Patent Publication Number: US-8974118-B2

Title: Reclosable bag having a sound producing zipper

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to closure mechanisms for reclosable pouches, and more particularly, to such closure mechanisms that create a desirable sound for the user during closure. 
     2. Background of the Related Art 
     Thermoplastic bags are used to store various items. Typically, a closure mechanism allows selective sealing and unsealing of the bag. Use of closure mechanisms has been widely used and well understood in the art. 
     Some examples are illustrated in the following: U.S. Pat. No. 3,656,147 discloses a plastic bag having male and female resealable interlocking elements integrally attached thereto for selectively opening and closing an end of the bag; U.S. Pat. No. 6,138,329 discloses a reclosable bag having an assembly that includes first and second male arrow-shaped profiles extending perpendicularly from a first base; and U.S. Pat. No. 6,167,597 discloses a zipper strip for a reclosable package, wherein the zipper strip includes a male and a female profile, wherein each male member has an asymmetrical arrow shape so that the zipper is easier to open from one side than the other. 
     Further, U.S. Pat. No. 6,953,542, issued to Cisek on Oct. 11, 2005, discloses a bag closure device with a stepped deflection of the closure device to result in a popping sound as the closure is opened or closed. U.S. Pat. No. 5,647,100, issued to Porchia et al. on Jul. 15, 1997 (the &#39;100 patent), discloses a deforming head apparatus for creating indentations in a portion of a bag zipper to create a bumpy feel and/or an audible clicking sound upon opening and closing. 
     Still further, U.S. Pat. No. 5,140,727, issued to Dais et al. on Aug. 25, 1992 (the &#39;727 patent), discloses a zipper for a reclosable bag which produced a bumpy feel and/or an audible clicking sound. The zipper of the &#39;727 patent has two opposing, longitudinally extending interlockable rib and groove profiles configured so that intermittent parts of the profiles are structurally discontinuous along a length thereof. The intermittent parts are created by a deformer wheel such that the segments with indentions have lesser relative length than those segments without indentions so as to minimize the likelihood or incidence of liquid leakage through the interlocked zipper. 
     Despite the advances in zippers for plastic bags, deficiencies remain in that one cannot be sure that the zipper is properly closed to seal the bag. For example, although the zipper may produce an audible sound, the sound may not be easily heard or recognized as closing the bag by the user. 
     SUMMARY OF THE INVENTION 
     There is a need for an improved zipper which produces a desirable sound upon closing and opening that allows a user to clearly discern that the bag is adequately closed. The subject technology is directed to a zipper for a bag that produces a more optimal sound for the user. In one embodiment, the closure sound is a relatively lower frequency (i.e., deeper) and higher level (i.e., louder) sound. 
     In one embodiment, the subject technology is directed to a zipper for a reclosable bag including an elongated groove profile having two arms which form a general U-shape to define an opening to a channel, and an elongated rib profile opposing the groove profile. A plurality of first segments of the rib profile alternate with a plurality of second segments of the rib profile to create a structural discontinuity along a length thereof. The first segments have larger cross-sections and shorter lengths than the second segments such that interlocking the groove and rib profiles creates the audible clicking sound when the groove and rib profiles are engaged. 
     Preferably, a ratio of the length of the second segments to the length of the first segments is greater than one. For example, the length of the first segments is less than about 0.152 of an inch {3.86080 mm}, the length of the second segments is greater than about 0.157 of an inch {3.98780 mm}, and the channel generally has a transverse diameter of about 0.0375 of an inch {0.95250 mm} 
     The rib profile also defines a stem extending from a base and terminating in a head, the stem being substantially unchanged between the first and second segments. A ratio of a thickness of the head to a thickness of the stem is about 2:1 in the first segments. In one embodiment, the thickness of the head in the first segments being in a range of 0.02989 inches {0.75921 mm} plus and minus one standard deviation of 0.00218 inches {0.0553720 mm} and the thickness of the head in the second segments is less than or equal to 0.00245 inches {0.062230 mm} The corresponding opening is about 0.010 of an inch {0.25400 mm} when the rib and groove profiles are separated. The groove profile includes a distal hook on each arm to provide: resistance to the rib profile interlocking within the channel; retention of the rib profile therein; and a sealing interface between the rib and groove profiles. 
     In another embodiment, the subject technology is directed to a zipper for a reclosable bag that generates audible sound continually therealong when interlocked. The zipper includes an elongated groove profile having two arms which form a general U-shape to define an opening to a channel, and an elongated rib profile opposing the groove profile. The rib profile includes a head to provide resistance to interlocking within the channel. A ratio of a thickness of the head of the rib profile to the opening of the groove profile is about 3:1 such that interlocking the groove and rib profiles creates the audible sound. The rib profile includes a stem extending from a base and terminating in the head and a second ratio of the thickness of the head to a thickness of the stem is about 2:1. 
     Still another embodiment is directed to an elongated including a groove profile having two arms which form a general U-shape to define an opening to a channel, and a rib profile opposing the groove profile, wherein the rib profile includes a head to provide resistance to interlocking within the channel and a ratio of a thickness of the head of the rib profile to the opening of the groove profile is about 3:1, and a plurality of first segments of the rib profile alternate with a plurality of second segments of the rib profile to create a structural discontinuity along a length thereof, the first segments having larger cross-sections and shorter lengths than the second segments such that interlocking the groove and rib profiles creates the audible clicking sound. Each of these zippers may also be used in recloseable pouches that define an interior by a first wall and a second wall opposing and partially sealed to the first wall to form a mouth for access to the interior. 
     It should be appreciated that the present technology can be implemented and utilized in numerous ways, including without limitation as a process, an apparatus, a system, a device, a method for applications now known and later developed. These and other unique features of the technology disclosed herein will become more readily apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that those having ordinary skill in the art to which the disclosed system appertains will more readily understand how to make and use the same, reference may be had to the following drawings. 
         FIG. 1  is a plan view of a reclosable pouch having a zipper in accordance with the subject technology. 
         FIG. 1A  is an enlarged isometric fragmentary view partly in section of the zipper in  FIG. 1 , wherein the rib and the groove profile are being interlocked by hand. 
         FIG. 2  is an enlarged isometric fragmentary view partly in section of the groove profile of the zipper shown in  FIG. 1 . 
         FIG. 2A  is an enlarged cross-sectional view of the groove profile of  FIG. 2  taken along line  2 A- 2 A. 
         FIG. 3  is an enlarged isometric fragmentary view partly in section of the rib profile of the zipper shown in  FIG. 1 . 
         FIG. 3A  is an enlarged cross-sectional view of the rib profile of  FIG. 3  taken along line  3 A- 3 A. 
         FIG. 4A  is an enlarged cross-sectional view through an undeformed section of the rib profile of the zipper of  FIG. 1  in a sealed position. 
         FIG. 4B  is an enlarged cross-sectional view through a deformed section of the rib profile of the zipper of  FIG. 1  in a sealed position. 
         FIG. 5  is perspective view of a deformer ring for use in a deforming apparatus in accordance with the subject technology. 
         FIG. 6  is top view of the deformer ring of  FIG. 5 . 
         FIG. 7  is cross-sectional view of the deformer ring of  FIG. 6  taken along line  7 - 7 . 
         FIG. 8  is a graph of sound level during closing of a preferred embodiment of the subject technology in contrast with a prior art embodiment. 
         FIG. 9  is a graph of sound level during opening of a preferred embodiment of the subject technology in contrast with a prior art embodiment. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present disclosure overcomes many of the prior art problems associated with sealing storage bags and the like. The advantages and other features of the technology disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present invention and wherein like reference numerals identify similar structural elements. 
     Unless otherwise specified, the illustrated embodiments can be understood as providing exemplary features of varying detail of certain embodiments, and therefore, unless otherwise specified, features, components, modules, elements, and/or aspects of the illustrations can be otherwise modified, combined, interconnected, sequenced, separated, interchanged, positioned, and/or rearranged without materially departing from the disclosed systems or methods. It is also noted that the accompanying drawings are somewhat idealized in that, for example without limitation, features are shown as substantially smooth and uniform when in practice, manufacturing variances and abnormalities would occur as is knows to those of ordinary skill in the art. 
     Referring to  FIG. 1 , a plan view of a reclosable pouch  50  having a zipper  43  in accordance with the subject technology is shown. The zipper  43  is preferred by users because the zipper produces a desirable sound upon closing and opening that allows a user to clearly discern that the bag is adequately closed without significantly compromising the closing force or seal integrity. The closure sound is a relatively lower frequency (i.e., deeper) and higher level (i.e., louder) sound. The recloseable pouch  50  includes opposing walls  58  partially sealed to the first wall to form defines an interior and a mouth for access to the interior. 
     Referring to  FIG. 1A , a zipper  43  of a preferred embodiment is shown being interlocked by the thumb  52  of a hand. The thumb  52  engages opposing longitudinally extending interlockable rib and groove profiles  40 ,  41 . Without being bound by any particular theory, it is believed that the zipper  43  produces a relatively more effective and desirable audible clicking sound when the zipper profiles  40 ,  41  are interlocked due to intermittent discontinuity in structure along portions of either or both of the rib profile  40  or the groove profile  41 . The discontinuity in structure is typically in those portions of the opposing profiles which in conventional constructions contact each other when a zipper  43  is zipped. The new structure of the profiles  40 ,  41  creates a lower frequency and generates increased energy to result in the louder sound. The terms “rib profile” and “groove profile” are used as terms of convenience to describe opposing interlockable male and female zipper profiles, and are not to be construed as limiting. 
     The zipper profiles  40 ,  41  may also produce a vibratory or bumpy feel during closure. The audible clicking and vibratory or bumpy feel on zipping are considered separable features of the present technology. Accordingly, a zipper may produce an audible clicking sound when zipped without imparting a vibratory or bumpy feel and vice versa while still being within the scope of the present technology. 
     Referring now to  FIGS. 2 and 2A , an enlarged isometric fragmentary view partly in section of the groove profile  41  of the zipper  43  and a cross-sectional view along line  2 A- 2 A are shown, respectively. The groove profile  41  includes opposing groove arms  47  which extend from a groove base  41   a  in a general U-shaped to define an opening  54  to a channel  55 . The channel  55  generally has a diameter of about 0.032 of an inch {0.81280 mm} The opening  54  is preferably about 0.010 of an inch {0.25400 mm} as noted on  FIG. 2A . The groove profile  41  is further characterized by intermittent and preferably alternating first and second segments  100 ,  102 . 
     In segments  100 , groove arms  47  have hooks  49  at the distal free ends whereas in segments  102 , the arms  47  have no such hooks. The indentions within segments  102  are manifest by the lack of such hooks. The groove arms  47  of segments  100  have surfaces  98  which are generally planar and perpendicular to the longitudinal extension of the groove arms  47 . Segments  102  define surfaces  99  which are generally planar and positioned at about right angles to surfaces  98 . 
     Referring now to  FIGS. 3 and 3A , an enlarged isometric fragmentary view partly in section of the rib profile  40  of the zipper  43  and a cross-sectional view along line  3 A- 3 A are shown, respectively. The rib profile  40  defines a stem  42  extending from a rib base  40   a  (see  FIG. 4 ) to terminate distally in a head portion  46   a ,  46   b . The rib profile  40  also defines intermittent and preferably alternating first segments  104  and second segments  106 . The segments  104 ,  106  have different shapes, which create a structural discontinuity. The head portion  46   a  of segments  104  has a relatively larger cross-section than the head portion  46   b  of the segments  106 . The rib profile  40  may also include ribs extending parallel on each side of the rib profile  40  and other features such as would be known by those of ordinary skill in the art. 
     The segments  104  and the head portion  46   a ,  46   b  have surfaces  109 , which interact with the groove profile  41  to create an audible clicking noise and a bumpy feel during closing. The surfaces  109  also produce an audible clicking noise and a bumpy feel during opening the profiles  40 ,  41  as well. Although shown as having a transition area between the segments  104 ,  106  that is at about right angles to the length of the rib profile  40 , the transition between the segments  104 ,  106  may taper somewhat. 
     Referring now additionally to  FIGS. 4A and 4B , enlarged cross-sectional views of the zipper  43  of  FIGS. 1-3  through sections  104 ,  106 , respectively, are shown in a sealed position. The rib profile  40  and the groove profile  41  interlock along their essentially continuous to provide a seal. Although structurally discontinuous, the profiles  40 ,  41  have the necessary surfaces to provide a substantially leak-proof seal along the entire length thereof. 
     Still referring to  FIGS. 3 and 3A , in the segments  104 , the head portion  46   a  is somewhat triangular or arrow head shaped in cross-section with a widest portion  51   a  adjacent the stem  42 . The shape of the head portion  46   a  is not limited to the embodiment shown and may be more or less triangular, bulbous, or round with variations thereto for creating protrusions, hooks, and the like. The widest portion  51   a  is oversized as compared to the prior art with a preferred width of 0.029 to 0.031 of an inch {0.73660 to 0.78740 mm} for a corresponding opening  54  of the groove profile  41  of 0.030 of an inch {0.76200 mm} The over-sizing of the widest portion  51   a  helps create a louder noise during opening and closing of the zipper  43 . 
     In the segments  106 , the head portion  46   b  is generally deformed at the widest portion  51   b  to a more generally bulbous shape. The term “bulbous” as used herein includes not only rounded cross-sections but also a generally arrow-shaped, triangular-shaped, quatrefoil-shaped, and like configurations in cross-section as may be created during deformation. Preferably, the deformation within segments  106  is largely removal of the widest part  51   b  of the head portion  46  of the segments  104  comparatively. 
     Still referring to  FIGS. 4A and 4B , when segments  106  of the rib profile  40  and segment  100  of the groove profile  41  interlock, the groove arms  47  straddle the head portion  46  to retain the profiles  40 ,  41  in the closed, sealed position. The widest portions  51   a ,  51   b  of the head portion  46  engage and are interlockingly coextensive with the hooks  49  of the groove arms  47 . The points of contact between the rib profile  40  and the groove profile  41  provide sealing, which maintains the interior of the pouch  50  in a leak-proof manner. Preferably, the opening  54  between the hooks  49  of the groove arms  47  is smaller than the diameter of the stem  42  of the rib profile  40  to create the sealing contact points. In one embodiment, the opening  54  is 0.010 of an inch {0.25400 mm}, the diameter or width of the stem  42  is about 0.015 to about 0.020 of an inch {0.38100 to 0.50800 mm}, and the head portion  46  is about 0.030 of an inch {0.76200 mm}. 
     Zippers of the present technology may have a plurality of intermittent or alternating segments of differing shape along one or both of the profiles, but preferably have intermittent or alternating segments of two different shapes as in the embodiments illustrated herein. The segments of differing shape may be of equal or unequal length. Surprisingly, the segments having indentions or deformations of greater relative length than those segments not having indentions optimizes the resulting audible clicking noise according to user preference without a loss in performance despite conventional wisdom that such an arrangement would perform poorly. 
     Preferably, a ratio of the length of the deformed segments  106  to the length of the undeformed segments  104  is greater than one. More preferably, the length of the undeformed segments is less than about 0.152 of an inch {3.86080 mm} and the length of the deformed segments  106  is greater than about 0.157 of an inch {3.98780 mm} In one embodiment, the length of each segment with an indention is preferably about 0.175 of an inch {4.44500 mm} whereas segments without an indentation are about 0.147 of an inch {3.73380 mm} 
     In Operation 
     Again, while not bound by any particular theory, the audible clicking sound and the vibratory or bumpy feel associated with the zipper  43  are believed to result from the hooks  49  of the groove arms  47  contacting the planar surfaces  107  and  109  of head  46  as the profiles  40 ,  41  are interlocked along the length of the zipper  43 . The extended length of the deformed segments  102 ,  104  contributes to the lower frequency of the sound and the oversizing of the head portion  46   a ,  46   b  with respect to the opening  54  contributes to the louder sound. The various elements of the profiles  40 ,  41  are proportioned and configured so that an optimal audible indication of closure is provided suprisingly without compromising the seal between the profiles  40 ,  41  or making the profiles  40 ,  41  too stiff to close or interlock without applying excessive force. 
     To provide an indication of the proportions of the various elements of the profiles  40 ,  41  with respect to one another for accomplishing these purposes, it has been found desirable for the upper laterally-disposed portions of the head  46   a  in segments  104  to be sized so that the widest part  51   a  the head portion  46   a  does not push the groove profile  41  open after insertion. The widest part  51   a  of the head portion  46   a  is substantial enough to provide some resistance to the interlocking of the profiles  40 ,  41  and, in this regard, are each preferably from about 0.029 to about 0.031 inches thick {0.73660 to 0.78740 mm} (measured from side to side at a maximum width). 
     The corresponding groove profile  41  is preferably dimensioned so that the opening  54  or juncture of the groove arms  47  with the hooks  49  is about 0.006 to about 0.015 of an inch {0.15240 to 0.38100 mm} Generally, the groove arms  47  are from about 0.015 to about 0.019 inches {0.38100 to 0.48260 mm} apart. In a preferred embodiment, the opening  54  to the channel  55  is approximately 0.010 of an inch {0.25400 mm} The hooks  49  are preferably from about 0.006 to about 0.020 inches {0.15240 to 0.50800 mm} in length, and the groove base  41   a  is preferably from about 0.005 to about 0.020 of an inch {0.12700 to 0.50800 mm} in thickness. 
     As would be appreciated by those of ordinary skill in the pertinent art, the subject technology is applicable to any type of bag, pouch, package, and various other storage containers with significant advantages for sandwich and quart size bags. The subject technology is also particularly adaptable to double zipper or closure mechanisms such as shown in U.S. Pat. No. 7,137,736 issued on Nov. 21, 2006 to Pawloski et al. and U.S. Pat. No. 7,410,298 issued on Aug. 12, 2008 also to Pawloski, each entitled “Closure Device for a Reclosable Pouch” and incorporated herein by reference in their entireties. In a multiple closure mechanism arrangement, such as a double zipper arrangement, the subject technology may be used for one or both of the closure mechanisms. 
     A Process and Apparatus for Making the Zipper 
     Now referring to  FIGS. 5-7 , perspective, top, and cross-sectional views of a deformer ring  70  for use in a deforming apparatus (not shown) in accordance with the subject technology are shown. The deforming apparatus may be that as shown in the &#39;727 patent or the &#39;100 patent. The deformer ring  70  may also be implemented in other deforming apparatus now known and later developed. The deformer ring  70  has an annular body  72  with a plurality of teeth  74  formed on an outer circumference thereof. A throughbore  76  is formed in the annular body  72  to receive a dowel  78 , which facilitates mounting the deformer ring  70  to the deforming apparatus. The teeth  74  are separated by gaps  80 , which create a tooth arc length  82  and gap arc length  84  on the outermost portion of the deformer ring  70 . In use, it is the size of the tooth arc length  82  and the gap arc length  84  that form the structural discontinuity in the profiles  40 ,  41 . Preferably, the tooth arc length  82  is about 0.175 of an inch {4.44500 mm} and the gap arc length  84  is about 0.148 of an inch {3.75920 mm} 
     One process for making a thermoplastic zipper  43  for a reclosable thermoplastic bag using the deformer ring includes the step of continuously extruding a longitudinally extending first zipper profile having a part interlockable with a longitudinally extending opposing second zipper profile while restricting at intervals the flow of molten polymer to a profile plate for forming the first zipper profile. Part of the first zipper profile is made intermittently structurally discontinuous along its length and defines at least a first undeformed segment of about 0.148 of an inch {3.75920 mm} and a second deformed segment of about 0.175 of an inch {4.44500 mm} therein characterized by cross-sections of different sizes but a common configuration imparting an audible clicking sound continually there along when the profiles are interlocked or separated from each other. The process may also interlock the first and second profiles so that the segmented part of the first profile is substantially free of interdigitation with the second profile. 
     An apparatus for making such a longitudinally extending zipper for a reclosable thermoplastic bag would include an extruder for providing longitudinally extending first and second profiles having a longitudinally extending part interlockable with a longitudinally extending opposing second zipper profile and a deformer ring for deforming the part to form indentions therein intermittently along its length at a desired spacing at any selected linespeed. 
     In one preferred embodiment of zipper  43 , the undeformed segments  100 ,  104  of a length equal to about 0.147 of an inch {3.73380 mm} and deformed segments  102 ,  106  of a length equal to about 0.175 of an inch {4.44500 mm} The thickness of the head portion  46   a  in the regular segments  104  of the rib profile  40  was about 0.02989 of an inch {0.75921 mm} and the thickness of the head portion  46   b  in the deformed segments  106  was about 0.0245 of an inch {0.62230 mm} The opening  54  to the channel  55  of the groove profile  41  was about 0.010 of an inch {0.25400 mm} when the rib and groove profiles  40 ,  41  are separated. 
     COMPARATIVE EXAMPLES 
     A palmograph unit (shown and described in U.S. Pat. Nos. 5,154,086 and 5,647,100) was also used to determine the degree of vibratory feel and the average closing force of prior art zippers and zippers in accordance with the subject technology. Generally, a palmograph unit performs three main functions: (1) closing the zipper; (2) monitoring the force required to close the zipper and the oscillations in closing force; and (3) analyzing the force required to close the zipper. 
     For palmograph values, prior art zippers as shown and described in FIG. 5 of U.S. Pat. No. 7,410,298 (the “prior art zipper”) were tested. For comparison, a plurality of zippers in accordance with the subject technology or preferred zippers were also tested. The preferred zippers were similar to the prior art zipper in that each included first and second closure mechanisms. The inner or product side zipper was unchanged, namely a single hook for a male profile. However, the outer or consumer side zipper was the new and improved clicking zipper with the modifications described herein. The test bags utilized a film for sidewall of approximately 0.075 of an inch {0.1905 mm} 
     The palmograph results surprisingly showed that closing force and palmograph values remained relatively unchanged. One of ordinary knowledge in the pertinent art would have expected the relatively larger deformed segments  100 ,  104  and/or the oversized head portion  46   a ,  46   b  would detrimentally impact the closing force. 
     Turning to measuring user preference (known as “paragon” values), the frequency of the audible clicking is an important factor in determining user preference. The same zippers were tested. The preferred embodiment in accordance with the subject disclosure exhibited a lower frequency or deeper sound, which was more easily heard, recognized, and preferred by users. 
     Referring now to  FIGS. 8 and 9 , graphs of sound level during closing and opening, respectively, of the same preferred zippers of the subject technology in contrast with the same prior art embodiment are shown. Referring to  FIG. 8  in particular, the average sound level for the preferred zippers was 57.37 dB whereas the prior art zippers was 49.10 dB, which makes for a significant 8.27 dB increase. The results are also presented graphically as each pair students t, which further illustrate how the preferred embodiment generates a louder sound. 
     In view of the above results, the novel structure of the closure member of the present technology advantageously provides a significant unexpected improvement in paragon and loudness, suprisingly without detrimentally impacting palmograph performance or closing force compared to commercially available zippers. 
     All patents, published patent applications and other references disclosed herein are hereby expressly incorporated in their entireties by reference. 
     While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as defined by the appended claims. For example, each claim may depend from any or all claims in a multiple dependent manner even though such has not been originally claimed.