Patent Publication Number: US-2003223654-A1

Title: Liquid tight closure mechanism

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates generally to a method of producing closure mechanisms for polymer packages, for example, plastic bags. In particular, the present invention relates to closure mechanisms having a liquid tight arrangement.  
       DISCUSSION OF RELATED ART  
       [0002] Many packaging applications use resealable containers to store various types of articles and materials. These packages may be used to store and ship food products, non-food consumer goods, medical supplies, waste materials, and many other articles. Resealable packages are convenient in that they can be closed and resealed after the initial opening to preserve the enclosed contents. The need to locate a storage container for the unused portion of the products in the package is thus avoided. As such, providing products in resealable packages appreciably enhances the marketability of those products.  
       [0003] Resealable packages typically utilize a closure mechanism that is positioned along the mouth of the package. The closure mechanism often comprises profile elements or closure profiles that engage one another when pressed together and disengage when pulled apart. The profile elements are often designed to disengage with the use of minimal force, to allow the package to be easily opened. However, this can cause the profile elements to disengage as the package is moved or placed in storage, because the profile elements can be jostled during such movement. Because a small force is all that is typically required to disengage the profile elements, the elements may become disengaged even when it is undesired. This is a significant concern when the product is a liquid or a small solid that can leak through even the smallest opening in the package. It is therefore desirable to provide a closure mechanism that can be fully sealed and will remain sealed in order to prevent product leakage.  
       SUMMARY OF THE INVENTION  
       [0004] In an embodiment of the present invention, a liquid tight closure mechanism is provided comprising first and second closure profiles, the first closure profile comprising a first base strip having a first interlocking member extending therefrom and the second closure profile comprising a second base strip having a second interlocking member extending therefrom. The first and second interlocking members are constructed and arranged to selectively interlock. The first closure profile further comprises a third base strip having a first sealing member extending therefrom, the first sealing member having a plurality of teeth disposed thereon and the second closure profile further comprising a fourth base strip with a second sealing member extending therefrom, the second sealing member also having a plurality of teeth disposed thereon. The teeth disposed on the first sealing member are designed and arranged to selectively engage the teeth disposed on the second sealing member.  
       [0005] In another embodiment of the present invention, a resealable package includes first and second panel sections joined together to define an enclosed region, first and second opposite side edges, a bottom edge, and a mouth that provides access to the enclosed region. The resealable package also includes a liquid tight closure mechanism for selectively opening and sealing the mouth. The closure mechanism includes structure as previously described herein. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0006] The various features and benefits of the present invention are apparent in light of the following detailed description and the accompanying drawings, in which:  
     [0007]FIG. 1 is a perspective view of a flexible, resealable package in accordance with an embodiment of the present invention.  
     [0008]FIG. 2 is an enlarged, fragmented, cross-sectional view of a liquid-tight closure mechanism according to an example embodiment of the present invention.  
     [0009]FIG. 3 is an enlarged, fragmented, cross-sectional view of the liquid-tight closure mechanism illustrated in FIG. 2, shown in the closed position.  
     [0010]FIG. 4 is an enlarged, fragmented, cross-sectional view of a liquid-tight closure mechanism according to an example embodiment of the present invention.  
     [0011]FIG. 5 is an enlarged, fragmented, cross-sectional view of the liquid-tight closure mechanism illustrated in FIG. 4, shown in the closed position.  
     [0012]FIG. 6 is an enlarged, fragmented, cross-sectional view of a liquid-tight closure mechanism according to an example embodiment of the present invention.  
     [0013]FIG. 7 is an enlarged, fragmented, cross-sectional view of the liquid-tight closure mechanism illustrated in FIG. 6, shown in the closed position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0014]FIG. 1 illustrates an example packaging arrangement in the form of a resealable, flexible package  110 , for example, a polymeric package such as a plastic bag, having a resealable closure mechanism  114 , for example, interlocking profile elements, constructed in accordance with the present invention. The flexible package  110  includes first and second opposed panel sections  116 ,  118 , typically made from a flexible, polymeric, plastic film, such as a low density polyethylene.  
     [0015] With some manufacturing applications, the first and second panel sections  116 ,  118  are heat-sealed together along two side edges  120 ,  122  and meet at a fold line  123  in order to form a three-edged containment section for a product within an interior  124  of the package  110 . In the embodiment shown, the fold line  123  comprises the bottom edge  125  of the package  110 . Alternatively, two separate panel sections  116 ,  118  of plastic film may be used and heat-sealed together along the two side edges  120 ,  122  and at the bottom edge  125 . Access is provided to the interior  124  of the package  110  through a mouth  126  at a top edge  127  of the package.  
     [0016] In the particular embodiment illustrated in FIG. 1, the mouth  126  extends the width of the package  110 . The resealable closure mechanism  114  is illustrated at the mouth  126  of the flexible package  110 . Preferably, the cross-section of the closure mechanism  114  is continuous along its length across the mouth  126  of the package  110 . Alternatively, the closure mechanism  114  could be positioned on the package  110  at a location different from the mouth  126  of the package  110 , depending on the application needs for the package  110 .  
     [0017] The resealable liquid tight closure mechanism  114  can be one of a variety of closure mechanisms. In the particular embodiment illustrated in FIG. 2, the resealable closure mechanism  114  is shown in the specific form of a zipper-type closure mechanism. By the term “zipper-type closure mechanism,” it is meant a structure having opposite interlocking or mating profiled elements that under the application of pressure will interlock and close the region between the profiles.  
     [0018] In the embodiment shown in FIG. 2, the resealable closure mechanism  114  comprises first and second closure profiles  130 ,  131 . The first and second closure profiles  130 ,  131  are connected to the two panel sections  116 ,  118 , respectively. The first and second closure profiles  130 ,  131  may be attached to the panel sections  116 ,  118  by any appropriate means known to those skilled in the art. For example, the first and second closure profiles  130 ,  131  may be formed separately, then heat sealed to the panel sections  116 ,  118 .  
     [0019] As shown in FIG. 2, the first closure profile  130  includes a first base strip  132  with a first interlocking member  134  extending therefrom. At a free end or tip of the first interlocking member  134  is a first hook or catch  174 . Likewise, the second closure profile  131  includes a second base strip  133  and a second interlocking member  135  extending therefrom. At a free end or tip of the second interlocking member  135  is a second hook or catch  175 .  
     [0020] The first and second closure profiles  130 ,  131  are designed and constructed to engage with one another to form a liquid tight resealable closure mechanism  114 . The first interlocking member  134  of the first closure profile  130  extends from the base strip  132  an engagement distance. The second interlocking member  135  of the second closure profile  131  also extends from the base strip  133  an engagement distance. These engagement distances that the first and second interlocking members  134 ,  135  extend are sufficient to allow mechanical engagement, or interlocking, between the first interlocking member  134  of the first closure profile  130  and the second interlocking member  135  of the second closure profile  131 .  
     [0021] In particular, the first catch  174  of the first interlocking member  134  hooks or engages with the second catch  175  of the second interlocking member  135 . Furthermore, the closure profiles  130 ,  131  remain sealed together at their ends, for example, as shown in FIG. 1, as first and second regions  153 ,  154  to further aid in aligning the remainder of closure profiles  130 ,  131  for interlocking. Pressure is applied to the closure profiles  130 ,  131  as they engage to form the re-openable sealed closure mechanism  114 . Pulling the first closure profile  130  and the second closure profile  131  away from each other causes the two closure profiles  130 ,  131  to disengage.  
     [0022] As stated above, as closure mechanisms are typically designed to easily disengage, some have the tendency to disengage even when it is undesired. This is especially troublesome when the product stored inside of the package  110  is a liquid that can escape through small openings in the closure mechanism  114 . Therefore, the liquid tight closure mechanism  114  of the present invention also includes first and second sealing members  138 ,  139 .  
     [0023] As shown in FIG. 2, the first closure profile  130  includes a third base strip  136  with a first sealing member  138  extending therefrom. The first sealing member  138  includes a plurality of teeth (referenced collectively as  140 ) disposed thereon. Likewise, the second closure profile  131  includes a fourth base strip  137  with a second sealing member  139  extending therefrom. The second sealing member  139  also includes a plurality of teeth (referenced collectively as  141 ) disposed thereon.  
     [0024] The teeth  140  disposed on the first sealing member  138  are disposed on the first sealing member  138  an engagement distance from the third base strip  136 . Likewise, the teeth  141  disposed on the second sealing member  139  are disposed on the second sealing member  139  an engagement distance from the fourth base strip  137 . These engagement distance that the teeth  140  and the teeth  141  are disposed on the first and second sealing members  138 ,  139 , respectively, are sufficient to allow mechanical engagement, or interlocking between the teeth  140  disposed on the first sealing member  138  and the teeth  141  disposed on the second sealing member  139 .  
     [0025] As stated above, pressure is applied to the closure profiles  130 ,  131  as they engage to form sealed closure mechanism  114 . As this occurs, the teeth  140  disposed on the first sealing member  138  engage the teeth  141  disposed on the second sealing member  139  to form a liquid-tight seal when the closure mechanism  114  is sealed. The liquid-tight seal prevents any of a liquid product placed in package  110  from escaping the package  110  through the closure mechanism  114 . The teeth  140  disposed on the first sealing member  138  and the teeth  141  disposed on the second sealing member  139  are configured so that when they are engaged, the force required to disengage them is greater than the force required to disengage the first and second interlocking members  134 ,  135 . In this way, the first and second sealing members  138 ,  139  also help prevent the closure mechanism  114  from unintended opening, for example, during transport.  
     [0026] In the example embodiment illustrated in FIG. 2, the first sealing member  138  comprises a body  188  and a head  198 . The second sealing member  139  comprises a body  189  and a head  199 . In this embodiment, the teeth  140  disposed on the first sealing member  138  are disposed on its head  198 . However, it should be understood that the teeth  140  may be disposed anywhere along the first sealing member  138 , as long as they are an engagement distance from the third base strip  136 , as described above. Likewise, the teeth  141  may be disposed anywhere along the second sealing member  139 , as long as they are an engagement distance from the fourth base strip  137 . However, in the embodiment illustrated in FIG. 2, the teeth  141  are disposed on the head  199  of second sealing member  139 .  
     [0027] In order for the first and second sealing members  138 ,  139  to form a liquid tight seal when engaged, it is desirable that their respective shapes be complimentary. Still in reference to FIG. 2, it can be seen that in the embodiment illustrated, the head  198  of the first sealing member  138  is curved along its length, i.e. it is generally arc-shaped. Likewise, the head  199  of second sealing member  139  is aslo curved along its length to be generally arc-shaped. More specifically, the head  199  of second sealing member  139  is shaped so as to be complimentary to, or to mesh with, or to mate with, or to engage the head  198  of the first sealing member  138 . In the embodiment shown, the teeth  140  disposed on the head  198  of the first sealing member  138  are disposed on the inside of the arc, while the teeth  141  disposed on the head  199  of the second sealing member  139  are disposed on the outside of the arc. In this way, the teeth  140 ,  141  may engage. It should beunderstood, that depending on the shape of the heads  198 ,  199 , that the teeth  140 ,  141  may be placed in various locations on the heads  198 ,  199 , so long as the teeth  140 ,  141  engage when the closure mechanism  114  is sealed.  
     [0028] In an alternate embodiment illustrated in FIGS.  4 - 5 , the closure mechanism  214  further includes a first guide post  243  extending from the second closure profile  231 . It should be noted that elements of this embodiment that are included in the embodiment illustrated in FIGS.  2 - 3  are referenced by the reference numbers used in FIGS.  2 - 3 , but increased by a factor of  100 . In the embodiment illustrated in FIGS.  4 - 5 , the resealable closure mechanism  214  comprises first and second closure profiles  230 ,  231 . The first and second closure profiles  230 ,  231  are connected to the two panel sections  216 ,  218 , respectively. The first and second closure profiles  230 ,  231  may be attached to the panel sections  216 ,  218  by any appropriate means known to those skilled in the art. For example, the first and second closure profiles  230 ,  231  may be formed separately, then heat sealed to the panel sections  216 ,  218 .  
     [0029] As shown in FIG. 4, the first closure profile  230  includes a first base strip  232  with a first interlocking member  234  extending therefrom. At a free end or tip of the first interlocking member  234  is a first hook or catch  274 . Likewise, the second closure profile  231  includes a second base strip  233  and a second interlocking member  235  extending therefrom. At a free end or tip of the second interlocking member  235  is a second hook or catch  275 . The second closure profile further includes a fifth base strip  241  with the first guide post  243  extending therefrom. The guide post  243  aids in holding the closure mechanism  214  closed and in aligning the first interlocking member  234  with the second interlocking member  235  for engagement.  
     [0030] The first and second closure profiles  230 ,  231  are designed and constructed to engage with one another to form the resealable closure mechanism  214 . The first interlocking member  234  of the first closure profile  230  extends from the base strip  232  an engagement distance. The second interlocking member  235  of the second closure profile  231  also extends from the base strip  233  an engagement distance. These engagement distances that the first and second interlocking members  234 ,  235  extend are sufficient to allow mechanical engagement, or interlocking, between the first interlocking member  234  of the first closure profile  230  and the second interlocking member  235  of the second closure profile  231 .  
     [0031] In particular, the first catch  274  of the first interlocking member  234  hooks or engages with the second catch  275  of the second interlocking member  235 . Furthermore, the closure profiles  230 ,  231  remain sealed together at their ends, for example, as shown in FIG. 1, as first and second regions  153 ,  154  to further aid in aligning the remainder of closure profiles  230 ,  231  for interlocking. Pressure is applied to the closure profiles  230 ,  231  as they engage to form the re-openable sealed closure mechanism  214 . Pulling the first closure profile  230  and the second closure profile  231  away from each other causes the two closure profiles  230 ,  231  to disengage.  
     [0032] The closure mechanism  214  also includes first and second sealing members  238 ,  239 , that have identical structures to the corresponding elements,  138 ,  139  described in relation to the embodiment illustrated in FIGS.  2 - 3 .  
     [0033] In an alternate embodiment illustrated in FIGS.  6 - 7 , the closure mechanism  314  further includes additional interlocking members  353 ,  354 . It should be noted that elements of this embodiment that are included in the embodiment illustrated in FIGS.  2 - 3  are referenced by the reference numbers used in FIGS.  2 - 3 , but increased by a factor of 200. In the embodiment shown in FIG. 6, the resealable closure mechanism  314  comprises first and second closure profiles  330 ,  331 . The first and second closure profiles  330 ,  331  are connected to the two panel sections  316 ,  318 , respectively. The first and second closure profiles  330 ,  331  may be attached to the panel sections  316 ,  318  by any appropriate means known to those skilled in the art. For example, the first and second closure profiles  330 ,  331  may be formed separately, then heat sealed to the panel sections  316 ,  318 .  
     [0034] As shown in FIG. 6, the first closure profile  330  includes a first base strip  332  with a first interlocking member  334  extending therefrom. At a free end or tip of the first interlocking member  334  is a first hook or catch  374 . Likewise, the second closure profile  331  includes a second base strip  333  and a second interlocking member  335  extending therefrom. At a free end or tip of the second interlocking member  335  is a second hook or catch  375 .  
     [0035] The first and second closure profiles  330 ,  331  are designed and constructed to engage with one another to form the resealable closure mechanism  314 . The first interlocking member  334  of the first closure profile  330  extends from the base strip  332  an engagement distance. The second interlocking member  335  of the second closure profile  331  also extends from the base strip  333  an engagement distance. These engagement distances that the first and second interlocking members  334 ,  335  extend are sufficient to allow mechanical engagement, or interlocking, between the first interlocking member  334  of the first closure profile  330  and the second interlocking member  335  of the second closure profile  331 .  
     [0036] In particular, the first catch  374  of the first interlocking member  334  hooks or engages with the second catch  375  of the second interlocking member  335 . Furthermore, the closure profiles  330 ,  331  reamain sealed together at their ends, for example, as shown in FIG. 1, as first and second regions  153 ,  154  to further aid in aligning the remainder of closure profiles  330 ,  331  for interlocking. Pressure is applied to the closure profiles  330 ,  331  as they engage to form the re-openable sealed closure mechanism  314 . Pulling the first closure profile  330  and the second closure profile  331  away from each other causes the two closure profiles  330 ,  331  to disengage.  
     [0037] In this embodiment, additional sets of interlocking closure members are included. It should be understood that the embodiment illustrates one additional set of interlocking closure members, but that in accordance with this embodiment, any number of additional sets of interlocking closure members may be included, depending on the requirements of the specific package. As shown, the first closure profile  330  further includes includes a sixth base strip  352  with a third interlocking member  354  extending therefrom. At a free end or tip of the first interlocking member  354  is a third hook or catch  394 . Likewise, the second closure profile  331  includes a seventh base strip  351  and a fourth interlocking member  353  extending therefrom. At a free end or tip of the second interlocking member  353  is a fourth hook or catch  395 .  
     [0038] The first and second closure profiles  330 ,  331  are designed and constructed to engage with one another to form the resealable closure mechanism  314 . The third interlocking member  354  of the first closure profile  330  extends from the sixth base strip  352  an engagement distance. The fourth interlocking member  353  of the second closure profile  331  also extends from the seventh base strip  351  an engagement distance. These engagement distances that the third and fourth interlocking members  354 ,  353  extend are sufficient to allow mechanical engagement, or interlocking, between the third interlocking member  354  of the first closure profile  330  and the fourth interlocking member  353  of the second closure profile  331 .  
     [0039] In particular, the third catch  394  of the third interlocking member  354  hooks or engages with the fourth catch  395  of the fourth interlocking member  353 . Furthermore, the closure profiles  330 ,  331  are sealed together at their ends, such as first and second regions  153 ,  154  of FIG. 1 to further aid in aligning the closure profiles  330 ,  331  for interlocking. Pressure is applied to the closure profiles  330 ,  331  as they engage to form the openable sealed closure mechanism  314 . Pulling the first closure profile  330  and the second closure profile  331  away from each other causes the two closure profiles  330 ,  331  to disengage.  
     [0040] The closure mechanism  314  also includes first and second sealing members  338 ,  339 , that have identical structures to the corresponding elements,  138 ,  139  described in relation to the embodiment illustrated in FIGS.  2 - 3 .  
     [0041] While specific embodiments and methods for practicing this invention have been described in detail, those skilled in the art will recognize various manifestations and details that could be developed in light of the overall teachings herein. Specifically, a variety of interlocking closure member designs are known in the art. While several specific embodiments have been illustrated and described in detail, any appropriate interlocking closure members may be used with the sealing members described herein to form the liquid tight closure mechanism of the present invention. Accordingly, the particular mechanisms disclosed are meant to be illustrative only and not to limit the scope of the invention which is to be given the full breadth of the following claims and any and all embodiments thereof.