Patent Publication Number: US-2003235352-A1

Title: Transverse direction zipper tape

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a transverse direction zipper tape for a reclosable container, such as a plastic bag. More specifically, the present invention relates to the attachment of a perforated cap zipper tape to a web in a transverse direction.  
       [0003] 2. Description of the Prior Art  
       [0004] In the prior art, tamper-evident, hermetic reclosable containers, such as plastic bags, are known. Typical examples of this prior art are U.S. Pat. No. 5,023,122 entitled “Easy Open Bag Structure” issued to Boeckmann et al. on Jun. 11, 1991 and U.S. Pat. No. 5,100,246 entitled “Pull Bead and Guide Rails for Easy Open Flexible Containers” issued to La Pierre et al. on Mar. 31, 1992. While this art is well-developed, improvements in various aspects are sought.  
       SUMMARY OF THE INVENTION  
       [0005] The present invention is a method and apparatus relating to a reclosable container, such as a plastic bag, with a segment of perforated cap zipper tape applied to the web in a transverse direction. This provides a hermetic, tamper-evident, easy opening package, even for polyethylene packages that would normally require the consumer to use scissors to open the package. The cap or base is typically made from a material that will keep the inner flanges from sealing together from the main seal but still allow the zipper segment end seals to fuse together. Alternatively, the thickness of the cap or base can be used to provide enough insulation from the main seal.  
       [0006] More particularly, the perforated cap zipper tape provides a loop between the flanges of two zipper profiles and perforations are provided within the loop, so that the loop, which forms a header, can be removed from the package to provide access to the package and to provide evidence of prior opening. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007] Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:  
     [0008]FIG. 1 is a perspective view of the perforated cap and related structure of the present invention.  
     [0009]FIG. 2 is a plan view of the formed bag of the present invention.  
     [0010]FIG. 3 is a plan view of a first embodiment of the end seals of the formed bag of the present invention.  
     [0011]FIG. 4 is a plan view of a second embodiment of the end seals of the formed bag of the present invention.  
     [0012]FIG. 5 is a plan view of a third embodiment of the end seals of the formed bag of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0013] Referring now to the drawings in detail wherein like numerals refer to like elements throughout the several views, one sees that FIG. 1 is a perspective view of perforated cap structure  10  of the present invention.  
     [0014] Zipper  12  includes male interlocking profile  14  and female interlocking profile  16 . Zipper tape  18  is secured to both male and female interlocking profiles  14 ,  16  thereby forming extended tack flange  20  below female interlocking profile  16 , extended tack flange  21  below male interlocking profile  14 , and loop  22  between interlocking profiles  14 ,  16 . Loop  22  of zipper tape  18  further includes interior reinforcing layer  24  thereby forming a “cap structure”. The upper interior apex of loop  22  further typically includes stiffener  26  therewithin. Moreover, a first line of perforation  28  (or a similarly weakened area) is formed through zipper tape  18  between the apex of loop  22  and male interlocking profile  14 . Similarly, a second line of perforation  30  (or a similarly weakened area) is formed through zipper tape  18  and between the apex of loop  22  and female interlocking portion  16 . In order to maintain a hermetic seal prior to the tearing of first and second lines of perforation  28 ,  30 , typically the internal reinforcing layer  24  is not perforated. However, first and second lines of perforation  28 ,  30  can extend through internal reinforcing layer  24  if the hermetic quality of the package is not necessary. As illustrated in FIG. 1, first and second lines of perforation  28 ,  30  allow the upper portion or header  32  of loop  28  to be removed. When perforated cap structure  10  is sealed to a web to form a reclosable container as shown in FIG. 2, this structure allows header  32  to be removed to provide access to zipper  12  and the contents of the reclosable container while further providing evidence of prior opening, or tamper evidence.  
     [0015]FIG. 2 is a plan view of a typical reclosable container or bag  100  formed with perforated cap structure  10 . Reclosable container or bag  100  includes front and rear panels  102 ,  104  (shown overlapping) of film with a bottom seal  106 , side seals  108 ,  110 . It is envisioned that one or more of seals  106 ,  108 ,  110  could be replaced by folds depending upon the particular method of formation of reclosable container or bag  100 . However, it is specifically envisioned that reclosable container or bag  100  is formed by placing zipper tape  18  in a transverse direction along a film in a form fill and seal operation.  
     [0016] Main seal  112  is formed between front panel  102  and a first side of zipper tape  18  and is likewise formed between rear panel  104  and a second side of zipper tape  18 . The zipper tape  18  can be made from a material that will keep the inner portions of the first and second sides of zipper tape  18  from sealing together during the formation of the main seal  112  but still allow the zipper segment end seals proximate to side seals  108 ,  110  to seal together. This may be done by providing a non-seal layer on the zipper segment but applying sufficient additional heat and pressure, such as with a hot knife or an ultrasonic welder, to form the zipper segment end seals. Alternately, the thickness of zipper tape  18  or cap  24  can be chosen to provide enough insulation from main seal  112  to prevent the inner portions of the first and second sides of zipper tape  18  from sealing to each other while similarly providing sufficient additional heat and pressure to form the zipper segment end seals.  
     [0017] An additional envisioned embodiment of bag  100  would include a seal or fold along top  111  and further include lines of perforation along front and rear panels  102 ,  104  downwardly adjacent from top  111 .  
     [0018] Additionally, as shown in FIGS. 2 and 3, the lateral ends of zipper tape  18  have wide flat crush areas  116 ,  118  formed inwardly adjacent from side seals  108 ,  110 , respectively. In crush areas  116 ,  118 , the interior of first and second sides of zipper tape  18  are sealed together. Notches  120 ,  122  are formed in the sides of crush areas  116 ,  118  aligned with the ends of first and second lines of perforation  28 ,  30  (first and second lines of perforation  28 ,  30  shown overlapping each other). Additionally, the bag film of front and rear panels  102 ,  104  is removed to form a semi-circular notch  126  inwardly adjacent from side seal  108  and downwardly adjacent from top  111  of bag  100 . This removal is typically done to the front and rear panels  102 ,  104  prior to the attachment of zipper tape  18  in order to avoid damage to the zipper tape  18 . The lower portion of semi-circular notch  126  is generally aligned with notch  120  and first and second lines of perforation  28 ,  30  in order to allow the user to grasp the portion of crush area  116  above notch  126  (that is, header  32  of loop  28  as shown in FIG. 1) and to easily tear along first and second lines of perforation  28 ,  30  above main seal  112  in order to provide access to zipper  12 . Upon opening zipper  12 , the user has access to the contents of reclosable package or bag  100 . This embodiment further requires zipper  12  to be segmented from the remaining supply of zipper by cutting in the middle of a large crush area to form the zipper segment and create the two separate crush areas  116 ,  118 .  
     [0019]FIG. 4 shows a second embodiment of the end seals of zipper tape  18 . In this embodiment, crush areas  116 ,  118  are somewhat narrower than that of the embodiment of FIGS. 2 and 3. Additionally, crush areas  116 ,  118  are inwardly inset from the ends of zipper tape  18 . This embodiment similarly requires zipper  12  to be segmented between the crush areas  116 ,  118 .  
     [0020]FIG. 5 shows a third embodiment of the end seals of zipper tape  18 . In this embodiment, the crush areas  116 ,  118  of FIGS. 2, 3 and  4  are replaced with seal ends  130 ,  132  which are segment sealed at the very edges.  
     [0021] Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.