1. Technical Field
The present invention relates to a vertical stand-up pouch having an integrated reclose strip constructed using a modified vertical form and fill packaging machine, and the method for making same, that provides for a single piece construction of a vertical stand-up bag suitable for retail snack food distribution. The invention allows for use of existing film converter and packaging technology to produce a stand-up package for moisture sensitive food products or the like with minimal increased costs and minimal modification. The resulting stand-up package may be opened, a part of the contents removed and the package resealed to prevent premature deterioration of the quality of the contents because of exposure to moisture in the air.
2. Description of Related Art
Vertical form, fill, and seal packaging machines are commonly used in the snack food industry for forming, filling, and sealing bags of chips and other like products. Such packaging machines take a packaging film from a sheet roll and forms the film into a vertical tube around a product delivery cylinder. The vertical tube is vertically sealed along its length to form a back seal. The machine applies a pair of heat-sealing jaws or facings against the tube to form a transverse seal. This transverse seal acts as the top seal on the bag below and the bottom seal on the package being filled and formed above. The product to be packaged, such as potato chips, is dropped through the product delivery cylinder 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, thus sealing it within the film tube and forming a package of product. The package below said transverse seal is separated from the rest of the film tube by cutting across the sealed area.
The packaging film used in such process is typically a composite polymer material produced by a film converter. For example, one prior art composite film used for packaging potato chips and like products is illustrated in
The prior art film composition shown in
Typical back seals formed using the film composition shown in
With reference to
The fin seal variation shown in
Regardless of whether a lap seal or fin seal is used for constructing a standard package using a vertical form, fill, and seal packaging machine, the end result is a package as shown in
Referring to
Further disadvantages of using horizontal stand-up pouches include the initial capital expense of the horizontal stand-up pouch machines, the additional gas flush volume required during packaging as compared to a vertical flex bag, increased down time to change the bag size, slower bag forming speed, and a decreased bag size range. For example, a Polaris model vertical form, fill, and seal machine manufactured by Klick Lock Woodman of Georgia, USA, with a volume capacity of 60-100 bags per minute costs in the range of $75,000.00 per machine. A typical horizontal stand-up pouch manufacturing machine manufactured by Roberts Packaging of Battle Creek, Mich., with a bag capacity of 40-60 bags per minute typically costs $500,000.00. The film cost for a standard vertical form, fill, and seal package is approximately $0.04 per bag with a comparable horizontal stand-up pouch costing roughly twice as much. Horizontal stand-up pouches further require more than twice the oxygen or nitrogen gas flush. Changing the bag size on a horizontal stand-up pouch further takes in excess of two hours, typically, while a vertical form and fill machine bag size can be changed in a matter of minutes. Also, the typical bag size range on a horizontal stand-up pouch machine is from 4 oz. to 10 oz., while a vertical form and fill machine can typically make bags in the size range of 1 oz. to 24 oz.
One advantage of a horizontal stand-up pouch machine over a vertical form, fill, and seal machine, however, is the relatively simple additional step of adding a reclosable seal or a zipper seal at the top of the bag for reclosing of the bag. Vertical form, fill, and seal machines typically require substantial modification and/or the use of reclosable or zipper seals premounted on the film oriented horizontally to the seal facings used to seal the horizontal transverse seals.
For example, U.S. Pat. No. 4,584,201 to Boston discloses a system for applying a segment of seal strip to the external surface of a bag manufactured using a vertical form, fill, and seal machine, such that, when it is desired, the bag may be closed (i.e., resealed) after it has been opened. According to the Boston '201 disclosure, the seal strip includes a peel strip which is removable to allow the package, when opened, to be folded down and sealed against an adhesive which will be exposed upon the removal of the peel strip. In accordance with the Boston '201 disclosure, the bag is typically folded a plurality of times in the direction of the seal strip and the external surface of the bag is applied to an exposed adhesive on the seal strip and thereby the bag is resealed for storage of the contents. However, the Boston '201 invention necessitate the precise placement of discrete segments of seal strip across the traverse of the sheet of packaging material such that the applied seal strip is positioned parallel to the top traverse seal on the resulting bag and perpendicular to the vertical back seal. While effective, the Boston '201 system is unduly complex. Moreover, the Boston '201 system is only directed at and adapted for the production of conventional vertical flex bags or pillow pouches.
An alternative approach taken in the prior art to producing a bag with more of a stand-up presentation is the construction of a flat bottom bag such as illustrated in
The prior art method described above forms a package with a relatively broad base due to the V-shaped vertical gussets 37. Consequently, it is commonly referred to in the art as a flat bottom bag. Such flat bottom bag is advantageous over the previously described horizontal stand-up pouch in that it is formed on a vertical form, fill, and seal machine, albeit with major modifications. However, the prior art method of making a flat bottom bag has a number of significant drawbacks. For example, the capital expense for modifying the vertical form, fill, and seal machine to include the moving triangular-shaped devices is approximately $30,000.00 per machine. The changeover time to convert a vertical form, fill, and seal machine from a standard pillow pouch configuration to a stand-up bag configuration can be substantial, and generally in the neighborhood of one-quarter man hours. The addition of all of the moving parts required for the triangular-shaped devices to move in and out of position during each package formation cycle also adds complexity to the vertical form, fill, and seal machine, inevitably resulting in maintenance issues. Importantly, the vertical form, fill, and seal machine modified to include the moving triangular-shaped devices is significantly slower than a vertical form, fill, and seal machine without such devices because of these moving components that form the vertical gussets. For example, in the formation of a six inch by nine inch bag, the maximum run speed for a modified vertical form, fill, and seal machine using the triangular-shaped moving devices is in the range of 15 to 20 bags per minute. A standard vertical form, fill, and seal machine without such modification can construct a similarly sized pillow pouch at the rate of approximately 40 bags per minute.
Consequently, a need exists for a method to form a stand-up pouch, similar in appearance and functionality to the prior art horizontal stand-up pouches, using vertical form, fill, and seal machine technology and a single sheet of packaging film. Moreover, a need also exists for a simpler method of incorporating a reclosable strip into such a formed stand-up pouch using the vertical form, fill, and seal machine technology. This method should allow for reduced film cost per bag as compared to horizontal stand-up pouches, ease in size change, little capital outlay, and the ability to easily add a zipper seal to the bags, all while maintaining bag forming speeds typical of vertical form, fill, and seal machine pillow pouch production. Such method should ideally produce a vertical stand-up pouch having an integrated reclose strip, and constructed of material commonly used to form standard vertical flex bags.
The proposed invention involves producing a vertical stand-up pouch or package having an integrated reclose strip, and constructed of a single sheet of packaging material using a slightly modified vertical form, fill, and seal machine. The modified machine includes a crease-forming mechanism and an apparatus for applying a reclose strip to the sheet of material. The crease-forming mechanism includes a tension bar and forming plates located below the forming tube and a stationary but adjustable tucker mechanism mounted to the frame of the machine which, when positioned between the two forming plates, creates a vertical tuck along the length of the package while it is being formed. The apparatus for applying a reclose strip is incorporated into the mechanism which supplies the continuous sheet of packaging material to the vertical form, fill, and seal machine. The reclose strip is attached along the longitudinal axis of the sheet of packaging material prior to forming the sheet into, a tube in the conventional manner. The reclose strip includes a peel strip which is removable to allow the package, when opened, to be folded down and sealed against an adhesive which will be exposed upon the removal of the peel strip. In a preferred embodiment, the reclose strip comprises a length of two-sided adhesive tape.
The graphics on the packages are oriented 90° from a standard presentation such that the tuck forms the bottom of the package. The reclose strip can be easily added to the manufacture of such a vertical stand-up package since the reclose strip, which is attached along the longitudinal axis of the sheet of packaging material, can accompany the single sheet of packaging film through a vertical form, fill, and seal machine in the conventional manner. The transverse seals on the formed package are therefore oriented vertically and the reclose strip is oriented horizontally when the package is placed on display. Thus, when opened, the top of the package can be double folded and pressed against the exposed adhesive strip thereby providing a reclosable seal feature.
The method disclosed and the package formed as a consequence is a substantial improvement over prior art horizontal stand-up pouches or packages and flat bottom bags. The method works on existing vertical form, fill, and seal machines requiring very little modification. There are no substantial moving parts or jaw carriage modifications involved with the crease-forming mechanism. Moreover, the apparatus for applying the reclose strip may be easily incorporated into the supply mechanism that supplies the continuous sheet of packaging material to the vertical form, fill, and seal machine.
The modified vertical form, fill, and seal machines can also be easily converted back to a conventional pillow pouch configuration by selectively disengaging the crease-forming mechanism and discontinuing the supply of reclose strip. The same metalized or clear laminations used as materials in pillow pouches can also be used with the invention therefore saving in per bag cost. The invention allows for the formation of bags that emulate a horizontal stand-up pouch using a completely different method that takes advantage of the economics of vertical form and fill machine technology.
The above as well as additional features and advantages of the present invention will become apparent in the following written detailed description.
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:
a is a schematic cross-section view of a tube of packaging film illustrating the formation of a prior art lap seal;
b is a schematic cross-section of a tube of packaging film illustrating the formation of a prior art fin seal;
a is a perspective view of a prior art vertical flex bag;
b is a perspective view of a prior art flat bottom bag;
a, 4b, and 4c are perspective views in elevation of a prior art horizontal stand-up pouch;
a and 7b are perspective views of the vertical stand-up bag of the present invention;
a and 13b are perspective views of the vertical stand-up bag or package having an integrated reclose strip of the present invention;
c is a perspective view of the vertical stand-up package having an integrated reclose strip shown in
d is a fragmentary sectional view taken along line 13d-13d of
Where used in the various figures of the drawing, the same numerals designate the same or similar parts. Furthermore, when the terms “top,” “bottom,” “first,” “second,” “upper,” “lower,” “height,” “width,” “length,” “end,” “side,” “horizontal,” “vertical,” and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawing and are utilized only to facilitate describing the invention.
All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.
As previously described, the practice in the prior art in the manufacture of a vertical flex bag involves feeding a continuous packaging film directed around the forming tube 101. A back seal is formed on a single layer of film in order to create a tube of film around the forming tube 101. The seal jaws 108 close on the thus formed tube of packaging film, thereby forming a bottom transverse seal. Product is then dropped through the forming tube 101 into the tube of packaging film. The tube is then driven downward by friction against rotating belts (not shown), and the seal jaws 108 are used to form another transverse seal above the level of the product found inside the tube. This seal is subsequently cut horizontally such that a top transverse seal is formed at the top of the filled bag below and a bottom transverse seal is formed on the tube of packaging film above. The packaging film during the prior art operation described above is oriented perpendicular to the longitudinal translation of the film so as to be readable by an operator of the machine as the film travels down the forming tube 101. This orientation provides graphics 39 on the formed prior art bag that are readable by a consumer when the formed bag is placed on a retail display shelf while resting on its bottom transverse seal 33 as seen in
The invention adds three basic components to a prior art vertical form, fill, and seal machine. Two forming plates 104 and one tension bar 102 are used to hold the packaging film tube in tension from inside the tube, as indicated by the arrows illustrated on
Tension is applied on the outside of the film and in the opposite direction of the tension provided by the forming plates 104 by a fixed or stationary tucker mechanism 106, alternatively referred to herein as a tucker bar 106, positioned between said forming plates 104. The tucker bar 106 is preferably attached to the sealing carriage for the vertical form, fill, and seal machine and is adjustable along all three axes (in/out, up/down, and front/back). Alternatively, the tucker bar 106 can be attached to the frame of the vertical form, fill, and seal machine or any other point that can supports its function outside the film tube. These adjustments in all three axes allow for the tucker bar 106 to be easily moved out of the way to convert the vertical form and fill machine back to standard operation and is accomplished, in the embodiment shown in
When moved forward into position (i.e., toward the forming plates 104), the tucker bar 106 provides a crease or fold in the tube of the packaging film between the two forming plates 104. This crease is formed prior to formation of the transverse seal by the seal jaws 108. Consequently, once the transverse seal is formed, the crease becomes an integral feature of one side of the package. The vertical form and fill machine thereafter operates basically as previously described in the prior art, with the sealing jaws 108 forming a lower transverse seal, product being introduced through the forming tube 101 into the sealed tube of packaging film (which now has a crease on one side), and the upper transverse seal being formed, thereby completing the package. The major differences between a prior art package and Applicants' package, however, are that a crease is formed on one side (which later becomes the bottom of the formed package) using the fixed mechanism described and that the graphics on the packaging film used by the invention are oriented such that when the formed package is stood onto the end with the crease, the graphics are readable by a consumer.
An example of the formed package of the instant invention is shown in
Returning to
The diversion plate 160 in a preferred embodiment accomplishes two functions. First, the diversion plate 160 keeps product that is dropped down the forming tube 101 away from the area where the crease is being formed on the tube of packaging film. Second, the diversion plate 160, can be used as a channel for a gas or nitrogen flush. In such instance, the diversion plate 160 at some point above the bottom of the forming tube 101 seals at the top of the plate 160 against the forming tube 101. Below such seal (not shown) an orifice can be drilled into the forming tube 101 in order to provide gas communication between an exterior gas (for example, nitrogen or oxygen) source and the cavity formed between the diversion plate 160 and the interior of the forming tube 101. The diversion plate 160 as shown in
By using the diversion plate 160 as a channel for the gas flush, the present invention eliminates the need for a separate gas tube to be placed inside the forming tube 101 that normally accomplishes the same function in the prior art. The added benefit of providing a relatively large volume channel formed by the diversion plate 160 and the interior of the forming tube 101 is that a relatively large volume of flushing gas can be introduced into a filled and partially formed package at a significantly lower gas velocity compared to prior art gas tubes. This allows for the filling of packages using this embodiment of the present invention that may contain low weight product that might otherwise be blown back into the forming tube by prior art flushing tubes.
The head 180 can comprise any non-stick material but is preferably a fluoropolymer, such as Teflon®. In an alternative embodiment, the tucker bar 106 can comprise one integral piece of metal with the head portion 180 being coated with a fluoropolymer. The curved contact area of the head 180 allows for the continuous formation of the tuck illustrated in
To further compensate for the change in the width of the film tube as the transverse seal is formed by the seal jaws 108 of
The present invention offers an economic method of producing a stand-up pouch with numerous advantages over prior art horizontal stand-up pouches and methods for making them. Examples of these advantages are illustrated in Table 1 below.
Referring now to
As shown in
As will be subsequently explained in greater detail, the supply mechanism 200 includes an apparatus incorporated therein, which attaches a length of reclose strip 140 to the underside of the sheet of packaging material 120 such that when the sheet of packaging material 120 is supplied to the vertical form, fill, and seal machine 100 and formed into a tubular shape in the conventional manner, the reclose strip 140 is positioned along a longitudinal axis on the outer surface of the formed tube 120A.
Referring now to
For example, in accordance with the conventional art, the supply mechanism 200 may comprise a horizontal spindle 210 and a series of rollers 212, 214. The supply spool 220 is placed on the spindle 210 and a sheet of packaging material 120 is unrolled and fed through the series of rollers 212, 214 in the direction of arrows a, b, and c. The rollers 212, 214 control the speed, direction, and tension of the continuous sheet of packaging material 120 directed to the towards the vertical form, fill, and seal machine 100. For example, roller 214 might be a powered roller which advances the sheet of packaging material 120 off the supply spool 220 while rollers 212 might be idler rollers, which support, smooth or direct the sheet of packaging material 120 during its course of travel through the supply mechanism 200 and control the tension imparted to the sheet of packaging material 120 as it is directed towards the vertical form, fill, and seal machine 100. In another embodiment, both the spindle 210 and roller 214 might be a powered rollers which advance the sheet of packaging material 120 off the supple spool 220 in a synchronized manner.
Of particular note, the supply mechanism 200 of the present invention also includes an apparatus for applying a length of reclose strip 140 to the sheet of packaging material or film 120. As shown in the Figures, the apparatus includes a spool arbor 204 onto which a spool 240 of reclose strip 140 is attached, and a pivoting arm assembly 230, which directs and applies the reclose strip 140 onto the sheet of packaging material 120. As shown in the embodiment illustrated in the Figures, the spool arbor 204 and pivoting arm assembly 230 are positioned and supported by a support bracket 202, which is integrally attached to the supply mechanism 200.
The pivoting arm assembly 230 comprises a pivot arm 232 pivotally attached to the support bracket 202 by a pivot pin 234. The pivot arm 232 is free to rotate about the pivot pin 234 in the directions shown by the arrows in
In accordance with the present invention, a length of reclose strip 140 is played out from spool 240 and applied, by means of the pivoting arm assembly 230, to the outer peripheral surface of the sheet of packaging material 120 being advanced from the supply spool 220 as described previously. The length of reclose strip 140 from spool 240 is threaded through a roller guide mechanism 250 and a bar guide 256 extending from accessory plate 232a, so as to position align, and apply the length of reclose strip 140 to the sheet of packaging material 120 being advanced from the supply spool 220. The application roller 236 located at the distal end of the pivot arm 232 further presses the length of reclose strip 140 onto the sheet of packaging material 120 ensuring a good bonding between the reclose strip 140 and the packaging material 120. A weight assembly 238 may be attached to accessory plate 232a to increase the force applied by the application roller 236 upon the reclose strip 140 and the sheet of packaging material 120 as well as stabilize the entire pivoting arm assembly 230.
While the spool 240 of reclose strip 140 utilized in the present invention could theoretically be a single wound spool, as shown in the Figures and particularly in
In order to smoothly accommodate the gentle oscillation of the unwinding reclose strip 140, the roller guide mechanism 250 is fitted with a guide frame 252, which is pivotally attached to the an stationary extension bar 254, extending from the accessory plate 232a, which in turn is attached to the pivot arm 232. The roller guide mechanism 250 may comprise a cylinder having flange elements on the outer edges that channel the lateral edges of the length of reclose strip 140. Thus, the roller guide mechanism 250 is automatically aligned with the relative angle of the length of reclose strip 140 unwinding from the spool 240 thereby smoothly guiding the length of reclose strip 140 along to the bar guide 256, which aligns the length of reclose strip 140 with the sheet of packaging material 120.
As shown particularly in
Once attached to the sheet of packaging material 120, the length of reclose strip 140 is, thereafter, continually and automatically unwound from spool 240 and applied to the sheet of packaging material 120 by the periodic advance of the sheet of packaging material 120 from the supply spool 220 of the supply mechanism 200 as described previously. Thus, as shown in the Figures, the length of reclose strip 140 is attached to the underside of the sheet of packaging material 120 such that when the sheet of packaging material 120 is supplied by the supply mechanism 200 of the present invention to the vertical form, fill, and seal machine 100 and formed into a tubular shape in the conventional manner, the reclose strip 140 is positioned along a longitudinal axis on the outer surface of the formed tube 120A.
With reference once again to
Also shown in
At the bottom of the forming/fill tube 91, a crease-forming mechanism, as previously described, comprised of two forming plates 104, a fixed or stationary tucker mechanism 106, and a tension bar 102, is installed which modifies the standard vertical form, fill, and seal machine 100 so as to produce a stand-up packages. As with previous embodiments, the forming plates 104 can swing towards each other by rotating about a hinge 105. This arrangement allows for the forming plates 104 to rotate towards one another and avoid ripping of the packaging film 120 when transverse seals are being formed below the forming plates 104 by the transverse seal jaws 108 as shown in
As in previously described embodiments, the two forming plates 104 and the tension bar 102 are used to hold the formed tube 120A in tension from inside of the tube 120A. Tension is applied on the exterior surface of the formed tube 120A and in the opposite direction of the tension provided by the forming plates 104 by the tucker mechanism 106, alternatively referred to herein as a tucker bar 106, positioned between said forming plates 104. The tucker bar 106 is preferably attached to the sealing carriage for the vertical form, fill, and seal machine 100 and is adjustable along all three axes (in/out, up/down, and front/back).
Alternatively, the tucker bar 106 can be attached to the frame of the vertical form, fill, and seal machine 100 or any other point that can supports its function outside the film tube 120A. These adjustments in all three axes allow for the tucker bar 106 to be easily moved out of the way to convert the vertical form and fill machine 100 back to standard operation and is accomplished, in the embodiment shown in
When moved forward into position (i.e., toward the forming plates 104), the tucker bar 106 provides a crease or fold in the tube of the packaging film between the two forming plates 104. This crease is formed prior to formation of the transverse seal by the seal jaws 108. Consequently, once the transverse seal is formed, the crease becomes an integral feature of one side of the package.
As with previous described embodiments of the invention, the forming/fill tube 91 illustrated in
The vertical form, fill, and seal machine 100 of the present invention shown in
This seal is subsequently cut horizontally across the traverse such that a top transverse seal is formed at the top of the filled bag below and a bottom transverse seal is formed on the tube of packaging film above. As previously describe, the packaging film during the prior art operation is typically oriented perpendicular to the longitudinal translation of the film so as to be readable by an operator of the machine as the film travels down the forming tube 91. Thus, as shown in
An example of the resulting formed package of the instant invention is shown in
The reclose strip 140 used in the present invention may be of any conventional construction. For example, as shown in
In typical use, the resulting vertical stand-up pouch or package having an integrated reclose strip shown in
While the reclose strip 140 is functional anyplace on the package, it is desirable that the reclose strip 140 be applied on the upper half of the resulting package and preferably a position about one-third of the way down from the top portion 118 of the resulting package. Placing the reclose strip 140 on the lower half of the bag could cause the user to crush the contents remaining in the bag when it is resealed. However, the exact location of the reclose strip 140 depends upon the goods being packaged.
Thus, as shown by comparing
As noted previously, the added ability to attach the length of reclose strip 140 to a package available on Applicants' invention, is not available using current vertical form, fill, and seal machine technology. This is due, in part, to the orientation of the film graphics used on the packaging film of the present invention. Since the graphics are oriented 90° from the prior art, a length of reclose strip 140 can be run longitudinally along the forming tube adjacent with the packaging film as it is being formed into a tube and subsequent package. This is not possible with the prior art, because such orientation of a vertical length of reclose strip would place such a strip in a vertical orientation once the package is formed and stood up for display
The invention is further an improvement over methods for manufacturing prior art flat bottom bags. Since the tucker mechanism of Applicants' invention is stationary during bag formation, the present invention eliminates the need for moving parts that push against the film tube for the formation of a gusset. This elimination of moving parts allows for increased bag production rates, significantly lower changeover times to pillow pouch production, and significantly fewer maintenance issues.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
This application is a continuation-in-part of U.S. patent application Ser. No. 10/100,370, filed on Mar. 18, 2002, the technical disclosure of which is hereby incorporated herein by reference.
Number | Date | Country | |
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Parent | 10696982 | Oct 2003 | US |
Child | 11358522 | Feb 2006 | US |
Number | Date | Country | |
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Parent | 10100370 | Mar 2002 | US |
Child | 10696982 | Oct 2003 | US |