Abstract:
The present disclosure relates to a method, apparatus and product in the art of reclosable packaging wherein the zipper is sealed to a film structure prior to treatment by the packaging machine for producing a thermoformed package. The zipper can be oriented in the machine direction, the transverse direction or at an angled orientation.

Description:
BACKGROUND OF THE DISCLOSURE 
       [0001]    This application claims priority under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 61/811,938, filed on Apr. 15, 2013, the disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE DISCLOSURE  
       [0002]    The present disclosure relates to a method, apparatus and product wherein the zipper of a reclosable thermoform package is sealed to a film structure prior to treatment by the packaging machine. The zipper can be oriented in the machine direction, the transverse direction or at an angled orientation. 
       DESCRIPTION OF THE PRIOR ART 
       [0003]    With respect to zippered reclosable packages, current pre-applied zipper applications are available in the transverse film direction, specifically to run on vertical form fill seal (VFFS) or overwrap machines. This may be achieved through the Innolok® process. There are also current applications for manufacturers to run zipper and film, separately, in the transverse direction on vertical form fill seal and overwrap machines. 
         [0004]    Manufacturers who want to supply their customers with packages with reclosable technology have the option to purchase equipment that has reclosable technology or to use equipment that does not have the capability to run zipper. Applications for having zipper in the machine or film direction on packages are currently limited to running film and zipper separately. This requires manufacturers who want a package with reclosable features to purchase or refit their packaging machine in order to run film and zipper. This is a costly choice for manufacturers who want to supply their customers with a reclosable package. Supplying a technology that will enable a film to have a pre-applied zipper will open opportunities to many manufacturers who would like to incorporate reclosable technology in their package, but for whatever reason, cannot purchase new equipment or retrofit existing equipment to achieve a resealable or reclosable package. 
         [0005]    Prior art includes U.S. Pat. No. 4,896,775 entitled “Zipper Thermal Form Tray System”; U.S. Pat. No. 4,949,527 entitled “Method of Forming a Reclosable Tray”; U.S. Pat. No. 6,941,726 entitled “Method and Apparatus for Makin; Reclosable Packages Having Slider-Actuated Siang Zippers”; U.S. Pat. No. 6,820,394 “Method for Forming Zippered Thermoformed Packages”; U.S. Pat. No. 7,302,782 entitled “Method and Apparatus for Making Reclosable Packages 1-laying Slider-Actuated String Zippers” and U.S. Pat. No. 7,325,378 entitled “Vertical Form Fill and Seal Method for Producing Reclosable Packages from Two Sheets of Web”. 
       OBJECTS AND SUMMARY OF THE DISCLOSURE 
       [0006]    It is therefore an object of the present disclosure to provide a method, apparatus and product wherein the zipper is sealed to a film structure prior to treatment by the packaging machine. This can be done in the machine direction, the transverse direction or at an angled orientation. This is particular applicable to thermoform applications. 
         [0007]    These and other objects are obtained by taking an existing zipper (such as, but not limited to a slider zipper or a zipper with a pre-activated peel seal) and sealing it to a film structure in the machine direction (also known as the film unwind direction) prior to the packaging machine. In the case of a thermoform machine, the zipper would be placed either on the non-forming film or the forming film inside of the machine-made seals, in the machine direction, typically configured so that the zipper is attached to the forming film which forms the top of the package. The only part of the zipper that would be sealed to the forming film (in the case of the zipper being pre-sealed onto the non-forming film) would be at the ends of the package (cross seal bars) and vice versa for the zipper being sealed onto the forming film. For the thermoform package, there may be several zippers being presealed if the machine was a two, three or four-up machine. On a vertical, horizontal or overwrap form film seal machine, the zipper would be sealed to the film prior to the packaging machine in the machine or film direction. 
         [0008]    Further, these and other advantages are obtained in that the zipper segments typically need to be attached to only one web on a two-web packaging system, such as a TFFS (transverse or thermoform form fill seal) system with a forming web and a separate lidding web. Further, in some embodiments of this disclosure, there are discrete zipper segments which can be made short enough that they do not extend into the cross-seals thereby greatly reducing the likelihood of leaks, which can be critical for TFFS packages which are typically modified atmosphere packages containing easily spoiled products. 
         [0009]    Likewise, these and other advantages are obtained by taking a similar zipper and sealing it to the forming or non-forming web of a thermoform machine in a transverse or angled direction. The zipper applied to the forming film in either the transverse or angled direction would be applied to the material at the bottom of the pocket area and the package/tooling would have to be designed to have minimal distortion and heat applied to the zipper area. Multiple applicators and spools could be employed to accommodate multiple lane thermoform machines. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Further objects and advantages of the disclosure will become apparent from the following description and from the accompanying drawings, wherein: 
           [0011]      FIG. 1  is a perspective view of a spool of film with a double zipper applied in the machine direction. 
           [0012]      FIG. 2  is a top view of a typical thermoformed package made from the film of  FIG. 1 . 
           [0013]      FIG. 3  is a perspective view of a spool of film with zipper applied in the transverse direction. 
           [0014]      FIG. 4  is a top view of a typical thermoformed package made from the film of  FIG. 3 . 
           [0015]      FIG. 5  is a plan view of a press-to-close zipper, diagonally directed on a forming or non-forming web. 
           [0016]      FIG. 6A  is a plan view of a press-to-close zipper in a machine direction on a forming or non-forming web. 
           [0017]      FIG. 6B  is a plan view of a press-to-close zipper in a transverse direction on a forming or non-forming web. 
           [0018]      FIG. 7  is a plan view of a pivoted applicator arm, for applying zipper in a transverse or angled orientation. 
           [0019]      FIG. 8A  illustrates a top plan view of the package of  FIG. 6A . 
           [0020]      FIG. 8B  illustrates a top plan view of the package of  FIG. 5 . 
           [0021]      FIG. 9  illustrates a cross-sectional view of the zipper configuration in a tray-type embodiment of the present disclosure. 
           [0022]      FIG. 10  illustrates a cross-sectional view of the embodiments of  FIGS. 2 ,  4 ,  5  and  6 . 
           [0023]      FIG. 11  illustrates a manufacturing process of embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    Referring now to the drawings in detail, wherein like numerals indicate like elements through the several views, one sees that  FIG. 1  is a spool  100  of film or web  102 , wherein the film or web  102  includes two pre-applied machine direction zippers  108  (pre-applied as a continuous length) thereby forming a double zipper, comprising zipper profiles  104 ,  106 . One zipper profile  104  or  106  is attached to the film or web  102  and the other zipper profile  104 ,  106  is engaged or interlocked with the profile attached to the film or web  102 . Film or web  102  is typically configured so that the zipper profiles  104 ,  106  are applied underneath the top film of a package with the opening flange facing upward against the film. The spool  100  of film or web  102  as illustrated in  FIG. 1  is provided to a packaging machine (not shown). The spool  100  of film or web  102  may be manufactured at a location either local or remote from the packaging machine. The packaging machine typically takes film or web  102  along with another film or web (not shown) which does not include zipper components, and forms top and bottom walls  110 ,  112  (wherein bottom wall  112  may be thermoformed with a pocket structure), with the zipper profiles  104 ,  106  on the interior of the package  200 , as illustrated in  FIG. 2 . The packaging machine forms first lengthwise seal  202 , side seals  204 ,  206  and second lengthwise seal  208  between the two sheets of film or web  102  and one sheet of film thereby forming the rectangular shape of the package  200 , wherein web  102  becomes the top wall of package  200 . Additionally, in order to provide access to the zipper  108 , lines of weakness  114  are formed in the film or web  102  above at least one of zipper profiles  104 ,  106  which form zipper  108  in top wall  110 . The zipper  108  is in contact with the top wall  110 , and not the bottom wall  112  or any of the seals between the top and bottom walls  110 ,  112 . The lines of weakness  114  form an easy-open element which is engaged by the zipper  108 . The easy-open element can be implemented in several ways which would be known to one skilled in the art, after review of the present disclosure, including, but not limited to, lines of weakness, perforations, score lines and adhesive patches. 
         [0025]    In tray-type embodiments, a cross-section such as is shown in  FIG. 9 , with a fold  140  behind the zipper  108 , formed in the sealing flange of zipper  108  may be necessary for a user to get his or her fingers behind the interlocking tracks and press them together or otherwise operate them. In the lack of such a structure, the contents of the package may interfere with one being able to press together the interlocking zipper tracks. The width of the film (with attached transverse zippers) controls whether one or more packages are produced from it. The fold  140  may be positioned within the zipper  108  or within the top wall  110 . 
         [0026]    In more detail, in the embodiment of  FIG. 4 , which illustrates an exemplary single zipper web arrangement, if the packaging machine is a thermoform machine, the zipper  108  would be placed either on the non-forming film or the forming film inside of the machine-made seals, in the machine direction. The only part of the zipper  108  that would be sealed to the forming film (in the case of the zipper being pre-sealed onto the non-forming film) would be at the ends of the package (cross seal bars) and vice versa for the zipper being sealed onto the forming film. For the thermoform package, there may be several zippers being presealed if the machine was a two, three or four-up machine. On a vertical, horizontal or overwrap form film seal machine, the zipper  108  would be sealed to the film prior to the packaging machine in the machine or film direction. In most cases, the zipper  108  will be on the lid, non-forming web or top side of the package. However, in some cases the zipper  108  may be found on the forming side of the package. 
         [0027]      FIG. 3  discloses a second embodiment wherein spool  100  of film or web  102  is provided. Transverse machine direction zipper profiles  108 ′ are attached periodically along the film or web  102 , and are provided as a series of discrete lengths of zipper material. Typically, the transverse machine direction zipper profiles  108 ′ are provided with zipper profiles  104 ,  106  in an interlocked configuration with one of the zipper profiles  104  or  106  sealed to the film or web  102 . This film or web  102  is provided to the packaging machine (not shown) as one web in a two-web packaging system wherein as shown in  FIG. 4 , similar to the embodiment of  FIG. 2 , first lengthwise seal  202 , side seals  204 ,  206  and second lengthwise seal  208  are formed thereby forming the rectangular shape of the package  200 . The spool  100  of film or web  200  may be manufactured at a location either local or remote from the packaging machine. Additionally, in order to provide access to the zipper  108 , lines of weakness  114  are formed in the film or web  102  above at least one of zipper profiles  104 ,  106  which form zipper  108 ′, typically in front or top wall  110 . 
         [0028]    In more detail, in the embodiment of  FIGS. 3 and 4 , the zipper segments typically need to be attached to only one web on a two-web packaging system, such as a TFFS (transverse or thermoform form fill seal) system with a forming web and a separate lidding web. Further, in some embodiments of this disclosure, there are discrete zipper segments which can be made short enough that they do not extend into the cross-seals thereby greatly reducing the likelihood of leaks, which can be critical for TFFS packages which are typically modified atmosphere packages containing easily spoiled products. 
         [0029]      FIGS. 5 ,  6 A and  6 B illustrate further embodiments of the package  200 , which may be thermoformed.  FIG. 5  illustrates an embodiment wherein the zipper  108  is placed in an angled orientation. The zipper  108  may be a press-to-close zipper, or some other style of zipper. The zipper  108  may further include peel seal  120 , and may still further include a line  122  including a color, such as may be provided in a Color Line™ bag or product.  FIG. 6A  is a similar embodiment but with a zipper  108  of a machine orientation in the middle of the package, while  FIG. 6B  illustrates an embodiment with a zipper in a transverse orientation in the middle of the package. In  FIGS. 5 ,  6 A and  6 B, the zipper  108  may be placed on the forming or non-forming web as provided to the packaging machine. 
         [0030]      FIGS. 9 and 10  are cross-sectional views of typical embodiments illustrated in  FIGS. 2 ,  4 ,  5  and  6 . In  FIG. 9 , the zipper  108  is formed within fold  140  behind the zipper  108  (formed in the sealing flange of zipper  108  which may be necessary for a user to get his or her fingers behind the zipper to operate the zipper). Zipper opening flange  107  is presented to the user after the user has opened line of weakness  114 , thereby allowing the user to grasp the zipper opening flange  107  to open the zipper.  FIG. 10  illustrates a similar configuration, including a peel seal  120  between the zipper opening flange  107  and the zipper  108 , but without a fold  140 , wherein closing the zipper does not interfere with the package contents. This configuration may be used for embodiments wherein reclosure is less important than with  FIG. 9 . 
         [0031]    As shown in  FIG. 7 , the packages of  FIGS. 5 and 6  may be formed by providing multiple lanes of packages  200  with a zipper applicator  300  pivoting on point  302 . With such a pivoting zipper applicator  300 , the zippers  108  may be provided at a chosen angled orientation, such as illustrated in  FIG. 5 , a machine direction as illustrated in  FIG. 6A , or at a transverse orientation as illustrated in  FIG. 6B . 
         [0032]      FIG. 8A  illustrates a top (or bottom) plan view of the package  200  of  FIG. 6A , while  FIG. 8B  illustrates a top (or bottom) plan view of the package  200  of  FIG. 5 . 
         [0033]      FIG. 11  illustrates a typical manufacturing process. Front film  102  is provided from spool  100 . Zipper material  108  is provided from spool  109  and is sealed to the front film  102  material. Tray material  500  is provided. The pockets within tray material  500  are formed, loaded and then sealed with the front film  102 , including the zipper material  108 . The front film  102  can be supplied separately from the tray material  500 . 
         [0034]    In more detail, the zipper  108  is applied underneath the front film  102  with the separating flange (element  107 ,  FIGS. 9 and 10 ) pointing upwardly. The zipper front film is then introduced to a packaging machine over a product loaded back film or tray and sealed thereto. Alternately, the zipper can be pre-applied to the film then spooled and then delivered to the packaging machine as a separate operation. Additionally, the film above the zipper typically has a weakened tear area that is removed to provide access to the zipper. Additionally, the zipper can be applied to the film in segments rather than continuously so that the zipper does not extend into the end seals. 
         [0035]    The illustrated embodiments will typically achieve many of the following advantages: 
         [0036]    1. Customers that have thermoform machines and want to produce a package with zipper would not have to buy or modify a new machine. 
         [0037]    2. If a customer has a thermoform machine and wants to retrofit it to run zipper, the OEMs require that they ship the machine to the OEM location to perform the retrofit. For most of the small customers in the meat industry, this is not an option because it would remove their only packaging machine. 
         [0038]    3. Pre-applied zipper in the machine direction would stimulate the meat industries in areas where the meat processors have only one machine. 
         [0039]    4. A customer can get into the resealable market in much shorter time frame than waiting for a new machine or a retrofit. This will allow a manufacturer to differentiate them from the traditional zipper package. 
         [0040]    5. There is less complexity to the manufacturer because they could run just film, rather than zipper and film. This will typically involve less scrap and changeover-related downtime than running a zipper in-line. This can include running lock-up style film. 
         [0041]    6. Angled direction of zipper application (pre- or machine-applied) would allow for larger product access through the zipper. 
         [0042]    7. Running machine applied zipper will allow the customer to run zipper packages at lower cost per package. 
         [0043]    8. Running machine applied zipper will allow the use of standard size/yield spools of flexible material and zipper. 
         [0044]    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.