U.S. patent application number 14/987238 was filed with the patent office on 2016-04-28 for process and apparatus for pouch-forming with optimized fill accuracy and headspace.
The applicant listed for this patent is Liqui-Box Corporation. Invention is credited to Jason G. Peterson, Joshua Michael Schutte.
Application Number | 20160114916 14/987238 |
Document ID | / |
Family ID | 42154226 |
Filed Date | 2016-04-28 |
United States Patent
Application |
20160114916 |
Kind Code |
A1 |
Peterson; Jason G. ; et
al. |
April 28, 2016 |
PROCESS AND APPARATUS FOR POUCH-FORMING WITH OPTIMIZED FILL
ACCURACY AND HEADSPACE
Abstract
This invention discloses a process for forming a pouch having an
evacuated headspace containing a flowable material. The process
relates to optimizing both, the evacuation of the headspace in the
pouch and the accuracy of the flowable material filled in the
pouch. Specifically, the present invention employs a process that
includes a multiple-step or a continuous compression of the pouch
headspace to accomplish the goals. Also disclosed is a vertical
form-fill-seal apparatus for forming a pouch containing a flowable
material and having an evacuated headspace.
Inventors: |
Peterson; Jason G.;
(Columbus, OH) ; Schutte; Joshua Michael;
(Columbus, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Liqui-Box Corporation |
Worthington |
OH |
US |
|
|
Family ID: |
42154226 |
Appl. No.: |
14/987238 |
Filed: |
January 4, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12707344 |
Feb 17, 2010 |
9266630 |
|
|
14987238 |
|
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|
|
61155287 |
Feb 25, 2009 |
|
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Current U.S.
Class: |
206/484.2 ;
206/484; 53/551 |
Current CPC
Class: |
B65B 9/2007 20130101;
B65B 9/213 20130101; B65B 9/2049 20130101; B65D 75/48 20130101;
B65B 9/207 20130101 |
International
Class: |
B65B 9/20 20060101
B65B009/20; B65D 75/48 20060101 B65D075/48 |
Claims
1. A pouch having an evacuated headspace and containing a flowable
material, formed according to a process comprising the steps of:
(A) providing a continuous tube of flexible and sealable film; (B)
supplying the continuous tube with a predetermined amount of
flowable material; (C) evacuating the headspace above said
predetermined amount of flowable material; wherein said evacuation
is performed in two steps: (i) transversely compressing said
continuous tube, at a point where said continuous tube comprises
the top portion of said predetermined amount of flowable material,
wherein said transverse compressing is accomplished by deflating
jaws while said pouch is indexing; and (ii) further transversely
compressing said continuous tube with deflating jaws near or at the
end of said indexing of said pouch; and wherein said transvers
compressing is accomplished without stopping said pouch for such
transverse compressions and wherein an evacuating passage is
provided for removing air from said headspace; (D) reducing
headspace in the pouch by evacuation and allowing flowable material
to remain in the pouch; (E) forming an optimized head space and a
pouch having the predetermined amount of flowable material; (F)
pinching said continuous tube above a sealing region so as to form
a pinched portion of said continuous tube; and (G) sealing said
continuous tube at said sealing region to form a top seal of said
pouch containing flowable material and a bottom seal of a
next-to-be filled pouch.
2. The pouch as recited in claim 1, containing an oxygen sensitive
product.
3. The pouch as recited in claim 1, wherein the pouch comprises an
oxygen scavenging material.
4. The pouch as recited in claim 1, wherein the pouch has a volume
of between about 1 L and about 12 L.
5. The pouch as recited in claim 1, wherein the pouch has a volume
of between about 3 L and about 5 L.
6. The pouch as recited in claim 1, wherein the headspace has a
volume equal to or less than about 2 percent by volume of the
pouch.
7. The pouch as recited in claim 1, wherein said pouch is prepared
from at least one ply.
8. The pouch as recited in claim 7, wherein said at least one ply
comprises only one single layer.
9. The pouch as recited in claim 8, wherein said single layer is
selected from the group consisting of linear low-density
polyethylene comprising butane copolymeric units, linear
low-density polyethylene comprising hexene copolymeric units,
linear low-density polyethylene comprising octene copolymeric
units, and copolymer of ethylene and propylene.
10. The pouch, as recited in claim 8, wherein said single ply
comprises polyethylene; the middle layer comprises metallized
biaxial polyester; and the inner layer comprises polyethylene.
11. The pouch as recited in claim 8, wherein single ply has an
outer layer comprising an EVOH co-extrusion; the middle layer
comprises biaxial nylon; and the inner layer comprises
polyethylene.
12. The pouch as recited in claim 8, wherein the single layer is
polyethylene functionalized with vinyl acetate or polyethylene
blended with ethylene vinyl acetate copolymer.
13. The pouch as recited in claim 8, wherein the single layer is
selected from the group consisting of polyethylene, polyethylene
modified with methacrylic acid, polyethylene modified with methyl
acrylate, polyethylene modified with acrylic acid, ionomers
partially-neutralized with zinc or sodium ions, and polyethylene
modified by reactive extrusion with maleic anhydride.
14. The pouch as recited in claim 8, wherein the single layer
comprises an outer layer of the single ply comprises material
selected from the group consisting of polyethylene, polyethylene
modified with methacrylic acid, polyethylene modified with methyl
acrylate, polyethylene modified with acrylic acid, ionomers
partially-neutralized with zinc or sodium ions, and polyethylene
modified by reactive extrusion with maleic anhydride; middle layer
comprises biaxial nylon; and an inner layer, comprises material
selected from the group consisting of polyethylene, polyethylene
modified with methacrylic acid, polyethylene modified with methyl
acrylate, polyethylene modified with acrylic acid, ionomers
partially-neutralized with zinc or sodium ions, and polyethylene
modified by reactive extrusion with maleic anhydride.
15. The pouch as recited in claim 7, wherein said pouch is prepared
from a multiple-ply film.
16. The pouch as recited in claim 15, wherein at least one ply of
said multiple-ply film comprises material selected from the group
consisting of polyethylene, polyethylene modified with methacrylic
acid, polyethylene modified with methyl acrylate, polyethylene
modified with acrylic acid, ionomers partially-neutralized with
zinc or sodium ions, and polyethylene modified by reactive
extrusion with maleic anhydride.
17. The pouch as recited in claim 7, wherein the wall thickness of
the pouch is in the range of from about 50 .mu.m to 175 .mu.m.
18. The pouch as recited in claim 7, wherein the wall thickness of
the pouch is in the range of from about 75 .mu.m to 150 .mu.m.
19. The pouch as recited in claim 7, wherein the wall thickness of
the pouch is in the range of from about 100 .mu.m to 125 .mu.m.
20. The pouch as recited in claim 7, wherein said pouch comprises a
fitment.
21. A package comprising the pouch of claim 7 inside a secondary
container.
22. The package as recited in claim 21, wherein said secondary
container is a cardboard box.
23. A vertical form-fill-seal apparatus for forming a pouch
containing a flowable material and having an evacuated headspace,
said apparatus comprising: (A) a tube-forming section for forming a
vertical continuous tube from a roll of film; (B) a horizontal
sealing section for forming a transverse seal across said vertical
continuous tube; (C) a filling station for supplying a
predetermined amount of flowable material to said vertical
continuous tube; (D) pinchers for transversely pinching said
vertical continuous tube to form a pinched portion of said
continuous tube; (E) an evacuating passage between said pinchers
that opens onto said headspace between the predetermined amount of
flowable material and the pinched portion; and (F) a deflating
apparatus for evacuating said headspace via the evacuating passage,
wherein said deflating apparatus is programmed to actuate in
multiple steps or continuously while the continuous film is
indexing.
24. The vertical form fill-seal apparatus as recited in claim 23,
wherein said deflating apparatus is actuated in an asynchronous
manner.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 12/707,344, filed Feb. 17, 2010, which claims
the benefit of U.S. Provisional Application No. 61/155,287, filed
Feb. 25, 2009, of which is incorporated by reference herein in its
entirety.
FIELD OF INVENTION
[0002] In one of its aspects, the present invention provides a
process for forming a pouch with optimized headspace volume and
optimized accuracy of the flowable material contained in the pouch.
In another of its aspects, the present invention provides an
apparatus for forming pouches with optimized headspace volume and
optimized accuracy of the flowable material contained in the
pouches. In yet another of its aspects, the present invention
provides a pouch with optimized headspace volume and optimized
accuracy of the flowable material contained in the pouch formed by
the process of the present invention.
BACKGROUND
[0003] Flexible liquid-packaging is used to package many consumer
goods, particularly food and beverages, which are often packaged in
pouches made from flexible materials. The term "liquid-packaging"
is understood by those of skill in the art to refer to both liquids
and other flowable materials or product.
[0004] Two aspects are important in flexible liquid-packaging: (i)
optimal headspace in the pouch; and (ii) optimal fill-accuracy of
the flowable material contained in each pouch. By "optimal" or
"optimized" is meant that the two important factors--headspace over
the product in the pouch, and fill-accuracy of the product amount
in the pouch--are minimized without sacrificing one over the other
such that both factors remain acceptable for packaging use. It
should be noted that minimizing one factor tends to adversely
affect the other factor. Ideally the goal is fill-accuracy of 100%
of target weight and a headspace of o cm.sup.3. Practically,
however, there is a trade-off between good fill-accuracy and the
amount of headspace in the pouch. Typically an improvement in
fill-accuracy will result in a larger headspace volume. Similarly,
lower headspace generally results in poor fill-accuracy. Therefore,
optimizing and controlling these two parameters is the challenge
for vertical form-fill-seal technology.
[0005] During pouch formation, oxygen is commonly trapped in the
headspace above the product. However, many pouch products are
particularly sensitive to oxygen degradation. Specifically in the
food industry, many products require minimal oxygen exposure to
protect their flavor, color, nutritive value, texture, and/or
shelf-life. Oxygen reacts readily with some of these product
components forming "off-flavors" and "off-colors". If oxygen is
removed during the packaging process, then, for example, shelf-life
of the food can be extended without loss of flavor. Thus,
minimizing oxygen, and in turn, minimizing headspace in a pouch, is
a desired objective in pouch formation.
[0006] Besides minimizing oxygen exposure, minimal headspace
facilitates pouch insertion into a secondary container a common
packaging arrangement in which the flexible pouch is inserted in a
cardboard box ("bag-in-box"). A slack pouch is easier to insert
into a box and will better form to shape than an inflated pouch
(that is, one with a large, air-filled headspace).
[0007] Fill-accuracy, that is reducing over-fill and under-fill of
the pouch, is important because it can have economic or government
regulatory implications. For example, many jurisdictions require
that the advertised product quantity must be the minimum product
quantity. Stated another way, the laws of the jurisdiction require
that the amount of product in the pouch may be more than what is
advertised, but not less. Thus, if the fill-accuracy is poor, a
vendor, to comply with the law, must fill the pouch with product
amount more than what is advertised. Therefore, poor fill-accuracy
raises business cost for the vendor. Consequently, both limiting
headspace and fill-accuracy should be adequately controlled. One
known method for minimizing headspace involves filling the tube for
making a pouch above the level of the pouch and sealing through the
product. However, this method can suffer from poor fill accuracy
and product interfering with seal formation.
[0008] Thus, achieving good fill-accuracy and/or minimal headspace
would help minimize product waste, minimize oxygen in the formed
pouch, and allow for the final product to fit more easily into
smaller packaging.
[0009] Several methods have been used to minimize fill-accuracy and
headspace. The best fill-accuracy can be achieved by limiting
interaction on the pouch in a way that relies only on the delivery
system and non-critical pouch making devices. However, this results
in unacceptably large headspace for production runs. On the other
hand, minimal headspace can be achieved by having the product
completely fill the current pouch and overfill into the next
upstream pouch, so when the final seal is made, there is little or
no air in the first pouch. Typical devices either press above or
below the product zone after the pouch has indexed. Devices that
press on the pouch above the product zone results in a minor
reduction of headspace while maintaining good fill-accuracy.
Devices that press on the pouch around the product zone can
effectively raise the product above the sealing apparatus
minimizing and/or eliminating headspace, but sacrificing
fill-accuracy. It is important to note that cautious control of any
device must be exercised while film is indexing to avoid film
hang-up which would result in machine shutdown.
[0010] It is an object of the present invention to limit the
above-mentioned disadvantages. Specifically, the present invention
provides a process, apparatus, and a pouch in which the headspace
has been minimized with a simultaneous increase in the accuracy of
filling of the flowable material into the pouch. In addition, the
present invention will also provide for higher pouch production
rates. The asynchronous deflation process (one of the embodiments
of the invention described infra) will allow the user to
accommodate variations in film runnability, allowing for variety in
film conditions without being limited by the speed of the
machine.
SUMMARY OF INVENTION
[0011] This invention relates to a process for forming a pouch,
said pouch having an evacuated headspace and containing a flowable
material, said process comprising the steps of: [0012] (A)
providing a continuous tube of flexible and sealable film; [0013]
(B) supplying the continuous tube with a predetermined amount of
flowable material; [0014] (C) evacuating the headspace above said
predetermined amount of flowable material; [0015] wherein said
evacuation is performed continuously or in multiple steps, and
wherein said continuous tube is transversely compressed at a point
on said continuous tube where said continuous tube comprises the
top portion of said predetermined amount of flowable material,
wherein said transverse compressing is accomplished by deflating
jaws while said pouch is indexing; and [0016] (D) pinching said
continuous tube above a sealing region so as to form a pinched
portion of said continuous tube; [0017] (E) sealing said continuous
tube at said sealing region to form a top seal of said pouch
containing flowable material and a bottom seal of a next-to-be
filled pouch.
[0018] This invention further relates to the above process, wherein
said evacuation is performed in two steps: [0019] (i) transversely
compressing said continuous tube, at a point where said continuous
tube comprises the top portion of said predetermined amount of
flowable material, wherein said transverse compressing is
accomplished by deflating jaws while said pouch is indexing; and
[0020] (ii) further transversely compressing said continuous tube
with deflating jaws near or at the end of said indexing of said
pouch.
[0021] This invention further relates to a pouch formed according
to a process comprising the steps of: [0022] (A) providing a
continuous tube of flexible and sealable film; [0023] (B) supplying
the continuous tube with a predetermined amount of flowable
material; [0024] (C) evacuating the headspace above said
predetermined amount of flowable material; [0025] wherein said
evacuation is performed continuously or in multiple steps, and
wherein said continuous tube is transversely compressed at a point
on said continuous tube where said continuous tube comprises the
top portion of said predetermined amount of flowable material,
wherein said transverse compressing is accomplished by deflating
jaws while said pouch is indexing; and [0026] (D) pinching said
continuous tube above a sealing region so as to form a pinched
portion of said continuous tube; [0027] (E) sealing said continuous
tube at said sealing region to form a top seal of said pouch
containing flowable material and a bottom seal of a next-to-be
filled pouch.
[0028] This invention further relates to a pouch as described
above, wherein said evacuation is performed in two steps: [0029]
(i) transversely compressing said continuous tube, at a point where
said continuous tube comprises the top portion of said
predetermined amount of flowable material, wherein said transverse
compressing is accomplished by deflating jaws while said pouch is
indexing; and [0030] (ii) further transversely compressing said
continuous tube with deflating jaws near or at the end of said
indexing of said pouch.
[0031] This invention also relates to a package comprising the
pouch described above inside a secondary container such as a
cardboard box.
[0032] This invention also relates to a vertical form-fill-seal
apparatus for forming a pouch containing a flowable material and
having an evacuated headspace, said apparatus comprising:
[0033] (A) a tube-forming section for forming a vertical continuous
tube from a roll of film;
[0034] (B) a horizontal sealing section for forming a transverse
seal across said vertical continuous tube; [0035] (C) a filling
station for supplying a predetermined amount of flowable material
to said vertical continuous tube; [0036] (D) pinchers for
transversely pinching said vertical continuous tube to form a
pinched portion of said continuous tube; [0037] (E) an evacuating
passage between said pinchers that opens onto said headspace
between the predetermined amount of flowable material and the
pinched portion; and [0038] (F) a deflating apparatus for
evacuating said headspace via the evacuating passage, wherein said
deflating apparatus is programmed to actuate in multiple steps or
continuously while the continuous film is indexing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Embodiments of the present invention will be described with
reference to the accompanying drawings, wherein like reference
numerals denote like parts, and in which:
[0040] FIG. 1 illustrates a schematic view of an apparatus of the
present invention.
[0041] FIG. 2 illustrates a partial front schematic view of an
embodiment of the apparatus with the first move of the activated
deflators on the pouch as it is indexing.
[0042] FIG. 3 illustrates a partial front schematic view of an
embodiment of the apparatus with the second move of the activated
deflators on the pouch at the completion of indexing.
[0043] FIG. 4 illustrates a partial front schematic view of an
embodiment of the apparatus with cutting and sealing jaws activated
and the pinchers in a closed position.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The present invention relates to forming sealed pouches from
a continuous film tube. Typically, the process steps for forming
sealed pouches include: (i) forming the continuous film tube; (ii)
forming a first seal in the continuous film tube; (iii) filling the
continuous film tube with product; and (iv) forming a second seal
above the product, thereby yielding a closed filled pouch.
Typically, all process steps are performed on a vertical
form-fill-seal ("VFFS") type machine. The continuous film tube is
made from a flexible film. Flexible films are known to a person of
ordinary skill in the art.
[0045] While pouch volume in the present invention is not
particularly restricted, preferred pouch volume ranges from about 1
L to about 12 L, and more preferably, from about 3 L to about 5 L.
The product volume in the pouch will depend on the pouch volume. In
this application, the terms "minimal headspace" or "evacuated
headspace" are used relative to standard pouches formed by the
standard form-fill-seal process. The pouch headspace, resulting
from the process of present invention, is less than about 2 percent
of pouch volume. The fill-accuracy in the present invention is
about 0.10%-0.67% of the total weight of the product.
[0046] Generally the pouch of the present invention should be
sealable and have suitable properties (that is, strength,
flexibility, etc.) for carrying the desired product. The pouch
comprises any suitable plastic film material, such as linear
low-density polyethylene. The pouch may comprise multiple plies.
Each ply can have multiple layers. Each ply can also be a single
layer. The film can have single or multiple plies. Thus, a film can
also be simply one layer of the polymeric material.
[0047] An outer ply may be a barrier lamination ply including a
layer made from a foil material or a suitable metallized substrate,
or any other recognized flexible barrier or substrate material
including non-metallized material. Alternatively, the barrier
lamination could comprise an outer layer of polyethylene, an
intermediate layer of metallized nylon, or metallized polyester, or
metallized polyvinyl alcohol, and an inner layer of
polyethylene.
[0048] In a preferred embodiment, the outer layer of the
multi-layer ply comprises polyethylene; the middle layer comprises
metallized uniaxial or biaxial polyester; and the inner layer, that
is the sealant layer comprises polyethylene.
[0049] In another preferred embodiment, the outer layer of the
multi-layer ply comprises ethylene-vinyl alcohol coextrusion; the
middle layer comprises biaxial nylon; and the inner layer, that is
the sealant layer comprises polyethylene.
[0050] An example of EVOH coextrusion is a ply comprising
polyethylene/tie layer/ethylene vinyl alcohol/tie
layer/polyethylene.
[0051] In yet another preferred embodiment, the inner layer, that
is, the sealant layer is polyethylene functionalized with vinyl
acetate that helps in sealing and/or bonding the entire laminate.
In another preferred embodiment, the outer layer of the multi-layer
ply comprises polyethylene; the middle layer comprises uniaxial or
biaxial nylon; and the inner layer, that is the sealant layer
comprises polyethylene. Generally, clear barrier laminates are
preferred.
[0052] In another preferred embodiment, the inner sealant layer can
be modified in several ways. The modification is required to ensure
good bonding between the inner sealant layer and the rest of the
laminate, especially for the thermal lamination process. The outer
polyethylene layer can also be modified in the same way.
Modifications for inner or the outer layer include, but are not
limited to, modification with vinyl acetate, blending with ethylene
vinyl acetate, modification with methacrylic acid, methyl acrylate,
acrylic acid, and other alkyl (alk) acrylates. The inner or the
outer layer can also be the Nucrel.RTM. resin (obtained from E. I.
du Pont de Nemours & Co., Wilmington, Del.). The inner layer
can also be a copolymer of ethylene and propylene. The inner layer
can be an ionomer neutralized with zinc or sodium, e.g., the
Surlyn.RTM. resin (obtained from E. I. du Pont de Nemours &
Co., Wilmington, Del.). Modification of polyethylene also includes
reactive extrusion with maleic anhydride, e.g., Bynel.RTM. and
Fusabond.RTM. resins (obtained from E. I. du Pont de Nemours &
Co., Wilmington, Del.).
[0053] In yet another embodiment, the outer polyethylene layer can
be modified as described above; the middle layer is biaxial nylon,
and the inner layer a polyethylene. A single-ply pouch containing a
single layer can also be a polyethylene or modified polyethylene as
described above. The plain polyethylene, can be a linear
low-density polyethylene containing butene, hexene or octene
copolymer.
[0054] In a preferred embodiment, one ply of a multi-ply laminate
is plain polyethylene, and the multi-ply laminate optionally
comprises a barrier ply.
[0055] Other alternate intermediate layers having suitable barrier
characteristics include unmetallized polyvinyl alcohol,
unmetallized ethyl vinyl alcohol, and metallized ethyl vinyl
alcohol.
[0056] While the thickness of the films is not limitation to
practicing the invention, an overall wall thickness of from about
50 .mu.m to 175 .mu.m is preferred. A wall thickness of from about
75 .mu.m to about 150 .mu.m is further preferred. A wall thickness
of from about 100 .mu.m to about 125 .mu.m is even more
preferred.
[0057] All materials are selected such that they can be sealed
together, giving due consideration to the packaged product.
Preferably, the package seal lines extend through the entire side
wall--that includes all plies--to form a secure pouch seal.
[0058] FIG. 1 describes a generalized process of the present
invention. A continuous film tube (10) is formed from a film roll
(15) using the vertical form-fill-seal machine (100). The film roll
(15) is unwound in the roll unwind (20) section. The unwound film
(25) advances to the forming section (30). In the forming section
(30), the film (25) folds itself vertically.
[0059] In the next step, that is, in the vertical sealing section
(35), the longitudinal edges (40) of the film (10) are sealed
together to form a vertical seal (35). Typical vertical seals
include "lap seal" or a "fin seal." The present invention, however,
does not restrict the vertical seal types. Other seal types are
within the purview of a person of ordinary skill in the art.
Suitable vertical sealing jaws include the thermic jaw, that is, a
constantly heated jaw, or impulse jaw, that is, an intermittently
powered jaw for each seal.
[0060] Also, as shown in FIG. 1, the form-fill-seal machine (100)
further includes a horizontal sealing section (45). In the
horizontal sealing section (45), the film tube (10) with its
longitudinal edges already sealed, undergoes transverse
heat-sealing. Typically, a pair of sealing jaws (50 & 55) helps
form the transverse heat seal. A person of ordinary skill in the
art understands that other sealing arrangements may be possible.
For this description, however, horizontal sealing will be described
in terms of sealing jaws (50 & 55). Typically, the sealing jaws
(50 & 55) are also associated with a cutting apparatus (not
shown). The cutting apparatus severs the pouch that has already
been made and filled from the next-to-be filled pouch.
[0061] The machine (100) can also include spreader fingers (not
shown) adapted to be inside the continuous film tube (10) that
shape the tubular film towards a layflat configuration. The layflat
configuration outwardly spreads the longitudinal edges of the
continuous film tube (10).
[0062] The apparatus of the present invention further comprises a
filling station, typically comprising a product balance tank (not
shown) and a supply conduit (60) above horizontal sealing section
(45).
[0063] After making the bottom horizontal seal (70), but before the
sealing jaws (50 & 55) are closed, a quantity of product (65)
is supplied to the continuous film tube (10) via the supply conduit
(60), which fills the continuous film tube (10) upwardly from the
transverse seal (70). The continuous film tube (10) is then caused
to move downwardly a predetermined distance. This movement in
called indexing (71) of the continuous film tube (10). This
movement may be under the weight of the material (65) in the
continuous film tube (10), or may be caused by pulling or
mechanical driving of the continuous film tube (10). During
indexing (71), the deflation apparatus (85) is activated and the
pouch (72) is squeezed in a two-step deflation process (see infra),
which helps minimize the headspace. After the deflation step, the
pinchers (56 & 57) are activated, closed and sealed. In the
next step, the sealing jaws (50 & 55) are closed, thus
collapsing the continuous film tube (10) at a second position. The
sealing jaws can be closed above the air/product interface (59).
The sealing jaws (50 & 55), in an alternate embodiment, can
also be closed below the air/product interface (59), and within the
section wherein there is only product. The sealing jaws (50 &
55) typically seal and sever the continuous film tube (10), or the
tube may be severed subsequently.
[0064] In the embodiment of FIG. 1, a pouch (72) is shown advancing
in between the deflator apparatus (85), which includes two sets of
deflators (86 & 87; second set of deflators is not shown in
FIG. 1). The first set of deflators (86 & 87) help squeeze the
product (65) in the pouch, while the second set of deflators (88
& 89; see FIG. 2) are used as a control to help keep the
product liquid level higher after the first set of deflators'
squeegee effect has diminished. While this embodiment shows one or
two set of deflators, multiple sets of deflators can also be
present and should be construed within the scope of the present
invention.
[0065] This advancing movement also known as indexing (71) occurs
prior to a two-step deflation process. The deflator apparatus (85)
is not yet actuated. Some amount of product (65) has already filled
into the pouch (72).
[0066] In the embodiments of FIG. 1 and FIG. 2, and subsequent
embodiments infra, we have described the present invention as a
two-step deflator action process. However, the two-step deflator
action is only for illustration purposes. This invention also
includes those embodiments with multiple deflator actions, that is
deflation carried out in multiple steps. This invention also
includes the embodiment in which the deflator action is continuous,
which would be equivalent to dividing the deflator action in
infinitesimally small steps.
[0067] Products suitable for the pouch of the present invention are
flowable materials. The term "flowable material" does not include
gases, but includes materials which are flowable under gravity, may
be pumped or otherwise transported through tubes. Such materials
include emulsions, e.g. ice cream mix; soft margarine; food
dressings; pastes, etc. meat pastes; peanut butter; preserves, e.g.
jams, pie fillings, marmalade, jellies; dough; ground meat, e.g.
sausage meat; powders, e.g. gelatin powders; detergents; liquids,
e.g. milk, oils; granular solids, e.g. rice, sugar; and mixtures of
liquids and solids, e.g. chunky soup, cole slaw, macaroni salad,
fruit salad, sliced pickles, cherry pie filling. In one
application, the flowable material is a liquid suitable for
consumption, for example fruit juice, milk, and wine.
[0068] Each pouch formed contains a predetermined amount of product
(65). Supplying each pouch with a predetermined amount of product
(65) can be achieved by accurately metering-in product by methods
known in the art for either continuous fill or intermittent fill
operations. Suitable methods of metering-in, for example, may
employ constant (continuous) flow of product and an accurate
sealing sequencing timer or any known dosing method enabling
intermittent filling of the product.
[0069] As shown in FIG. 2, while the continuous film tube (10) is
indexing (71), a deflating apparatus (85) is employed to evacuate
the headspace, for example, through an evacuating passage (74; see
also FIG. 1; described infra) in case where the film tube (10) is
already pinched-off. In one embodiment, the deflating apparatus
(85), through its deflators (86-89), squeezes the portion (75) of
the pouch that already contains the product and not simply that
portion that corresponds to the headspace.
[0070] In a preferred embodiment, the deflation process is
accomplished in two steps, or two squeezing actions ("moves") on
the pouch (72). The first step (as shown in FIG. 2), occurs while
the pouch (72) is indexing (71) through the VFFS device. This move
is coordinated in such manner that the two sets of deflators
(86-89) actuate and engage the pouch (72) only at a certain point
(91) in time when the likelihood of pouch (72) hang-up has receded.
A person skilled in the art can set-up an automated process that
coordinates such actuation and engagement. If the timing of the
deflation is inaccurate, the deflators (86-89) will interfere with
the indexing process and the pouch (72) will hang up, with the
product (65) now filling in the pouch (72) as it rests on the
deflators (86 & 87). Stated another way, the weight of the
pouch (containing some amount of product) that has already passed
between the deflators is not sufficient that the pouch can move
vertically downward, simply under gravity. The product filling into
the pouch, which has hung-up, makes the indexing furthermore
difficult.
[0071] The second step of the deflation process, as shown in FIG.
3, occurs to further squeeze the pouch (72) near the end of the
indexing process (71). As shown in FIG. 2, the initial squeeze (91)
dramatically decreases the headspace in the pouch (72) by a
"squeegee" action, minimizes the amount of oxygen allowed to enter
the pouch, and allows for the product to drain through the two sets
of deflators (86-89). The draining action allows for improved
fill-accuracy and also allows for the pouch (72) to index more
easily. The second squeeze (92) of the deflators (86-89) further
decreases the headspace in the pouch (72). The squeezing action can
be accomplished with pneumatics, servos, or jets of air. Multiple
surfaces can be used to construct the deflators, by those
knowledgeable in the art, such as sheet metal or rollers. While
this newly discovered process greatly reduces headspace and reduces
the variability of the fill-accuracy, the settings (width and
timing of the deflator's actuation) are dependent on how and when
the device makes contact with the pouch while indexing.
[0072] FIG. 4 shows that while the pouch is undergoing the second
step of deflation and is under a "squeeze" from the deflators
(86-89), the pinching mechanism (56 & 57) is actuated and the
sealing jaws (50 & 55) form the transverse seal. Suitably, the
pouch (72) is simultaneously heat sealed and severed from a
subsequent pouch (73). Alternatively, the pouch (72) may be sealed
and subsequently cut from the subsequent pouch (73), such as by a
knife. Another example for severing pouches formed in this manner
could be through the use of a perforated or weakened tear line,
which can be produced in any number of known ways. Suitable methods
for separating pouches are known to those of skill in the art.
[0073] In this embodiment, after the two-step deflation process,
and with the predetermined amount of product (65) metered-in to the
continuous film tube (10), the set of pinchers (56 & 57) are
closed to ensure product (65) stays inside the continuous film tube
(10). In a continuous filling operation, the pinchers (56 & 57)
also separate product (65) from the next pouch (73) being produced,
as the product constantly pours in. The evacuating passage (74)
permits evacuation of the headspace through the open or closed
pinchers (56 & 57) while preventing flow of product from one
pouch to the next. "Passage" refers to a path or route through
which air can pass to evacuate the headspace between the
pinchers.
[0074] In an alternative embodiment, the deflator width, that is,
the distance between two deflators, is adjusted to control the
fill-accuracy and the headspace volume. In an alternative
embodiment, the deflator width is dynamically adjusted, that is,
while the pouch is indexing and is being squeezed by the deflators,
to control the fill-accuracy and the headspace volume.
[0075] In one embodiment, during the squeezing action, in both the
first move and the second move, the pinchers (56 & 57) are
generally open. However, in another embodiment, the pinchers can
also be closed (FIG. 4). If the pinchers are closed, they are
closed against the evacuating tube (74) (see FIGS. 1-4), which acts
as the evacuating passage. The pinchers (56 & 57) can have a
sealing material, such as a rubber ribbon for pinching about the
evacuating tube (74). Securely pinching about the evacuating tube
(74) so as to minimize product leaks promotes fill-accuracy.
[0076] The evacuating tube (74) passes between the pinchers (56
& 57) so that its head (79) opens on to the headspace between
supplied predetermined amount of product (65) and the pinchers (56
& 57).
[0077] In another embodiment of the evacuating passage, the
pinchers (56 & 57) extend across the width of the continuous
film tube (10), but are closed with a force which allows evacuation
through the closed faces of the pinchers (56 & 57), while
limiting product flow. We incorporate in entirety the disclosure of
U.S. patent application Ser. No. 12/074,571 by reference herein,
which, inter alia, discusses different evacuation tubes for
removing air from headspace of a pouch and different deflation
apparatuses that can be used in the present invention.
[0078] Other deflating apparatuses are known to those of skill in
the art; for example, blowers for impinging air blasts or
aspiration can be used for deflating. The set of deflators is
actuated to push air out to reduce or eliminate headspace. The
deflators are suitably located below the sealing jaws and are
designed to gently push air out through the evacuating passage
until product is coming out and entering the evacuating passage.
The particular pressure with which the deflators deflate the
headspace will be readily ascertained by a person skilled in the
art, and will depend on such variables as the size of the pouch,
the machine speed, and the properties of the product being
packaged. Preferably, the pressure applied is relatively gentle in
order to limit build-up of pressure in the system, which may weaken
seals. The low levels of applied pressure also facilitate headspace
removal. As will be apparent to a person skilled in the art, the
deflators could compress all or part of the headspace directly or
could compress a portion of the pouch containing the predetermined
amount of product. Where the evacuating passage is formed by
closing of the pinchers with a reduced pressure, the air is pushed
out between the pinchers, while product flow is prevented.
Suitably, the distance of travel of the deflators can be
controlled, which enables the production of a consistent volume in
the pouch (or shape control). The distance travelled may be
controlled by various apparatuses, including e.g. air or hydraulic
cylinders or electric actuators.
[0079] One embodiment of the present invention includes a product
sensor to monitor intake of product by evacuating tube and a
control device for effecting this step. The deflators are
controlled to optimally evacuate the headspace, while limiting
evacuation of flowable product. Where an evacuating tube is
employed, the deflators are controlled so as to cease evacuating
air from the headspace into the evacuating tube once the product
starts to flow into the evacuating tube. Settings are made to
ensure that minimal flowable product enters the evacuating tube.
Suitable sensors are known to persons skilled in the art and
include, for example, a capacitance probe, an ultrasonic sensor and
a light sensor. The product sensor may be mounted inside or outside
the evacuating passage, and inside or outside the continuous film
tube. The present invention provides an accurate method for
determining when headspace has been minimized, because once product
comes out, essentially all headspace has been eliminated. Further,
this method is independent of fill control or reliability. This
method is suitable for both continuous or intermittent filling
operations.
[0080] In one embodiment of the invention, the squeezing times of
the deflators are changed asynchronously or dynamically. By
asynchronous or dynamic deflation is meant that while the two
deflator widths are fixed, the point in time at which the squeezing
is initiated, changes. This changing starting point is based on the
position of a known location on the film during indexing, for each
and every individual pouch. As a result, rather than the deflator
mechanism getting actuated at specific periodicity, the deflators
are actuated depending upon the advancement or indexing of the
film/pouch. The asynchronous deflation is accomplished by adding a
sensor to detect the film position as it passes through a known
relative position on the machine. This asynchronous timing allows
the filler to accommodate variations in film runnability, allowing
the filler to change with different film conditions and is not
limited by the speed of the machine.
[0081] In another embodiment, as described above, where the
squeezing times of the deflators are changed asynchronously or
dynamically, the gap between the deflators is changed based on when
a known locus on the film passes a references point during
indexing.
[0082] The critical process discovery is making contact with the
pouch while indexing. Many possible combinations exist to yield
similar effects like multiple squeezing actions or a computer-aided
manufacturing profile that would provide continuous squeezing of
the pouch while pouches are indexing.
[0083] As described previously, in all embodiments, in order to
form the final pouch, the pouch is severed from the next adjacent
pouch. As explained above, typically the sealing jaws are
associated with a cutting apparatus for severing the pouch from the
next adjacent pouch. These steps of sealing and cutting can be
performed in a simultaneous operation, commonly called a
"seal-and-cut operation."
[0084] The process of the present invention can further include
additional steps for minimizing product oxidation, examples of
which are known in the art. An example of such a technique for
minimizing product oxidation is nitrogen displacement (inerting
with gaseous nitrogen or liquid nitrogen dosing) to obtain desired
headspace oxygen levels. Another technique would be to form the
continuous film tube using a film structure with oxygen absorbers
or oxygen scavengers incorporated into the structure.
[0085] As will be apparent to a person skilled in the art, the
minimal headspace itself minimizes product oxidation. In some
applications, this can actually enable packaging of an improved
product. In the case of wine, for example, sulfites are added as a
preservative. The acceptable level of sulfites in wine products is
regulated to ensure acceptable levels for consumption. Limiting
sulfite levels can improve taste and a low preservative product
appeals to consumers. The minimal headspace pouch of the present
invention is particularly suitable for packaging a reduced sulfite
wine.
[0086] As will be apparent to a person skilled in the art, forming
a pouch of the present invention may involve additional
manufacturing steps (whether prior, during or after the process of
the present invention); for example, the pouch may be fitted with a
fitment prior to filling (i.e., by way of a fitment application
press 54, such as is shown in FIG. 1.). The pouch may also form
part of a larger package; for example, it may be inserted into a
cardboard box (i.e., according to the "bag-in-box" principle).
[0087] While this invention has been described with reference to
illustrative embodiments and examples, the description is not
intended to be construed in a limiting sense. Thus, various
modifications of the illustrative embodiments, as well as other
embodiments of the invention, will be apparent to persons skilled
in the art upon reference to this description. For example, as will
be apparent to persons skilled in the art, while a number of parts
are described as being present in the singular or as a pair, there
could be one, two or more of these components present in the
apparatus of the present invention, for example, there could be
multiple supply conduits, evacuating tubes, deflators, spreader
fingers, pinchers, etc. Further, the present invention also
encompasses a system for performing the process of the present
invention. As will be apparent to a person skilled in the art,
while the invention has been described in terms of a single
apparatus, the various steps of the process could be performed by
different apparatuses that form part of a larger system.
EXPERIMENTAL
Comparative Example 1
[0088] A prototype filler Crystalon.TM. Vertical Form Fill Seal
(VFFS) machine was set up to run 3000 g-pouches at the rate of 25
pouches per minute. The filler used a gravity-fed balance tank with
a constant-flow delivery system and sequenced, timed sealing
system. Deflators were set to a wide position to allow pouches to
be sealed. The deflators made contact with the pouch only after
indexing and before the seal operation. Deflator move-1 and move-2
widths were set to 5 mm. Widths denote the gap between the deflator
jaws. The system also had an aspirated valve-controlled evacuation
head extended through a set of pouch pinchers. Under steady state
operation, pouches were collected, and weighed. The purpose of this
example was to show the best fill-accuracy that this system can
achieve. Fifty pouches were collected in a single run after the
filler has stabilized. The pouches were then weighed and a standard
deviation was calculated. While the reported fill-accuracy (pouch
weight standard deviation) was 2 g, the head space was unacceptably
greater than 150 cm.sup.3, or 5% of the product volume. Results are
summarized in Table 1.
Comparative Example 2
[0089] The prototype filler Crystalon.TM. Vertical Form Fill Seal
(VFFS) machine used in Comparative Example 1 and set to run 3000
g-pouches was modified with a set of sequenced, two-move deflators.
The first move was a preparatory step to get it proximate to the
pouch. The second move made contact with the pouch after the index.
There was no contact of the deflators with the pouch during
indexing. Deflator move 1 width was held at 20 mm and move 2 width
was held at 1 mm. Under steady state operation, twenty-five pouches
were collected in a single run, weighed, and headspace was
estimated from every fifth collected pouch. The reported
fill-accuracy was 5.59 g and the average headspace was estimated at
78.4 cm.sup.3. The purpose of this experiment was to show the
typical operation of deflators without the new process improvement.
Results are summarized in Table 1.
Example 1
Synchronous Deflator Timing
[0090] The prototype filler Crystalon.TM. Vertical Form Fill Seal
(VFFS) machine used in Comparative Example 2 and set to run 3000
g-pouches was modified with a set of sequenced, two-move deflators.
Timing of deflators was adjusted to make contact with the pouches
as the pouches were indexing. In both moves, the deflators
contacted the pouch while it indexed. Deflator move 1 width was
maintained at 40 mm while move 2 width was maintained at 3 mm. Two
different film rolls were tested. Under steady state operation,
fifty pouches were collected in nine runs, weighed, and headspace
was estimated from every other pouch for seven of the nine runs,
and from every fifth pouch for two of the nine runs. The reported
fill-accuracy ranged from 5.19 g to 15.49 g and the average
headspace range was estimated at 28.5 cm.sup.3 to 50.0 cm.sup.3.
Results are summarized in Table 1.
Example 2
Asynchronous Deflator Timing
[0091] The machine used in Example 1 and set to run 3000 g-pouches
was modified to allow the deflators moves to be
asynchronously-triggered by a predetermined index position on the
pouch. Sequenced timers were updated by offsets when the
predetermined index position reached the sensor. Again, the
deflators in both moves contacted the pouch only during indexing.
Deflator move 1 width was held at 5 mm and move 2 width was held at
1 mm. Two different film rolls were tested. Under steady state
operation, fifty pouches were collected in three runs, weighed and
headspace was estimated from every other collected pouch. The
reported fill-accuracy ranged from 8.29 g to 11.59 g and the
average headspace range was estimated at 27.3 cm.sup.3 to 31.7
cm.sup.3.
[0092] Results are summarized in Table 1, which shows the results
for a 3-liter pouch filled with water on the Crystalon.TM. Vertical
Form Fill Seal (VFFS) machine utilizing asynchronous deflator
timing. The deflator moves were setup widths that are adjustable
via a Human Machine Interface (HMI) screen. The width of the
deflators move 1 and move 2 was in reference to the gap between the
deflators at the end of the motion. The fill-accuracy was
determined by weighing fifty consecutive pouches. Headspace was
estimated by an inverted cone measurement and calculation.
Example 3
Asynchronous Deflator Timing
[0093] The machine used in Example 2 and set to run 3000 g-pouches
was modified with different setup widths for the two deflator
moves. Again, the deflators in both moves contacted the pouch while
it was being indexed. Deflator move 1 width was maintained at 6 mm
and move 2 width was held at 0 mm. Two different film rolls were
tested. Under steady state operation, fifty pouches were collected
in four runs, weighed and headspace was estimated from every other
pouch. The reported fill-accuracy (pouch weight standard deviation)
ranged 7.80 g to 10.56 g and the average headspace range was
estimated at 30.5 cm.sup.3 to 35.0 cm.sup.3. Results are summarized
in Table 1.
Example 4
Asynchronous Deflator Timing
[0094] The machine used in Example 3 and set to run 3000 g-pouches
was modified with different widths for the two deflator moves. Two
different film rolls were tested. Again, the deflators in both
moves contacted the pouch while it was being indexed. Deflator move
1 width was 5 mm and move 2 width was 0 mm. Under steady state
operation, fifty pouches were collected from two runs, weighed and
headspace was estimated from every other pouch. The reported
fill-accuracy ranged 13.37 g to 13.75 g and the average headspace
range was estimated at 22.4 cm.sup.3 to 25.3 cm.sup.3.
[0095] All results are summarized in Table 1 on the next page. Also
in Table 1, the headspace was calculated as percentage of the
target volume of the product, which is 3 L. We note that the
product for all the above Examples was water.
TABLE-US-00001 TABLE 1 Crystalon .TM. Fill-Accuracy and Headspace
Results Headspace Deflators Deflators Fill-Accuracy Range % Move 1
Move 2 Range (g) Headspace Product Width Width Standard Range
Volume Examples Deflator Timing Gap Gap Deviation 1.sigma.
(cm.sup.3) (3 L)** Comp. Synchronous, 5 mm 5 mm 2 150 5.0 Ex. 1
after film index Comp. Synchronous, 20 mm 1 mm 5.59 78.4 2.613 Ex.
2 after film index Ex. 1 Synchronous, 40 mm 3 mm 28.5 28.5-50.0
0.950-1.667 while film is indexing Ex. 2. Asynchronous/ 5 mm 1 mm
8.29-11.59 27.3-31.7 0.910-1.057 Dynamic, while film is indexing
Ex. 3. Asynchronous/ 6 mm 0 mm 7.80-10.56 30.5-35.0 1.017-1.167
Dynamic, while film is indexing Ex. 4. Asynchronous/ 5 mm 0 mm
13.37-13.75 22.4-25.3 0.747-0.843 Dynamic, while film is indexing
**[(Headspace Range * 100)/3000)]%
LISTING OF PARTS
FIG. 1
[0096] 100 Vertical form-fill seal machine [0097] 10 continuous
film tube [0098] 15 roll of film [0099] 20 roll unwind section
[0100] 25 unwound film [0101] 30 forming section [0102] 35 vertical
sealing section [0103] 40 longitudinal edges of the film [0104] 45
horizontal sealing section [0105] 50 & 55 horizontal sealing
jaws [0106] 54 fitment application press [0107] 56 & 57
pinchers [0108] 59 air/product interface [0109] 60 supply conduit
[0110] 65 predetermined amount of product [0111] 70 bottom
horizontal seal [0112] 71 indexing process [0113] 72 pouch [0114]
74 evacuating tube [0115] 79 evacuation tube head at pincher
interface [0116] 85 deflator apparatus [0117] 86-87 first set of
deflators
FIG. 2
[0117] [0118] 10 continuous film tube [0119] 40 longitudinal edges
of the film [0120] 50 & 55 horizontal sealing jaws [0121] 56
& 57 pinchers [0122] 59 air/product interface [0123] 60 supply
conduit [0124] 65 predetermined amount of product [0125] 70 bottom
horizontal seal [0126] 71 indexing process [0127] 72 pouch [0128]
74 evacuating tube [0129] 79 evacuation tube head at pincher
interface [0130] 85 deflator apparatus [0131] 86-87 first set of
deflators [0132] 88-89 second set of deflators [0133] 91 squeeze
from first move of deflators
FIG. 3
[0133] [0134] 10 continuous film tube [0135] 40 longitudinal edges
of the film [0136] 50 & 55 horizontal sealing jaws [0137] 56
& 57 pinchers [0138] 59 air/product interface [0139] 60 supply
conduit [0140] 65 predetermined amount of product [0141] 70 bottom
horizontal seal [0142] 71 indexing process [0143] 72 pouch [0144]
74 evacuating tube [0145] 79 evacuation tube head at pincher
interface [0146] 85 deflator apparatus [0147] 86-87 first set of
deflators [0148] 88-89 second set of deflators [0149] 92 squeeze
from the second move of the deflators
FIG. 4
[0149] [0150] 10 continuous film tube [0151] 40 longitudinal edges
of the film [0152] 50 & 55 horizontal sealing jaws [0153] 56
& 57 pinchers [0154] 65 supply conduit [0155] 65 predetermined
amount of product [0156] 70 bottom horizontal seal [0157] 71
indexing process [0158] 72 pouch [0159] 74 evacuating tube [0160]
79 evacuation tube head at pincher interface [0161] 85 deflator
apparatus [0162] 86-87 first set of deflators [0163] 88-89 second
set of deflators [0164] 92 squeeze from the second move of the
deflators
* * * * *