Patent Document

BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a flat bottom pillow pouch constructed using a modified vertical form fill and seal packaging machine, and the method for making the same that provides for a single-piece construction of a bag suitable for retail snack food distribution. 
         [0003]    2. Description of Related Art 
         [0004]    Many snack foods, like chips, pretzels, etc. are packaged in pouches formed of a very thin packaging film. These packages can be manufactured on vertical form, fill, and seal packaging machines that, as the name implies, forms a package, fills it with product, and seals the filled package. An example of a vertical form, fill, and seal machine for making pillow-pouch packages is exemplified in FIG. 1 of U.S. Pat. No. 6,718,739. Such packaging machines take 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 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 and 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, thereby making a bag and sealing the product within the bag while simultaneously forming a film tube above the product. The package below said transverse-seal is separated from the rest of the film tube by cutting across the sealed area. An example of the resultant standard pillow pouch bag is depicted by FIG. 3a of U.S. Pat. No. 6,722,106. 
         [0005]    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 in a standard pillow pouch bag uses a sealable inside, or product side, layer which typically comprises metalized oriented polypropylene (“OPP”) or metalized polyethylene terephtalate (“PET”). A sealant layer disposed upon the product side of the metalized film enables a hermetic seal to be formed by the transverse sealing jaws at a temperature lower than the melt temperature of the film. Typical prior art sealant layers include an ethylene-propylene co-polymer and an ethylene-propylene-butene-1 ter-polymer. The metalized film layer, which is usually metalized with a thin layer of aluminum, provides excellent barrier properties. 
         [0006]    Barrier properties in one or more layers are important in order to protect the product inside the package from light, oxygen or moisture. Such a need exists, for example, for the protection of foodstuffs, which may run the risk of flavor loss, staling, or spoilage if insufficient barrier properties are present to prevent transmission of such things as light, oxygen, or moisture into the package. 
         [0007]    Adjacent to the metalized inside layer is a laminate layer, typically a polyethylene extrusion, and an outer ink or graphics layer. The ink layer is typically used for the presentation of graphics that can be viewed through a transparent outside layer, which layer is typically OPP or PET. The overall film thickness of this prior art film composition is typically less than 225 gauge. Such prior art film composition is well known in the art and disclosed in the discussion related to FIG. 1 in U.S. Pat. No. 7,189,300, which is hereby incorporated by reference. 
         [0008]    The prior art film composition discussed above is ideally suited for use on vertical form and fill machines for the packaging of food products. The use of OPP or PET for the outside layer and the inside layer 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. 
         [0009]    Ideally, every seal on every package would be hermetic, or leak-proof, even under pressure changes. Without a hermetic seal, any barrier properties provided by the film are ineffective against oxygen, moisture, or aroma transmission between the product in the package and the outside. Hermetic seals are especially important with snack foods, so that flavor and freshness are preserved. Areas where the package has a back seal, folds, or gussets provide extra layers of material in the seal, but this problem becomes more acute with thicker packaging materials, additional folds in the package design, and smaller packages. 
         [0010]    One problem with pillow-pouch packages is that they have a narrow, single-edge base made from the bottom transverse seal and therefore such prior art packages are not stable and are unable to stand independently (e.g., without leaning on something) on the bottom transverse seal. It would be desirable to have a pillow-pouch package capable of independently standing on its bottom-transverse seal. 
         [0011]      FIGS. 1   a - 1   d  depict a vertical, stand-up pouch  100  having a front  102  defined by a top-transverse seal  120  and a bottom-transverse seal  130 . Also depicted is a side  110  with a sealed gusset  112  adjacent to the bottom transverse seal  130  and an open gusset  114  adjacent the top transverse seal  120 . A gusset is created on the side  110  of a package when four layers of film are captured because of film being pushed or folded inward and sealed together by the transverse sealing jaws when the transverse seal is made. It is not necessary that the transverse seals actually seal all four layers of packaging film together to form a gusset, as demonstrated by the open gusset  114 . However, sealing all four layers together can result in a closed gusset  112 . 
         [0012]    Referring to  FIGS. 1   c  and  1   d,  four layers of film are also sealed together in the vicinity of the middle of the rear face  106  of the package in the areas indicated by  127   137  if a fin seal is used as the backseal  140 . Because such overlapping film is not on the side of the package and is not a result of being pushed inward or folded inward, such areas are not considered a gusset for purposes of this application. 
         [0013]    As used herein, a “gusset” is defined as a gusset on the side  110  of a package and includes both open gussets  114  and closed gussets  112 . 
         [0014]    As shown, the front of the package  102  and the rear-package face  106  are bounded on the sides by heat-sealed creases  104  that run from the top transverse seal  120  to the bottom transverse seal  130 . The package depicted in  FIGS. 1   a - 1   d  is similar to the package disclosed in U.S. Pat. No. 5,398,486. The package depicted in  FIGS. 1   a - 1   d  is constructed in a method similar to that described above with regard to prior art pillow-pouches. However, to form the side gussets  110  on either side of the bag, the vertical, form, fill and seal machine must be substantially modified by the addition of two moveable devices on opposite sides of the sealing carriage that move in and out to make contact with the packaging film to form the tuck that becomes the side  110  shown in  FIGS. 1   a - 1   d . Further, instead of using a single back-sealer to make a back seal  140 , the package made in  FIGS. 1   a - 1   d  require an additional heat sealing device for each crease  104  that is made in the package to provide additional stability to the package. Consequently, a total of five vertical sealing devices are used. Methods for making such vertical creases  104  are described and taught in U.S. Pat. Nos. 5,862,652 and 3,785,112. 
         [0015]    As discussed above, it is important that the transverse seals on every package made from this film be a hermetic or leak-proof, transverse seal. This is especially important with low moisture shelf-stable foods and/or other products that are susceptible to oxygen and/or moisture. 
         [0016]      FIG. 1   d  is a top perspective rear view of the prior art package depicted in  FIG. 1   a  and illustrates the relative position and portion of the problem areas  125   126   127  of the transverse seal  120 .  FIG. 1   e  is an exaggerated top cross-sectional view of the problem area  125  of the package depicted in  FIG. 1   d . Referring to  FIGS. 1   d  and  1   e , regions  121  and  123  of the top transverse seal  120  each have four film layers that must be sealed together while region  122  has only two layers except at the intersection of the backseal. Similarly, if a lap seal is used to make the back seal  140  the area  127  will have three layers of packaging film and if a fin seal is used, the area  127  will have four layers of packaging film. Because of the change in the number of layers of packaging film, triangularly-shaped capillary leaks, pin-hole leaks, or void spaces  150  (as depicted by  FIG. 1   e ) can occur in packages when side gussets  110  are made in the packaging film. Similar void spaces occur in each problem area as shown by numerals  125   126   127 .  FIG. 1   c  depicts locations where these problem areas  135   136   137  can occur on the bottom, transverse seal  130 . The problem areas can occur in packages having an open gusset  114  as shown by the top portion of the package in  FIG. 1   d  or in packages having a closed gusset  112  as shown the problem areas  135   136   137  illustrated by the bottom portion of the package in  FIG. 1   c.    
         [0017]    The prior art solutions to overcoming pinhole leaks requires the film from prior art pillow packages to be modified in some manner. For example, while the top and bottom transverse seals  120   130  have the potential of having a problem areas  127   137 , as depicted by  FIGS. 1   c  and  1   d , such problem areas can be addressed by use of the film disclosed in U.S. Patent Application Publication No. 2007/0128386, assigned to the same Assignee as the present invention. 
         [0018]    Unfortunately, such prior art solution still requires film modification may not adequately address the problem areas  125   126   135   136  that can facilitate oxygen and moisture penetration into a package via the capillary void space  150  as depicted in  FIG. 1   e.    
         [0019]    Another prior art solution for overcoming pinhole leaks is to add two or three times more sealant to the product facing layer, such as the product facing OPP layer. Another solution to overcoming such shortcoming is to use an additional film layer to try to fill up the capillary void space. The additional film layer is typically a 1 to 2.5 mil (100 to 250 gauge) linear low density polyethylene that must be laminated to the inner metalized OPP layer. Consequently, such films typically require a tandem lamination to make the requisite multi-layer film and substantially more film material must be used than is required for a standard pillow pouch package. The thickness of a film typically used for packages having gussets is usually greater than 300 gauge, which is at least about 33% more film than used in standard pillow pouch packages. 
         [0020]    For example, U.S. Pat. No. 7,122,234 teaches that laminates used to make such packages require sufficient bending stiffness to be suitable for continuous high speed packaging. The &#39;234 Patent teaches that sufficient stiffness occurs when the laminate thickness exceeds  110  micrometers or 433 gauge units (1 micron or micrometer=3.937 gauge; 100 gauge=1 mil=0.001 inches). European Patent Application 1 283 179 discloses a microwave heatable food product package associated with the trade name TETRAWEDGE. When measured, the TETRAWEDGE package revealed a thickness of 12.5 mil or 1250 gauge. One apparent consequence of using such thick material is that a crease pattern is applied to the packaging material prior to package formation to permit the material to be folded along inclined lateral corners and along base corners. Similarly, U.S. Pat. No. 5,508,075 discloses the need for crease lines to be stamped or otherwise impressed into the surface of the packaging material. It would be desirable to make a flat bottom pillow pouch using the same film as is used with prior art pillow packages without compromising the hermetic sealing properties of the transverse seal. 
         [0021]    In one aspect, the package should be made to avoid open or closed gussets and to minimize the problem areas at an upper or lower transverse seal that occurs because of a change in the number of layers and regions of transition that can create capillary void spaces  150  in the transverse seals. In one aspect, the package should have three or more distinct edges defining the package bottom to permit the package to stand upright on the bottom transverse seal. In one aspect, the package should be made of the same film material and utilize the same film thickness used to make standard pillow pouch packages. In one aspect, the package is made with a film material without the need for crease lines to be stamped or otherwise impressed into the package film. 
       SUMMARY OF THE INVENTION 
       [0022]    The present invention in one embodiment is directed towards a method of making a flat bottom pillow pouch comprising the steps of forming a bottom transverse seal, using an extension to form a package bottom with defined edges and flaps, folding the transverse seal, and folding the flaps beneath the package. In one embodiment, the present invention is directed towards a flat bottom pillow pouch having no gussets wherein the pouch stands on the bottom transverse seal. In one embodiment, the present invention is directed towards an improved vertical form fill and seal machine comprising an extendable and retractable extension below a product tube, a folding device for folding a transverse seal, and at least two side folding members to fold flaps formed by the extension in the extended position. 
         [0023]    Other aspects, embodiments and features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. The accompanying figures are schematic and are not intended to be drawn to scale. In the figures, each identical, or substantially similar component that is illustrated in various figures is represented by a single numeral or notation. For purposes of clarity, not every component is labeled in every figure. Nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. All patent applications and patents incorporated herein by reference are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    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: 
           [0025]      FIG. 1   a  is a front perspective view of a prior art package that stands on the bottom transverse seal. 
           [0026]      FIG. 1   b  is a side view of the prior art package depicted in  FIG. 1   a.    
           [0027]      FIG. 1   c  is a bottom rear perspective view of the prior art package depicted in  FIG. 1   a.    
           [0028]      FIG. 1   d  is a top rear perspective view of the prior art package depicted in  FIG. 1   a.    
           [0029]      FIG. 1   e  is a top cross-sectional view of a portion of the package depicted in  FIG. 1   d.    
           [0030]      FIG. 2   a  is a front perspective view of a flat bottom pillow pouch made in accordance with one embodiment of the present invention, 
           [0031]      FIG. 2   b  is a side view of the package depicted in  FIG. 2   a.    
           [0032]      FIG. 2   c  is a rear bottom-perspective view of the package depicted in  FIG. 2   a.    
           [0033]      FIG. 2   d  is a top rear perspective-view of the package depicted in  FIG. 2   a.    
           [0034]      FIGS. 3   a - 3   g  are perspective views showing the sequence of operation of the formation of a package in accordance with one embodiment of the present invention. 
           [0035]      FIGS. 4   a - 4   g  are perspective views showing the sequence of operation of the formation of a package in accordance with one embodiment of the present invention. 
           [0036]      FIGS. 5   a - 5   d  are perspective views showing the sequence of operation of the formation of the packaging film in accordance with one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0037]      FIG. 2   a  is a top front perspective view of a flat bottom bottom pillow pouch package made in accordance with one embodiment of the present invention.  FIG. 2   b  is a side view of the package depicted in  FIG. 2   a .  FIG. 2   c  is a rear bottom-perspective view of the package depicted in  FIG. 2   a .  FIG. 2   d  is a top rear perspective-view of the package depicted in  FIG. 2   a . Referring to  FIGS. 2   a - 2   d , in one embodiment, the present invention comprises a flat-bottom, pillow-pouch bag or package  200  having no pleats or gussets along the side of a package. Rather the package of the present invention, in one embodiment comprises a side  210  between the front face  202  and the rear face  206 , that tapers upwardly from the bottom portion  212  adjacent the bottom edge  262  upwardly to the top transverse seal  220 . Consequently, the area  214  near the top transverse seal  220  of the present invention is much like the area near the top transverse seal of a prior art pillow-pouch bag as depicted by FIG. 3a of U.S. Pat. No. 6,722,106 because both packages have no gussets adjacent to the top transverse seal as clearly shown by FIGS. 2 a - 2   d.    
         [0038]    Referring to  FIG. 2   c , the package of the present invention comprises a pair of inwardly-folded ears  260  that are positioned beneath the package bottom  250 .  FIG. 2   c  further depicts the bottom transverse seal  230  oriented as substantially perpendicular to the top transverse seal  220 . In one embodiment, a portion of the bottom transverse seal  230  on the inwardly folded ears  260  is heat scaled to the bottom  250 . The package bottom  250  as depicted Is substantially rectangular in shape. In one embodiment, the periphery of the package bottom  250  comprises a substantially perpendicular front and rear edge  252  such that the bottom  250  is substantially perpendicular to the front  202  and rear  206 . In one embodiment, the periphery of the package bottom  250  comprises a substantially perpendicular side edge  262  such that the bottom  250  is substantially perpendicular to the side  210 . Those skilled in the art will recognize that the front  202 , rear  206 , and sides  210  will be slightly less than perpendicular to the bottom  250  because of the tapering of the sides  210  of the package from bottom to top. 
         [0039]      FIGS. 3   a - 3   g  are perspective views showing the sequence of operation of the formation of a package on an improved vertical form fill and seal machine in accordance with one embodiment of the present invention. For purposes of simplification, the top portion of the vertical form fill and seal machine has been omitted from  FIGS. 3   b - 3   g . Flexible packaging film  301  having barrier properties is taken from a roll of film (not shown) and passed over a former  316  which directs the film into a vertical tube around a product delivery tube  318 , as depicted in  FIG. 3   a . As used herein, flexible packaging film having barrier properties is defined as flexible film having an oxygen transmission rate of less than about 150 cc/m 2 /day (ASTM D1434) and a water vapor transmission rate of less than about 5 grams/m 2 /day (ASTM F372-99). 
         [0040]      FIGS. 5   a - 5   d  are perspective views showing the sequence of operation of the formation of the packaging film in accordance with one embodiment of the present invention. The formation of the package shown in  FIGS. 2   a - 2   d  will now be described with reference to  FIGS. 3   a - 3   g  and  FIGS. 5   a - 5   d . As shown by  FIGS. 3   a  and  5   a , while the tube is pulled downward by drive belts  320 , the vertical tube of film is sealed along its length by a vertical sealer  322 , forming a back-seal  240 . As shown in  FIG. 3   a , the product delivery tube  318  comprises an extension  330  beneath the product delivery tube  318 . In the embodiment shown the extension  330  comprises a pair of flaps in the extended position. As used herein, the extended position refers to an extension  330  that is oriented in a manner which creates outward tension on the film tube upon completion of the bottom transverse seal  230 . In the embodiment shown, the extended position occurs when the extension  330  is parallel to the portion of the product delivery tube  318  to which the extension  330  is attached. 
         [0041]    Referring to  FIGS. 3   b  and  5   b , the sheet of film  301  is pulled downward below the product delivery tube  318 . The bottom end-seal  230  is made with a pair of sealing jaws  326  beneath the product delivery tube  318  having an extension  330  in the retracted position to form an open-ended tube. As used herein, the retracted position refers to an extension  330  position that permits a bottom transverse end-seal to be made beneath the product delivery tube  318  with a pair of sealing jaws  326 . The flexible flaps comprising the extension  330  shown in  FIG. 3   b  can be made of 0.035 inches of spring steel or any suitable flexible material. Such embodiment advantageously permits the flexible flaps to flex inwardly into a retracted position via actuation of a closing mechanism  340  to permit the sealing jaws  326  to close to form a transverse seal to minimize or eliminate the creation of tucks or pleats. 
         [0042]    As shown by  FIGS. 3   c  and  5   c , upon completion of the bottom transverse seal, the closing mechanism  340  is released, and the flexible flaps  330  automatically flex back outwardly back into the extended position thereby defining the package bottom  250  having a pair of outwardly-extending flaps  260 , as best shown by reference to  FIG. 5   c . The transverse seal  230  moves upward in elevation as the extension  330  moves into the extended position and as the package bottom  250  becomes defined. A folding device  350 , at an elevation higher than the sealing jaws  326  can then be engaged beneath the extended extension  330  to fold the bottom transverse seal  230 . In one embodiment, the residual heat imparted by the heat sealing jaws  326  on the bottom transverse seal causes the folded bottom transverse seal to stick to the bottom of the package when the folding device  350  has been engaged. In one embodiment, the folding device  350  comprises heated edges. After the folding device  350  has been engaged, the flaps  260  advantageously bend downward. Such bending of the flaps  260  can help ensure the side folding members  360  can engage the flaps  260  as discussed below. Product can be dropped through the product delivery tube  318  any time after the forks  350  have been engaged and the bottom seal  230  (as shown in  FIG. 5   c ) has been folded over. 
         [0043]      FIG. 3   d  depicts another step of the package formation in accordance with one embodiment of the present invention. The side folding members  360  are positioned in elevation such that the side folding members  360  are below the folding device  350  and above the terminal ends of the flaps  260 . As shown in  FIGS. 3   d  and  5   d , a pair of side folding members  360  fold each of said flaps  260  inwardly and beneath the package bottom  250 . In one embodiment, the folding device  350  remains beneath the package bottom  250  while the folding members  360  fold the flaps  260  beneath both the package bottom  250  and the folding device  350 . In one embodiment, heat from the folding device  350  and/or the folding members  360  softens the outer film layers of the flaps  260  and the package bottom  250  which helps fuse and seal the flaps  260  to the package bottom  250 . In one embodiment, the folding device  350  comprises a fork having at least two fingers. In one embodiment, the folding device  350  comprises a three-fingered fork which advantageously provides an open area for contact between the package bottom  250  and flaps  260  as shown in  FIG. 3   d . In one embodiment, because the bottom transverse seal  230  is still relatively hot from the heated sealing jaws  326 , the bottom transverse seal on the flaps  260  is sealed via residual heat to the bottom transverse seal on the package bottom  250  in the open areas between the folding device  350  fingers. In one embodiment, a pedestal  370  (shown in  FIG. 3   c ) is disposed below the product delivery tube  318  and inside the extension  330 . In one embodiment, the pedestal  370  is substantially flush in elevation with the extension  330  when the extension  330  is in the extended position. 
         [0044]      FIG. 3   e  is a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. As shown in  FIG. 3   e , the side folding member  360  comprises a mount  364  for a pivoting extension  362 . After the side folding members  360  have folded the flaps  260  beneath the package bottom  250 , a pivoting extension  362  placed on a mount  364  that is flush with each side folding member  360  is moved upward in the direction depicted by the arrows so as to engage the pedestal  370 , the pedestal  370  being depicted in  FIG. 3   c . Consequently, referring to  FIGS. 3   e  and  5   d , the pivoting extensions  362  apply vertical pressure between the respsective flaps  260  and the package bottom  250 . The pedestal  370  (depicted in  FIG. 3   c ) holds the package bottom in place  250  such that pressure is applied between the flaps  260  and the package bottom  250 . In one embodiment, because the transverse seal  230  has residual heat from the heat sealing jaws, and because of the pressure applied by the pivoting extension  362  against the flaps and the pedestal  370 , the portion of the transverse seal from the flaps  260  is sealed to the portion of the transverse seal on the package bottom  250 . In one embodiment the side folding members  360  can be heated and in one embodiment the pivoting extension  362  and/or the pedestal  370  is heated to further facilitate the seal between the flaps  260  and the package bottom. 
         [0045]      FIG. 3   f  is a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. Once the flaps  260  have been folded inwardly and optionally sealed to the package bottom  250 , the folding device  350  can then be removed from beneath the package bottom  250 . 
         [0046]      FIG. 3   g  is a bottom perspective view of one step of the present invention. As shown in  FIG. 3   f , the folding members  360  can then be moved outwardly from beneath the package bottom  250 . The sheet of film can then be pulled downwardly prior to making the top transverse seal. 
         [0047]      FIGS. 4   a - 4   g  are perspective views showing the sequence of operation of the formation of a package on an improved vertical form fill and seal machine in accordance with one embodiment of the present invention. For purposes of simplification, the top portion of the vertical form fill and seal machine has been omitted from  FIGS. 4   b - 4   g . Flexible packaging film  301  having barrier properties is taken from a roll of film (not shown) and passed over a former  316  which directs the film into a vertical tube around a product delivery tube  318 . While the tube is pulled downward by drive belts  320 , the vertical tube of film is sealed along its length by a vertical sealer  322 , forming a back-seal  240 . As shown in  FIG. 4   a , the product delivery tube  318  comprises an extension  430  beneath the product delivery tube  318 . In the embodiment shown in  FIG. 4   a - 4   f , the extension  430  comprises a telescoping extension that is slidably movable in the vertical direction between a retracted position and an extended position. The telescoping extension can be movably disposed within the product delivery tube  318  and the telescoping extension can be attached to a control cylinder via a pneumatically operated or other suitable rod assembly to move the telescoping extension as needed. Such telescoping extensions are known in the art as illustrated by U.S. Pat. No. 5,505,040, which is hereby incorporated by reference. 
         [0048]    Referring to  FIG. 4   b , the sheet of film  301  is pulled downward below the product delivery tube  318 . Referring to  FIGS. 4   b  and  5   b,  the bottom end-seal  230  is made with a pair of sealing jaws  326  beneath the product delivery tube  318  having an extension  430  in the retracted position. 
         [0049]    As shown by  FIGS. 4   c  and  5   c,  upon completion of the bottom transverse seal  230 , the extension  430  is slid into an extended position thereby forming the package bottom  250  having a pair of outwardly-extending flaps  260 , as best shown by reference to  FIG. 5   c . The transverse seal  230  moves upward in elevation as the extension moves into the extended position and as the package bottom  250  becomes defined. 
         [0050]    A folding device  350  at an elevation higher than the sealing jaws  326  can then be engaged beneath the extended extension  430  to fold the bottom transverse seal  230 . In one embodiment, the residual heat on the bottom transverse seal from the heat sealing jaws  326  causes the folded bottom transverse to stick to the bottom of the package when the folding device  350  has been engaged. In one embodiment, the folding device  350  comprises heated edges. After the folding device  350  has been engaged, the flaps  260  advantageously bend downward. Such bending of the flaps  260  can help ensure the side folding members  360  can engage the flaps  260  as discussed below. Product can be dropped through the product delivery tube  318  anytime after the forks  350  have been engaged and the bottom seal (as shown in  FIG. 5   c ) has been folded over, 
         [0051]      FIG. 4   d  depicts another step of the package formation in accordance with one embodiment of the present invention. The side folding members  360  are positioned in elevation such that the side folding members  360  are below the folding device  350  and above the terminal ends of the flaps  260 . As shown in  FIGS. 4   d  and  5   d , a pair of side folding members  360  fold each of said flaps  260  inwardly and beneath the package bottom  250 . In one embodiment, the folding device  350  remains beneath the package bottom  250  while the side folding members  360  fold the flaps beneath both the package bottom  250  and the folding device  350 . In one embodiment, heat from the folding device  350  and/or the folding members  360  softens the outer film layers of the flaps  260  and the package bottom  250  which helps fuse and seal the flaps  260  to the package bottom  250 . In one embodiment, the folding device  350  comprises a fork having at least two fingers. In one embodiment, the folding device  350  comprises a three-fingered fork which advantageously provides an open area for contact between the package bottom  250  and flaps  260  as shown in  FIG. 4   d . In one embodiment, because the bottom transverse seal  230  is still relatively hot from the heated sealing jaws  326 , the bottom transverse seal on the flaps  260  is sealed via residual heat to the bottom transverse seal on the package bottom  250  in the open areas between the folding device  350  fingers. In one embodiment, a pedestal  470  (shown in  FIG. 4   c ) is disposed below the product delivery tube  318  and inside the extension  430 . In one embodiment, the pedestal  470  is substantially flush in elevation with the bottom end of the extension  430  when the extension  430  is in the extended position. The pedestal  470  can be attached to and move with the telescoping extension  430 . 
         [0052]      FIG. 4   e  is a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. As shown in  FIG. 4   e , the side folding member  360  comprises a mount  364  for a pivoting extension  362 . After the side folding members  360  have folded the flaps  260  beneath the package bottom  250 , a pivoting extension  362  placed on a mount  364  that is flush with each side folding member  360  is moved upward in the direction depicted by the arrows so as to engage the pedestal  470 , the pedestal  470  being depicted in  FIG. 4   c . Consequently, referring to  FIGS. 4   e  and  5   d , the pivoting extensions  362  apply pressure between the respsective flaps  260  and the package bottom  250 . The pedestal  470  (depicted in  FIG. 4   c ) holds the package bottom in place  250  such that pressure is applied between the flaps  260  and the package bottom  250 . In one embodiment, because the transverse seal  230  has residual heat from the heat sealing jaws, and because of the pressure applied by the pivoting extension  362  against the flaps and the pedestal  470 , the portion of the transverse seal from the flaps  260  is sealed to the portion of the transverse seal on the package bottom  250 . In one embodiment the side folding members  360  can be heated and in one embodiment the pivoting extension  362  and/or the pedestal  470  is heated to further facilitate the seal between the flaps  260  and the package bottom. 
         [0053]      FIG. 4   f  is a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. Once the flaps  250  have been folded inwardly and optionally sealed to the package bottom  250 , the folding device  350  can then be removed from beneath the package bottom  250 . 
         [0054]      FIG. 4   g  is a bottom perspective view of one step of the present invention. As shown in  FIG. 4   f , the folding members can then be moved outwardly from beneath the package bottom  250 . The sheet of film can then be pulled downwardly where the top, transverse seal is made. 
         [0055]      FIGS. 5   a - 5   d  are partial simplified rear perspective bottom views depicting the sequential method of how the bottom of the package depicted in  FIG. 2   c  is made from the packaging film. The vertical form fill and seal equipment has been omitted.  FIG. 5   a  represents the film tube having a backseal  240  and corresponds to the film tube depicted in  FIGS. 3   a  and  4   a .  FIG. 5   b  represents the open ended film tube after the bottom transverse seal has been made and corresponds to the film tube depicted in  FIGS. 3   b  and  4   b.    FIG. 5   c  depicts the package bottom  250  having a folded bottom transverse seal  230  and an edge  252  that is substantially perpendicular to the rear package face  204 .  FIG. 5   c  corresponds to the film tube depicted in  FIGS. 3   c  and  4   c .  FIG. 5   d  depicts the completed package bottom  250  having a pair of inwardly-folded ears  260  positioned beneath the package bottom and corresponds to the package depicted in  FIG. 3   d  and  4   d . To make the package of the present invention, a transverse seal is made on an open ended film tube as shown in  FIG. 5   b . Edges  252  are then formed to define a fiat package bottom  250 . Formation of the edges  252  creates a pair of flaps  260  as shown by  FIG. 5   c . The flaps  260  are then folded inwardly and beneath the package bottom  250  to create side edges  262 . 
         [0056]    There are several advantages provided by the present invention. First, because the package comprises no gussets, use of a lower gauge flexible film can be used because of the reduction in the number of problem areas where pinhole leaks can occur. The flat bottom pouch of the present invention can be made from film than is less than 180 gauge in thickness. Consequently, the flat bottom pillow pouch can be made with at least 33% less film than is required for the prior art embodiment depicted in  FIG. 1   a - 1   d.  In one embodiment, the film used for the present invention consists of a metalized OPP layer having a sealant layer and a reverse printed polymer layer that is laminated with polyethylene or other suitable adhesive layer to the metalized OPP film. Consequently, in one embodiment, the package of the present invention is made from the same film as a pillow package. The invention provides a package and method for making the same from a flexible material without the need for crease lines to be stamped or otherwise impressed into the package film prior to making the package. 
         [0057]    An advantage of the present invention is that the top and bottom transverse seals are made without any side gussets. Further, because there are fewer locations for the occurrence of pinholes, the package of the present invention provides more consistent shelf-life. The present invention provides a way to make flat bottom pillow pouches by modifying a standard vertical form fill and seal machine. 
         [0058]    While this 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 in form and detail may be made therein without departing from the spirit and scope of the invention.

Technology Category: b