Abstract:
A flexible pouch including first and second flexible sheets and first and second seal arrangements is provided. The first and second flexible sheets are permanently sealed to one another along less than the entire periphery thereof and define a storage compartment therebetween. The first seal arrangement has a first portion on the first flexible sheet and a second portion on the second flexible sheet. The first and second portions extend across the un-sealed portion of the periphery. When the first and second portions are mechanically locked, a permanent seal is around the entire periphery preventing access to the storage compartment absent visible destruction of the flexible pouch. The second seal arrangement has a third portion on the first flexible sheet and a fourth portion on the second flexible sheet. When the third and fourth portions are mechanically locked, a reclosable seal is provided preventing access to the storage compartment.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This patent application claims the benefit of U.S. Provisional Patent Application No. 61/292,325, filed Jan. 5, 2010, the entire teachings and disclosure of which are incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention generally relates to flexible film pouches with resealable zipper seals. 
       BACKGROUND OF THE INVENTION 
       [0003]    Multilayer flexible films or paper are currently used as a substrate to create flexible packages for storing food and other products. Typically, products are sealed in flexible packages using permanent seals created by heat sealing equipment or by reclosable seals made by zippers or other reclosable technologies. Typically, permanent seals are used in transport of material and zippers are used as reusable package. 
         [0004]    To create a permanent seal in a multilayer flexible film pouch, pouches are heat sealed after contents have been placed inside the pouch. A heat source is required to melt the seal layer (inside layers of the pouch) and permanently bond the two layers together. In order to access the contents, the seal must be destroyed or entirely removed from the pouch. This prevents the pouch from being able to be resealed for future use without using a secondary resealing system. 
         [0005]    One secondary resealing system includes the mechanical reclosable zipper feature placed at the top of the pouch to allow for reuse of the package as a storage vessel after opening. However, by their very nature, reclosable zippers can easily be opened and contents can be tampered with if the top of the pouch above the reclosable zipper has not been permanently sealed. To ensure contents are not tampered with, some packages are heat sealed to provide a permanently sealed pouch and provide assurance that contents are of their original state. 
         [0006]    Most delis and/or supermarkets do not have heat sealing equipment within their food preparation areas to permanently close and seal the top of flexible pouches after loading the pouches with product. Heat sealers can malfunction and can easily be misused by deli personnel creating ineffective tamper resistant top seals. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Embodiments of the invention provide a method of permanently sealing the top of deli pouches (such as rotisserie chicken bags) to prevent tampering with the products such as when they are merchandised or otherwise stored in the stores until they are taken by a consumer. More particularly, embodiments of the invention provide an improved dual zipper system for flexible pouches and typically flexible (multi-layer) pouches that provides simple means to provide a permanent seal as well as a re-closable seal avoiding the use of a heat sealer in food preparation areas with supermarkets and delis. Embodiments of the invention will provide a dual zipper arrangement that will provide assurances against tampering of contents without requiring the use of a heat seal as well as providing for reusability of the pouch after the consumer has purchased the product and removed it from the store or deli. 
         [0008]    To that end, in one embodiment, two zippers are implemented on an embodiment of pouch having top zipper providing a permanent closure/seal and a bottom zipper that is re-closable. When products are enclosed in the flexible packaging and top zipper is closed to provide a permanent seal, packaging is complete and tamper resistant. Hence, when products are enclosed in dual zipper system, the permanent zipper provides a guarantee that the contents cannot be tampered with while the re-closable zipper can be used by consumers to reseal the package for reuse as a storage compartment for the product. 
         [0009]    However, when the consumer takes the packaging to a private setting where there is no fear of tampering, the consumer may remove the permanent zipper seal and access the contents of the packaging. However, as the re-closable or resealable second zipper is still provided, the consumer can still re-seal the packaging to secure the contents within the pouch until later desired use. 
         [0010]    The use of the top zipper provides a permanent seal when closed. The permanent seal provides security from outside tampering of contents stored in the sealed pouch. When contents are stored in the pouch with dual seal, or at least the permanent seal, any attempt to tamper with the contents in a finished pouch can easily be detected because an outside cut or tear will typically be created to access the contents. This system provides secure storage of products without involving a high temperature or chemical sealer required to physically bond the layers of plastic together. In an embodiment, the permanent seal is an entirely mechanical zipper arrangement that is engaged by pressing opposed cooperating zipper portions into engagement with one another, but are so engaged that they may not be separated by the user by pulling with fingers. The two zipper portions are engaged such that the permanent seal provided by the permanent zipper must be destroyed so as to permit access to the contents of the pouch. 
         [0011]    More specific versions of the flexible pouch according to the invention are provided. For instance, in one embodiment, a flexible pouch including first and second flexible sheets and first and second seal arrangements is provided. The first and second flexible sheets are permanently sealed to one another along less than the entire periphery thereof and define a storage compartment therebetween. The un-sealed portion of the entire periphery defines an opening to the storage compartment. The first seal arrangement has a first portion on the first flexible sheet and a second portion on the second flexible sheet. The first and second portions extend across the un-sealed portion of the periphery between sealed portions of the periphery. When the first and second portions are mechanically locked, a permanent seal is around the entire periphery preventing access to the storage compartment absent visible destruction of the flexible pouch or a force of greater than at least 3.0 kgf/15 mm width of the seal. The second seal arrangement has a third portion on the first flexible sheet and a fourth portion on the second flexible sheet. The third and fourth portions extend across the un-sealed portion of the periphery between sealed portions of the periphery. When the third and fourth portions are mechanically locked, a reclosable seal is provided selectively preventing access to the storage compartment. 
         [0012]    In a particular embodiment, the second seal arrangement is positioned inward from the first seal arrangement and the first seal arrangement may be removed from the first and second flexible sheets, along with the portions of the flexible sheets to which they are connected, to provide access to the second seal arrangement. 
         [0013]    In preferred embodiments, the first and second flexible sheets are generally rectangular with first and second opposed sides and third and fourth opposed sides extending between the first and second opposed sides. The first, second and third sides are permanently sealed forming the sealed portion of the periphery. The first and second seal arrangements are at the fourth side and extending laterally between the first and second sides. 
         [0014]    The second seal arrangement is preferably positioned closer to the third side than the first seal arrangement such that the first seal arrangement is closer to the fourth side. The first seal arrangement is spaced apart from and generally parallel to the second seal arrangement as well as the third and fourth sides. 
         [0015]    In some embodiments, the first and second portions of the first seal arrangement are substantially identical in cross-section to one another, but oriented at 180 degrees from one another. Further, in a preferred first seal arrangement, the first portion includes a first pair of hook portions and a first support wall. The first pair of hook portions both extending towards the first support wall. The second portion includes a second pair of hook portions and a second support wall. The second pair of hook portions both extending towards the second support wall. Further yet, in an engaged condition permanently sealing the storage compartment with the first seal arrangement, the first and second pairs of hook portions are laterally interposed and bounded by the first and second support walls. More particularly, the first support wall being closer to the fourth side than the first and second pairs of hook portions and the second support wall. The second support wall being closer to the third side than the first and second pairs of hook portions and the first support wall. 
         [0016]    To provide for the tamper evidence, the first seal arrangement cannot be disengaged, when in an engaged position, by pulling by a person using their fingers. However, after the consumer has purchased the package, the second seal arrangement can be disengaged, when in an engaged position, by pulling by a person using their fingers such as to provide the reclosable seal. 
         [0017]    In preferred embodiments, the third portion is a female portion that receives the fourth portion being in the form of a male portion. The female portion defines a channel having opposed hook portions that extend toward one another. The male portion has a head portion that engages the pair of opposed hook portions such that the male portion is generally T-shaped. 
         [0018]    To facilitate removal of the permanent seal, i.e. the first seal arrangement, the pouch further includes a tear notch in at least one of the first and second sides being interposed between the first and second seal arrangements. This permits a user to permanently remove the first seal arrangement from the pouch to provide access to the second seal arrangement and storage compartment. 
         [0019]    Alternatively, the tear notch or a tear score could be formed in a base portion of the zipper members of the permanent seals. This prevents undesirable tearing of the flexible film, particularly when no reclosable seal is present to stop vertical tearing. 
         [0020]    A method of packaging a product is also provided. The method includes the steps of inserting a product into storage compartment of a pouch; closing a first seal arrangement of the pouch to permanently secure the product in the storage compartment absent removal of the first seal arrangement or application of a load of at least 3.0 kgf/15 mm width of the seal; removing the first seal arrangement after being closed to provide access to the storage compartment; and closing a second seal arrangement providing a non-permanent seal. 
         [0021]    Preferred methods also include opening the second seal arrangement without damaging the pouch to provide access to the storage compartment. Further yet, the step of removing the first seal arrangement may include tearing the pouch between the first and second seal arrangements. This tearing may be initiated at a tear notch in the side of the pouch. Further, the step of closing a first seal arrangement includes mechanically engaging a first portion of the seal arrangement with a second portion of the seal arrangement. The step of closing a first seal arrangement is preferably performed free of heat sealing. 
         [0022]    Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
           [0024]      FIG. 1  is a simplified front view illustration of a flexible pouch according to an embodiment of the present invention; 
           [0025]      FIG. 2  is a side view illustration of the flexible pouch of  FIG. 1 ; 
           [0026]      FIG. 3  is an enlarged cross-sectional illustration of a permanent seal arrangement of the flexible pouch of  FIG. 1 ; 
           [0027]      FIG. 4  is an enlarged cross-sectional illustration of a reclosable seal arrangement of the flexible pouch of  FIG. 1 ; 
           [0028]      FIG. 5  is an enlarged front view of a portion of the reclosable seal arrangement of the flexible pouch of FIG.  1 .; 
           [0029]      FIG. 6  is a perspective partial illustration of the zipper members of  FIG. 3  removed from any pouch; and 
           [0030]      FIG. 7  is a profile illustration of the zipper members of  FIG. 6 . 
       
    
    
       [0031]    While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    Turning now to  FIG. 1  illustrating an embodiment of a flexible pouch  4  according to the present invention. The flexible pouch  4  is generally rectangular in shape including sides  5 - 8 . Three sides, including sides  5 - 7  are permanently continuously sealed, such as by way of heat sealing, to define an internal storage compartment  10  in which products may be stored. This storage compartment  10  is formed between two sheets of the flexible, generally multi-layer, film which are sealingly and permanently connected to one-another along sides  5 ,  6 ,  7 . The two sheets of flexible film are not heat sealed along fourth side, side  8  such that, at least initially, the user may have access to storage compartment  10 . The portion of the periphery proximate side  8  between the free ends of the seal around sides  5 - 7  defines the opening into storage compartment  10 . 
         [0033]    The pouch  4  includes two separate seals  12 ,  14  along fourth side  8  that can be used to entirely close storage compartment  10  on all four sides. The two separate seals  12 ,  14  provide two separate functions. Seal  12  provides a permanent seal that cannot be reopened and seal  14  provides a re-sealable or re-closeable seal that can be opened and closed numerous times. Thus, when the user desires to provide permanent seal the user will use seal  12 . 
         [0034]    This may be done for example at the deli or supermarket. For instance, the deli or supermarket may place a rotisserie chicken in storage compartment  10  of pouch  4  and display the chicken for sale. As it is desired to be sure that no tampering has occurred of the contents of the pouch  4 , i.e. the chicken, the permanent seal  12  will be used. Further, at that point and until the chicken is sold and taken by a consumer, there is no need to access the pouch. 
         [0035]    However, once the consumer purchases the package of chicken, he or she will remove the permanent seal  12  to provide access to storage compartment  10  and the chicken stored therein. At that time, if the user would like to reseal the pouch  4  he or she may use seal  14  to reclose the package to continue storing the contents, i.e. chicken, within pouch  4 . At that time, however, there is no need to be afraid of tampering so the resealable seal  14  is sufficient for closing the storage compartment  10 . 
         [0036]    As illustrated in  FIGS. 1 and 2 , the two seals  12 ,  14  are vertically oriented relative to one another as they extend across the top side  8  of the pouch  4  between vertical sides  5 ,  7 . Seal  14  is positioned between the storage compartment  10  and seal  12 . Seal  12  is positioned closer to free edge  15  of pouch  4  while seal  14  is positioned closer to side  6  of pouch  4  than seal  12 . 
         [0037]    Seals  12 ,  14  are preferably zipper type seals that are entirely mechanical interlocking arrangements free of heat sealing or chemical bonding to provide engagement. Preferably, both seals  12 ,  14  are located in the upper twenty-five (25) percent of the pouch  4 , more preferably in the upper twenty (20) percent. Seal  12  is preferably located in the upper fifteen (15) percent of pouch  4 , more preferably in the upper ten (10) percent of pouch  4 . 
         [0038]    Positioned between seals  12 ,  14  is a tear notch  16  that facilitates initiating tearing of the pouch  4  laterally between sides  5  and  7  so as to remove seal  12  from the pouch  4 . Again, with seal  12  removed from pouch  4 , the consumer has reclosable access to storage compartment  10 . However, if seal  12  has been removed prior to being purchased by the consumer, the consumer can be concerned about potential tampering of the contents of storage compartment  10 . 
         [0039]    Seal  12  is illustrated in the enlarged cross-sectional illustration of  FIG. 3 . The seal  12  is formed by two substantially identical zipper members  21 ,  22 . These zipper members  21 ,  22  are typically formed separate from the flexible film sheets forming the pouch  4 . The zipper members  21 ,  22  are then typically heat or ultrasonically welded or otherwise affixed to the flexible film sheets. Zipper members  21 ,  22  are typically formed from an extrusion or molding process. 
         [0040]    As illustrated in  FIGS. 3 ,  6  and  7 , the zipper members  21 ,  22  are oriented  180  degrees relative to one another. Each zipper member  21  includes a pair of female zipper hooks  26 . Zipper member  22  includes an identical pair of female zipper hooks  25  that engage zipper hooks  26  of zipper member  21 . Both zipper members  21 ,  22  include a support wall  28  that supports the engagement of the hooks  25 ,  26  of zipper members  21 ,  22  to as to prevent disengagement thereof. 
         [0041]    The engagement between zipper members  21 ,  22  is such that a person gripping the free ends of the flexible sheets between seal  12  and free edge  15  cannot separate zipper members  21 ,  22  from one another. Support wall  28  also protects the engagement between zipper members  21 ,  22  such that a potential tamperer cannot insert or wedge a device between the engaged hooks  25 ,  26  to facilitate disengagement therebetween. 
         [0042]    However, as noted above, the profile of zipper members  21 ,  22  are identical, in a preferred embodiment, but oriented opposite one another such that support wall  28  of zipper member  21  is proximate free edge  15  while the support wall of zipper member  22  is proximate side  6  with hooks  25 ,  26  interposed therebetween. Further, the zipper members  21 ,  22  are oriented such that the hook (i.e. barb) portion of hooks  26  of zipper member  21  extend vertically upward toward free edge  15  while the hooks  25  of zipper member  22  extend vertically downward toward side  6 . In this arrangement the barbs of hooks  25 ,  26  engage one another to increase engagement therebetween. 
         [0043]    The engagement of the zipper members  21 ,  22  in preferred embodiments requires greater than 3 kgf/15 mm of width and more preferably greater than 3.5 kgf/15 mm of width and even more preferably greater than 4 kgf/15 mm of width. These values are measured using the American Society for Testing and Materials (ASTM) standard testing having Designation F 88-00 entitled “Standard Test Method for Seal Strength for Flexible Barrier Materials.” 
         [0044]    This force is applied to the portion of the pouch positioned vertically between the seal  12  and free edge  15 . Seals having engagement characteristics greater than these values provides one means of determining whether or not it is a permanent seal. Other means of determining a permanent seal will be discussed below as being a relative engagement relative to seal  14  or alternatively the need for physical destruction to the pouch  4 . 
         [0045]    Zipper  12  may be of the form illustrated in Korean Patent Application No. 20-2008-0007596, the teachings and disclosures of which are incorporated herein by reference thereto. 
         [0046]    With reference to  FIG. 4 , secondary seal  14  is illustrated. Seal  14  is intended to reclosable and has a different structural arrangement than that of seal  12 . In this embodiment, zipper member  32  is a female zipper member having a pair of opposed hooks defining a channel therebetween for receipt of male zipper member  34 . Male zipper member includes a shaft portion having an enlarged head portion that is received in female zipper member  32 . This zipper seal  14  is such that a user grasping the free material of the flexible sheets can separate zipper member  32  from  34  to open storage compartment  10 . Other recloseable zipper member arrangements can be used for seal  14 . 
         [0047]    The engagement of the zipper members  32 ,  34  in preferred embodiments requires less than 0.3 kgf/15 mm of width and more preferably less than 0.25 kgf/15 mm of width for disengagement. Preferably, the engagement of zipper members  32 ,  34  is sufficient that the force required for disengagement is at least 0.1 kgf/15 mm and at least 0.15 kgf/15 mm. This force is applied to the portion of the pouch positioned vertically between the seal  14  and free edge  15  or alternatively between seal  14  and any free edge generated when seal  12  has been removed using tear notch  16 . 
         [0048]    As illustrated in  FIG. 5 , the free ends  36  of zipper seal  14  are separated from the free edges  35  of the pouch  4 . This arrangement maintains the seal provided by zipper seal  14  and prevents the potential of an undesirable leak path. 
         [0049]    From the engagement data above, seal  12  (seal members  21 ,  22 ) provides for an engagement of at least 10 times greater than seal  14  (seal members  32 ,  34 ). More preferably, seal  12  provides for an engagement of at least 15 times greater than seal  14 . In some embodiments, seal provides for an engagement of at least 20 times greater than seal  14 . This relative engagement values between seals  12 ,  14  is a further way of determining whether both a permanent and reclosable seal are provided. 
         [0050]    A further way of determining whether a permanent seal has been provided is to determine whether or not the pouch  4  must be damaged in any way to provide access to the pouch. One example of damage is merely tearing seal  12  from the bag using tear notch  16 . Alternatively, damage may occur on either seal member  21  or  22 . 
         [0051]    With reference to  FIGS. 6 and 7 , the zipper members  21  and  22  of the permanent seal are illustrated. The zipper members  21 ,  22  are not attached to the flexible films forming the pouch. 
         [0052]    In some embodiment of a pouch, only a permanent seal  12  will be provided. In these embodiments, the permanent seal is removed from the top portion of the pouch to provide access to the pouch. At that time, the pouch is therefore no longer resealable as the only seal that was provided was the permanent seal  12 . 
         [0053]    Typically, the sheets of flexible film that are used to form the pouch are thinner and provide significantly less strength than portions of the zipper members  21 ,  22 . As such, when a score line is added to the flexible film to provide a tear location for removing the permanent seal  12 , the film will tend to tear at different locations other than at the desired score line. This is particularly due to the fact that the film is so thin and has limited strength. 
         [0054]    Therefore, in some embodiments, the permanent seal  12 , and particularly the zipper members  21 ,  22  include the tear notch or tear score for providing the desired location for removal of the permanent seal  12 . 
         [0055]    As illustrated in  FIGS. 6 and 7 , the zipper members  21 ,  22  include elongated base portions  40 ,  42 . The individual zipper hooks  25  are attached to base portion  40  of zipper member  21 . Similarly, zipper hooks  26  of zipper member  22  are attached to base portion  42 . The base portions  40 ,  42  also include tear notches  44 ,  46 , respectively. These tear notches  44 ,  46  may also be referred to as “laser score lines,” “tear scores” or “score lines.” These tear notches  44 ,  46  are scores or channels formed in the length of the base portion  40 ,  42 . These tear notches  44 ,  46  provide a weakened location within the base portions  40 ,  42  to facilitate and promote tearing thereat. These tear notches  44 ,  46  thus control the location of a tear for removal of the permanent seal  12  from a pouch  4  (see  FIG. 1 ). Further, because the base portions  40 ,  42  are formed from a thicker or harder material than the flexible films forming the pouch  4 , when the user goes to tear off or remove permanent seal  12 , the tear will not run vertically and will remain in the desired location along the tear notches  44 ,  46  preventing undesirable tearing of the flexible film destroying the pouch  4 . 
         [0056]    In some embodiments, the maximum depth of the tear notches  44 ,  46  is at least 15 percent of the thickness T of the base portion  40 ,  42 . In further embodiments, the depth of notches  44 ,  46  is at least 25 percent of the thickness T of base portions  40 ,  42 . In other embodiments, the depth of tear notches  44 ,  46  is at least 40 percent of the thickness of the base portions  40 ,  42 . However, other depths are contemplated therebetween the identified ranges. 
         [0057]    In some embodiments, the thickness T of the base portion  40 ,  42  is between about eight (8) mils and ten (10) mils (where mils are 1/1000 of an inch) while the thickness of the flexible film is between about two (2) mils and four (4) mils. Even though the thicknesses of the film and the base portions  40 ,  42  appears to be similar in the figures, from the numerical data herein, it can be seen that the thickness T of the base portions  40 ,  42  may be significantly greater than the thickness of the flexible film in some embodiments. 
         [0058]    Thus, as the tear notches  44 ,  46  are located in the sturdier/stronger base portions  40 ,  42  of the zipper members  21 ,  22  rather than being formed merely in the flexible film, the tear resulting in removal of the seal  12  from the pouch  4  is more controlled and less susceptible to run away from those tear notches  44 ,  46  and destroy the pouch generally. 
         [0059]    Further, this permanent seal  12  may be used on both pouches  4  that include both a permanent and reclosable seal  12 ,  14 , as well as pouches that only provide for a single seal and more particularly, for pouches that only include a permanent seal such as seal  12 . 
         [0060]    Zipper members  21 ,  22  are formed from a plastic material that allows them to be laser or heat welded to the inner surface of the flexible films forming the pouch to which they are attached. Further, notches  44 ,  46  need not be continuous notches and could be intermittent. Further, it is noted that notches  44 ,  46  will be positioned between the hook members  25 ,  26  and the bottom edge of the pouch. In this arrangement, it assures that the seal  12  is removed from the pouch upon tearing along notches  44 ,  46 . Further, the tear notches  44 ,  46  are axially aligned with one another. Thus, notch  44  is further away from support wall  28  of zipper member  21  as compared to the distance between support wall  28  of zipper member  22  and tear notch  46 . 
         [0061]    All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0062]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0063]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.