Abstract:
A product and method for producing a string of individual sealed, filled packages separated by perforations. A string of separate packages optionally may be enclosed in a cardboard or other container designed to sit in a pantry or other location for dispensing of individual units. Perforations in the packaging film between separate packages provide a tear point to aid in separating one package from the next. There are several advantages to this format including easy placement of the string of packages into a carton for shipping or dispensing, and the ability to hang a string of packages in locations without the need to attach the packages to a backing strip. The perforations between packages facilitate the packaging and transportation of the entire string or bandolier, and facilitate the removal and use of a separate package.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. application Ser. No. 10/721,953, entitled “Double-Bag Package and Perforation Knife” and filed on Nov. 25, 2003, now U.S. Pat. No. 6,935,086, which application is itself a continuation-in-part of U.S. application Ser. No. 10/100,370, entitled “Vertical Stand-Up Pouch” and filed on Mar. 18, 2002, now U.S. Pat. No. 6,722,106. 

   BACKGROUND 
   1. Technical Field 
   The present invention relates to a double-bag package constructed using a modified vertical form and fill packaging machine and a modified perforation knife, and the method for making same, that provides for a single piece construction of a package having two horizontally adjacent bags joined together by a perforated vertical seal having self-correcting directional perforations. The package is suitable for retail snack food distribution. The invention allows for use of existing film converter and packaging technology to produce a double-bag package with minimal increased costs and minimal modification. Further, this invention relates to creating a string of connected individual packages separated by perforations between each package. A string of packages can thus be further packaged, labeled, handled, shipped, sold, and used. 
   2. Description of Related Art 
   Vertical Form, Fill and Seal Machines 
   Vertical form, fill and seal packaging machines are commonly used in the snack food industry for forming, filling and sealing bags of chips and other like products. Such packaging machines take a packaging film from a sheet roll and form the film into a vertical tube around a product delivery cylinder. The vertical tube is vertically sealed along its length to form a back seal. The machine applies a pair of heat-sealing jaws or facings against the tube to form a transverse seal. This transverse seal acts as the top seal on the bag below and the bottom seal on the package being filled and formed above. The product to be packaged, such as potato chips, is dropped through the product delivery cylinder, into the formed tube, and is held within the tube above the bottom transverse seal. After the package has been filled, the film tube is pushed downward to draw out another package length. A transverse seal is formed above the product, thus sealing it within the film tube and forming a package of product. The package below said transverse seal is separated from the rest of the film tube by cutting across the sealed area. 
   One such packaging machine is seen diagrammatically in  FIG. 9 . This drawing is simplified, and does not show the cabinet and support structures that typically surround such a machine, but it demonstrates the working of the machine well. Packaging film  910  is taken from a roll  912  of film and passed through tensioners  914  that keep it taut. The film then passes over a former  916 , which directs the film into a vertical tube around a product delivery cylinder  918 . As the tube is pulled downward by drive belts  920 , the vertical tube of film is sealed along its length by a vertical sealer  922 , forming a back seal  924 . The machine then applies a pair of heat-sealing jaws  926  against the tube to form a transverse seal  928 . This transverse seal  928  acts as the top seal on the bag  930  below the sealing jaws  926  and the bottom seal on the bag  932  being filled and formed above the jaws  926 . After the transverse seal  928  has been formed, a cut is made across the sealed area to separate the finished bag  930  below the seal  928  from the partially completed bag  932  above the seal. The film tube is then pushed downward to draw out another package length. Before the sealing jaws form each transverse seal, the product to be packaged is dropped through the product delivery cylinder  918  and is held within the tube above the transverse seal  928 . 
   The material that is fed into the form, fill and seal machine is typically a packaging film, such as polypropylene, polyester, paper, polyolefin extrusions, adhesive laminates, and other such materials, or from layered combinations of the above. For many food products, where flavor retention is important, a metalized layer will form the innermost layer. 
   The form, fill and seal machines are quite expensive, in the range of $250,000 each, but pay for themselves easily when compared to the cost of pre-formed bags and the machinery to fill them. However, in order to maximize the productivity of the form, fill and seal machines, it is common for the product delivery tube  918  and former  916  to be made as a unit that is easily interchangeable in less than 15 minutes. The length of the transverse seal can also be changed, by exchanging the sealing jaws, or in some cases, merely by exchanging the facing (the portion of the sealing jaws which actually makes contact with the packaging film). By changing these elements, as well as the width of film roll feeding into the machine and the programming of the machine, one form, fill and seal machine can handle a number of different products in different size packages, limited primarily by the width of film the machine will handle, the maximum length of bag the machine is designed to handle, and the available former/delivery tube assemblies. 
   Packaging Film 
   The packaging film used in such process is typically a composite polymer material produced by a film converter. For example, one prior art composite film used for packaging potato chips and like products is illustrated in  FIG. 1 , which is a schematic of a cross-section of the film illustrating each individual substantive layer.  FIG. 1  shows a sealable inside, or product side, layer  16  which typically comprises metalized oriented polypropylene (“OPP”) or metalized polyethylene terephtalate (“PET”). This is followed by a laminate layer  14 , typically a polyethylene extrusion, and an ink or graphics layer  12 . The ink layer  12  is typically used for the presentation of graphics that can be viewed through a transparent outside layer  10 , which layer  10  is typically OPP or PET. 
   The prior art film composition shown in  FIG. 1  is ideally suited for use on vertical form and fill machines for the packaging of food products. The metalized inside layer  16 , which is usually metalized with a thin layer of aluminum, provides excellent barrier properties. The use of OPP or PET for the outside layer  10  and the inside layer  16  further makes it possible to heat seal any surface of the film to any other surface in forming either the transverse seals or back seal of a package. 
   Typical back seals formed using the film composition shown in  FIG. 1  are illustrated in  FIGS. 2   a  and  2   b .  FIG. 2   a  is a schematic of a “lap seal” embodiment of a back seal being formed on a tube of film.  FIG. 2   b  illustrates a “fin seal” embodiment of a back seal being formed on a tube of film. 
   With reference to  FIG. 2   a , a portion of the inside metalized layer  26  is mated with a portion of the outside layer  20  in the area indicated by the arrows to form a lap seal. The seal in this area is accomplished by applying heat and pressure to the film in such area. The lap seal design shown in  FIG. 2   a  insures that the product to be placed inside the formed package will be protected from the ink layer by the metalized inside layer  26 . 
   The fin seal variation shown in  FIG. 2   b  also provides that the product to be placed in the formed package will be protected from the ink layer by the metalized inside layer  26 . Again, the outside layer  20  does not contact any product. In the embodiment shown in  FIG. 2   b , however, the inside layer  26  is folded over and then sealed on itself in the area indicated by the arrows. Again, this seal is accomplished by the application of heat and pressure to the film in the area illustrated. 
   Packaging 
   Regardless of whether a lap seal or fin seal is used for constructing a standard package using a vertical form and fill packaging machine, the end result is a package as shown in FIG.  3   a  with horizontally oriented top and bottom transverse seals  31 ,  33 . Such package is referred to in the art as a “vertical flex bag” or “pillow pouch,” and is commonly used for packaging snack foods such as potato chips, tortilla chips, and other various sheeted and extruded products. The back seal discussed with reference to  FIGS. 2   a  and  2   b  runs vertically along the bag and is typically centered on the back of the package shown in  FIG. 3   a , thus not visible in  FIG. 3   a . Because of the narrow, single edge base on the package shown in  FIG. 3   a  formed by the bottom transverse seal  33 , such prior art packages are not particularly stable when standing on one end. This shortcoming has been addressed in the packaging industry by the development of a horizontal stand-up pouch such as the embodiment illustrated in  FIGS. 4   a ,  4   b , and  4   c . As can be seen by reference to said figures, such horizontal stand-up pouch has a relatively broad and flat base  47  having two contact edges. This allows for the pouch to rest on this base  47  in a vertical presentation. Manufacture of such horizontal stand-up pouches, however, does not involve the use of standard vertical form, fill, and seal machines but, rather, involves an expensive and relatively slow 3-piece construction using a pouch form, fill, and seal machine. 
   Referring to  FIGS. 4   b  and  4   c , the horizontal stand-up pouch of the prior art is constructed of three separate pieces of film that are mated together, namely, a front sheet  41 , a rear sheet  43 , and a base sheet  45 . The front sheet  41  and rear sheet  43  are sealed against each other around their edges, typically by heat sealing. The base sheet  45  is, however, first secured along its outer edges to the outer edges of the bottom of the front sheet  41  and rear sheet  43 , as is best illustrated in  FIG. 4   c . Likewise, the mating of the base sheet  45  to the front sheet  41  and the rear sheet  43  is also accomplished typically by a heat seal. The requirement that such horizontal stand-up pouch be constructed of three pieces results in a package that is significantly more expensive to construct than a standard form and fill vertical flex bag. 
   Further disadvantages of using horizontal stand-up pouches include the initial capital expense of the horizontal stand-up pouch machines, the additional gas flush volume required during packaging as compared to a vertical flex bag, increased down time to change the bag size, slower bag forming speed, and a decreased bag size range. For example, a Polaris model vertical form, fill, and seal machine manufactured by Klick Lock Woodman of Georgia, USA, with a volume capacity of 60-100 bags per minute costs in the range of $75,000.00 per machine. A typical horizontal stand-up pouch manufacturing machine manufactured by Roberts Packaging of Battle Creek, Mich., with a bag capacity of 40-60 bags per minute typically costs $500,000.00. The film cost for a standard vertical form, fill, and seal package is approximately $0.04 per bag with a comparable horizontal stand-up pouch costing roughly twice as much. Horizontal stand-up pouches further require more than twice the oxygen or nitrogen gas flush. Changing the bag size on a horizontal stand-up pouch further takes in excess of two hours, typically, while a vertical form and fill machine bag size can be changed in a matter of minutes. Also, the typical bag size range on a horizontal stand-up pouch machine is from 4 oz. to 10 oz., while a vertical form and fill machine can typically make bags in the size range of 1 oz. to 24 oz. 
   One advantage of a horizontal stand-up pouch machine over a vertical form and fill machine, however, is the relatively simple additional step of adding a zipper seal at the top of the bag for reclosing of the bag. Vertical form and fill machines typically require substantial modification and/or the use of zipper seals premounted on the film oriented horizontally to the seal facings used to seal the horizontal transverse seals. 
   An alternative approach taken in the prior art to producing a bag with more of a stand-up presentation is the construction of a flat bottom bag such as illustrated in  FIG. 3   b . Such bag is constructed in a method very similar to that described above with regard to prior art pillow pouches. However, in order to form the vertical gussets  37  on either side of the bag, the vertical form, fill, and seal machine must be substantially modified by the addition of two movable devices on opposite sides of the sealing carriage that move in and out to make contact with the packaging film tube in order to form the tuck that becomes the gussets  37  shown in  FIG. 3   b . Specifically, when a tube is pushed down to form the next bag, two triangular shaped devices are moved horizontally towards the packaging film tube until two vertical tucks are formed on the packaging film tube above the transverse seals by virtue of contact with these moving triangular shaped devices. While the two triangular shaped devices are thus in contact with the packaging tube, the bottom transverse seal is formed. The package is constructed with an outer layer  30  that is non-sealable, such as paper. This causes the formation of a V-shaped gusset  37  along each vertical edge of the package when the transverse seals  31 ,  33  are formed. While the triangular shaped devices are still in contact with the tube of packaging material, the product is dropped through the forming tube into the tube of packaging film that is sealed at one end by virtue of the lower transverse seal  33 . The triangular shaped devices are then removed from contact with the tube of packaging film and the film is pushed down for the formation of the next package. The process is repeated such that the lower transverse seal  33  of the package above and upper transverse seal  31  of the package below are then formed. This transverse seal is then cut, thereby releasing a formed and filled package from the machine having the distinctive vertical gussets  37  shown in  FIG. 3   b.    
   The prior art method described above forms a package with a relatively broad base due to the V-shaped vertical gussets  37 . Consequently, it is commonly referred to in the art as a flat bottom bag. Such flat bottom bag is advantageous over the previously described horizontal stand-up pouch in that it is formed on a vertical form, fill, and seal machine, albeit with major modifications. However, the prior art method of making a flat bottom bag has a number of significant drawbacks. For example, the capital expense for modifying the vertical form, fill, and seal machine to include the moving triangular-shaped devices is approximately $30,000.00 per machine. The changeover time to convert a vertical form, fill, and seal machine from a standard pillow pouch configuration to a stand-up bag configuration can be substantial, and generally in the neighborhood of one-quarter man hours. The addition of all of the moving parts required for the triangular-shaped devices to move in and out of position during each package formation cycle also adds complexity to the vertical form, fill, and seal machine, inevitably resulting in maintenance issues. Importantly, the vertical form, fill, and seal machine modified to include the moving triangular-shaped devices is significantly slower than a vertical form, fill, and seal machine without such devices because of these moving components that form the vertical gussets. For example, in the formation of a six inch by nine inch bag, the maximum run speed for a modified vertical form, fill, and seal machine using the triangular-shaped moving devices is in the range of 15 to 20 bags per minute. A standard vertical form, fill, and seal machine without such modification can construct a similarly sized pillow pouch at the rate of approximately 40 bags per minute. 
   Multipacks 
   A popular marketing concept is that of packaging two or more individually sealed items together. While the marketing idea of multi-packs may be simple, the translation of that idea to current packaging technology can be more difficult. Often, rather than packaging a product into several different packages at the same time, each package is separately produced, as usual, then the various packages are boxed together or over-wrapped to form a multi-pack. It would be preferable to be able to produce multiple packages fastened together for sales, but which could be separated by the consumer for convenience. 
   One example of a prior art multi-pack package is disclosed in U.S. patent application Ser. No. 10/100,360, Publication No. US 2003/0009989.  FIG. 5   a  is a perspective view of a multi-pack package  500  in accordance with the &#39;360 application.  FIG. 5   b  is a top-down cross-sectional view of the multi-pack package  500  shown in  FIG. 5   a . The multi-pack package  500  has two side-by-side bags  510   a ,  510   b  attached together by a vertical seal  506  having perforations  508 . The package also has top and bottom horizontal/transverse seals  502 ,  504 , as well as vertical gussets on the left and right sides of the package. The double-bag package of the &#39;360 application provides consumers with two containers conveniently fastened together. However, there are several disadvantages to the &#39;360 application&#39;s multi-pack package and method for making the package. 
   One disadvantage is that the package  500  requires a special, complex vertical form, fill and seal (VFFS) machine having two feed tubes.  FIG. 6   a  is a front view of the former/delivery tube assembly of such of a twin-feed VFFS machine, and  FIG. 6   b  is a side view of the former/delivery tube assembly shown in  FIG. 6   a .  FIG. 7  is a cross-section of the former/delivery tube assembly taken at point  7 - 7 ′ of  FIG. 6   b , and  FIG. 8  is a cross-section of the former/delivery tube assembly taken at point  8 - 8 ′ of  FIG. 6   b . A twin-feed VFFS having a special former/delivery tube assembly such as that depicted in  FIG. 6   a  has a greater initial capital cost than a traditional VFFS machine. Furthermore, such a modified twin-feed VFFS machine requires a substantially wider film stock than traditional VFFS machines. The use of non-standard film stock and former/delivery tube assemblies undesirably increases the capital and operating costs. Additionally, no equipment currently exists to make seals wider than 18 inches, severely limiting bag sizes. 
   Another disadvantage is that each container of the multi-pack package disclosed in the &#39;360 application has more restrictive extremities than does a pillow pouch (or vertical flex bag), such as that shown in  FIG. 3   a , formed from a traditional VFFS machine. Whereas a traditional pillow pouch bag has flat seals on only two opposing sides, each container of the multi-pack package shown in the &#39;360 application, which is depicted in  FIG. 5   a , has flat seals on every side but one. Each flat seal flattens the package in the surrounding area, thus decreasing the available volume within the package. Because the multi-pack package disclosed in the &#39;360 application has more flat seals per container than traditional pillow pouches, the multi-pack package disclosed therein has less available volume for product than traditional pillow pouches. 
     FIG. 5   c  is a perspective view of a prior art saddle-bag package, which is another example of a multi-pack package. The saddle-bag package  550  comprises two pouch-type bags  552 ,  554  that share a top transverse seal  558 . The saddle-bag package  550  is typically oriented so that the back sides of each of the connected pouches  552 ,  554  face each other. The package  550  then stands on the bottom transverse seals  556 ,  560  of each pouch  552 ,  554 . The graphics and/or text on both pouches  552 ,  554  of the saddle-bag package  550  typically appear upright when the package  550  is so positioned. When forming saddle-bag packages using a vertical form, fill and seal machine, the film feed typically has graphics/text units that alternate between upside-down and right-side up and are linked together vertically (as a column of graphical/text units as opposed to a row of graphical/text units). Printing graphics and/or text units in such an alternating fashion can require modifications to the printing process and thus undesirably increase costs. 
   Perforations and Perforating Knife 
   It is well known in the art that films or sheets can be perforated to make such films or sheets easily separated into two or more pieces. Perforations allow films or sheets of material to be more controllably torn along a perforation path.  FIG. 12  is an elevated top view of a common prior art perforation pattern comprising a series of oval-shaped perforations  1220  that are spaced along a perforation path  1210  in a film  1202 . Such oval-shaped perforations  1220  are often formed using an anvil and a rotating perforating wheel having oval-shaped blades or punchers.  FIG. 13  is an elevated top view of another common prior art perforation pattern comprising a series of I-shaped perforations  1330  that are spaced along a perforation path  1310  in a film  1302 . Such I-shaped perforations  1330  can be formed using an anvil and a rotating perforating wheel having I-shaped blades or punchers, or they can be formed using a perforating blade having teeth that form I-shaped incisions. 
   While films having little or no orientation, such as low-density polyethylene (LDPE), are generally more resistant to tearing than oriented films, once a tear is initiated in films having low orientation, it will generally propagate in the direction of the tearing force. Thus, a tear initiated along a perforation path in a low-orientation film tends to propagate predictably from one perforation to the next. In contrast, while oriented films such as biaxially oriented polypropylene (BOPP) generally have a lower tearing resistance than films having low orientation, once a tear is initiated, it will not necessarily propagate in the direction of the tearing force. This is because the tears have a tendency to propagate along the direction (or directions) of orientation/stretching. Oriented films are thus more likely to suffer from errant or stray tears than non-oriented films. 
   Many prior art perforation knife designs do not produce perforations that are adequate for reliable separation of oriented-film flexible packages along the desired perforation paths. The perforations created by such prior art knife designs require that the tears between perforations propagate in a straight line for separation to be successful. For example, if the film  1202  with prior art oval perforations  1220  shown in  FIG. 12  comprises BOPP, errant tears  1230  will likely miss the next perforation along the perforation path  1210 . Likewise, if the film  1302  with prior art I-shaped perforations  1320  shown in  FIG. 13  comprises BOPP, an errant tear  1330  propagating from the end of an I-shaped perforation will likely miss the next I-shaped perforation  1320  along the perforation path  1310 . While the use of certain expensive films, such as polyester (PET), can improve the predictability of tearing, it still does not provide a fail-safe solution. Thus, it would be desirable to have a perforation pattern capable of capturing and redirecting errant tears for fail-safe separation. It would be desirable to have a perforation knife for creating such perforation patterns. Furthermore, it would be desirable to have a low-cost oriented packaging film with more predictable tearing properties. 
   Bandolier Packaging 
   Several patents disclose packaging inventions wherein vertically adjacent packages are connected. For example, U.S. Pat. No. 4,979,617 granted to Benoit on Dec. 25, 1990, describes a dispensing system for a bundle of continuous and severable packages wherein perforations separate individual packages. However, Benoit &#39;617 does not describe having any product in each package, but discloses shipping a string of empty packages that may be subsequently filled and separated by tearing a perforation in the packaging film between each package. Further, Benoit &#39;617 does not disclose use of such packages with a vertical form, fill and seal machine. 
   U.S. Pat. No. 5,094,657 granted to Dworak on Mar. 10, 1992, discloses a method of creating a continuous strip of pouches during manufacturing and filling each one with a product. Dworak &#39;657 describes folding, sealing, and perforating a film material to form a strip of open pouches as shown in  FIG. 19 . A heat seal  1902  is formed on both sides of a perforation  1904  across the folded width of a film. Heat seals  1902  create compartments, open ended envelopes, or pouches  1906 . A strip of pouches then moves along a conveyor, where each pouch is blown open by forced air, a product is pushed into the open package, and the pouch  1906  is sealed. Each sealed package is then separated at the perforation for further packaging and transportation as individual units. However, Dworak &#39;657 does not disclose shipping a connected string of packages, selling such connected string, and allowing consumers to separate packages from the string. Dworak &#39;657 also does not disclose creating such a string of packages with a vertical form, fill and seal machine. 
   U.S. Patent Application published on Dec. 18, 2003 by Rabiea and having Ser. No. 10/461,047 discloses a method of supplying a continuously attached plurality of bags to be filled by a consumer. Each bag is separated from the next one by a perforated tear line. Such tear line allows a consumer to remove individual bags at the time a consumer fills a bag with a product. Rabiea &#39;047 does not disclose filling each bag before a string of bags ships to consumers. 
   Consequently, a need exists for a method for forming a multi-pack package using standard vertical form, fill, and seal machine technology and a single sheet of packaging film. This method should ideally produce a double-bag package having two horizontally adjacent bags detachably connected by a perforated seal. Such method should produce such a package using a single vertical form, fill, and seal machine and a modified perforation knife. The modified perforation knife should create perforation patterns capable of capturing and redirecting errant tears for fail-safe separation along a desired perforation path. 
   Further, a need exists for creating a string, multi-pack, or bandolier of packages, each being filled with a product before being further packaged and transported. A further need exists for such method to be used in conjunction with a vertical form, fill and seal machine. A need exists to provide a string of packages whereby a consumer may separate an individual package from the rest of the string before consuming the contents of the package. A need exists for providing a string of packages in a dispensing container whereby a consumer may more easily isolate an individual package from the rest of the string. Further, a need exists whereby a consumer may more easily store a string of packages in a pantry or other location in such dispensing container. A need exists for providing an improved means for shipping and handling of individual packages. The present invention meets these needs and is described more fully in the detailed description below. 
   SUMMARY OF THE INVENTION 
   The proposed invention involves a method for making a novel double-bag packaging by using existing film converter and packaging technology and a modified perforation knife to produce a double-bag package with minimal increased costs and minimal modification. The method provides for a single piece construction of a package having two horizontally adjacent bags joined together by a perforated vertical seal. The package is suitable for retail snack food distribution. 
   An existing VFFS machine can be used with the present invention with the following minor modifications: 1) a roll of film (or other film supply) having graphics printed sideways rather than vertically, and 2) a novel perforating/cutting knife in accordance with the present invention. The manner of operation of the VFFS machine must also be slightly modified in a preferred embodiment. In particular, the heat-sealing and cutting steps must be modified to create mutli-pack packages such as double-bag packages. 
   The double-bag package of the present invention has two bags removably attached to each other by a perforated vertical seal. The package has three vertical seals when placed upright, with each bag having two vertical flat seals on opposite sides of the bag. The double-bag package has graphics that are properly viewable when two bags are horizontally adjacent to each other such that the transverse seals are vertically oriented. Because both product bags are formed from the same piece of film and are connected to each other, graphics and/or text can be spread across both bags, if desired. The double-bag package can also stand upright without assistance by arranging the bags in a non-linear fashion when viewed from above. 
   The vertical seal that connects the two bags of the double-bag package has perforations so that the two bags can be easily separated. In a preferred embodiment, the vertical seal between the two bags of a double-bag package has self-correcting perforation patterns that are capable of capturing and redirecting errant tears for fail-safe directional separation. Each of the perforation patterns has a wide base for catching an errant leading tear and at least one apex incision connecting the wide base to the desired perforation path. 
   Various perforating knives or blades can be used to create self-correcting perforation patterns. In a preferred embodiment, the perforating knife used with the VFFS machine has an elongate base upon which perforating teeth are located in single file. Each tooth has the shape of an oblique triangular pyramid and has three cutting edges. One face of the pyramid (the “vertical face”) has a normal vector that is parallel to the elongate base of the knife. 
   The proposed invention also involves a method for producing a string of individual sealed, filled packages separated by perforations. This string of separate packages optionally may be enclosed in a cardboard or other container designed to sit in a pantry or other location for dispensing of individual units. The perforation of the packaging film between separate packages provides a tear point to separate one package from the next. There are several advantages to this format including easy placement of the string of packages into a carton for shipping or dispensing, and the ability to hang a string of packages in locations without the need to attach the packages to a backing strip. The perforations between packages facilitate the packaging and transportation of the entire string or bandolier, and facilitate the removal and use of separate packages. 
   The above as well as additional features and advantages of the present invention will become apparent in the following written detailed description. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a schematic cross-section view of a prior art packaging film; 
       FIG. 2   a  is a schematic cross-section view of a tube of packaging film illustrating the formation of a prior art lap seal; 
       FIG. 2   b  is a schematic cross-section of a tube of packaging film illustrating the formation of a prior art fin seal; 
       FIG. 3   a  is a perspective view of a prior art vertical flex bag; 
       FIG. 3   b  is a perspective view of a prior art flat bottom bag; 
       FIGS. 4   a ,  4   b , and  4   c  are perspective views in elevation of a prior art horizontal stand-up pouch; 
       FIG. 5   a  is a perspective view of a prior art multi-pack package; 
       FIG. 5   b  is a top-down cross-sectional view of the multi-pack package shown in  FIG. 5   a;    
       FIG. 5   c  is a perspective view of a prior art saddle-bag package; 
       FIG. 6   a  is a front view of the former/delivery tube assembly of a prior art twin-feed vertical form, fill and seal machine; 
       FIG. 6   b  is a side view of the former/delivery tube assembly shown in  FIG. 6   a;    
       FIG. 7  is a cross-section of the former/delivery tube assembly taken at point  7 - 7 ′ of  FIG. 6   b;    
       FIG. 8  is a cross-section of former/delivery tube assembly taken at point  8 - 8 ′ of  FIG. 6   b;    
       FIG. 9  is a perspective view of a prior art vertical form, fill and seal machine; 
       FIG. 10  is a perspective view of a vertical form, fill and seal machine being fed with film having graphics printed sideways and operated to form double-bag packages in accordance with one embodiment of the present invention; 
       FIG. 11  is a perspective view of a double-bag package, standing upright, in accordance with one embodiment; 
       FIG. 12  is a top elevational view of a film having a series of prior art oval-shaped perforations along a perforation path; 
       FIG. 13  is a top elevational view of a film having a series of prior art I-shaped perforations along a perforation path; 
       FIG. 14  is a top elevational view of a film having a series of T-shaped perforations in accordance with one embodiment of the present invention; 
       FIG. 15  is a top elevational view of a film having a series of triangular-shaped perforations in accordance with one embodiment of the present invention; 
       FIG. 16  is a top elevational view of a film having a series of diamond-shaped perforations in accordance with one embodiment of the present invention; 
       FIG. 17   a  is a top elevational view of a perforating blade capable of creating T-shaped perforations in accordance with one embodiment of the present invention; 
       FIG. 17   b  is a side elevational view of the perforating blade shown in  FIG. 17   a;    
       FIG. 17   c  is a front cross-sectional view of the perforating blade shown in  FIG. 17   a  taken at  17   c - 17   c′;    
       FIG. 17   d  is a perspective view of the perforating blade shown in  FIG. 17   a;    
       FIG. 18   a  is a top elevational view of another perforating blade capable of creating T-shaped perforations in accordance with one embodiment of the present invention; 
       FIG. 18   b  is a side elevational view of the perforating blade shown in  FIG. 18   a.    
       FIG. 19  is an overhead drawing of a string of bags separated by perforations according to the prior art and disclosed by U.S. Pat. No. 5,094,657; 
       FIG. 20   a  is a perspective view of a string of bags in a closed dispenser according to the present invention; and, 
       FIG. 20   b  is a perspective view of a string of bags in an open dispenser according to the present invention. 
   

   REFERENCE NUMERALS 
   
       
         10  transparent outside layer 
         12  ink layer 
         14  laminate layer 
         16  sealable or metalized inside layer 
         20  outside layer 
         30  non-sealable outer layer 
         31  upper transverse seal 
         33  lower transverse seal 
         37  vertical gussets 
         41  front sheet 
         43  rear sheet 
         45  base sheet 
         47  flat base 
         500  multi-pack package 
         502  top horizontal/transverse seal 
         504  bottom horizontal/transverse seal 
         506  vertical seal 
         508  perforation 
         510   a ,  510   b  side-by-side bag 
         550  saddle-bag package 
         552 ,  554  connected pouch-type bag 
         558  top transverse seal 
         556  bottom transverse seals 
         560  bottom transverse seal 
         910  packaging film 
         912  prior art film roll 
         914  tensioner 
         916  package former 
         918  product delivery cylinder 
         920  drive belts 
         922  vertical sealer 
         924  back seal 
         926  heat-sealing jaws 
         928  transverse seal 
         930  finished bag 
         932  partially completed bag 
         1010  multi-pack packaging film 
         1012  multi-pack film roll 
         1014  tensioners 
         1016  former 
         1018  product delivery cylinder 
         1020  drive belts 
         1022  vertical sealer 
         1024  back seal 
         1026  heat-sealing jaws 
         1028  transverse seal 
         1030  multi-pack package 
         1032  partially completed bag 
         1100  double-bag package 
         1110   a ,  1110   b  bag of double-bag package 
         1102 ,  1106 ,  1104  vertical transverse seal 
         1106  vertical seam 
         1108  perforation 
         1110   a ,  1110   b  bag 
         1112  pre-cut slit 
         1202  package film 
         1210  perforation path 
         1220  prior art oval perforation 
         1230  errant tears 
         1302  package film 
         1310  perforation path 
         1320  prior art I-shaped perforation 
         1330  I-shaped perforation 
         1402  film 
         1410  perforation path 
         1420  T-shaped perforation 
         1430  apex 
         1510  perforation path 
         1520  triangular-shaped perforations 
         1530  apex 
         1602  film 
         1610  perforation path 
         1620  perforation 
         1630  apex 
         1700  perforating knife or blade 
         1702  elongate base 
         1704  center apex 
         1706  centerline of cutting edge or knife 
         1708  vertical face of pyramid 
         1710  top edge line 
         1712  bottom contour line 
         1714  top ontour line 
         1802  elongate base 
         1804  center apex 
         1806  centerline of cutting edge or knife 
         1808  vertical face of pyramid 
         1810  tooth-bottom edge line 
         1814  contour line 
         1902  heat seal 
         1904  perforation separating contiguous packages 
         1906  individual package 
         2002  dispenser 
         2004  opening in dispenser 
         2006  closable flap of dispenser 
         2008  dispensing flap 
         2010  slit in closed dispenser 
         2020  string of packages in a dispenser 
         2024  exposed end of string of packages 
         2026  enclosed end of string of packages 
     
  
   DETAILED DESCRIPTION 
   Vertical Form, Fill and Seal Machine 
     FIG. 10  depicts a standard vertical form, fill and seal (VFFS) machine forming a roll of film  1012  into double-bag packages  1030  in accordance with a preferred embodiment of the present invention. The same reference numbers are used to identify the same corresponding elements throughout all drawings unless otherwise noted. Except for a few minor modifications, the VFFS machine itself is the same as that described above with respect to  FIG. 9 . In a preferred embodiment, the minor modifications include: 1) a roll of film (or other film supply) having graphics printed sideways rather than vertically, and 2) a novel perforating/cutting knife in accordance with the present invention. The manner of operation of the VFFS machine must also be slightly modified in a preferred embodiment. In particular, the heat-sealing and cutting steps must be modified to create mutli-pack packages such as double-bag packages. Note that while  FIG. 10  is simplified and does not show the cabinet and support structures that typically surround such a machine, it depicts the parts that are critical to forming multi-pack packages. Note also that while a preferred method for forming a double-bag package in accordance with the present invention is explained with reference to an intermittent-motion type VFFS, other VFFS machine types, such as continuous or rotary type VFFS machines, can be used. 
   The material that is fed into the form, fill, and seal machine is typically a packaging film, such as polypropylene, polyester, polyethylene, paper, polyolefin extrusions, adhesive laminates, and other such materials, or from layered combinations thereof. For many food products, where flavor retention is important, a metalized layer will form the innermost layer. As explained above, the inner and outer layers of the packaging film often both comprise OPP (or BOPP). Such packaging film is typically oriented in the machine direction, which is the direction in which the film is fed and run through a VFFS machine, as well as the transverse direction (or seal direction), which is perpendicular to the machine direction. Because the packaging film is oriented in both the machine direction and the transverse direction, it can be quite difficult to reliably and controllably tear along a perforated transverse seal, as the orientation in the machine direction can invite tears to stray from the perforation path. In accordance with a preferred embodiment of the present invention, a modified packaging film replaces the OPP of the outer layer with biaxially-oriented high-density polyethylene (BOHDPE) that is more highly oriented in the transverse seal direction than the machine direction. The BOHDPE layer is preferably highly oriented in the transverse direction and only slightly oriented in the machine direction. This modified packaging film containing BOHDPE improves the film&#39;s ability to tear in the transverse direction and increases its resistance to tearing in the machine direction, which therefore improves the reliability of separation along perforated transverse seals. Enhanced ability to tear in the transverse direction allows perforations to be spaced further apart, which increases the strength and durability of perforated seals. Therefore, the modified packaging film improves both the reliability of separation and the potential strength of the seal. In a preferred embodiment, BOHDPE-modified packaging film is used with the present invention&#39;s method for forming multi-bag packages. Other film compositions, however, can also be used. 
   Unlike the packaging film used in standard VFFS machines, which has graphics/text printed vertically, the packaging film of the present invention has graphics/text printed sideways. Furthermore, while prior art film supply rolls have packaging film units that are arranged vertically with respect to each other, a multi-pack film supply roll in accordance with the present invention has packaging film units that are arranged horizontally with respect to each other. For example, the prior art film roll  912  shown in  FIG. 9  has graphics printed vertically (in an upright orientation) so that the graphics/text appear either upright or upside down as the film forms into a tube and runs down the VFFS machine. In the prior art film roll  912 , the packaging film units, represented by the labels “SNACKS,” are linked to one another in vertical fashion with the top of one unit attached to the bottom of the next unit. In contrast, the multi-pack film roll  1012  shown in  FIG. 10  has graphics/text printed sideways so that the graphics/text appear sideways as the film forms into a tube and runs down the VFFS machine. The multi-pack film units, represented by the labels “SNACKS,” are linked to one another in a horizontal fashion with the left side of one unit attached to the right side of the next unit. 
   As explained above, the prior art packaging film is oriented to be readable by an operator of the machine as the film travels down the forming tube. This orientation provides graphics on the formed prior art bag that are readable by a consumer when the formed bag is placed on a retail display shelf while resting on its bottom transverse seal. In contrast, the orientation of the graphics on the film packaging for Applicants&#39; invention is 90° off of the prior art orientation, such that the graphics appear sideways as viewed by the operator of the vertical form and fill machine as the film is pulled down the forming tube, as shown in  FIG. 10 . Unlike the prior art process of forming and filling product bags from top-to-bottom or bottom-to-top, the current invention&#39;s process forms and fills multi-pack product packages sideways (i.e. from left-to-right or right-to-left). 
   The multi-pack packaging film  1010  is taken from the multi-pack film roll  1012  and passed through tensioners  1014  that keep it taut. The film  1010  then passes over a former  1016 , which directs the film into a vertical tube around a product delivery cylinder  1018 . As the tube is pulled downward by drive belts  1020 , the vertical tube of film is sealed along its length by a vertical sealer  1022 , forming a back seal  1024 . The machine then applies a pair of heat-sealing jaws  1026  against the tube to form a first transverse seal  1028 . When the multi-pack package is completed and turned upright so that the connected bags are horizontally adjacent to each other, the first transverse seal  1028  will serve as either the left-most or the right-most vertical seal of the multi-pack package  1030 . After the first transverse seal  1028  has been formed, a perforating/cutting knife positioned within one of the heat-sealing jaws  1026  cuts across the sealed area to separate the finished bag  930  below the seal  1028  from the partially completed bag  1032  above the seal. The film tube is then moved downward a first time to draw out another package length. Before the sealing jaws form a second transverse seal, the product to be packaged is dropped through the product delivery cylinder  1018  and is held within the tube above the first transverse seal  1028 . The heat-sealing jaws  1026  close again to form a second transverse seal  1028  above the first transverse seal, thereby forming a first bag. The perforating/cutting knife then partially penetrates the second transverse seal  1028  to form perforations along the second seal  1028 . The film tube is moved downward a second time to draw out another package length. Another charge of product is dropped through the product delivery cylinder  1018  and is held within the tube above the second transverse seal  1028 . The heat-sealing jaws  1026  close again to form a third transverse seal  1028  above the second transverse seal, thereby forming a second bag. If forming a double-bag package  1030 , the third transverse seal  1028  is then cut across its width using the perforating/cutting knife to separate the double-bag package  1030  from the vertical tube. The process then repeats itself starting with the step of moving the film tube downward a first time. If forming a multi-pack (multi-bag) package having three or more packages, the third transverse seal is perforated with the perforating/cutting knife, and the vertical tube is repeatedly moved downward, filled with product, and transversely sealed until the desired number of connected bags have been produced. When the last connected bag is sealed, the last transverse seal is then cut across its width to separate the multi-pack/multi-bag package from the vertical tube. Stated in another way, the moving, filling, sealing and perforating steps are repeated until a second to last bag is formed. Then the tube of film is moved a final time down the vertical form, fill and seal machine. Product is introduced a final time into the tube of film, a final transverse seal is formed above the other transverse seals to form a final bag, and the final transverse seal is cut across its width using the perforating/cutting knife to separate the multi-pack package from the tube of film. 
   If a rotary or continuous type of VFFS machine is used rather than an intermittent-motion type VFFS machine, the same essential steps are performed in a slightly different manner. In a rotary or continuous type VFFS machine, the tube of film is moved downward continuously rather than intermittently. As the tube of film moves downward, a pair of transverse sealing jaws move downward with the tube of film and form a first transverse seal. Once the first seal is formed, a perforating/cutting knife positioned within the transverse sealing jaws completely cuts across the seal to separate the film below the first transverse seal. The transverse sealing jaws and the perforating/cutting knife then rotate upwards in preparation for the next sealing cycle. In the meantime, product is dropped down the forming tube, into the tube of film and is held by the first transverse seal. The transverse sealing jaws again move downward with the tube of film and form a second transverse seal, thereby forming a first bag/pouch. The perforating/cutting knife, which travels along with the sealing jaws, then perforates the second transverse seal by partially piercing the film. Product is again dropped down the forming tube and into the film tube, and the sealing jaws again move upwards in preparation for the next sealing cycle. The sealing jaws then form a third transverse seal to create a second bag. If a double-bag package is to be formed, the perforating/cutting knife then completely cuts across the third transverse seal to separate the double-bag package from the tube of film. If a multi-pack package having three or more connected bags is to be formed, the cycle of sealing, perforating, and filling is repeated until the last bag is sealed. Instead of perforating the last transverse seal, the last transverse seal is completely cut across in order to separate the completed multi-pack package from the tube of film. 
   No matter which type of VFFS machine is used, the perforating/cutting knife follows a specific cycle of perforating and cutting. The perforating and cutting cycle depends upon the number of bags to be formed per package. A processor, such as a computer or programmable logic controller (PLC), can be used to control the alternating or cyclical operation of the perforating/cutting knife. For example, when making double-bag packages, the perforating/cutting knife can be directed by a processor to alternate between completely cutting across the seal area and perforating by partially penetrating the seal area. When making multi-bag packages having three or more connected pouches or bags, the perforating/cutting knife can be directed by a processor to follow a cycle in which the seal area is completely cut across at the beginning of the cycle but is merely perforated throughout the rest of the cycle. If a four-bag package is being manufactured, for instance, the perforating/cutting knife will be directed to completely cut the first seal and perforate the next three transverse seals before beginning the cycle again. 
   If desired, a tucking mechanism can be used on one side or both sides of the VFFS machine to form gussets down the length of the tube of film. Such gussets will eventually become the top and/or bottom sides of the multi-bag packages. For example, when a tucking mechanism is used to form gussets on the bottom sides of the multi-bag packages, the resulting packages will have expandable bases that enable each bag to stand upright. Such bottom gussets can also be expanded to give the bags flat bottoms upon which the bags can stand. 
   Double-Bag Package 
   In a preferred embodiment, the method described above forms a double-bag package having two bags removably attached to each other by a perforated vertical seal.  FIG. 11  is a perspective view of a double-bag package  1100 , standing upright, in accordance with one embodiment. Unlike the prior art double-bag package shown in  FIG. 5   a , which has both horizontal and vertical flat seals, the double-bag package  1100  of the present invention has only vertical flat seals. Furthermore, each bag  1110   a ,  1110   b  of the double-bag package  1100  of the present invention has two opposing vertical seals, whereas each bag of the prior art double-bag package shown in  FIG. 5   a  has a flat seal on every side but one. Each flat seal flattens the package in the surrounding area, thus decreasing the available volume within the package. Because the double-bag package  1100  of the present invention has fewer flat seals per container than the prior art double-bag package, the double-bag package  1100  of the present invention has more available volume per surface area of film for product than the prior art package. 
   The double-bag package  1100  shown in  FIG. 11  has graphics that are properly viewable when the first bag  1110   a  and second bag  1110   b  are horizontally adjacent to each other such that the first, second and third transverse seals  1102 ,  1106 ,  1104  are vertically oriented. In this orientation, the front sides of both packages are facing in the same general direction. Because both product bags are formed from the same piece of film and are connected to each other, the graphics/text can be spread or spanned across both bags, if desired. For example, the double-bag package  1100  shown in  FIG. 11  has graphics and text that is displayed continuously across both bags such that both bags must be viewed together to properly view the graphics/text. Multi-pack packages made in accordance with the present invention provide a larger surface area across which graphics and text can be displayed. Such packages thus enable large continuous graphics and text displays that were previously not possible with individual prior art packages. With multi-bag packages such as the double-bag package  1100  depicted in  FIG. 11 , for instance, it is possible to display one or more large, continuous images that extend from the left-most vertical seal of the left-most bag to the right-most vertical seal of the right-most bag without a break in the image. 
   This ability to span graphics across connected bags is a significant improvement over prior art saddle-bags, an example of which is shown in  FIG. 5   c . Because the front sides of saddle-bag pouches face opposite directions when the package is in an upright position, it is undesirable to span graphics and text across both pouches. Furthermore, each pouch typically has its own discrete graphics/text unit that is oriented 180 degrees from the graphics/text unit located on the adjacent attached pouch. Thus, it would not be feasible to span graphics across a saddle-bag package because the graphics would appear right-side up on one pouch but up-side down on the attached package. 
   Another advantage of the multi-pack/multi-bag packages (including double-bag packages) in accordance with the present invention is the ease with which the film can be scored to give the final packaging score lines for easy openability. Whereas score lines must be placed intermittently across the width of a film feed in order to give saddle-bag packages transverse score lines for easy opening, score lines can be continuously placed along the length of a film feed for multi-bag packages (such as double-bag packages) in accordance with the present invention. This is because saddle-bags are formed vertically (bottom-to-top or top-to-bottom) in a VFFS machine with score lines oriented transversely, whereas the present invention&#39;s packages are formed sideways (left-to-right or right-to-left) with score lines oriented lengthwise (in the machine direction). 
   As seen in  FIG. 11 , the double-bag package  1100  can be angled at the vertical seam  1106  between the two bags  1110   a ,  1110   b  so that the front faces of each bag are facing in slightly different directions. The two bags  1110   a ,  1110   b  form a v-shape when viewed from above. Positioning the bags  1110   a ,  1110   b  at an angle allows the double-bag package  1100  to stand upright without external support. A multi-pack package having three or more connected bags can be similarly positioned to enable it to stand upright without external support. Such a multi-pack package can be placed in a zig-zag orientation, for example. Any arrangement of the bags that is non-linear when viewed above will help give the package the stability required to stand upright. 
   If the VFFS machine used to make the double-bag package  1100  includes a tucking mechanism, the double-bag package  1100  can also have a gusseted (creased) or flat bottom. Bottom gussets (creases) or flat bottoms provide stable bases upon which the package can stand upright. In addition, such gusseted or flat bottoms enable each individual package to stand upright even after they are separated from one another. 
   If desired, the double-bag package  1100  can also include score lines near the top of the bags to guide tears initiated at pre-cut slits  1112  across the top of the bags for easy opening. Score lines can be pre-existing in the multi-pack packaging film. For example, the score lines can be made on one or more layers of the packaging film during manufacturing/lamination. Before all of the layers are laminated together, one or more layers can be slit-scored. In a preferred embodiment, three parallel slit-scores are placed on one of the outer layers so that the inner barrier layer is not disturbed while simultaneously providing several guiding slits for tearing. 
   Self-Correcting Perforations 
   The vertical seal  1106  that connects the two bags  1110   a ,  1110   b  of the double-bag package  1100  shown in  FIG. 11  can have various means or aides for separation, which include but are not limited to score lines, one or more lengthwise slits, and perforations. If desired, the vertical seal  1106  connecting the two bags  1110   a ,  1110   b  can even be completely cut along its length to initially separate the two bags  1110   a ,  1110   b , and then the two sides of the seal can be rejoined with an adhesive that allows for easy separation. In a preferred embodiment, the vertical seal  1106  connecting the two bags  1110   a ,  1110   b  has perforations  1108  so that the two bags can be easily separated. If a film having little or no orientation is used, such as low-density polyethylene (LDPE), prior art perforation patterns will suffice to enable the packages to be separated along their shared seal. In such a case, the perforated seal can be torn in either direction, from top to bottom or from bottom to top. If an oriented packaging film is used, however, the connected bags may not separate cleanly along the desired perforation path. Oriented films such as biaxially oriented polypropylene (BOPP) will not necessarily tear in the direction of a given tearing force and may instead tear in the direction or directions of orientation (or stretching). Furthermore, even if the desired perforation path runs in the general direction of orientation, the film may not tear exactly along the desired path. 
   In a preferred embodiment, the vertical seal between the two bags of a double-bag package has perforation patterns that are capable of capturing and redirecting errant tears for fail-safe directional separation. Each of the perforation patterns has a wide base for catching an errant leading tear and at least one apex incision connecting the wide base to the desired perforation path. Perforation patterns that have wide bases and apex incisions include but are not limited to T-shapes, triangles, kites, hearts, arrowheads and chevrons. The perforation patterns are spaced along a desired perforation path and are arranged so that the wide base of one pattern is near the apex of the next/previous pattern. The wide base of each pattern should extend beyond the perforation path on both sides so that it can catch an errant tear propagating from the apex of the previous pattern. Furthermore, the perforation patterns should be spaced close enough together so the wide bases of the patterns can catch an errant tear from the previous pattern. As a tear propagates through a perforation pattern, the tear will be redirected to the apex of the pattern along the desired perforation path. A tear then initiates at the apex of the pattern and will then propagate towards the wide base of the next pattern. No matter where the tear encounters the base of the next pattern, the tear will be redirected to the apex of the next pattern. This self-correcting characteristic of the perforation patterns provides a fail-safe means for controllably separating attached packages. Note, however, that such directional perforations must be tom from the apex of one perforation towards the base of the next perforation, or in that general direction, in order for the self-correcting perforations to properly capture and redirect errant tears. 
   Whereas perforations previously had to be spaced very close to one another, especially in films having poor tearing characteristics, the self-correcting perforation patterns of the present invention now allow perforations to be spaced a greater distance apart while still allowing a reliable separation. This increases the strength of the perforated seal connecting two adjacent packages. Increased strength allows the multi-bag packages to withstand more shipping and handling stress before suffering from premature separation. 
     FIG. 14  is a top elevational view of a film  1402  having a series of T-shaped perforations  1420  in accordance with one embodiment of the present invention. Each one of the T-shaped perforations has a wide base incision that is perpendicular to the perforation path  1410 . An apex incision runs along the perforation path  1410  and connects the center of the wide base incision to the apex of the pattern, which is the right-most portion of each pattern  1420  shown in  FIG. 14 . As a tear propagates through one of the T-shaped perforations  1420  from its base towards its apex, the tear is redirected to the apex of the pattern. Even if the tear from the apex  1430  wanders off the perforation path  1410 , it will be caught and redirected by the wide base of the next T-shaped perforation  1420 . 
     FIG. 15  is a top elevational view of a film  1502  having a series of triangular-shaped perforations  1520  in accordance with one embodiment of the present invention. Each one of the triangular-shaped perforations  1520  has a wide base that is perpendicular to the perforation path  1510 . Two apex incisions connect the ends of the wide base to the apex of the pattern, which is located on the perforation path  1510 . The apex of the pattern is the right-most portion of each pattern  1520  shown in  FIG. 15 . As a tear propagates through one of the triangle-shaped perforations  1520  from its base towards its apex, the tear is redirected to the apex of the pattern. Even if the tear from the apex  1530  wanders off the perforation path  1510 , it will be caught and redirected by the wide base of the next T-shaped perforation  1520 . 
     FIG. 16  is a top elevational view of a film  1602  having a series of kite-shaped perforations  1620  in accordance with one embodiment of the present invention. Each one of the kite-shaped perforations  1620  has a wide base that extends beyond the perforation path  1610  on both sides. Two apex incisions connect the ends of the wide base to the apex of the pattern, which is located on the perforation path  1610 . The apex of the pattern is the right-most portion of each pattern  1620  shown in  FIG. 16 . As a tear propagates through one of the kite-shaped perforations  1620  from its base towards its apex, the tear is redirected to the apex of the pattern. Even if the tear from the apex  1630  wanders off the perforation path  1610 , it will be caught and redirected by the wide base of the next T-shaped perforation  1620 . 
   Perforating/Cutting Knife 
     FIG. 17   a  is a top elevational view of a perforating knife (or blade)  1700  capable of creating T-shaped perforations, such as the T-shaped perforations  1420  shown in  FIG. 14 , in accordance with one embodiment of the present invention.  FIG. 17   b  is a side elevational view of the perforating blade shown in  FIG. 17   a .  FIG. 17   c  is a front cross-sectional view of the perforating blade shown in  FIG. 17   a  taken at  17   c - 17   c ′.  FIG. 17   d  is a perspective view of the perforating blade shown in  FIG. 17   a .  FIG. 18   a  is a top elevational view of another perforating blade capable of creating T-shaped perforations in accordance with one embodiment of the present invention.  FIG. 18   b  is a side elevational view of the perforating blade shown in  FIG. 18   a.    
   Each perforating knife of the embodiments shown in  FIGS. 17   a - d  and  18   a - b  has an elongate base  1702 ,  1802  upon which perforating teeth are located in single file. Each tooth has the shape of an oblique triangular pyramid. The base of the pyramid is an isosceles triangle (shown as the bottom contour line  1712  in  FIG. 17   a , and outlined by the tooth-bottom edge lines  1810  shown in  FIG. 18   a ) having a first, second and third side. While the base has at least two equal sides, the base can also have three equal sides (as “isosceles” means at least two equal sides). One face of the pyramid (the “vertical face”)  1708 ,  1808  has a normal vector that is parallel to the elongate base  1702 ,  1802  of the knife (and is thus perpendicular to the length of the knife). The first side is at the base of the vertical face  1708 ,  1808  and runs along the width of the knife. The second and third sides run from the ends of the first side to the centerline  1706 ,  1806  of the knife. The apex (“the center apex”)  1704 ,  1804  of the pyramid shape is located along the centerline  1706 ,  1806  above the first side. The apex  1704 ,  1804  and the first side are both contained within a vertical face  1708 ,  1808  of the pyramid. Contour lines  1712 ,  1714 ,  1814  help show the shape of the each tooth. 
   Each tooth has three cutting edges. A centerline cutting edge  1706 ,  1806  connects the center apex  1704 ,  1804  to the intersection of the second and third sides. Two base cutting edges connect the center apex  1704 ,  1804  to the ends of the first side. When the knife is pressed into a sheet of film, the center apexes  1704 ,  1804  of the teeth first pierce the sheet. As the knife is pressed further into the sheet of film, the two base edges form a wide base incision that runs perpendicular to the length of the knife. The centerline edge  1706 ,  1806  forms an apex incision that extends from the center of the wide base incision out along the perforation path towards the next perforation. The size of the perforations can be controlled by controlling the depth to which the knife pierces the sheet of film. The embodiments of perforating/cutting knives shown in  FIGS. 17   a - d  and  18   a - b  can be used to form the perforation patterns shown in  FIG. 14 . If heated enough to melt or soften the film to be perforated, the perforating/cutting knives can also form the patterns shown in  FIG. 15 . In addition, the perforating knife can also be used to completely cut through a film. 
   In  FIGS. 17   a - d , the center apex  1704  is the highest point of the vertical face  1708  that is perpendicular to the length of the blade. The vertical face  1708  has a triangular upper portion. A surface centerline  1706  follows the surface of the knife along the knife&#39;s center and runs from one centerline cutting edge  1706  to the next. When viewed from the side, as shown in  FIG. 17   b , the surface centerline  1706  and two top edge lines  1710  on either side of the centerline all follow zig-zag patterns down the length of the knife. The surface centerline  1706  drops downward at an angle from a center apex to a center low point at the vertical face  1708  of the next tooth where it rises vertically (or perpendicular to the length of the knife) to the next apex. Each of the two top edge lines  1706  runs parallel to the centerline  1706  at a lower elevation, dropping at an angle from an edge apex to an edge low point before rising vertically to the next edge apex. The surface centerline  1706 , top edge lines  1706  and the base cutting edges (the top edges of the vertical faces  1708 ) define the top surfaces of the blade&#39;s teeth. 
   In a preferred embodiment, the width D 1  of the perforating knife is approximately 0.0625 inches. The height D 2  of the perforating portion of each tooth is preferably about 0.0541 inches. The length D 3  of each tooth is preferably about 0.1964 inches. The angle A 1  between the line containing one base cutting edge and the connected base cutting edge is preferably about 120 degrees, which means that each vertical face forms an equilateral triangle. 
   In another embodiment, the width D 1  of the perforating knife is approximately 0.188 inches. The height D 2  of the perforating portion of each tooth is about 0.1628 inches. The length D 3  of each tooth is about 0.094 inches. The angle A 1  between the line containing one base cutting edge and the connected base cutting edge is about 120 degrees. 
   In yet another embodiment, the width D 1  of the perforating knife is approximately 0.188 inches. The height D 2  of the perforating portion of each tooth is about 0.1628 inches. The length D 3  of each tooth is about 0.112 inches. The angle A 1  between the line containing one base cutting edge and the connected base cutting edge is about 120 degrees. 
   Bandolier Format Packaging 
   Individual bags or packages of snack foods and other food products are generally shipped, displayed, purchased and consumed disconnected from other bags. Individual bags are produced at a factory and loosely packed in large shipping containers before eventually reaching retail outlets. Such packing, shipping and handling of these bags from factory to retail outlet is relatively inefficient as they occupy relatively large volumes of space compared to the actual volume of product reaching a consumer. 
   One method to facilitate packing, shipping and handling of these packages is to form them into a string of packages. In one embodiment of the present invention, a string of individual food packages is formed at the time of manufacture. As food product is introduced into a bag, two or more bags are not separated from each other. However, a perforation is formed between successive bags. Such perforation allows separation of individual bags at a later time. 
   In another embodiment, a string of bags is produced on a vertical form, fill, and seal (VFFS) machine. A VFFS machine first creates a tube of packaging material, seals one end of the tube, and drops food product into the other, open end of the tube. Normally, after food product is introduced into the open end, a package is formed by sealing the open end and cutting the package free from the tube of packaging material above the newly formed seal. The process is again repeated to make subsequent packages. 
   According to the present invention, a perforation, not a cut, is made between sequential packages made on a VFFS machine. Sequential packages are instead packaged as a string of packages made from the tube of packaging material. A string of packages having an arbitrary number of packages is thus formed. Such string of packages is more easily packaged and handled than the same number of individual packages. 
   A string of packages may be placed in one embodiment of a dispenser such as the one shown in  FIG. 20   a . With reference to  FIG. 20   a , a string of packages  2020  may be placed inside a dispenser  2002  through an opening with a re-closeable flap  2006 . Such dispenser  2002  may be more easily handled in the chain of distribution to the ultimate consumer than individual packages  1906  of products. Such dispenser  2002  provides increased protection to the string of packages  2020  as compared to the handling of an equivalent number of individual packages  1906 . A dispensing slit  2010  may be formed on one or more sides of a dispenser  2002 . 
   With reference to  FIG. 20   b , a dispensing opening  2004  may be made by opening a dispensing flap  2008  which enlarges a dispensing slit  2010  where such slit  2010  is shown in  FIG. 20   a . A loose end  2024  of a string of packages  2020  may be extended from a dispensing opening  2004 . A user may separate one or more packages  1906  by tearing a perforation  1904  between successive packages  1906 . The remainder of the packages  2026  remains inside the dispenser  2002 . A string of packages  2020  may be introduced into a dispensing container  2002  through a dispensing opening  2004  instead of an opening having a re-closeable flap  2006 . When all individual packages  2026  have been consumed, another string of packages  2020  may be reloaded into an existing dispenser  2002 . 
   A dispenser  2002  of packages  1906  may be maintained in a variety of settings including, but not limited to, a pantry, store shelf, kitchen counter, concession stand, recreational vehicle, garage, or other desired location. When such dispenser  2002  is displayed in a retail setting, individual packages  1906  may be for individual resale. For individual resale, it would then be required to separate one or more individual packages  1906  before purchasing them. A package dispenser  2002  facilitates the storage, display and sale of individual packages  1906  and string of packages  2020 . Such package dispenser  2002  is particularly advantageous when used in conjunction with a string of packages  2020  wherein a package contains one or more servings of a food product. 
   While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes inform and detail may be made therein without departing from the spirit and scope of the invention.