustrates the next step of forming the present invention out of a flat sheet of material.  
         [0030]      FIG. 10  is a perspective assembled view of the present invention.  
         [0031]      FIG. 11  is a perspective view of the first step in collapsing the present invention for storage.  
         [0032]      FIG. 12  is a perspective view of the next step in collapsing the present invention for storage.  
         [0033]      FIG. 13  is a perspective view of an embodiment of the present invention in a flat collapsed form for storage. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]     Referring now to the drawings and in particular  FIGS. 1, 4  and  10  the present invention provides an improved packaging transport system for perishables and the like. The invention provides a container  10  that is designed to be removably inserted and closely correspond to the dimensions of an outer container  12  such as a corrugated box. As will be described in more detail to follow, the inner container  10  is designed to be simply and easily constructed from a sheet of material. In its finished form the container  10  closely follows the shape and configuration of the outer container  12 . Once constructed the container  10  can readily be collapsed into a space saving configuration for storage and then be subsequently reformed without necessitating further assembly when it is desired to be used.  
         [0035]     As illustrated in  FIGS. 1 and 10 , the container  10  has a bottom  14  with oppositely disposed ends  16  and  18  and sides  20  and  22  all extending upwardly therefrom. The bottom  14  and ends  16  and  18  and sides  20  and  22  together form a gusseted pouch-like container  10  that will retain both liquid and moisture and prevent leakage therefrom.  
         [0036]     The ends  16  and  18  and sides  20  and  22  respectively are designed to extend above the sidewalls and ends of the outer container  12  when the inner container is inserted therein. When the container  10  is used a top  24  is formed by folding the side flaps  25   a  and  25   b  inwardly along the fold lines  21   a  and  21   b  that are at approximately the same height as the sidewalls of the container  12 . The end flaps  27   a  and  27   b  are then folded inwardly along the fold lines  23   a  and  23   b  over the side flaps  25   a  and  25   b . Alternatively, the side flaps  25   a  and  25   b  could be folded over the end flaps  27   a  and  27   b  to form the top  24 .  
         [0037]     The top  24  is sealed by providing a self-sealing strip  26  along or connected to the top edges of one or more of the flaps  25   a ,  25   b ,  27   a  and  27   b  respectively to form a closed container  10  that fits entirely within an outer container that as illustrated in  FIG. 4 . Other alternative tape or sealing closures could be used in place of or in addition to the self-seal strip  26 . The formation and closing of the top  24  results in a tight seal that significantly seals the contents of container  10  off from any air that might otherwise enter through the top of the container  12 .  
         [0038]     It has been found that the superior sealing of the container  10  attained by use of the strip  26  has been quite important to the overall thermal effectiveness of the container. Since the inner container  10  is designed to be readily constructed to closely resemble the dimensions of the outer container  12 , the container  10  maximizes the amount of useable packaging space for transporting perishable materials within the outer container  12 . Additionally, the inner container  10  is designed so that it can be tightly wrapped around its contents whether completely full or not in order to minimize the air space within the container.  
         [0039]     Referring to  FIGS. 2 and 3 , the inner container  10  is preferably constructed of a material having a metalized polyethylene or metallic foil laminated on one of its sides. One such material is commercially available from Astro-Valcour.  FIG. 2  illustrates a first preferred material which is a foil laminated bubble pack generally referred to as  28 . This material has a sidewall constructed of a thin foil laminate  32  such as metalized polyethylene. The foil laminate  32  is attached to a layer of polyethylene bubble packing material  36  that has a plastic or polyethylene sidewall  38  opposite the foil laminate  32  and features a number of air pockets  34  within the material.  
         [0040]     When formed into a container  10  having ½ inch thick walls the foil laminated bubble pack  28  has exhibited similar insulating characteristics to EPS foam containers having 1 inch thick walls. In addition, the cost of a foil laminated bubble pack container in accordance with the present invention is often about half of the cost of a similar size EPS container. The foil laminated bubble pack  28  can be used to form the container  10  with the laminate  32  forming either the inner or the outer sidewall of the container  10 .  
         [0041]     Most preferred results have been found when the foil laminate  32  is utilized as the inner sidewall of the container  10 . A variety of different thicknesses of laminated bubble pack  28  may be used depending upon the requirements of the product to be shipped in the container  10 . It has been found that a laminated bubble pack having a thickness of ½ inch to 3/16 inch has been particularly effective in certain circumstances.  
         [0042]     Referring now to  FIG. 3 , an alternative insulating material for forming the inner container  10  is illustrated. This alternative material referred to generally as  30  consists of a thickness of polyethylene or polyurethane foam material  40  with a sheet of metalized polyethylene or metallic foil  42  laminated to one side of the foam material  40 . The material  30  is preferably used with the metalized polyethylene  42  forming the inner wall of the container  10 . Again, although a variety of thicknesses of polyethylene or polyurethane foam material  40  have been found effective and the given thickness will depend upon the desired properties for any particular shipment, beneficial results have been found with a foam material thickness of as little as ⅛ to ¼ inch.  
         [0043]     As described above, the container  10  of the present invention is designed to be simply formed from a flat sheet of material such as laminated bubble pack  28  or laminated microfoam material  30 . The formation of a container  10  will now be described in detail with particular reference to  FIGS. 5-10 .  
         [0044]      FIG. 5  illustrates all of the folds that are made to the sheet  13  in order to form the container  10 . To begin with a sheet  13  of foil laminated bubble pack material  28  is cut from a continuous roll having dimensions that will form a container  10  of a desired size. In order to determine the proper size of the sheet the dimensions of the outer container  12  that the inner container  10  will be designed to fit in should be known. As can readily be appreciated, the dimensions of the sheet of material  28  can easily be varied and selected to match virtually any size outer container  12 .  
         [0045]     Referring now to  FIGS. 1, 5 ,  6  and  10 , the sheet  13  of material  28  is cut to a dimension so that the distance between A and B as illustrated in  FIG. 6  is equal to or slightly greater than the sum of twice the width of the bottom  14  and the height of the individual sides  20  and  22 . The opposite dimension illustrated as dimension C-D in  FIG. 6  is designed to be slightly longer than the length or opposite dimension of the bottom  14  of the container  10 . In order to form the container  10 , the corner  46  is folded over the remainder of the sheet  13  to a point  61  midway between the dimension A-B. In its folded position the corner  46 , side edge  47  and end edge  48  occupy the new positions designated as  46 ′,  47 ′ and  48 ′ respectively in dashed lines.  
         [0046]     As illustrated in  FIG. 7 , a similar fold to the one previously described is next done utilizing the opposite corner  50 . The corner  50  is folded over the sheet  13  to a position indicated as  50 ′ where it meets the opposite corner  46 ′. In this position the end edge  52  has moved to a position  52 ′ butting against the end edge  48 ′. The end edges  48 ′ and  52 ′ are joined by taping or otherwise securing them together along their entire length. A variety of securing mechanisms can be used for this purpose. Two preferred commercially available mechanisms are two inch filament tape manufactured by Anchor Tape, or use of filament or edge line heat sealer.  
         [0047]     In the stage of construction illustrated in  FIG. 7 a  pouch  55  has been formed and one of the ends  16  of the container  10  is outlined in dashed lines. In addition, at this stage of construction a pocket  54  has been formed. That pocket  54  can either be severed and heat sealed along the line  56  using known means or can be folded up in the direction indicated by the arrow and taped or otherwise adhered to the seal  58  that joins the end edges  48 ′ and  52 ′.  
         [0048]     Formation of the container  10  is continued as illustrated in  FIG. 7  by raising the top edge  64  of the pouch  55  as indicated by the arrow in  FIG. 1  until the end  16  is substantially perpendicular to the bottom  14 . Next the opposite end  18  of the container  10  is formed by similarly folding the corner  60  inwardly over the bottom  14  of the sheet  13  until it reaches the mid-point  61  of the dimension D. The opposite corner  62  is then folded so that the end edge  72  meets the edge  70  along the line  61 . The edges  70  and  72  are then joined by taping or other suitable sealing means across their entire lengths.  
         [0049]     A second pocket  74  is likewise formed by the joining of the end edges  70  and  72 . As previously described, the pocket  74  can either be cut and heat sealed or folded upwardly along the line  33  as indicated by the arrows in  FIG. 8  and subsequently taped or otherwise sealed to the outside of the end  18 . As illustrated in  FIG. 11 , when the end edges  70  and  72  are joined and the end  18  is resting against the bottom  14  a portion of the side edges  35  and  37  form a top of the end  18  against the bottom  14 . The remainder of the end edges  35 ′ and  37 ′ extend upwardly in a substantially perpendicular manner from the bottom  14  and the end  18  in this configuration.  
         [0050]     In order to finish formation of the container  10  the top  65  of the end  18  is raised from the bottom  14  until the end  18  extends upwardly substantially perpendicular from the bottom  14  as illustrated in  FIG. 10 . When in the configuration in  FIG. 9  the finished container  10  can be inserted into an outer container  12  as illustrated in  FIGS. 1 and 4  and filled and sealed for shipment as previously described.  
         [0051]     In the alternative, once the container  10  has been fully constructed, it can readily be collapsed into a flat configuration and stored in a manner that occupies a minimum of space. Once it is desired to use the container  10  it can be easily reassembled to the configuration illustrated in  FIG. 10  in a matter of seconds. The process of collapsing the constructed container  10  for storage will now be described in detail with reference to  FIGS. 11-13 .  
         [0052]     Referring now to  FIG. 11 , in order to collapse the container  10  for storage the top  65  of the end  18  is folded downwardly along the line  33  until it meets the bottom  14  of the container  10 . This causes the sides  20  and  22  respectively to partially fold inwardly The top  64  of the opposite end  16  is then likewise folded downwardly as indicated by the arrow on top of the bottom  14  along the line  56 . When the side  16  is folded completely down it likewise overlaps a substantial portion of the side  18  as indicated in  FIG. 12 .  
         [0053]     The action of folding the end  16  down on top of the opposite end  18  completes the formation of folds  76  and  78  that collapse the sides  20  and  22  respectively and form flaps  80  and  82 . The flaps  80  and  82  are then folded one over another as indicated by the arrows in  FIG. 12  to form the final storage configuration of the container  10  illustrated in  FIG. 13 .  
         [0054]     In this configuration, the footprint of the container  10  is the same size as the bottom thereof  14 . The collapsed container  10  can then be readily stacked in this manner and requires a space that is only several times the thickness of the foil laminated bubble pack  28  to be stored in a flat space-saving condition. The container  10  then can readily be reformed by performing the steps indicated to collapse the container in reverse order as they were described in connection with  FIGS. 10-13 . The compact storage and ease of collapsing and reconstructing the formed container  10  provides substantial advantages over existing EPS containers.  
         [0055]     The following examples are given to aid in understanding the invention and it is to be understood that the invention is not limited to the particular procedures or the details given in these examples.  
       EXAMPLE I  
       [0056]     A set of tests were performed in order to attempt to analyze the performance of the present invention compared to other assorted inner insulating containers under various conditions for a fresh food product. The test was designed to measure the insulating ability of containers not refrigerated prior to packing that contained fresh fish and were exposed to a harsh (95° F.) environment.  
         [0057]     In order to insure accurate results, a number of parameters were held constant for all of the inner insulated containers tested. To begin with, the inner insulating containers were all placed within a regular slotted single wall “C” flute corrugated shipping container with a mottled white liner. The empty insulating containers were all conditioned together in the same chamber at 95° F. and greater than or equal to 75% relative humidity for more than 24 hours prior to testing.  
         [0058]     The corrugated containers were sized to maintain an internal volume of approximately 1 cubic foot and were each lined with a 0.003″ gauge polyethylene bag. Fresh fish was provided and conditioned together to the same state specifically 36° F. and approximately 70% relative humidity for more than 24 hours prior to packing. At that time, 2-3 fish (or approximately 10 pounds) were placed in the bottom of each insulating container and two thermocouples were inserted into and/or placed onto the fish for test cycle monitoring.  
         [0059]     Two pound gel packs were provided and conditioned to 0° F. for more than 24 hours prior to testing. Two gel packs or four pounds total were placed on top of the fish packed within each insulated container. The gel packs were received frozen but in non-uniform pillow shapes. The units were therefor thawed and then refrozen in a flat orientation to achieve a uniform configuration prior to testing.  
         [0060]     All insulating containers constructed in accordance with the present invention were double sealed with a self sealing tear strip as well as an additional strip of 2 inch filament tape, except carton number 6 as noted below. The EPS sheet boxes and chests were not sealed. After packing under ambient conditions nominally 68° F., 50% relative humidity. The seven fresh product containers were placed into a chamber maintained at approximately 90-95° F. and 75% relative humidity at the same time.  
         [0061]     The test chamber was maintained at a uniform state by means of convection, however, the air was constantly submitted to mixing fan systems running at all times. The recorder monitored the temperature every 30 minutes for the test duration. The insulated containers were retained in the test chamber until all of them reached an internal temperature over 65° F. defined as maximum break through time.  
         [0062]     The empty insulated packing systems numbers  1 - 7  were conditioned together in the same chamber and to the identical states, specifically 95° F. and greater than or equal to 75% relative humidity for more than 24 hours prior to testing. The following insulating inner containers were tested:  
                                       Carton               (#)   Insulating Inner Container   Style                   1   Present invention-a gusseted bag   Flexible bag           constructed of a ½ inch thick           bubble pack with a sheet of metalized           polyethylene laminated on the inside           of the bag.       2   Six (6) sheets of 1.0 pound per   Rigid EPS box           cubic foot density of expanded   from sheets           polystyrene foam ½ inch thick           custom cut to line the top, bottom,           sides and ends of the corrugated           container.       3   Six (6) sheets of 1.0 pound per   Rigid EPS box           cubic foot density of expanded   From sheets           polystyrene foam 1 inch thick           custom cut to line the top, bottom,           sides and ends of the corrugated           container.       4   A two piece container molded from   Molded Rigid           EPS foam, 1.25 pound per cubic foot   EPS Chest           density with 1 inch thick walls.       5   Present invention-a gusseted bag   Flexible Bag           constructed of a ½ inch thick           bubble pack with a sheet of metalized           polyethylene laminated on the inside           of the bag.       6   Present invention-a gusseted bag   Flexible Bag           constructed of a ½ inch thick           bubble pack with a sheet of metalized           polyethylene laminated on the inside           of the bag sealed with tear strip only.       7   Gusseted bubble pack bag ½ inch   Flexible bag           thick without metalized polyethylene           lamination.                  
 
         [0063]     The following results were observed  
                                                                                     Carton       Max           Rank   (#)   Insulating System/Thickness   Time                                        1   6   Present invention, no tape - ½″   19.0           2   3   6 sheets 1#/ft 3  EPS - 1″   17.5           3   5   Present invention - ½″   17.0           4   4   Molded 1.25#/ft 3  EPS - 1″   14.5           5   1   Present invention- ½″   14.5           6   2   6 sheets 1#/ft 3  EPS - ½″   14.0           7   7   No metalized laminate - ½″   8.0                      
 
         [0064]     As can be seen from the above test results, the ½ inch thick metalized bubble container constructed in accordance with the present invention performed better than the ½ inch EPS insulation system. The ½ inch metalized bubble container constructed in accordance with the present invention performed comparably to both 1 inch EPS insulation systems (sheet and chest). The non-metalized bubble bag insulated container of carton #7 performed significantly worse than the metalized systems constructed in accordance with the present invention.  
       EXAMPLE II  
       [0065]     Another test was conducted to compare the performance of various insulating inner containers where the containers were refrigerated prior to packaging to approximate a cold packing situation. The parameters for this test were the same as those described in Example I above, except as indicated below. In this test the cartons and their inner containers were conditioned together in the same chamber at 36° F. and 70% relative humidity for more than 24 hours prior to testing. The following insulating inner containers were tested:  
                                                     Carton               (#)   Insulating Inner Container   Style                                8   Present invention - a gusseted bag   Flexible bag           constructed of a ½ inch thick bubble           pack with a sheet of metalized polyethylene           laminated on the inside of           the bag.       9   Six (6) sheets of 1.0 pound per cubic   Rigid EPS box           foot density of expanded polystyrene   from sheets           foam, 1 inch thick custom cut to           line the top, bottom, sides and ends           of the corrugated container.       10   A two piece container molded from   Rigid EPS box           EPS foam, w.25 pound per cubic foot   From sheets           density with 1 inch thick walls.                  
 
         [0066]     The containers were again tested to determine the time required to achieve a maximum break through temperature of 65° F. within the inner container. The results were as follows:  
                                                                                     Carton       Max           Rank   (#)   Insulating System/Thickness   Time                                        1   10   Molded 1.25#/ft 3  EPS - 1″   18.5           2   9   6 sheets 1#/ft 3  EPS - 1″   17.5           2   8   Present invention - ½″   17.5                      
 
         [0067]     The test results set forth above indicate that the inner container constructed in accordance with the present invention having a ½ inch thick metalized bubble material performed comparably to the containers with the 1 inch EPS insulation systems (both sheet and chest). The conclusions for the samples submitted to the high temperature preconditioning in Example I were about the same for the samples submitted to the low temperature preconditioning in Example II, with the low temperature preconditioning affording an average performance improvement of 1 to 3.5 hours of additional break through time. From these examples it is clear that the present invention was demonstrated to produce very effective desired results.