U.S. patent application number 10/778839 was filed with the patent office on 2004-08-19 for vertical stand-up pouch.
Invention is credited to Bartel, Lawrence Joseph, Knoerzer, Anthony Robert, Kohl, Garrett William, Tucker, Steven Kenneth.
Application Number | 20040161174 10/778839 |
Document ID | / |
Family ID | 28039796 |
Filed Date | 2004-08-19 |
United States Patent
Application |
20040161174 |
Kind Code |
A1 |
Bartel, Lawrence Joseph ; et
al. |
August 19, 2004 |
Vertical stand-up pouch
Abstract
A vertical stand-up pouch or flexible package, and method for
manufacturing same, constructed by modification to existing
vertical form and fill packaging machines. The invention involves
producing a vertical stand-up pouch from a single sheet of
packaging film by creating a vertical crease along one edge of a
packaging film tube prior to forming a transverse seal on the tube.
Said vertical crease is formed using a stationary tucker bar
positioned outside the packaging film tube and between two forming
plates positioned inside the packaging film tube.
Inventors: |
Bartel, Lawrence Joseph;
(Pilot Point, TX) ; Knoerzer, Anthony Robert;
(Plano, TX) ; Kohl, Garrett William; (Allen,
TX) ; Tucker, Steven Kenneth; (Hurst, TX) |
Correspondence
Address: |
Carstens, Yee & Cahoon, LLP
Suite 900
13760 Noel Road
Dallas
TX
75240
US
|
Family ID: |
28039796 |
Appl. No.: |
10/778839 |
Filed: |
February 13, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10778839 |
Feb 13, 2004 |
|
|
|
10100370 |
Mar 18, 2002 |
|
|
|
6722106 |
|
|
|
|
Current U.S.
Class: |
383/104 ;
383/122 |
Current CPC
Class: |
B65B 9/20 20130101; B65B
61/188 20130101; B65D 33/1691 20130101; B65B 9/213 20130101; B65D
75/008 20130101; B65B 9/22 20130101; B65B 9/2042 20130101 |
Class at
Publication: |
383/104 ;
383/122 |
International
Class: |
B65D 030/16 |
Claims
What is claimed is:
1. A method for making a flexible package, said method comprising
the steps of: a) forming a tube of packaging film on a vertical
form, fill, and seal machine; b) forming a vertical crease in said
tube of packaging film prior to sealing said tube horizontally; c)
forming a first horizontal seal on said tube, wherein said first
horizontal seal includes a portion of said vertical crease; d)
forming a second horizontal seal on said tube, wherein said second
horizontal seal includes a portion of said vertical crease; and e)
cutting said tube segment from the remainder of said tube at said
second horizontal seal, thus forming a flexible package having a
crease along one edge.
2. The method of claim 1 wherein the crease of step b) is formed by
at least one stationary tucker bar positioned between a pair of
forming plates.
3. The method of claim 2 wherein said tucker bar comprises
teflon.
4. The method of claim 2 wherein said tucker bar comprises one or
more gas ports and wherein further a metered blast of gas from said
ports is used during the forming step b).
5. The method of claim 1 wherein the forming of step b) further
comprises holding said tube in tension with at least three
extensions below the bottom of a forming tube on said vertical
form, fill, and seal machine, wherein said extensions apply said
tension on said tube from inside said tube pressing outwards on
said tube and, wherein further, said vertical crease is formed by
tension applied on the outside of said tube by a stationary device
pressing inwardly on said tube at a point between two of said at
least three extensions.
6. The method of claim 5 wherein said device pressing inwardly on
said tube comprises a tucker bar.
7. The method of claim 6 wherein said tucker bar comprises
teflon.
8. The method of claim 6 wherein said device comprises at least one
pressurized gas port.
9. The method of claim 1 wherein the tube of packaging film
comprises graphics on the exterior of said tube, wherein said
graphics are oriented perpendicular to the direction of film travel
on the vertical form, fill, and seal machine.
10. A vertical stand-up pouch formed by the method of claim 1.
11. A flexible package formed by a form, fill, and seal packaging
machine from a sheet of composite polymer film, said package
comprising after formation: a single sheet, composite film body,
said film comprising a graphics layer; two vertical transverse
seals on opposite vertical edges of said package; and a horizontal
crease at the bottom of said package, said crease being
substantially perpendicular to said vertical transverse seals.
12. The flexible package of claim 11 wherein said graphics layer is
oriented for viewing by a consumer when said package is stood on
its bottom, crease end.
13. The flexible package of claim 11 wherein said package is formed
on a vertical form, fill, and seal machine.
14. An improved vertical form, fill, and seal machine having a
forming tube, said improvement comprising: two forming plates
attached to and extending below said forming tube; at least one
tension bar attached to and extending below said forming tube at a
location approximately opposite from said forming plates; and at
least one stationary tucker bar positioned between said forming
plates.
15. The improved vertical form, fill, and seal machine of claim 14
further comprising a means for blowing a pressurized gas against
packaging film formed in a tube around said forming tube, wherein
said gas is blown against the exterior of said tube of packaging
film at a point between said forming plates.
16. The improved vertical form, fill, and seal machine of claim 14
wherein said means for blowing a pressurized gas comprises gas
ports in said tucker bar in communication with a pressurized gas
source.
17. The improved vertical form, fill, and seal machine of claim 14
wherein said tucker bar comprises teflon.
18. The improved vertical form, fill, and seal machine of claim 14
wherein said two forming plates further comprise horizontal hinges
between the forming plates and said forming tube.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to a vertical stand-up pouch
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 with minimal increased costs and minimal modification.
[0003] 2. Description of Related Art
[0004] 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.
[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 .sctn.packaging
potato chips and like products is illustrated in FIG. 1, which is a
schematic of a cross-section of the film illustrating each
individual substantive layer. FIG. 1 shows a sealable inside, or
product side, layer 16 which typically comprises metalized oriented
polypropylene ("OPP") or metalized polyethylene terephtalate
("PET"). This is followed by a laminate layer 14, typically a
polyethylene extrusion, and an ink or graphics layer 12. The ink
layer 12 is typically used for the presentation of graphics that
can be viewed through a transparent outside layer 10, which layer
10 is typically OPP or PET.
[0006] The prior art film composition shown in FIG. 1 is ideally
suited for use on vertical form and fill machines for the packaging
of food products. The metalized inside layer 16, which is usually
metalized with a thin layer of aluminum, provides excellent barrier
properties. The use of OPP or PET for the outside layer 10 and the
inside layer 16 further makes it possible to heat seal any surface
of the film to any other surface in forming either the transverse
seals or back seal of a package.
[0007] Typical back seals formed using the film composition shown
in FIG. 1 are illustrated in FIGS. 2a and 2b. FIG. 2a is a
schematic of a "lap seal" embodiment of a back seal being formed on
a tube of film. FIG. 2b illustrates a "fin seal" embodiment of a
back seal being formed on a tube of film.
[0008] With reference to FIG. 2a, a portion of the inside metalized
layer 26 is mated with a portion of the outside layer 20 in the
area indicated by the arrows to form a lap seal. The seal in this
area is accomplished by applying heat and pressure to the film in
such area. The lap seal design shown in FIG. 2a insures that the
product to be placed inside the formed package will be protected
from the ink layer by the metalized inside layer 26.
[0009] The fin seal variation shown in FIG. 2b also provides that
the product to be placed in the formed package will be protected
from the ink layer by the metalized inside layer 26. Again, the
outside layer 20 does not contact any product. In the embodiment
shown in FIG. 2b, however, the inside layer 26 is folded over and
then sealed on itself in the area indicated by the arrows. Again,
this seal is accomplished by the application of heat and pressure
to the film in the area illustrated.
[0010] Regardless of whether a lap seal or fin seal is used for
constructing a standard package using a vertical form and fill
packaging machine, the end result is a package as shown in FIG. 3a
with horizontally oriented top and bottom transverse seals 31, 33.
Such package is referred to in the art as a "vertical flex bag" or
"pillow pouch," and is commonly used for packaging snack foods such
as potato chips, tortilla chips, and other various sheeted and
extruded products. The back seal discussed with reference to FIGS.
2a and 2b runs vertically along the bag and is typically centered
on the back of the package shown in FIG. 3a, thus not visible in
FIG. 3a. Because of the narrow, single edge base on the package
shown in FIG. 3a formed by the bottom transverse seal 33, such
prior art packages are not particularly stable when standing on one
end. This shortcoming has been addressed in the packaging industry
by the development of a horizontal stand-up pouch such as the
embodiment illustrated in FIGS. 4a, 4b, and 4c. As can be seen by
reference to said figures, such horizontal stand-up pouch has a
relatively broad and flat base 47 having two contact edges. This
allows for the pouch to rest on this base 47 in a vertical
presentation. Manufacture of such horizontal stand-up pouches,
however, does not involve the use of standard vertical form, fill,
and seal machines but, rather, involves an expensive and relatively
slow 3-piece construction using a pouch form, fill, and seal
machine.
[0011] Referring to FIGS. 4b and 4c, the horizontal stand-up pouch
of the prior art is constructed of three separate pieces of film
that are mated together, namely, a front sheet 41, a rear sheet 43,
and a base sheet 45. The front sheet 41 and rear sheet 43 are
sealed against each other around their edges, typically by heat
sealing. The base sheet 45 is, however, first secured along its
outer edges to the outer edges of the bottom of the front sheet 41
and rear sheet 43, as is best illustrated in FIG. 4c. Likewise, the
mating of the base sheet 45 to the front sheet 41 and the rear
sheet 43 is also accomplished typically by a heat seal. The
requirement that such horizontal stand-up pouch be constructed of
three pieces results in a package that is significantly more
expensive to construct than a standard form and fill vertical flex
bag.
[0012] 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.
[0013] One advantage of a horizontal stand-up pouch machine over a
vertical form and fill machine, however, is the relatively simple
additional step of adding a zipper seal at the top of the bag for
reclosing of the bag. Vertical form and fill machines typically
require substantial modification and/or the use of zipper seals
premounted on the film oriented horizontally to the seal facings
used to seal the horizontal transverse seals.
[0014] An alternative approach taken in the prior art to producing
a bag with more of a stand-up presentation is the construction of a
flat bottom bag such as illustrated in FIG. 3b. Such bag is
constructed in a method very similar to that described above with
regard to prior art pillow pouches. However, in order to form the
vertical gussets 37 on either side of the bag, the vertical form,
fill, and seal machine must be substantially modified by the
addition of two movable devices on opposite sides of the sealing
carriage that move in and out to make contact with the packaging
film tube in order to form the tuck that becomes the gussets 37
shown in FIG. 3b. Specifically, when a tube is pushed down to form
the next bag, two triangular shaped devices are moved horizontally
towards the packaging film tube until two vertical tucks are formed
on the packaging film tube above the transverse seals by virtue of
contact with these moving triangular shaped devices. While the two
triangular shaped devices are thus in contact with the packaging
tube, the bottom transverse seal is formed. The package is
constructed with an outer layer 30 that is non-sealable, such as
paper. This causes the formation of a V-shaped gusset 37 along each
vertical edge of the package when the transverse seals 31, 33 are
formed. While the triangular shaped devices are still in contact
with the tube of packaging material, the product is dropped through
the forming tube into the tube of packaging film that is sealed at
one end by virtue of the lower transverse seal 33. The triangular
shaped devices are then removed from contact with the tube of
packaging film and the film is pushed down for the formation of the
next package. The process is repeated such that the lower
transverse seal 33 of the package above and upper transverse seal
31 of the package below are then formed. This transverse seal is
then cut, thereby releasing a formed and filled package from the
machine having the distinctive vertical gussets 37 shown in FIG.
3b.
[0015] 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.
[0016] 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. 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 constructed of material
commonly used to form standard vertical flex bags.
SUMMARY OF THE INVENTION
[0017] The proposed invention involves producing a vertical
stand-up pouch constructed of a single sheet of material using a
vertical form, fill, and seal machine slightly modified with 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 bag while it is
being formed. The graphics on the bag are oriented 90.degree. from
a standard presentation such that the tuck forms the bottom of the
bag. The transverse seals on the formed bag are therefore oriented
vertically when the bag is placed on display. A zipper seal or
reclose seal can be easily added to the construction of such a
vertical stand-up bag since the zipper seal can accompany the
single sheet of film in a continuous strip along one edge of the
film.
[0018] The method disclosed and the bag formed as a consequence is
a substantial improvement over prior art horizontal stand-up
pouches and flat bottom bags. The method works on existing vertical
form and fill machines requiring very little modification. There
are no moving parts or jaw carriage modifications involved. The bag
makers can be easily converted back to a pillow pouch configuration
with a simple former change. 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.
[0019] The above as well as additional features and advantages of
the present invention will become apparent in the following written
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] 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:
[0021] FIG. 1 is a schematic cross-section views of prior art
packaging films;
[0022] FIG. 2a is a schematic cross-section view-of a tube of
packaging film illustrating the formation of a prior art lap
seal;
[0023] FIG. 2b is a schematic cross-section of a tube of packaging
film illustrating the formation of a prior art fin seal;
[0024] FIG. 3a is a perspective view of a prior art vertical flex
bag;
[0025] FIG. 3b is a perspective view of a prior art flat bottom
bag;
[0026] FIGS. 4a, 4b, and 4c are perspective views in elevation of a
prior art horizontal stand-up pouch;
[0027] FIG. 5 is a schematic cross-section of a tube of packaging
film formed by the present invention methods;
[0028] FIG. 6 is a perspective view of the tucker mechanism,
forming plates, and tension bar in elevation of the present
invention in relation to a forming tube and sealing jaws of a
vertical form and fill machine;
[0029] FIGS. 7a and 7b are perspective views of the vertical
stand-up bag of the present invention; and
[0030] FIG. 8 is a perspective view of one embodiment of the tucker
mechanism of the present invention.
DETAILED DESCRIPTION
[0031] FIGS. 5 and 6 illustrate the basic components used with the
method of the proposed invention. The same reference numbers are
used to identify the same corresponding elements throughout all
drawings unless otherwise noted. FIG. 5 is a schematic
cross-section of a tube of packaging material (film) formed by the
present invention method. The tube of packaging film shown in FIG.
5 is illustrated as a cross-sectional area immediately below the
forming tube 101 of FIG. 6. The tube of packaging film comprises an
outer layer 116 and an inner layer 110, and can comprise material
typically used in the field of art for making a standard vertical
flex bag, such as discussed in relation to FIG. 1. The tube in FIG.
5 has been formed by sealing one sheet of film with a vertical back
seal, as previously described with regard to discussions of prior
art vertical form and fill machine methods.
[0032] FIG. 6 shows a forming tube 101 typical in most respects to
those used with prior art vertical form, fill, and seal machines.
This forming tube 101 can be a cylinder, have a rectangular cross
section, or any number of shapes, but is preferably cylindrical as
illustrated. The film illustrated in FIG. 5 is initially formed
around the forming tube 101 of FIG. 6. This forming tube 101 is
shown in elevation but would normally be integrally attached to the
vertical form, fill, and seal machine. Also shown in FIG. 6 are a
pair of prior art sealing jaws 108 likewise illustrated in
elevation. Not shown in FIG. 6 is the sealing jaw carriage on which
such sealing jaws 108 would be mounted below the forming tube
101.
[0033] 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 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 FIG. 3a. As will be described
in further detail below, the orientation of the graphics on the
film packaging for Applicants' invention is 90.degree. off of the
prior art orientation, such that the graphics appear sideways as
viewed by the operator of the vertical form and fill machine as the
film is pulled down the forming tube 101 of FIG. 6. In other words,
the graphics on the packaging film are oriented perpendicular to
the direction of film travel.
[0034] 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 FIG. 5. As shown in FIG. 6, the forming plates 104
and tension bar 102 can be attached directly to the forming tube
101 or, alternatively, to any supporting structure on the vertical
form, fill, and seal machine, as long as the forming plates 104 and
tension bar 102 are positioned within the tube of packaging
material, below the bottom of the forming tube 101, and above the
heat sealing jaws 108.
[0035] 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 FIG. 6, by a tension screw 162 that can lock
the tucker bar 106 in place when tightened. While the tucker bar
106 is adjustable, unlike in the prior art, it is fixed or
stationary during operation. Therefore, the present invention is a
substantial improvement over the art in that there are no moving
parts to the tucker mechanism during bag making. This improvement
is what Applicants intend to describe when referring to the tucker
bar 106 as "stationary" or "fixed." Because of this stationary
tucker bar feature, bag making speeds can match typical pillow
pouch manufacturing rates.
[0036] When moved forward into position (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.
[0037] An example of the formed package of the instant invention is
shown in FIGS. 7a and 7b, which show the outside layer of the
packaging film 116 with the graphics 179 oriented as previously
described. As can be seen from FIGS. 7a and 7b, the construction of
the invention's vertical stand-up pouch shares characteristics with
the prior art vertical flex bags shown in FIG. 3a. However, the
transverse seals 131, 133 of the vertical stand-up bag of the
invention are oriented vertically once the bag stands up on one
end, as shown in FIG. 7b. FIG. 7a shows the crease 176 that was
formed by the tucker bar 106 and forming plates 104 discussed in
relation to FIGS. 5 and 6.
[0038] Returning to FIG. 6, another optional feature that can be
incorporated into this invention is the use of a diversion plate
160 within the forming tube 101. This diversion plate 160, in the
embodiment illustrated, is a flat plate welded vertically inside
the forming tube 101 that extends from the bottom of the forming
tube 101 to some distance above (for example, at least two or three
inches) the bottom of the forming tube 101, where it then is sealed
against the inside of the forming tube 101.
[0039] 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 FIG. 6 is a flat plate, but it
should be understood that it can be of any variety of shapes, for
example, having a curved surface, provided that it accomplishes the
functionality of diverting the product away from the area where the
tuck is formed on the tube of film.
[0040] 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.
[0041] FIG. 8 illustrates a preferred embodiment of the tucker bar
106. This embodiment of the tucker bar 106 comprises a head 180
attached to a support 182. Drilled within the support 182 and head
180 is a gas channel 184 shown in phantom on FIG. 8. This gas
channel 184 provides a gas communication from an exterior gas
source (not shown) through the support 182, through the head 180,
and out three orifices 186. The gas channel 184 allows for a
metered burst of pressurized gas (typically air) that helps keep
the tuck illustrated in FIG. 5 taut throughout the forming and
sealing operation without the necessity of moving the tucker bar in
and out during bag formation. It should be noted that during
operation (bag making) the tucker bar 106 is always stationary. It
should further be noted that the head 180 necessarily cannot extend
along the entire length of the crease formed by the tucker bar 106
and forming plates 104. Further, it should be understood that when
the sealing jaws 108 close onto the tube of film, the lateral
dimensions of the tube of film change. All of these facts are
compensated for by the use of the pressurized air bursting from the
orifices 186. The pressurized air keeps an even amount of pressure
on the tuck as it is being formed in the various stages of the
forming and sealing process. The air burst can be continuous, but
is preferably metered to start as the film for the next bag is
being pulled down through the completion of the transverse
seal.
[0042] The head 180 can comprise any non-stick material but is
preferably teflon. In an alternative embodiment, the tucker bar 106
can comprise one integral piece of metal with the head portion 180
being teflon coated. The curved contact area of the head 180 allows
for the continuous formation of the tuck illustrated in FIG. 5
without tearing the packaging film as it is pushed down below the
forming tube. While shown with three orifices 186, the head 180 can
comprise any number of orifices from one on.
[0043] 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
FIG. 6, it should be noted that the tension bar 102 bends outwardly
away from the center of said tube of film along the length of the
tension bar 102 and the forming plates 104 are hinged by a
horizontal hinge 105. If the tension bar 102 is designed otherwise
(strictly vertical) excess slack occurs in the area of the film
tube near the transverse seal. The forming plates 104 comprise
horizontal hinges 105 that allow the forming plates to fold inward
(toward each other) slightly while the lower transverse seal is
formed. Otherwise, the tube of packaging film would be ripped by
the tips of the forming plates 104 during this step.
[0044] 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.
1 TABLE 1 Commercially Current Available Horizontal Applicants'
Vertical Vertical Flex Bag Stand-Up Pouches Stand-Up Bag Machine
Type Standard Vertical FFS Pouch Form, Fill, Seal Standard Vertical
FFS Machine Cost $75,000.00 $500,000.00 $75,000.00 Film Cost
$0.04/bag $0.08/bag $0.04/bag Gas Flush Less than 2% O.sub.2 Only
to 5% O.sub.2 Less than 2% O.sub.2 Size Change Easy, change former
2 hours Easy, change former Format Change Flex Bag Only Stand-Up
Pouch Only Both, simple change Continuous Feed No Yes Yes Zipper
Option Bag Size Range in (Width/Height) (Width/Height)
(Width/Height) Inches 5/5 through 14/24 5/5 through 10/12 5/5
through 24/11
[0045] As noted above, a continuous feed zipper option is available
on Applicants' invention, which is not available using current
vertical form, fill, and seal machine technology. This is because
of the orientation of the film graphics used on the packaging film
of the present invention. Since the graphics are oriented
90.degree. from the prior art, a zipper seal can be run
continuously in a vertical line down the forming tube along 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 continuous vertical strip of a zipper seal would
place such seal in a vertical orientation once the package is
formed and stood up for display.
[0046] 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.
[0047] 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.
* * * * *