Patent Publication Number: US-2018029324-A1

Title: Reclosable polymeric bag

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved reclosable storage bag made from polymeric film. Particularly, the present invention relates to a bag with a closure mechanism of interlocking profiles that is adapted for high speed and cost effective manufacturing. 
     2. Description of the Related Art 
     Thermoplastic films are used in a variety of applications. For example, thermoplastic films are used in sheet form for applications such as drop cloths, vapor barriers, and protective covers. Thermoplastic films can also be converted into plastic bags, which may be used in a myriad of applications. The present invention is particularly useful for reclosable bags constructed from thermoplastic film. 
     Polymeric bags are ubiquitous in modern society and are available in countless combinations of varying capacities, thicknesses, dimensions, and colors. The bags are available for numerous applications including typical consumer applications such as long-term storage, food storage, shopping, and trash collection. Like many other consumer products, increased demand and new technology have driven innovations in polymeric bags improving the utility and performance of such bags. The present invention is an innovation of particular relevance to reclosable storage bags of polymeric film. 
     Polymeric bags are manufactured from polymeric film produced using one of several manufacturing techniques well known in the art. The two most common methods for manufacture of polymeric films are blown-film extrusion and cast-film extrusion. In blown-film extrusion, the resulting film is tubular while cast-film extrusion produces a generally planar film. The present invention is generally applicable to bags manufactured from a blown-film extrusion process resulting in tubular film stock and cast film which results in monolayer film stock. 
     In blown film extrusion, polymeric resin is fed into an extruder where an extrusion screw pushes the resin through the extruder. The extrusion screw compresses the resin, heating the resin into a molten state under high pressure. The molten, pressurized resin is fed through a blown film extrusion die having an annular opening. As the molten material is pushed into and through the extrusion die, a polymeric film tube emerges from the outlet of the extrusion die. 
     The polymeric film tube is blown or expanded to a larger diameter by providing a volume of air within the interior of the polymeric film tube. The combination of the volume of air and the polymeric film tube is commonly referred to as a bubble between the extrusion die and a set of nip rollers. As the polymeric film tube cools travelling upward toward the nip rollers, the polymeric film tube solidifies from a molten state to a solid state after it expands to its final diameter and thickness. Once the polymeric film tube is completely solidified, it passes through the set of nip rollers and is collapsed into a collapsed polymeric tube, also referred to as a collapsed bubble. 
     Cast film is extruded from a flat die into a flat web or sheet. Typically, the film is extruded onto a chilled roller to facilitate quick cooling of the film for improved throughput. 
     Reclosable plastic bags are available in a variety of different sizes and configurations. Most commonly, reclosable plastic bags have one or more pairs of opposing, interlocking closures near the top opening of the reclosable bag. The closure may generally be opened and closed many times and are typically designed to ensure that the contents of the reclosable plastic bag are securely contained within the bag when the opposing closures, or interlocking profiles, are mutually engaged. 
     The closures of reclosable bags can be opened and closed in a number of different ways. For example, a slider or zipper device can be incorporated into the bag design to facilitate the engagement and disengagement of the opposing closures. However, many reclosable bags have closures that are designed to be opened by physically pulling the closures apart. The present invention provides an improved system and method of manufacturing a reclosable bag with pull-apart closures, commonly referred to as press to close reclosable bags. The assembly of closure elements for press to close bags is typically referred to as a zipper even though an actual sliding zipper is not employed. 
     U.S. Pat. No. 3,565,147 (the &#39;147 patent) discloses a plastic bag having male and female resealable interlocking elements integrally incorporated for selectively opening and closing the top of the bag. Since the &#39;147 patent discloses forming the interlocking elements integrally with the bag film material, the formation of the bag takes an undesirably long time to form due to the additional cooling time required of the fasteners to prevent deformation of the fastening elements. 
     It is further known that interlocking elements, also referred to as zipper elements, may be formed separately from the bag material and then sealed onto the bag material. However, this bag manufacturing technique requires the use of non-continuous motion which leads to an undesirably slow rate of manufacture. It also known to place the zipper elements on to the bag material in a molten state as the bag film material is formed. However, the speed of this bag manufacturing technique is limited to the rate at which the molten zipper may be properly formed. 
     In consideration of the shortcomings of the above discussed prior art, it would be desirable to provide a system and method for manufacturing a reclosable bag that may be formed with a continuous process. It would further be desirable to provide such a bag that takes advantage of high-speed manufacturing processes utilizing blown-film roll stock. The present invention represents a novel solution to address these needs. 
     SUMMARY OF THE INVENTION 
     According to one embodiment of the present invention, a bag is formed from a continuous web of polymeric film by a first bag converting process. A multi-layer continuous web of polymeric film with opposing first and second folded edges may be supplied to the converting process. The continuous web may comprise a lower layer extending from the first to the second edge, a first upper flap above the lower layer extending from the first edge towards a longitudinal central axis of the continuous web, and a second upper flap above the lower layer extending from the second edge towards the longitudinal central axis. A length of the continuous web may extend lengthwise in a machine direction. In at least one embodiment of the present invention, the bag converting process may fold a web of material accordingly to arrive at the above-described configuration of the continuous web. 
     Once the multi-layer web is provided as described above, a zipper material that extends in the machine direction may be provided to the converting process. The zipper material may comprise upper and lower mutually interlocking sections and upper and lower mounting surfaces. An adhesive may be applied to each mounting surface of the zipper material. The lower mounting surface of the zipper material may be affixed to an inner surface of the lower layer of the continuous web and the upper mounting surface of the zipper material may be affixed to inner surfaces of the first and second flaps of the continuous web by the adhesive. Once the zipper material is affixed to the continuous web, the continuous web may be slit in the machine direction into a first web half and a second web half along the central axis of the continuous web in the machine direction. A plurality of side seals may then be formed in each web half by a burn through seal operation. Each side seal may seal the first and second flaps to the lower layer of the continuous web and the burn through seals may further sever the polymeric film of the continuous web to form a plurality of individual bags. 
     In certain embodiments of the present invention, a gap may be defined between a distal edge of the first flap and a distal edge of the second flap. The gap may be formed by removal of a center strip from an upper layer of the web of polymeric film. The lower mounting surface of the zipper material may be affixed to the inner surface within the gap between the distal edge of the first and second flaps. Furthermore, the zipper material may be slit in conjunction with the continuous web such that it separates apart first and second sections of the zipper material. The distal edge of the first flap may be moved towards the first folded edge and the distal edge of the second flap may be moved towards the second folded edge prior to affixing the zipper material to the continuous web. The distal edge of the first and second flaps may also be moved back towards each other once the zipper material is affixed to the continuous web. 
     In at least certain embodiments, the upper zipper section may be comprised of first and second zipper sections. Each upper zipper section may have a separate base with a separate mounting surface. The lower zipper section may comprise first and second lower sections. The first and second lower zipper sections may share a common base with a single mounting surface. The mounting surface of the first upper zipper section may be mounted to the first flap and the mounting surface of the second upper section may be mounted to the second flap. Each of the zipper sections may further comprise an interlocking profile opposite from its base. Additionally, the plurality of side seals may be formed by a rotary sealing drum comprising a plurality of sealing bars. 
     In a further embodiment of the present invention, a bag is formed from a tube of polymeric film by a second bag converting process. In the bag converting process the tube of polymeric film may be collapsed to form a collapsed tube. The collapsed tube may have upper and lower layers, opposing first and second folded edges, and a machine direction. A center strip may be removed from the upper layer of the collapsed tube with a length of the center strip extending in the machine direction. The removal of the center strip may then form first and second flaps in the upper layer of the collapsed tube. A distal edge of the first and second flaps may then be moved away from each other and towards the first and second folded edges to expose a central inner surface of the lower layer of the collapsed tube. 
     Once the central inner surface of the lower layer of the collapsed tube is exposed, zipper stock comprising first and second upper and first and second lower sections may be supplied to the collapsed tube. Each section of the zipper stock may comprise a mounting surface and an adhesive may be applied to each mounting surface. The mounting surface of the first and second lower zipper sections may be affixed to the collapsed tube by the adhesive. The distal edge of the first and second flaps may be folded or moved back towards each other and thereafter the mounting surface of the first upper zipper sections may be affixed to an inner surface of the first flap by the adhesive. The mounting surface of the second front upper section may also be affixed to an inner surface of the second flap by the adhesive. Once the zipper stock is affixed to the collapsed tube, the collapsed tube may be slit into a first collapsed tube half and a second collapsed tube half. A plurality of burn through side seals may be formed in each collapsed tube half by a rotary drum severing the polymeric film of the collapsed tube at each side seal to form a plurality of individual bags. 
     In at least one embodiment, pressure may be applied to the zipper stock and the collapsed tube by a set of rollers to ensure adequate adhesion between the two once the zipper stock is placed on the collapsed tube. Additionally, the mounting surface of the lower zipper section may be affixed to the collapsed tube at a central inner surface of the collapsed tube. The mounting surface of the first upper zipper section may be affixed to the inner surface of the first flap proximate to a distal edge of the first flap and the mounting surface of the second front upper zipper section may be affixed to the inner surface of the second flap proximate to a distal edge of the second flap. The lower zipper sections may share a common base with a single mounting surface. The first lower zipper section may be interlocked with the first front zipper section and the second rear zipper section may be interlocked with the second front zipper section. Furthermore, each side seal formed on each collapsed tube half may be generally perpendicular to the machine direction. The rotary drum may feed the individual bags to a belt material handler and the belt material handler may feed the individual bags onto an indexing table. The first upper and lower zipper sections may be separated from the second upper and lower zipper sections when slitting the collapsed tube into a first collapsed tube half and a second collapsed tube half. 
     In an alternative embodiment of the present invention a reclosable bag may be formed from a web of polymeric film. Front and rear panels of the reclosable bag may be joined at a first side and a second side by opposing first and second side seals and at a folded bottom edge. The reclosable bag may be selectively closable at a top end opposite from the bottom edge by a zipper. The zipper may comprise a lower section and an upper section. The lower section may be affixed to an inner surface of the rear panel by a first layer of adhesive and the upper section may be affixed to an inner surface of the front panel by a second layer of adhesive. 
     In certain embodiments, the front and rear panels may be formed from upper and lower layers of a collapsed tube of polymeric film. Furthermore, the bottom edge of the reclosable bag may comprise a section of a folded edge of the collapsed tube. The top end of the reclosable bag may comprise a center section of the collapsed tube with the collapsed tube slit generally along a centerline in a machine direction of the collapsed tube. Additionally, the lower and upper sections of the zipper may be adapted to be pulled apart to open the bag and pressed together to close the bag. 
     It is contemplated that the present invention may be utilized in ways that are not fully described or set forth herein. The present invention is intended to encompass these additional uses to the extent such uses are not contradicted by the appended claims. Therefore, the present invention should be given the broadest reasonable interpretation in view of the present disclosure, the accompanying figures, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE RELATED DRAWINGS 
       A full and complete understanding of the present invention may be obtained by reference to the detailed description of the present invention and the preferred embodiments when viewed with reference to the accompanying drawings. The drawings can be briefly described as follows. 
         FIG. 1 a    provides a side view of a method and system for forming a reclosable bag. 
         FIG. 1 b    provides an alternative embodiment of a method and system for forming a reclosable bag. 
         FIGS. 2 a     1 ,  2   a   2  and  2   b - 2   f  provide cross-sectional views of a continuous web as the web is formed into a plurality of reclosable bags according to the methods of  FIGS. 1 a    and  1   b.    
         FIGS. 3 a  and 3 b    provide detailed cross-sectional views of a zipper stock or material utilized to form the reclosable bags according to the methods of  FIGS. 1 a    and  1   b.    
         FIGS. 4 a -4 c    provide top views of the continuous web as it is formed into the plurality of reclosable bags according to the methods of  FIGS. 1 a    and  1   b.    
         FIGS. 5 a -5 c    provide a front view, cross-sectional side view, and a detailed cross-sectional side view of the reclosable bag formed by the methods of  FIGS. 1 a    and  1   b.    
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present disclosure illustrates one or more preferred embodiments of the present invention. It is not intended to provide an illustration or encompass all embodiments contemplated by the present invention. In view of the disclosure of the present invention contained herein, a person having ordinary skill in the art will recognize that innumerable modifications and insubstantial changes may be incorporated or otherwise included within the present invention without diverging from the spirit of the invention. Therefore, it is understood that the present invention is not limited to those embodiments disclosed herein. The appended claims are intended to more fully and accurately encompass the invention to the fullest extent possible, but it is fully appreciated that certain limitations on the use of particular terms is not intended to conclusively limit the scope of protection. 
       FIG. 1 a    provides a side view of a system for forming reclosable bags from a continuous web of polymeric film. The web is shown provided to the system as roll stock. The web can be formed by a blown film extrusion or a cast film extrusion process. 
     The extrusion process begins by molten polymeric resin being extruded through a die to form a web of molten polymeric film. The direction that the film is extruded out of the die is commonly referred to as the machine direction. The direction of extrusion may also be referred to as the lengthwise direction of the web. Hence, the length of the web extends parallel with the machine direction. The direction transverse to the machine direction is commonly referred to as the cross direction. 
     The polymeric resin used in the extrusion process may vary. However, for forming polymeric bags, a polyethylene resin is commonly used. In the current state of the art for polymeric bags, a blend of various polyethylene polymers may be used. A polymer blend can have linear low-density polyethylene (LLDPE) as the primary component, but other polymers may be utilized including, but not limited to, other polyethylene resins such as high-density polyethylene (HDPE) or low-density polyethylene (LDPE). Other than polyethylene and other related polymers, additives may also be included with the polymeric resin, such as coloring additives, anti-blocking agents, and/or odor control additives. 
     As shown in  FIG. 1   a,  a roll stock  102  of a continuous web  106  of polymeric film is provided to the bag converting system  100 . As used herein, the term continuous web refers to the web being continuous and unbroken through the bag converting process until it is formed into individual bags.  FIG. 2 a     1  shows a cross-sectional view of web  106  that can be provided by roll stock  102 .  FIG. 2 a     1  illustrates continuous web  106  as a collapsed tube of polymeric film, typically manufactured by a blown film extrusion process. Web  106  is shown having an upper layer  106   a  and an opposite lower layer  106   b , and a first folded edge  106   c  and an opposite second folded edge  106   d . For ease of illustration, web or tube  106  is shown with a gap between its upper and lower layers  106   a  and  106   b ; however, typically, the inner surfaces of the two layers of collapsed tube  106  will be in contact with each other with the layers of web  106  essentially flat. 
     As further shown in  FIG. 1   a,  once web  106  is unrolled such that it extends lengthwise in its machine direction, a trimming operation  110  can trim a center strip of film from the upper layer  106   a  from web  106 . The removed center strip extends with its length in the machine direction. In at least one alternative embodiment, the trimming of center strip can be integrated into the extrusion process of web  106  such that after the film is formed, such as by a blown film extrusion process, the center strip can be removed prior to the web of film being rolled into roll stock. 
     Illustrated in  FIG. 2 b    is a cross-sectional view of web  106  with the center strip removed, which results with a gap in upper layer  106   a  of web  106 . The forming of the gap in upper layer  106   a  results in the forming of first and second flaps  106   f  and  106   g  in upper layer  106   a . The trimming of the center strip further results in distal edges  106   h  and  106   i  defined in first and second flaps  106   f  and  106   g . Further shown by  FIG. 4 a    is a top view of web  106  after the trimming operation defines flaps  106   f  and  106   g , and distal edges  106   h  and  106   i  in web  106  with distal edges  106   h  and  106   i  extending in the machine direction of web  106 . After removal of the center strip,  FIG. 2 c    illustrates that flaps  106   h  and  106   i  folded or moved away from the centerline of web  106  with the distal edges moved closer to adjacent web edges  106   b  and  106   c . The process of folding or rotating of flaps  106   h  and  106   i  is illustrated in  FIG. 1 a    by folding operation  112 . It may be desirable for folding operation  112  to not form creases in web  106  since flaps  106   h  and  106   i  are only temporarily moved or folded away to allow placement of zipper stock  114  onto web  106 . 
     Rather than roll stock  102  comprising a collapsed tube of polymeric film as discussed above, in an alternative embodiment, roll stock  102  can be comprised of a single layer of a continuous web of polymeric film  107  as shown in the cross-sectional view of  FIG. 2 a     2 . For ease of illustration, web  107  is not shown to scale, with its width less than would be required to form the two-layered web of  FIG. 2 b   . For this embodiment, trimming operation  110  is not necessary. However, folding operation  112 , in this alternative embodiment, can fold the opposing distal edges  107   a  and  107   b  of web  107  towards a centerline of continuous web  107 . Once both distal edges are folded towards each other, the single layer web  107  of  FIG. 2 a     2  can take the form of the continuous web  106  of the cross-section as shown in  FIG. 2 b   . The folding results in distal edges  107   a  and  107   b  relocated towards a centerline of continuous web  106  with the distal edges  107   a  and  107   b  taking the place of distal edges  106   h  and  106   i . The folding operation can further define the outer edges  106   c  and  106   d  with upper flaps  106   f  and  106   g  extending from the edges  106   c  and  106   d  towards a centerline of web  106  and opposite from lower layer  106   b . Once single layered web  107  of  FIG. 2 a     2  is folded into the configuration as shown in  FIG. 2 b    to form web  106  with two layers, folding operation can continue as described above to arrive at the configuration of web  106  is shown in  FIG. 2   c.    
     Once flaps  106   h  and  106   i  are moved towards the position shown in  FIG. 2 c   , zipper stock or zipper material  114  may be supplied to web  106  as illustrated in  FIG. 1 a   . Zipper stock  114  is supplied to the bag conversion process from zipper roll stock  104 . Shown in  FIGS. 3 a  and 3 b    is a detailed cross-sectional view of zipper stock  114 .  FIG. 3 a    shows zipper stock fully assembled while  FIG. 3 b    shows an exploded cross-sectional view of the zipper assembly including first and second lower zipper sections  114   a  and  114   b  and first and second upper zipper sections  114   c  and  114   d . As shown in  FIG. 3 a   , the lower sections can interlock with the upper sections. First and second lower zipper sections  114   a  and  114   b  further include first and second lower interlocking profiles  114   a   1  and  114   b   1  and a common base  114   ab   2  that interconnects first and second lower sections  114   a  and  114   b . The common base  114   ab   2  includes a generally flat mounting surface on an opposite side of zipper sections  114   a  and  114   b  from interlocking profiles  114   a   1  and  114   b   1  . 
     As further shown in  FIGS. 3 a  and 3 b   , first and second upper sections  114   c  and  114   d  have interlocking profiles  114   c   1  and  114   d   1  along with separate opposing bases  114   c   2  and  114   d   2 . Bases  114   c   2  and  114   d   2  include a generally flat mounting surface on an opposite side of each zipper section from interlocking profiles  114   c   1  and  114   d   1 . In at least one embodiment, the profiles of zipper stock  114  disclosed in  FIGS. 3 a  and 3 b    can extend throughout the length of zipper stock or zipper material  114 . For ease of illustration, the details of zipper stock  114  are only shown in  FIGS. 3 a  and 3 b    while other figures of the disclosure refer to zipper stock  114  in general.  FIGS. 3 a  and 3 b    disclose a rudimentary interlocking zipper design; however, the invention contemplates that multitudes of various zipper configurations that are known in the art can be adapted for use with the disclosed invention. In at least one embodiment, the zipper stock  114  can be formed by extrusion into a water bath for improved cooling of the molten material 
     As further shown in  FIG. 1   a,  prior to zipper stock  114  being supplied to the converting system, an adhesive can be applied to the mounting surfaces of bases  114   ab   2  ,  114   c   2 , and  114   d   2  by adhesive applicator  116 . Adhesive applicator may comprise open cell foam rollers that deliver a pressure sensitive adhesive to the bases of the mounting bases of zipper stock  114 . Adhesive applicator may also comprise hot melt applicators that supply a hot melt adhesive to the mounting surfaces of zipper stock  114 . Adhesive may also be applied to the mounting surface of zipper stock or material  114  by other various methods as known in the art. 
     Once the adhesive is applied to the mounting surfaces of the zipper stock  114 , the zipper stock  114  may be placed on to web  106  with the mounting surface of lower common base  114   ab   2  placed into contact with an inner surface of the lower layer  106   b  of web  106 , as shown in the cross-sectional view of  FIG. 2 d   . Once placed into contact, the inner surface of web  106  is affixed to mounting surface of base  114   ab   2  by the adhesive between the mounting surface and inner surface of the web. 
     As additionally shown in  FIG. 1   a,  a further folding operation  120  can fold or move back flaps  106   f  and  106   g  of web  106  to their original position so that an inner surface of the flaps are placed in contact with the adhesive on the mounting surfaces of the upper section zipper bases  114   c   2  and  114   d   2 .  FIG. 2 e    illustrates the cross-sectional view of web  106  once this step is completed. As further shown in  FIG. 1   a,  applicator rollers  122  can apply pressure to the outer surfaces of web  106  and zipper stock  114  to ensure that adequate pressure is applied to the adhesive to adhere web  106  and zipper stock  114  together at upper zipper section bases  114   c   2  and  114   d   2  and lower zipper section base  114   ab   2  . 
     Once the upper zipper sections  114   c  and  114   d  are affixed to web  106 , web  106  can be slit along its central axis so that it is split into a first and second web halves  106   l  and  106   m  as shown in  FIG. 2 f   . The web  106  can be split into the first and second halves  106   l  and  106   m  by a slitting operation  124  as shown in  FIG. 1   a.  In at least one preferred embodiment, the slitting operation  124  extends along a central axis of the continuous web  106 , the central axis extending in the machine direction of the web  106  and centrally located between the opposing edges  106   c  and  106   d . The slitting operation  124  further slits zipper stock  114  into two halves about lower zipper section base  114   ab   2  . The slitting of zipper stock  114  results in first upper and lower zipper sections  114   a  and  114   c  defining an enclosed edge of the first web half  106   l  and second upper and lower zipper section  114   b  and  114   d  defining an enclosed edge of second web half  106   m  as illustrated in  FIG. 2   f.    
       FIG. 4 b    further provides a top view of web  106  after zipper stock  114  is affixed to web  106 .  FIG. 4 b    further shows web  106  split into two halves  106   l  and  106   m  by slitting operation  124  as the web  106  travels in the machine direction. Web halves  106   l  and  106   m  are shown with a gap between each other for purposes of illustration. It is contemplated, however, that both halves  106   l  and  106   m  will remain travelling substantially in the machine direction and adjacent to each other until the bag manufacturing process is completed. 
     Once the web  106  is split into halves  106   l  and  106   m , the two halves may enter side-sealing operation  130  as further shown in  FIG. 1   a.  The sealing operation  130  is shown with a rotary drum  134  with a plurality of sealing bars  132 . Each of the sealing bars  132  can form a burn through seal on both the web halves  106   l  and  106   m  which seals together the upper and lower layers  106   a  and  106   b  of web halves  106   l  and  106   m . Web halves  106   l  and  106   m  can be held in place against sealing drum by sealing drum blanket or belt  136  working in conjunction with a plurality of rollers  135 . Each of the seal bars  132  can extend in a direction perpendicular to the machine direction so that each side seal is generally perpendicular to web edges  106   c  and  106   d  and zipper stock  114 . 
     As further illustrated in  FIGS. 1 a    and  4   c,  the burn through seals weld together and sever both layers of film of the upper and lower layers  106   a  and  106   b  to separate each web half  106   l  and  106   m  into a plurality of bags  200 .  FIG. 4 c    illustrates a planar top view of web halves  106   l  and  106   m  as sealing operation  130  produces a plurality of burn through side seals  140  on web halves  106   l  and  106   m  and forms a plurality of bags  200  from web halves  106   l  and  106   m  as the two halves travel in the machine direction. The use of rotary drum  134  allows for conversion process  100  to be continuous such that continuous web  106  travels at a constant speed from being fed from roll stock  102  until web  106  is formed into individual bags. This is in contrast to a reciprocating process, where web  106  would be required to vary in speed and where seal bars would need to move back and forth to engage and disengage web  106 . 
     As further shown in  FIG. 1   a,  once web halves  106   l  and  106   m  are converted into a plurality of bags  200  by sealing operation  130 , belt  136  in conjunction with belt conveyance or material handler  137  can deliver the plurality of bags  200  to index table  138  which can vertically stack a quantity of bags  200  for packaging. 
       FIGS. 5 a  and 5 b    illustrate a front view and cross-sectional side view of bag  200  formed by the aforementioned bag manufacturing method and system  100 . Bag  200  is shown with zipper  214  which corresponds to a length of zipper stock  114 . Further shown are first and second side edges  208  and  210  formed by one of the plurality of sealing bars  132  of  FIG. 1   a.  Also shown is a top edge and opening of bag  204  which corresponds to one of the distal edges  106   h  or  106   i  of web  106 . Additionally, bottom folded edge  202  is shown which corresponds to either side edge  106   c  or  106   d  of web  106 . Further shown by  FIG. 5 b    are a front panel  206   a  and a rear panel  206   b  of bag  200  which correspond to a partial section of lower and upper layers  106   a  and  106   b  of web  106 . Lower and upper layers  106   a  and  106   b  are sealed together at edges  208  and  210  due to the aforementioned sealing operation  130 . 
     Shown in  FIG. 5 c    is a detailed cross-sectional view of an upper section of bag  200 .  FIG. 5 c    shows a lower section  214   a  of zipper  214 , which corresponds to a section of first lower section  114   a  of zipper stock  114 . The lower zipper section  214   a  is shown affixed to the rear panel  206   b  of bag  200  by an adhesive layer  220   a .  FIG. 5 c    further shows an upper section  214   c  of zipper  214 , which corresponds to a section of first upper section  114   c  of zipper stock  114 . Upper zipper section  214   c  is shown affixed to the front panel  206   a  of bag  200  by an adhesive layer  220   b . The two zipper sections  214   a  and  214   c  are shown joined together to form an enclosed upper edge  204  of bag  200 . A user of bag  200  may pull apart the two zipper sections  214   a  and  214   c  to open the bag and press back together the two zipper sections  214   a  and  214   c  to reclose bag  200 . 
     Now turning to  FIG. 1   b,  the figure illustrates an alternative embodiment of the aforementioned system and method. The bag making method  101  disclosed by  FIG. 1 b    only differs by the steps regarding the application of the adhesive to zipper stock  114  and adhering the zipper stock to web  106 . Hence, only these steps are explained for  FIG. 1 b    while the remaining steps mirror the process for the  FIG. 1 a    embodiment. Beginning with adhesive applicator  116 , the applicator may only apply adhesive to zipper stock  114  along the mounting surface of lower base  114   ab   2  (as shown by  FIGS. 3 a  and 3 b   ). Zipper stock  114  may then be placed into contact with web  106  with lower base  114   ab   2  affixed to the inner surface of the lower layer  106   b  of web  106 . Whereupon, pressure rollers  118  may apply pressure to zipper stock  114  and web  106 . Additional adhesive applicator  119 , as shown in  FIG. 1 b   , may then apply adhesive to upper bases  114   c   2  and  114   d   2 . Then, folding operation  120  may fold flaps  106   f  and  106   g  back and place the flaps on to upper bases  114   c   2  and  114   d   2  (as shown by  FIGS. 3 a  and 3 b   ). Pressure rollers  122  may then apply pressure to zipper stock  114  and web  106  to ensure the adhesive on upper bases is adequately affixed to the zipper stock  114  and web  106 . The process may then proceed as previously discussed for  FIG. 1 a   . 
     As previously noted, the specific embodiments depicted herein are not intended to limit the scope of the present invention. Indeed, it is contemplated that any number of different embodiments may be utilized without diverging from the spirit of the invention. Therefore, the appended claims are intended to more fully encompass the full scope of the present invention.