Method and apparatus for making a flat bottom pillow pouch

The present invention discloses a flat bottom pillow pouch that can stand upright on its bottom transverse seal. The flat bottom pillow bag can be made from the same film as a standard pillow pouch and requires less film than prior art stand up packages. The flat bottom pillow pouch disclosed herein has no gussets.

BACKGROUND OF THE INVENTION

1. Technical Field

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.

2. Description of Related Art

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.

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 terephthalate (“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.

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.

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.

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.

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.

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.

FIGS. 1a-1ddepict a vertical, stand-up pouch100having a front102defined by a top-transverse seal120and a bottom-transverse seal130. Also depicted is a side110with a sealed gusset112adjacent to the bottom transverse seal130and an open gusset114adjacent the top transverse seal120. A gusset is created on the side110of 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 gusset114. However, sealing all four layers together can result in a closed gusset112.

Referring toFIGS. 1cand1d, four layers of film are also sealed together in the vicinity of the middle of the rear face106of the package in the areas indicated by127137if a fin seal is used as the back seal140. 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.

As used herein, a “gusset” is defined as a gusset on the side110of a package and includes both open gussets114and closed gussets112.

As shown, the front of the package102and the rear-package face106are bounded on the sides by heat-sealed creases104that run from the top transverse seal120to the bottom transverse seal130. The package depicted inFIGS. 1a-1dis similar to the package disclosed in U.S. Pat. No. 5,398,486. The package depicted inFIGS. 1a-1dis constructed in a method similar to that described above with regard to prior art pillow-pouches. However, to form the side gussets110on 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 side110shown inFIGS. 1a-1d. Further, instead of using a single back-sealer to make a back seal140, the package made inFIGS. 1a-1drequire an additional heat sealing device for each crease104that 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 creases104are described and taught in U.S. Pat. Nos. 5,862,652 and 3,785,112.

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.

FIG. 1dis a top perspective rear view of the prior art package depicted inFIG. 1aand illustrates the relative position and portion of the problem areas125126127of the transverse seal120.FIG. 1eis an exaggerated top cross-sectional view of the problem area125of the package depicted inFIG. 1d. Referring toFIGS. 1dand1e, regions121and123of the top transverse seal120each have four film layers that must be sealed together while region122has only two layers except at the intersection of the back seal. Similarly, if a lap seal is used to make the back seal140the area127will have three layers of packaging film and if a fin seal is used, the area127will 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 spaces150(as depicted byFIG. 1e) can occur in packages when side gussets110are made in the packaging film. Similar void spaces occur in each problem area as shown by numerals125126127.FIG. 1cdepicts locations where these problem areas135136137can occur on the bottom, transverse seal130. The problem areas can occur in packages having an open gusset114as shown by the top portion of the package inFIG. 1dor in packages having a closed gusset112as shown the problem areas135136137illustrated by the bottom portion of the package inFIG. 1c.

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 seals120130have the potential of having a problem areas127137, as depicted byFIGS. 1cand1d, 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.

Unfortunately, such prior art solution still requires film modification may not adequately address the problem areas125126135136that can facilitate oxygen and moisture penetration into a package via the capillary void space150as depicted inFIG. 1e.

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.

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 '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.

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 spaces150in 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

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.

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.

DETAILED DESCRIPTION

FIG. 2ais a top front perspective view of a flat bottom pillow pouch package made in accordance with one embodiment of the present invention.FIG. 2bis a side view of the package depicted inFIG. 2a.FIG. 2cis a rear bottom-perspective view of the package depicted inFIG. 2a.FIG. 2dis a top rear perspective-view of the package depicted inFIG. 2a. Referring toFIGS. 2a-2d, in one embodiment, the present invention comprises a flat-bottom, pillow-pouch bag or package200having no pleats or gussets along the side of a package. Rather the package of the present invention, in one embodiment comprises a side210between the front face202and the rear face206, that tapers upwardly from the bottom portion212adjacent the bottom edge262upwardly to the top transverse seal220. Consequently, the area214near the top transverse seal220of 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 byFIGS. 2a-2d.

Referring toFIG. 2c, the package of the present invention comprises a pair of inwardly-folded ears260that are positioned beneath the package bottom250.FIG. 2cfurther depicts the bottom transverse seal230oriented as substantially perpendicular to the top transverse seal220. In one embodiment, a portion of the bottom transverse seal230on the inwardly folded ears260is heat sealed to the bottom250. The package bottom250as depicted is substantially rectangular in shape. In one embodiment, the periphery of the package bottom250comprises a substantially perpendicular front and rear edge252such that the bottom250is substantially perpendicular to the front202and rear206. In one embodiment, the periphery of the package bottom250comprises a substantially perpendicular side edge262such that the bottom250is substantially perpendicular to the side210. Those skilled in the art will recognize that the front202, rear206, and sides210will be slightly less than perpendicular to the bottom250because of the tapering of the sides210of the package from bottom to top.

FIGS. 3a-3gare 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 fromFIGS. 3b-3g. Flexible packaging film301having barrier properties is taken from a roll of film (not shown) and passed over a former316which directs the film into a vertical tube around a product delivery tube318, as depicted inFIG. 3a. 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/m2/day (ASTM D1434) and a water vapor transmission rate of less than about 5 grams/m2/day (ASTM F372-99).

FIGS. 5a-5dare 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 inFIGS. 2a-2dwill now be described with reference toFIGS. 3a-3gandFIGS. 5a-5d. As shown byFIGS. 3aand5a, while the tube is pulled downward by drive belts320, the vertical tube of film is sealed along its length by a vertical sealer322, forming a back-seal240. As shown inFIG. 3a, the product delivery tube318comprises an extension330beneath the product delivery tube318. In the embodiment shown the extension330comprises a pair of flaps in the extended position. As used herein, the extended position refers to an extension330that is oriented in a manner which creates outward tension on the film tube upon completion of the bottom transverse seal230. In the embodiment shown, the extended position occurs when the extension330is parallel to the portion of the product delivery tube318to which the extension330is attached.

Referring toFIGS. 3band5b, the sheet of film301is pulled downward below the product delivery tube318. The bottom end seal230is made with a pair of sealing jaws326beneath the product delivery tube318having an extension330in the retracted position to form an open-ended tube. As used herein, the retracted position refers to an extension330position that permits a bottom transverse end seal to be made beneath the product delivery tube318with a pair of sealing jaws326. The flexible flaps comprising the extension330shown inFIG. 3bcan 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 mechanism340to permit the sealing jaws326to close to form a transverse seal to minimize or eliminate the creation of tucks or pleats.

As shown byFIGS. 3cand5c, upon completion of the bottom transverse seal, the closing mechanism340is released, and the flexible flaps330automatically flex back outwardly back into the extended position thereby defining the package bottom250having a pair of outwardly-extending flaps260, as best shown by reference toFIG. 5c. The transverse seal230moves upward in elevation as the extension330moves into the extended position and as the package bottom250becomes defined. A folding device350, at an elevation higher than the sealing jaws326can then be engaged beneath the extended extension330to fold the bottom transverse seal230. In one embodiment, the residual heat imparted by the heat sealing jaws326on the bottom transverse seal causes the folded bottom transverse seal to stick to the bottom of the package when the folding device350has been engaged. In one embodiment, the folding device350comprises heated edges. After the folding device350has been engaged, the flaps260advantageously bend downward. Such bending of the flaps260can help ensure the side folding members360can engage the flaps260as discussed below. Product can be dropped through the product delivery tube318any time after the forks350have been engaged and the bottom seal230(as shown inFIG. 5c) has been folded over.

FIG. 3ddepicts another step of the package formation in accordance with one embodiment of the present invention. The side folding members360are positioned in elevation such that the side folding members360are below the folding device350and above the terminal ends of the flaps260. As shown inFIGS. 3dand5d, a pair of side folding members360fold each of said flaps260inwardly and beneath the package bottom250. In one embodiment, the folding device350remains beneath the package bottom250while the folding members360fold the flaps260beneath both the package bottom250and the folding device350. In one embodiment, heat from the folding device350and/or the folding members360softens the outer film layers of the flaps260and the package bottom250which helps fuse and seal the flaps260to the package bottom250. In one embodiment, the folding device350comprises a fork having at least two fingers. In one embodiment, the folding device350comprises a three-fingered fork which advantageously provides an open area for contact between the package bottom250and flaps260as shown inFIG. 3d. In one embodiment, because the bottom transverse seal230is still relatively hot from the heated sealing jaws326, the bottom transverse seal on the flaps260is sealed via residual heat to the bottom transverse seal on the package bottom250in the open areas between the folding device350fingers. In one embodiment, a pedestal370(shown inFIG. 3c) is disposed below the product delivery tube318and inside the extension330. In one embodiment, the pedestal370is substantially flush in elevation with the extension330when the extension330is in the extended position.

FIG. 3eis a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. As shown inFIG. 3e, the side folding member360comprises a mount364for a pivoting extension362. After the side folding members360have folded the flaps260beneath the package bottom250, a pivoting extension362placed on a mount364that is flush with each side folding member360is moved upward in the direction depicted by the arrows so as to engage the pedestal370, the pedestal370being depicted inFIG. 3c. Consequently, referring toFIGS. 3eand5d, the pivoting extensions362apply vertical pressure between the respective flaps260and the package bottom250. The pedestal370(depicted inFIG. 3c) holds the package bottom in place250such that pressure is applied between the flaps260and the package bottom250. In one embodiment, because the transverse seal230has residual heat from the heat sealing jaws, and because of the pressure applied by the pivoting extension362against the flaps and the pedestal370, the portion of the transverse seal from the flaps260is sealed to the portion of the transverse seal on the package bottom250. In one embodiment the side folding members360can be heated and in one embodiment the pivoting extension362and/or the pedestal370is heated to further facilitate the seal between the flaps260and the package bottom.

FIG. 3fis a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. Once the flaps260have been folded inwardly and optionally sealed to the package bottom250, the folding device350can then be removed from beneath the package bottom250.

FIG. 3gis a bottom perspective view of one step of the present invention. As shown inFIG. 3f, the folding members360can then be moved outwardly from beneath the package bottom250. The sheet of film can then be pulled downwardly prior to making the top transverse seal.

FIGS. 4a-4gare 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 fromFIGS. 4b-4g. Flexible packaging film301having barrier properties is taken from a roll of film (not shown) and passed over a former316which directs the film into a vertical tube around a product delivery tube318. While the tube is pulled downward by drive belts320, the vertical tube of film is sealed along its length by a vertical sealer322, forming a back-seal240. As shown inFIG. 4a, the product delivery tube318comprises an extension430beneath the product delivery tube318. In the embodiment shown inFIG. 4a-4f, the extension430comprises 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 tube318and 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.

Referring toFIG. 4b, the sheet of film301is pulled downward below the product delivery tube318. Referring toFIGS. 4band5b, the bottom end seal230is made with a pair of sealing jaws326beneath the product delivery tube318having an extension430in the retracted position.

As shown byFIGS. 4cand5c, upon completion of the bottom transverse seal230, the extension430is slid into an extended position thereby forming the package bottom250having a pair of outwardly-extending flaps260, as best shown by reference toFIG. 5c. The transverse seal230moves upward in elevation as the extension moves into the extended position and as the package bottom250becomes defined.

A folding device350at an elevation higher than the sealing jaws326can then be engaged beneath the extended extension430to fold the bottom transverse seal230. In one embodiment, the residual heat on the bottom transverse seal from the heat sealing jaws326causes the folded bottom transverse to stick to the bottom of the package when the folding device350has been engaged. In one embodiment, the folding device350comprises heated edges. After the folding device350has been engaged, the flaps260advantageously bend downward. Such bending of the flaps260can help ensure the side folding members360can engage the flaps260as discussed below. Product can be dropped through the product delivery tube318any time after the forks350have been engaged and the bottom seal (as shown inFIG. 5c) has been folded over.

FIG. 4ddepicts another step of the package formation in accordance with one embodiment of the present invention. The side folding members360are positioned in elevation such that the side folding members360are below the folding device350and above the terminal ends of the flaps260. As shown inFIGS. 4dand5d, a pair of side folding members360fold each of said flaps260inwardly and beneath the package bottom250. In one embodiment, the folding device350remains beneath the package bottom250while the side folding members360fold the flaps beneath both the package bottom250and the folding device350. In one embodiment, heat from the folding device350and/or the folding members360softens the outer film layers of the flaps260and the package bottom250which helps fuse and seal the flaps260to the package bottom250. In one embodiment, the folding device350comprises a fork having at least two fingers. In one embodiment, the folding device350comprises a three-fingered fork which advantageously provides an open area for contact between the package bottom250and flaps260as shown inFIG. 4d. In one embodiment, because the bottom transverse seal230is still relatively hot from the heated sealing jaws326, the bottom transverse seal on the flaps260is sealed via residual heat to the bottom transverse seal on the package bottom250in the open areas between the folding device350fingers. In one embodiment, a pedestal470(shown inFIG. 4c) is disposed below the product delivery tube318and inside the extension430. In one embodiment, the pedestal470is substantially flush in elevation with the bottom end of the extension430when the extension430is in the extended position. The pedestal470can be attached to and move with the telescoping extension430.

FIG. 4eis a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. As shown inFIG. 4e, the side folding member360comprises a mount364for a pivoting extension362After the side folding members360have folded the flaps260beneath the package bottom250, a pivoting extension362placed on a mount364that is flush with each side folding member360is moved upward in the direction depicted by the arrows so as to engage the pedestal470, the pedestal470being depicted inFIG. 4c. Consequently, referring toFIGS. 4eand5d, the pivoting extensions362apply pressure between the respective flaps260and the package bottom250. The pedestal470(depicted inFIG. 4c) holds the package bottom in place250such that pressure is applied between the flaps260and the package bottom250. In one embodiment, because the transverse seal230has residual heat from the heat sealing jaws, and because of the pressure applied by the pivoting extension362against the flaps and the pedestal470, the portion of the transverse seal from the flaps260is sealed to the portion of the transverse seal on the package bottom250. In one embodiment the side folding members360can be heated and in one embodiment the pivoting extension362and/or the pedestal470is heated to further facilitate the seal between the flaps260and the package bottom.

FIG. 4fis a bottom perspective view of the next sequential step in accordance with one embodiment of the present invention. Once the flaps250have been folded inwardly and optionally sealed to the package bottom250, the folding device350can then be removed from beneath the package bottom250.

FIG. 4gis a bottom perspective view of one step of the present invention. As shown inFIG. 4f, the folding members can then be moved outwardly from beneath the package bottom250. The sheet of film can then be pulled downwardly where the top, transverse seal is made.

FIGS. 5a-5dare partial simplified rear perspective bottom views depicting the sequential method of how the bottom of the package depicted inFIG. 2cis made from the packaging film. The vertical form fill and seal equipment has been omitted.FIG. 5arepresents the film tube having a back seal240and corresponds to the film tube depicted inFIGS. 3aand4a.FIG. 5brepresents the open ended film tube after the bottom transverse seal has been made and corresponds to the film tube depicted inFIGS. 3band4b.FIG. 5cdepicts the package bottom250having a folded bottom transverse seal230and an edge252that is substantially perpendicular to the rear package face204.FIG. 5ccorresponds to the film tube depicted inFIGS. 3cand4c.FIG. 5ddepicts the completed package bottom250having a pair of inwardly-folded ears260positioned beneath the package bottom and corresponds to the package depicted inFIGS. 3dand4d. To make the package of the present invention, a transverse seal is made on an open ended film tube as shown inFIG. 5b. Edges252are then formed to define a flat package bottom250. Formation of the edges252creates a pair of flaps260as shown byFIG. 5c. The flaps260are then folded inwardly and beneath the package bottom250to create side edges262.

An embodiment has been disclosed wherein the extension330comprises a pair of flaps. Another embodiment has been disclosed wherein the extension330comprises a telescoping extension. In yet another embodiment the extension330comprises two or more movable fingers which are movable between an extended position and a retracted position. In one embodiment the extension330comprises two pair of movable fingers.

In one embodiment the movable fingers are a part of a vertical drive system. As used herein a vertical drive system is a system which converts a vertical force into either a rotational or horizontal force.FIG. 6ais a side view showing the drive system in an extended position in one embodiment. As depicted the vertical drive system comprises a lever674which is laterally movable relative to a base679. In one embodiment the base679is stationary.

Coupled to the base679is at least one pair of fingers672. In one embodiment, as depicted, the fingers672comprise a needle-like shape. Such a shape allows the fingers672to extend within, and define, the corners of a package. In other embodiments the fingers672comprise a planar flap which moveable between an extended position and a retracted position. Virtually any shape which can be converted from an extended position, in which the fingers direct opposing forces, to a retracted position can be utilized. For example, in one embodiment comprising fingers the fingers define four points in space. These points define the footprint of the bottom of the bag. Virtually any shape which provides for these points in space which define the bottom of the bag can be utilized.

As depicted the fingers672and the base679are coupled via pivots673. The pivots673can comprise rivets, screws, bolts, or any such device which allows the fingers672to rotate. As depicted there is only one pivot673per finger672. In other embodiments more than one pivot673can be used per finger672. The pivots673enable the fingers672to rotate relative to the base679.

As depicted the lever674comprises two notches675. The notches675are sized to receive a handle682located on the fingers672. The notches675and handles682are so sized so that if the lever674is pulled in the upward direction, the handle682can move accordingly within the notch675. While the lever674is shown as having a notch675, in other embodiments the lever674comprises a handle682whereas the fingers672comprise the notch675. Other devices which rotatably couple the fingers672to the lever674can also be suitably used. For example, in one embodiment the notch675and handle682comprises a ball and socket. Likewise, the notch and handle can comprise many different shapes. Different shapes will affect the maneuverability of the handle682within the notch675.

As noted,FIG. 6ashows the fingers in an extended position. In one embodiment the fingers672are substantially parallel with the sides of the product delivery tube318. As can be seen, the fingers672are maintained in their position by the lever674; the top of the fingers672butt up against the lever674preventing the fingers672from further extending. For example, the level674prevents the finger672on the right side ofFIG. 6afrom rotating in the counter-clockwise direction. If, however, an upward force is applied to the lever674both fingers672will rotate to a retracted position.

FIG. 6bis a side view showing the drive system in a retracted position in one embodiment. As can be seen, now the fingers672butt against the low end676of the lever674. The low end676prevents the fingers672from further retracting. For example, the low end676prevents the finger672on the right side ofFIG. 6bfrom rotating in the clockwise direction. If, however, a downward force is applied to the lever674then both fingers672will rotate to the extended position. It can be seen that the base679comprises a wedge shape at the bottom end. In one embodiment the wedge shape mimics the shape of the fingers672in the retracted position. The wedge can be wider or narrower than the fingers672in the retracted position. One benefit from this wedge shape is that it prevents the wedge from rubbing or otherwise interfering with the film. As such, having a wedge which is narrower than the fingers672in the retracted position prevents the wedge from contacting, and possibly damaging, the film.

As described, the position of the fingers672can be adjusted by lateral movement of the lever674. The lateral movement of the lever674can be controlled by any means known in the art including, but not limited to, actuators which apply a force upon a lever674.

One embodiment wherein the extension330comprises movable fingers is shown inFIG. 7a.FIG. 7ais a perspective view showing the product delivery tube in one embodiment.FIG. 7bis a top view showing the product delivery tube in one embodiment. As can be seen, in one embodiment, the product delivery tube318comprises partitions881. A partition is a physical boundary. As depicted the product delivery tube318comprises two partitions881which separates the product delivery tube318into three chambers though other number of chambers can be suitably used. The food or other product to be packaged flows through the bulk chamber778. A vertical drive system is located in the left chamber777aand the right chamber777b. In one embodiment the bulk chamber778comprises about 80% of the product delivery tube318. In one embodiment the left and/or right chamber777has a width of about ½ inch or less. The width is defined as the distance between the partition881and the external wall of the tube318. In one embodiment the bulk chamber778has a width of between about 3 inches to about 7 inches between partitions881. The thickness of the product delivery tube318, measured from the front wall to a back wall, varies for the widths of the bags. In one embodiment the product delivery tube318ranges from a thickness of between about 2.5 and about 4 inches. Having a vertical drive system which is contained within a chamber having a width of ½ inch or less is beneficial in that it requires very little space to operate.

In one embodiment, as depicted inFIG. 7b, the partitions881are attached to the product delivery tube318. In another embodiment the base679of the drive system acts as the partition. In such an embodiment the product delivery tube318is a single chamber which is separated into three chambers by the insertion of two vertical drive systems. In other embodiments, however, the product delivery tube318comprises partitions881which are coupled or otherwise affixed to the product delivery tube318. In such embodiments the product delivery tube318comprises multiple chambers even in the absence of a vertical drive system.FIGS. 7aand7billustrate an embodiment wherein the product delivery tube318comprises partitions881.

The partitions881separate the bulk chamber778from the left777aand right chambers777b. Such an embodiment separates the vertical drive system from the food which is to be packaged. This allows the vertical drive system to be made from a variety of materials as it is not required that the vertical drive system comprise food grade parts. Further, because the vertical drive system is separate from the food product, the vertical drive system requires less cleaning than would a drive system exposed to the oil, particulates, etc. of the food.

As depicted inFIG. 7a, there are two vertical drive systems, each located on a side of the product delivery tube318. As can be seen, virtually all parts necessary for the operation of the fingers672are contained within the product delivery tube318. In one embodiment all parts required for the operation of the fingers672save for the equipment which acts upon the lever674is contained within the product delivery tube318. This is a vast improvement of the prior art which often required external air cylinder activation located at or near the extension330to operate the extension330. For example, referring toFIG. 3a, air cylinders or devices for activating the air cylinders such as buttons were often located below the drive belt320and along the upper portion of the extension330. Because of the presence of air cylinders located in the vicinity of the extension330, the foot print of the vertical form, fill, and seal machine was increased. As can be seen fromFIG. 7a, however, a vertical drive system, in one embodiment, requires far less space. Further, as noted, the vertical drive system permits a vertical force to be converted into a horizontal or rotational force. Such conversion results in an efficient use of the space around and within the product delivery tube318. As noted, this conversion eliminates the need to have bulky equipment located near the fingers672which would provide the horizontal or rotational force. As described, an actuator or other equipment can be located near the top of the product delivery tube318and can apply a vertical force to the lever674. The vertical drive system then converts the vertical force into a rotational or horizontal force as needed. As such, the vertical drive system allows the actuator or other such equipment to be remotely located relative to the fingers672.

Furthermore, in one embodiment the vertical drive system requires fewer moving parts. Having fewer moving parts is an advantage because fewer moving parts typically equates to less down time due to maintenance. As can be seen inFIG. 6a, the lever674and the fingers672are really the only moving parts aside from the equipment which operates the lever674. Additionally, by requiring fewer parts, there are fewer parts which could potentially break off during operation. This is always a concern in food packaging as it is undesirable that machinery parts would be packaged in a food package. Further, because the vertical drive system is partitioned from the bulk chamber778, even if a part such as the pivot673became loose, the likelihood that it would be packaged is significantly minimized. Additionally, in one embodiment the vertical drive system and its parts are so dimensioned so that the vertical drive system fits snugly within the chamber. In such embodiments because the vertical drive system is snugly situated within a chamber if parts did break off it would be very difficult, if not virtually impossible, for the broken piece to fall downstream where it could be packaged. As stated the friction and compressive forces maintain dislodged pieces within the chamber. As such, loose or dislodged machinery is prevented from falling and becoming packaged.

The lever674can be operated with any equipment known in the art. In one embodiment, as shown inFIG. 7a, the lever674is manipulated with an actuator.

The vertical drive system operates as previously described. For example, in one embodiment the fingers672are manipulated into the refracted position. In the retracted position the sealing jaws326make an end seal. When retracted, in one embodiment, the fingers672point in the direction of the centerline of the sealing jaws326. Such operation permits the sealing jaws326to close and form a transverse seal while simultaneously minimizing or eliminating the creation of tucks or pleats. In one embodiment, as shown inFIG. 7a, there are two vertical drive systems each with a pair of fingers672. Each pair of fingers672act on one end of a package. Thus, in one embodiment an end seal is formed with a pair of sealing jaws to form an open-ended tube.

Thereafter, the fingers672are manipulated into an extended position. As noted, in one embodiment this step comprises vertically displacing the lever674relative to the base679so that the fingers672rotate about the pivot673. Thus, the vertical displacement results in the fingers672achieving the extended position. While in the extended position the fingers create and define the package bottom250which has a pair of outwardly-extending flaps260, as shown inFIG. 5c. A folding device350then folds the bottom transverse seal230. The outwardly-extending flaps260can be folded and sealed to the bottom of the package as previously described. For example a folding member360such as shown inFIG. 3ecan be utilized. Likewise, in one embodiment the folding member360comprises a pivoting extension362such as shown inFIG. 3e. In one embodiment the fingers672maintain the extended position until the other machinery has been moved. For example, in one embodiment the fingers672maintain the extended position while the folding device350is removed. The fingers672maintain the extended position when the folding member360is withdrawn. Thereafter the fingers672are manipulated into the retracted position, and the process is repeated.

As previously noted, a pedestal470can be utilized to apply vertical pressure to the package bottom250which aids in the sealing of the flaps260. In one embodiment the pedestal470is coupled to the base679of the vertical drive system. As can be seen inFIG. 7a, in one embodiment the pedestal470only extends outward from the base679in one direction. As depicted, the pedestal470does not extend in the direction of the fingers672. This ensures the pedestal470does not disrupt the operation of the fingers672. Furthermore, in some embodiments if the pedestal470extended in the direction of the fingers672this would interfere with the folding device350. It should be noted that while the folding device350is depicted as having three forks this should not be deemed limiting. In other embodiments the fork can comprise virtually any number of forks. Applicants have discovered in one embodiment that increased surface area of the folding device350in the area which contacts the seals results in better folds. As such, in one embodiment wherein the folding device350comprises three forks, the middle fork is wider compared to the outer forks. This results in increased surface area on the front edge of the folding device350. However, in one embodiment comprising a pedestal470, the folding device350does not cover the area above the location of the pedestal470. Put differently, in some embodiments, there are gaps, holes, etc., such as those shown inFIG. 3e, in the folding device350so that the pedestal470is not covered by the folding device350. This allows pressure to be applied to the pedestal470.

In another embodiment, the pedestal470extends in both directions from the face of the base679. This increases the available surface area of the pedestal470. In one embodiment the pedestal extends outwardly in substantially a perpendicular direction from the face of the base679. The pedestal470can be welded, soldered, or otherwise affixed to the base679. In other embodiments the pedestal470is made integral to the base679.

In one embodiment the vertical drive system can be slidably removed from its chamber777. As shown inFIG. 7a, due to the presence of the pedestal470, the vertical drive system is installed and removed through the bottom of the product delivery tube318.

In one embodiment the vertical form, fill, and seal machine further comprises a product delivery tube brace.FIG. 8is a side profile view of one embodiment utilizing a product delivery tube brace. Often when the vertical sealer322makes its seal it applies pressure to the product delivery tube318which causes the product delivery tube318to move slightly. This is not typically a problem if making typical pillow pouch packages. However, because the outwardly-extending flaps260can be folded and sealed to form the flat bottom, if the product delivery tube318undesirably moves the flaps260become misaligned during the fold. Thus, rather than resulting in the package of5dwherein the flaps260are folded over the seal230, the flaps260do not overlay the seal230. In one embodiment, providing a brace880which limits the movement of the product delivery tube limits or eliminates flap260misalignment. The brace880can comprise a variety of devices. In one embodiment the brace880comprises a wheel or other rotatable device. Because film is being pulled downward, when the product delivery tube318, and consequently the film, is pressed against the brace880, the rotatable device prevents the downwardly moving film from becoming stuck or undesirably slowed by the brace880. The brace880can be positioned at virtually any location along the product delivery tube318. The brace880, as used herein, refers to any device which applies pressure to counter the pressure applied by the vertical sealer322. In one embodiment the brace880is located at the same height as the vertical sealer322and positioned approximately 180° away from the vertical sealer322. In one embodiment the brace880is positioned between about 1/16 to about 1/32 of an inch from the product delivery tube318.

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 inFIG. 1a-1d. In other embodiments film with a thickness of between 150 and 300 gauge is used. 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.

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.

ADDITIONAL DESCRIPTION

The following clauses are offered as further description of the disclosed invention.

1. A method for making a pillow pouch having a flat bottom, said method comprising the steps of:

a) forming a first end seal with a pair of sealing jaws to form an open-ended tube wherein said first end seal is formed beneath a product delivery tube having at least one pair of fingers in a retracted position;

b) providing said at least one pair of fingers in an extended position thereby forming a package bottom having a pair of outwardly-extending flaps;

c) folding said end seal with a folding device;

d) folding each of said flaps inwardly and beneath said package bottom.

2. The method according to any preceding clause, wherein said providing in step b) comprises vertically displacing a lever, wherein said lever is coupled to said at least one pair of fingers, such that said vertical displacement results in said at least one pair of fingers achieving said extended position.
3. The method according to any preceding clause, wherein said folding of said first end seal comprises folding with a fork having at least two fingers and an open area therebetween.
4. The method according to any preceding clause, wherein said tube comprises film having a thickness of between 150 and 300 gauge.
5. The method according to any preceding clause, wherein said folding of said first end seal occurs such that a folded end seal is created that is substantially 90 degrees from the top end seal.
6. The method according to any preceding clause, wherein said flaps are sealed to said bottom of said package.
7. The method according to any preceding clause, wherein step d) further comprises the step of applying vertical pressure between each of said flaps and said package bottom.
8. The method according to any preceding clause, further comprises sealing said flaps to the bottom of the package.
9. The method according to any preceding clause, wherein said product delivery tube further comprises a pedestal.
10. The method according to any preceding clause, wherein said folding of step d) is performed by a folding member, wherein said folding member comprises a pivoting extension.
11. The method according to any preceding clause, wherein said pivoting extension apply a vertical pressure.
12. The method according to any preceding clause, wherein said fingers are substantially parallel with said product delivery tube when in said extended position.
13. The method according to any preceding clause, further comprising the step of forming a second end seal with a pair of sealing jaws.
14. A vertical form, fill, and seal machine, said machine comprising:

a product delivery tube having an extension, wherein said extension comprises at least one pair of fingers being movable between an extended position and a retracted position;

a folding device for folding a bottom, transverse seal adjacent to a package bottom thereby creating a pair of flaps; and

a pair of side folding members wherein each folding member holds each flap beneath said package bottom.

15. The machine according to clause 14, wherein each of said side folding members further comprise a pivoting extension.

16. The machine according to clauses 14-15, wherein said extension further comprises at least one pedestal.

17. The machine according to clauses 14-16, wherein said machine consists of a single vertical sealing device.

18. The machine according to clauses 14-17, wherein said product delivery tube comprises partitions.

19. The machine according to clause 18, wherein said partitions form three chambers, wherein said chambers comprise a bulk chamber, a left chamber, and a right chamber.

20. The machine according to clause 19, wherein said left chamber comprises an extension, and wherein said right chamber comprises an extension.

21. The machine according to clauses 14-20, wherein said extension is coupled to a vertical drive system.

22. The machine according to clauses 14-21, wherein said at least one pair of fingers is coupled to a lever.

23. The machine according to clause 22, wherein when said lever is vertically displaced said at least one pair of fingers moves between said extended and retracted position.

24. The machine according to clause 22, wherein said lever comprises two notches and wherein each of said fingers comprises a handle, and wherein of said handle fits within said notch.

25. The machine according to clauses 14-24, further comprising a product delivery tube brace.

26. The machine according to clause 25, wherein said machine further comprises a vertical sealer, and wherein said brace is located about 180 degrees from said vertical sealer.

27. The machine according to clauses 14-26, wherein said extension extends below said product delivery tube.

28. A method for making a pillow pouch having a flat bottom, said method comprising the steps of:

a) forming a tube of packaging film on a vertical form fill and seal machine;

b) forming an end seal on said tube, wherein said end seal comprises no tucks, wherein said end seal is formed beneath a product delivery tube having at least one pair of fingers in a retracted position, wherein said fingers extend down below said product delivery tube;

c) positioning said fingers in an extended position thereby defining a flat bottom;

d) folding said end seal with a folding device to make a plurality of flaps; and

e) folding each of said flaps inwardly and beneath said package bottom.

29. The method according to clause 28, wherein said packaging film comprises a thickness of between 150 and 300 gauge.

30. The method according to clause 28, further comprising the step of applying vertical pressure between each of said flaps and said package bottom.