Abstract:
A flexible, plastic thin film food package is provided having an elongate opening check valve with an air removal port that allows repeated opening and resealing of the package followed by removal of air and moisture by vacuuming. The top open edge of the food package is bonded to a flexible but rigid frame that fits a lid with the air removal port flat valve. The flat valve is a compressed foam sponge and a thin film housed in a rigid case that is bonded to the lid. Air is removed with a spatula attachment of the vacuum pump that is inserted into the space between the lid and the flat check valve. Once vacuum is induced in the interior of the food package, the film covering the frame is sucked against the lid thereby shutting off influx of air into the package.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of applicant&#39;s co-pending application Ser. No. 12/880,253 filed Sep. 13, 2008 and is a continuation-in-part of applicant&#39;s co-pending application Ser. No. 12/079,847 filed Mar. 27, 2008 the entire contents of which is hereby expressly incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not Applicable 
       INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0004]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    1. Field of the Invention 
         [0006]    This invention relates to a new and improved collapsible film food package suitable for vacuum storage of frozen fresh or cooked foods at low temperature and for an extended period of time. The food package of this invention allows repeated opening and closing to facilitate the addition and/or removal of food without significant loss of flavor or edibility. 
         [0007]    2. Description of Related Art including Information Disclosed under 37 CFR 1.97 and 1.98 
         [0008]    The food packaging industry includes vacuum or non-vacuum sealed food products, many of which packages are intended for use in storage at extremely low temperatures over long periods of time. Products include raw meat, poultry, fish, and other sea foods such as crustaceans, fresh vegetables, fully cooked foods such as pizza, and frozen confections such as ice cream. 
         [0009]    Current re-sealable vacuum packages utilizing zipper strips and a flat disk check valve for removal of air from the interior of the containers. These packages are limited to a flat configuration, namely bags. Testing has indicated that these seals provided by the zipper strips fail to maintain vacuum over-night in about 20-30% of the time. A flat disk check valve is used in the current re-sealable vacuum food packages on the market. Testing has further found that sometimes it is difficult to aspirate air by a vacuum pump even when the food package is placed on a hard flat table surface. 
         [0010]    The problem with presently designed factory sealed food packages is two-fold, the first being that ice is formed on the food content if the package is sealed without vacuum and the second being that no measures are provided to reseal the package for restoring the vacuum following opening of the sealed package for addition of food or for removing a portion of its content. In both cases, when the seal is broken to allow removal and/or addition of food, the entry of air and moisture into the package frequently causes ice formation. The result is a deterioration of the food and a reduction in flavor and edibility. Also the long term storage viability of the food contained therein is reduced upon resealing. 
         [0011]    Various patents have been disclosed pertaining to closures and sealing systems for food packages, and they include U.S. Pat. Nos. 4,941,310; 5,009,828; 5,070,584; U.S. 2003/0152296 A1; U.S. Pat. No. 6,692,147; B2; 2004/0114837 A1; 2004/0161178 A1; 2005/0196077 A1 ; 2005/0244083 A1; and, 2007/0110340 A1. However, as noted, supra, none of the above patents provide a solution to the problem of ice formation and air and moisture contamination following opening of a food package to access the contents therein. Also, these patents do not provide long term vacuum sealing at very low temperatures for square or cylindrical food containers. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    It is an object of the plastic re-sealable food package with an air removal port to provide an inexpensive, flexible, plastic package for vacuum storage of food which enables a user to easily access the contents therein and, to reseal and vacuum the package for continued, long term storage at extremely low temperatures. 
         [0013]    It is another object of the plastic re-sealable food package to use a square shape of packages because this shape is the most space efficient in storing in a square box carton. There is no square re-sealable food package available on a market. Current re-sealable food package employs zipper strips, which allow only a linear locking engagement. Our elongate check valve facilitates closure of a food package of various shapes. In this patent application, we describe a square, cylindrical and flat bag shape food package. 
         [0014]    A trough shape elongate check valve of previous applications is replaced with a simpler and more efficient elongate check valve. 
         [0015]    Testing indicated that the air removal via a needle through the compressed foam sponge of previous application was found too slow. In the present application, it was replaced with the air removal port consisting of compressed foam sponge, a thin film and rigid housing. This compressed foam sponge valve blocks a large opening of the lid or side wall of the food package. A large diameter flat check valve allows much quicker air removal from the package. 
         [0016]    One-way check valves are in common use to allow flow of gas or liquid through a tube or pipe in one direction while blocking in the opposite direction. These check valves are designed to fit a circular opening of a tube or pipe, but not for an elongate opening of square, cylindrical or linear food package. This plastic re-sealable food package relates to a new elongate check valve that fits into an elongate opening of a plastic film food package and for maintaining a vacuum within the package, hence enabling storing fresh or cooked foods at low temperature for a long time. The food package allows repeated opening and closing the check valve followed by restoring a vacuum to facilitate adding and/or removal of food without significant flavor or edibility loss. 
         [0017]    It is another object of the plastic re-sealable food package to have a flexible but rigid rectangular, round or linear frame made of common polymer, e.g. high or low density polyethylene, polycarbonate or equivalent. For a square box type food package, the frame is encased by the top edge of a plastic film food package with a gusseted bottom. The film is made of thermo-plastics, e.g. polypropylene, polyethylene, etc., of about 2-3 mils in thickness. The free edge of the film is bonded to the side wall of the package, or lower edge of the frame, thus encasing the frame. A flexible but rigid lid is made of similar polymers, e.g. high or low density polyethylene, polycarbonate, nylon. The lid fits the frame snugly but this does not create air-tight closure. Thin polymer film is sandwiched between the frame and lid all way around the ridge of the square or round food container lid. When the air is removed from the interior of the package, the sandwiched film is sucked against rigid receptacle of the lid, inducing an air-tight sealing in a reproducible fashion. 
         [0018]    A flat check valve with a compressed foam sponge and thin plastic film encased inside a rigid housing is installed on the lid opposing to a large opening of the lid. A flat hollow spatula attachment of a vacuum pump can be inserted into the flat check valve housing between the compressed foam sponge and the lid. When the large opening of the lower wall of the spatula faces the large opening of the lid, vacuum pump is activated to aspirate air from the food package. When the air is removed, the vacuum around −90 kPa is generated interior of the film package which sucks the wrapping film of the package around the frame to the lid. The firmly sucked film against the lid shuts off the influx of air into the package. The lid can be opened easily by hands against the vacuum pressure of −90 kPa. After the food content is taken out/or added from/to the food package, the lid is placed back to the frame over the elongate check valve and air is removed, establishing vacuum inside the sealed package. The resealed vacuum package then can be stored in a freezer. 
         [0019]    If a conventional rectangular or square rigid food container is preferred in storing foods in a freezer or refrigerator, but at the same time, the vacuum packaging is desired, a collapsible film package with an air removal port may be used. A few rigid food containers with air removal ports are on a market. When the air is sucked out of these containers, the air pressure inside the container can be reduced but vacuum can never be achieved because the rigid structure prevents its collapse. The air removal port of a traditional design ( FIG. 8 ) is installed on a plastic film square package that fits the entire interior wall of the rigid container ( FIG. 9 ). After foods to be stored are placed inside the rigid square container ( FIGS. 9 , B &amp; C), the film package with the air removal port is snapped on to the upper rim of the container ( FIG. 9 , A). When the air is aspirated from the interior of the package, the film package collapses, compressing the foods and the upper edge of the film is firmly sucked against the upper rim of the container, shutting off the influx of air into the package ( FIG. 9 , D). A rigid lid (not shown) is capped simply to cover the container. This maneuver may be repeated as often as required. Since the air removal port drops down into the container along with the film liner, a conventional check valve as shown in  FIG. 9  may be easier to use than a flat valve ( FIG. 4 ). 
         [0020]    For a bag-type food package, the film of the package wraps around a male polymer strip. When the male polymer strip is pushed into the female strip, the plastic film is sandwiched between them. When the air is vacuumed from the interior of the bag, the vacuum induces an air-tight fitting between the film and the female plastic strip. 
         [0021]    The suction force generated by the vacuum, e.g. −90 kPa, is strong enough to shut off the air inflow into the interior of the food package but is weak enough to allow manual opening of the package. Opening of the elongate check valve enables access to the food package for removal and/or addition of food. After a desired portion of the food is taken out of the package, the lid is placed back on the rectangular, square or cylindrical frame or plastic strips of the bag and is closed so the vacuum can be reinstated by removing air from the interior of the package. 
         [0022]    The bottom and or sidewall structure of the food package comprises a flexible, plastic film material such as low and high density polyethylene&#39;s, nylons, polyesters, possibly polyurethanes, and laminates thereof, with sufficient thickness to reduce significant migration of air through the film. Preferred materials of construction of the compressible foam are silicone foam rubbers and possibly polyurethane foams. Other rubber foams may be useful providing they have suitable characteristics similar to those of silicone and polyurethane foams without toxicity. These foam rubbers are listed in the Encyclopedia of Chemical Technology, by Kirk-Othmer, 3.sup.rd Edition, 1982 at: Vol. 11, page 78; Vol. 18, page 470; and, Vol. 20, pages 365-368 and 943; ISBN 0-471-02073-7; and incorporated herein by reference. 
         [0023]    Periodic inspection of the film package during storage would be appropriate to determine if any migration of air through the plastic sidewalls of the package has occurred, causing a reduction in vacuum. This can be simply rectified by entering the package with the aspirating spatula, and in conjunction with the aspirating pump vacuuming out any air, and moisture. The presented re-sealable food storage package represents a significant improvement of frozen food storage that requires repeated open and closure for food retrieval, resealing the package, and restoring a vacuum. Aspiration will restore the vacuum and reseal the food package to enable storage at extremely low temperature, e.g. −60° C. with minimal ice formation on the stored food contents. 
         [0024]    Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0025]      FIG. 1A  is an isometric view of a square box type food package. 
           [0026]      FIG. 1B  is an isometric view of a cylindrical food package. 
           [0027]      FIG. 1C  is an isometric view of a flat bag type food package. 
           [0028]      FIG. 2A  is perspective view of a package frame of square shape. 
           [0029]      FIG. 2B  is a side view of the package frame of square shape. 
           [0030]      FIG. 2C  is a cross-sectional view of the package frame along the line  2 C- 2 C of  FIG. 2A . 
           [0031]      FIG. 3A  is a perspective view of a lid. 
           [0032]      FIG. 3B  is a cross-sectional view of the lid through the line  3 B- 3 B of  FIG. 3A . 
           [0033]      FIG. 3C  is an enlarged cross-sectional view of the peripheral rim of the lid from detail line  3 C in  FIG. 3B . 
           [0034]      FIG. 4A  is a perspective view of the top of a flat air removal port. 
           [0035]      FIG. 4B  is a perspective view of the underneath the air removal port. 
           [0036]      FIG. 4C  is a perspective view of a thin film valve leaflet. 
           [0037]      FIG. 4D  is a cross-sectional view of the air removal port along the line  4 D- 4 D in  FIG. 4B . 
           [0038]      FIG. 4E  is a frontal view of the air removal port. 
           [0039]      FIG. 5A  is a cross-sectional view of the package wrapping the frame. 
           [0040]      FIG. 5B  is a cross-sectional view of the peripheral rim of the lid. 
           [0041]      FIG. 5C  is a cross-sectional view of the assembled lid-film covered frame. 
           [0042]      FIG. 6A  shows a perspective view of a flat bag type food package. 
           [0043]      FIG. 6B  is an enlarged cross-sectional view along the  6 B- 6 B of  FIG. 6A  before the strips are engaged. 
           [0044]      FIG. 7A  shows a perspective view of a vacuum bag with a rigid top housing in an open configuration. 
           [0045]      FIG. 7B  shows a perspective view of a vacuum bag from  FIG. 7A  as it is being vacuumed. 
           [0046]      FIG. 7C  shows a perspective view of a vacuum bag from  FIG. 7A  in a vacuumed condition. 
           [0047]      FIG. 8A  shows a plan view of a conventional check valve. 
           [0048]      FIG. 8B  shows a cross sectional side view cut along line  8 A- 8 A 
           [0049]      FIG. 9A  shows is a perspective view of a collapsible film foods package attached to a rigid square foods container. 
           [0050]      FIG. 9B  shows a side view of a collapsible film foods package attached to a rigid square foods container. 
           [0051]      FIG. 9C  shows illustrates a cross-sectional view of the collapsible foods package. 
           [0052]      FIG. 9D  shows the film is pulled down to the inside wall of the rigid foods container. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0053]      FIG. 1A  shows an isometric view of a square shape collapsible plastic film food package  101 . The top edge  103  of the collapsible film food package  102  is turned over the top ridge of the frame ( 105 ) and covered under the rigid but flexible lid  104 . An air removal port  401  is installed on the lid. 
         [0054]      FIG. 1B  shows a cylindrical food package  105 . The top edge  109  of a cylindrical film package  106  is turned over the top edge of a rigid but flexible ring ( 107 ). A flexible but rigid lid  108  is pushed against the ring frame ( 107 ) to close the container. The air removal port  401  is installed on the lid. 
         [0055]      FIG. 1C  illustrates a bag-type food package  110 . Three sides  113 ,  114  and  115  of two film walls  111  &amp; ( 112 ) are sealed. The top portions of the film walls  118  &amp;  119  are sandwiched between two plastic strips  116  &amp; ( 117 ). An air removal port  401  is bonded to the one side of wall of the bag  111 . 
         [0056]      FIG. 2A  shows a perspective view of the rigid but flexible frame  201  of the square shape collapsible film package.  FIG. 2B  shows a side view of the frame  202 . Its top portion is made round inwards (not visible).  FIG. 2C  shows an enlarged cross-sectional view of the frame  201 , along the line  2 C- 2 C of  FIG. 2A . Its top portion  203  is rounded inwards. 
         [0057]      FIG. 3A  shows a perspective view of the lid  301  of the square food package. Its peripheral rim  303  is made round, matching the top rim of the frame  203 . A large opening  304  is made on the central part of the lid  302 . 
         [0058]      FIG. 3B  shows a cross-sectional view of the lid along the line  3 B- 3 B of  FIG. 3A . The central portion of the lid  302  has a large opening  304 . Its periphery forms a round recess  303 ,  305  all the way around its periphery that fits the top rim of the frame  203  of  FIG. 2C . 
         [0059]      FIG. 3C  shows an enlarged cross-sectional view of the rim of the lid  3 C- 3 C of 
         [0060]      FIG. 3B . A round recess  307  is formed between the outer rim  305  and the inner rim  306  of the lid  303 . 
         [0061]      FIG. 4A  is a perspective view of the flat film check valve  401 . Its housing  402  is made of rigid plastic, such as polycarbonate or high density polyethylene.  FIG. 4B  shows the undersurface of the flat check valve. Three sides  403 - 405  are elevated slightly. A foam sponge  407  is placed between the housing  402  and a film valve leaflet  406 . The valve leaflet is bonded to the front surface of the housing  408 .  FIG. 4C  shows a valve leaflet  407  made of a thin plastic film such as polypropylene or polyethylene. 
         [0062]      FIG. 4D  shows a cross-sectional view of the valve along line  4 D- 4 D before it is installed on the lid. Rectangular foam sponge  407  is placed between the valve housing  402  and the film valve leaflet  406 . The valve leaflet is bonded to the front surface of the valve housing  408 . 
         [0063]      FIG. 4E  shows a frontal view of the flat valve installed on the lid  409 . The foam sponge block (not visible in this view) is compressed between the valve housing and the lid  409 . The valve leaflet  406  runs between the lid  409  and the compressed foam sponge block. 
         [0064]      FIG. 5A  illustrates a cross-sectional view of the elongate film valve  501 . The film  503  wraps around the frame  202 . The top edge of the film  502  is bonded to the film below the frame  504 .  FIG. 5B  shows a cross-sectional view of the periphery of the lid  302 . It forms a round groove  305 ,  303  &amp;  306  along the periphery of the lid  202 .  FIG. 5C  demonstrates how the elongate check valve  501  is engaged. The round recess  303 , 305  &amp;  306  of the lid  302  is pushed to the frame  202 , sandwiching the film  503 . After vacuum is applied to the interior of the food package  505 , the thin film  503  is sucked against the inner rim of the lid  306 , shutting the influx of air into the interior of the package. 
         [0065]      FIG. 6A  shows a perspective view of a flat package  601 . Three sides of two thin films  602  &amp; ( 603 ) are bonded on three sides,  604 , 605  &amp;  606 . Female  607  and male ( 608 ) strips are made of flexible but rigid plastics, such as low or high density polyethylene. The front plastic film wall  602  is boded to the low inner edge of the female plastic strip  607 , whereas the top edge of the back film wall ( 608 ) is bonded to the top inner edge of the male plastic strip ( 608 ). A flat film check valve  609  is bonded to the front film wall  602  of the film package. 
         [0066]      FIG. 6B  illustrates a cross-sectional view of the plastic strips  607  &amp;  608  before they are engaged. Anterior film wall  602  is bonded to the low inner side of the female strip. Posterior film wall  603  is bonded to the top inner edge  614  of the male strip  608 . When the male protrusion  611  is pushed into the female groove  610 , the bag is closed. This closure is, however, not air-tight. When vacuum pressure is generated in the interior of the package  613 , the top portion of the film wall  612  is sucked against the female round groove  610 , shutting the air influx into the interior of the package. 
         [0067]      FIG. 7A  shows a perspective view of a vacuum bag with a rigid top housing in an open configuration,  FIG. 7B  shows a perspective view of a vacuum bag from  FIG. 7A  as it is being vacuumed and  FIG. 73C  shows a perspective view of a vacuum bag from  FIG. 7A  in a vacuumed condition. From these figures the expandable bag  70  is shown on or placed over the compression rim  62  such that the free end  71  is draped over the compression rim  62 . A labeling area  75  is shown on the front of the bag  70  in  FIG. 7A . This labeling area  75  can be used to write information regarding the contents of the bag or when the bag was stored to indicate and expiration date of the contents. The rigid end housing lid  60  is shown with the air removal port  401  extending from the lid  60  with the air removal port  401 . The lid also shows an optional burp or vent port  63  that can be operable as a burp valve to quickly exhaust air out of the expandable bag  70  by squeezing the bag  70  or as a vent valve to make the lid  60  easier to remove by providing a vacuum release. 
         [0068]    From  FIG. 7A  the bag  70  is shown in a filled condition. The aspiration spatula  82  of the vacuum device  80  is brought onto the air removal port  401  and the activation button  81  is depressed  83  to begin removal of the air. In  FIG. 7B  the bag  72  is partially vacuumed and the pleats  74  or bellows of the bag  72  begin to show as the bag  72  is reduced in size. From  FIG. 7C , sufficient air has been removed from bag  73  and the bag can be placed into storage. 
         [0069]    Rigid foods container with air removal port installed on the rigid lid is on a market. However, it is technically impossible to induce vacuum inside the rigid container. If vacuum is to be induced inside the rigid square foods container, it can be achieved only by installing a collapsible foods package with the air removal inside the container. For the collapsible film foods package, a conventional tubular check valve may be technically easier to use the bottom the rigid container than the flat valve ( FIG. 4 ). 
         [0070]      FIG. 8  illustrates a conventional tubular check valve. (A) is a perspective view and (B), cross-sectional view along the line  8 A- 8 A. A hole  807  is created in the film package  806 . The base  801  is bonded to the film package  806  against the hole,  807 . Tubular valve housing  802  facilitates attaching the vacuum pump (not shown). A thin flat disk  808  can move up and down inside the tubular housing  803  between the disk stop  805  and the film  806 . When the disk is sucked against the hole  807  of the film by vacuum, it shuts off the influx of air into the interior of the package. When the disk  808  is pulled up against the valve stop  805 , the disk  808  does not close the passage of the tubular housing  802 , leaving the spaces,  809 - 812 , though which the air is sucked out of the package. 
         [0071]      FIG. 9  (A) is a perspective view of a collapsible film foods package  902  attached to a rigid square foods container  901 . The air removal tubular port  802  is installed in the center of the collapsible film foods package  902 .  FIG. 9  (B) shows a side view. In this view, the collapsible film package is pulled below the ridge of the container  901 . A ring  907  of the container is provided for the ease of handling.  FIG. 9  (C) illustrates a cross-sectional view of the collapsible foods package  902  which is attached to the upper rim  905  of the rigid square foods container  901 . The tubular valve housing  802  is readily accessible in the center of the film collapsible package  902 . When the air is sucked out of the interior of the package  903 , the film  902  is pulled down to the inside wall of the rigid foods container  FIG. 9  (D)  901 . The film is sucked against the inside wall of the upper rim  FIG. 9  (C)  904 , creating an elongate check valve. The pulled down tubular check valve  802  is still accessible since it is located on the top of the collapsible film package  902 . 
         [0072]    Thus, specific embodiments of a plastic re-sealable food package have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims.