Note: Descriptions are shown in the official language in which they were submitted.
CA 02509057 2005-06-02
ENHANCED SLIDER ZIPPER MULTIWALL BAG
AND ASSOCIATED METHODS
Related Application
This continuation-in-part patent application claims the benefit of co-pending
non-provisional patent application with the United States Serial No.
10/290,681, filed
on November 8, 2002, which hereby is incorporated by reference in its
entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates generally to the packaging industry. In more
specific
aspects, the invention relates to multiwall packaging and methods for forming
multiwall packaging that have zippers associated with the package.
2. Description of the Related Art
[0002] As more and plo~e consumer products are packaged, the need for enhanced
consumer end product packaging continues to grow. End product packaging not
only
1 S has to keep the products fresh, the product packaging needs to protect the
envirorunent from the product contents and protect the product contents from
the
environment. The packaging must also be strong enough to hold materials of
varying
weights, without being damaged, in order to provide packaging for a vast array
of
consumer products. Of particular importance is the ease of access to the
materials
within the packaging. Another important aspect includes tamper resistance to
prevent
the likelihood of tampering with the contents within the bags.
[0003) To increase access to contents within a bag, others have developed many
types of bags with many types of closures. Examples of user friendly bags can
be
found in U.S. Patent No. 6,376,035 titled "Zipper Fins For Plastic Bags" by
Dobreski
2S et al. and U.S. Patent No. 5,919,535 titled "Fins For Plastic Bags" by
Dobreski et al.
These plastic bags are provided with a zipper or a slider, a zipper track, and
one or
more fin members. The consumer can initially open the zippered bag, use a
portion of
the product, and then easily reclose the bag until the product is needed
again. This
zipper combination is easily operated and can withstand stronger forces
applied
thereto than zippers previously used on plastic bags. Applicants have
recognized that
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CA 02509057 2005-06-02
these zipper combinations described in Dobreski are limited to plastic bags.
Although
plastic bags can provide adequate packaging for some products, they are simply
not
durable enough to provide adequate protection for many types of products.
[0004] Tampering with consumer goods has also become a problem throughout the
years. Packaging producers have been developing better mechanisms to enable
consumers to determine if the product within the packaging may have been
subjected
to some form of tampering or unwanted opening prior to customer purchase.
Examples of bags with a tamper evident feature can be found in U.S. Patent
No. 6,286,999 by Catchman titled "Tamper-Evident Reclosable Bag" and U.S.
Patent
No. 6,439,770 by Catchman titled "Reclosable Bags Having A Tamper-Evident
Retaining Member Extending Through A Slider." These patents describe many
types
of devices that can be installed along the zipper track of zippered bags to
determine if
tampering has occurred. Examples include a removable cardboard, paper, or
plastic
member covering or adjacent to a zipper slider in the closed position and then
attached to the bag in some way. If the zipper is moved, the removable member
will
show signs of tampering. Applicants have recognized that the tamper-evident
features
in the Catchman patents require the use of some additional element that has to
be
damaged in order to show signs of tampering.
SUMMARY OF THE INVENTION
[0005] In view of the foregoing, an embodiment of the present invention
advantageously provides multiwall end product packaging that is finable from
the
bottom with a slidable zipper assembly. The end product packaging can include
a bag
seal zone. In addition to the end product packaging, the present invention
also
advantageously provides methods of forming such bags. An embodiment of the
present invention also advantageously provides a multiwall bag of tubular form
having a tamper-evident feature, which is integral with the bag. Further
embodiments
of the present invention advantageously provide user friendly bags capable of
holding
products of varying weights, that are strong and durable, that provide
consumers with
easy access to the products within the bags, and that have a dependable anti-
tampering
alert mechanism.
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[0006] More particularly, a multiwall bag according to an embodiment of the
present invention includes an inner tube, an outer tube, a bag seal zone, a
fin member,
a zipper track, and a zipper block. The inner tube preferably has at least one
layer of a
polymeric material. The inner tube includes an inner front wall region and an
imler
back wall region positioned to face opposite the imier front wall region. The
outer
tube preferably has at least one Iayer of paper material and is positioned to
substantially surround outer surfaces of the inner tube. The at least one
layer of paper
material can include at least one layer of a polymeric material that is
positioned ~o
that the polymeric material is in the outermost position of the outer tube.
The outer
tube has an open end region, a closed end region, an outer front wall region,
and an
outer back wall region. The closed end region is typically initially in an
open position
and is adapted to receive filling material therethrough. The closed end region
is then
sealingly closed to a closed position. The outer front wall region is
positioned
between the open end region and the closed end region. The outer back wall
region is
positioned between the open end region and the closed end region and is
positioned to
face opposite the outer front wall region.
[0007] The bag seal zone is formed adjacent the open end of the outer tube so
that
the at Ieast one layer of polymeric material of inner surfaces of the inner
front wall
region of the inner tube abuttingly contacts and seals to inner surfaces of
the inner
back wall region of the inner tube. The bag seal zone can be formed using heat
sealing or by using an adhesive material. Other ways to form the bag seal zone
will
be known to those of ordinary skill in the art and are to be considered within
the scope
of the present invention.
[0008] The fm member is formed of a plastic material and is connected to the
bag
seal zone, if present. If the bag does not have a bag seal zone, then the fin
member is
attached adjacent the open end of the outer tube. The fin member extends
substantially the entire lateral extent of and along the outer front and back
wall
regions. The fin member includes at least a pair of spaced-apart elongate fin
strips
positioned to face opposite each other.
[0009] The zipper track is connected to each of the pair of elongate fin
strips of the
fin member. The zipper track includes a first track strip and a second track
strip. The
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CA 02509057 2005-06-02
first and second track strips are adapted to be positioned between an open
position
defined by the first and second track strips being spaced apart to allow
access to inner
portions of the bag and a sealingly closed position defined by the first and
second
track strips abuttingly contacting each other to prevent ready access to the
imler
portions of the bag.
[0010] The zipper block is slidably connected to the zipper track to allow the
zipper block to slidably move along the zipper track and move the first and
second
track strips between the open position and the closed position. The fin
member, the
zipper track, and the zipper block together or in combination define a slider
zipper
and fin combination. The fin member of the zipper and fm combination can also
include a fin seal zone associated with and positioned between the pair of fin
strips
and positioned adjacent the open end of the outer tube proximal to the zipper
track.
The fin seal zone can include a score line positioned between the fin strips
so that
initial opening of the zipper track allows the fin seal zone to be readily
separated
along the score line.
[0011] According to another embodiment of the present invention, the multiwall
bag can be altered, for example, by forming a tube body having a plurality of
material
layers or with the inner tube and outer tube as described above. The tube body
has at
least one inner Layer of polymeric material and at least one outer layer of
paper
material positioned to substantially surround outer surfaces of the inner
layer of
polymeric material. The tube body has a pair of opposing tube ends. An outer
front
wall region is positioned between the pair of opposing tube ends. An outer
back wall
region is positioned to face opposite the outer front wall region and between
the pair
of opposing tube ends.
[0012] The multiwall bag described herein can also include an outer layer of
polymeric material positioned to substantially surround at least one inner
layer of
polymeric material and a layer of paper material. For example, the multiwall
bag can
have a three-ply construction with an inner layer of polymeric material, a
middle layer
of paper material, and an outer layer of polymeric material.
[0013] According to another embodiment of the present invention, the multiwall
bag can include a plurality of gussets that are formed between the outer front
wall
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region and the outer back wall region of the multiwall bag. At least a first
one of the
plurality of gussets are formed in a first region between the outer front and
back wall
regions to define a first outer side wall region. At least a second one of the
plurality
of gussets is formed in a second region between the outer front and back wall
regions
to define a second outer side wall region. The second outer side wall region
is
advantageously positioned opposite the first outer side wall region. The
multiwall
bag further includes an adhesive material positioned adjacent the plurality of
gussets
to thereby define a plurality of sealed gussets. The sealed gussets
advantageously
increase drop and abuse resistance of the bag, reduce the risk of access to
contents of
a bag by a pest, and reduce sifting of filling material when positioned in the
bag. To
further secure the plurality of sealed gussets, the multiwall bag can also
include an
external reinforcement that is positioned to overlie each of the plurality of
sealed
gussets. The external reinforcement preferably extends past each of the sealed
gussets
to cover regions of the front and back wall regions adjacent to each of the
sealed
1 S gussets. The external reinforcement enhances the strength and stiffness of
each of the
sealed gussets and further reduces the risk of access to contents of the bag
by a pest.
[0014] The external reinforcement can include various types of reinforcements.
For example, tape, ribbons, labels, clips, brads, or bands could be used.
Other
suitable types of external reinforcement means will be known to those of skill
in the
art and are to be considered within the scope of the present invention.
[0015] In addition to the multiwall bottom finable bags, the present invention
also
advantageously provides methods of forming a multiwall bag having a zipper
associated therewith. A method of forming the multiwall bag includes
laminating a
plurality of layers of material. Complete, continuous, or a combination of
complete
and continuous lamination is preferred in the bag seal zone, as understood by
those of
skill in the art. The plurality of layers preferably includes at least one
layer of
polymeric material and at least one layer of paper material. Once the layers
of
material are laminated, the layers are formed into a tube body. At least one
layer of
the polymeric material defines an inner surface of the tube body and the at
least one
layer of paper material defines an outer surface of the tube body. The tube
body has a
front wall and a back wall positioned to face opposite the front wall. An end
portion
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of the inner surface of the front wall is sealed to an opposite facing end
portion of the
inner surface of the back wall to thereby define a bag seal zone. A
combination of a
fin member, a zipper track connected to the fin member, and a zipper block
connected
to the zipper track are connected to or attached to the bag seat zone of bag.
[0016] The method of forming the multiwall bag, for example, can be altered by
supplying layers of materials that are already laminated according to the
present
invention. If the materials are already laminated, then the tube body can be
fornied
without having to laminate the materials.
[0017] It is envisioned that the bottom fillable multiwall packaging end
products of
the present invention can be used for any type of product that requires easy
access to
the contents within and the strength of a multiwall bag. Such product uses
include
bags for various food items, pet food, charcoal, building materials, seed,
lawn and
garden supplies, and other uses as will be known to one skilled in the art and
are to be
considered within the scope of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] So that the manner in which the features and advantages of the
invention, ,
as well as others which will become apparent, may be understood in more
detail, more
particular description of the invention briefly summarized above may be had by
reference to the embodiments thereof which are illustrated in the appended
drawings,
which form a part of this specification. It is to be noted, however, that the
drawings
illustrate only various embodiments of the invention and are therefore not to
be
considered limiting of the invention's scope as it may include other effective
embodiments as well.
[0019] FIG. 1 is a perspective view of a multiwall bag with a bag seal zone
and a
slider zipper and fin combination according to an embodiment of the present
invention;
[0020] FIG. 2 is an enlarged fragmentary sectional view of a multiwall bag
taken
along line 2-2 of FIG. 1 according to an embodiment of the present invention;
[0021] FIG. 3 is a perspective view of a tube body having a plurality of
gussets
fowled therein according to an embodiment of the present invention;
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[0022) FIG. 4 is a fragmentary perspective view of heat being applied to a
tube
body to form a bag seal zone of a multiwall bag according to an embodiment of
the
present invention;
[0023] FIG. S is a fragmentary perspective view of a tube body with a bag seal
zone being connected to a slider zipper and fin combination according to an
embodiment of the present invention;
[0024] FIG. 6 is an enlarged perspective fragmentary view of a slider zipper
and
fin combination connected to the bag seal zone of a multiwall bag according to
an
embodiment of the present invention;
[0025] FIG. 7 is a fragmentary sectional view of a slider zipper and fin
combination connected to the bag seal zone of a multiwall bag taken along line
7-7 of
FIC'J. 6 according to an embodiment of the present invention;
[0026] FIG. 8 is perspective view of a multiwall bag being bottom filled with
a
filling material according to an embodiment of the present invention;
[0027] FIG. 9 is a perspective view of a multiwall bag having slider zipper
and fin
combination filled with a product and having a closed end region in closed
position
according to an embodiment of the present invention;
[0028] FIG. 10 is a fragmentary perspective view of a multiwall bag having a
zipper block opened and prior to breaking a seal within the bag seal zone
according to
an embodiment of the present invention;
[0029] FIG. 11 is a fragmentary perspective view of a multiwall bag being
opened
along a score line and the seal being opened within the bag seal zone
according to an
embodiment of the present invention;
[0030] FIG. 12 is a fragmentary perspective view of a multiwall bag having a
zipper block and a bag seal zone in an open position according to an
embodiment of
the present invention;
[0031 ] FIG. 13 is a fragmentary perspective view of a multiwall bag having a
zipper block in a closed position and a bag seal zone remaining in an open
position
according to an embodiment of the present invention;
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[0032) FIG. l~l is a perspective view of a multiwall bag with a bag seal zone
using
an adhesive material as the inner layers oi_the bag seal zone and a slider
zipper and fin
combination according to an embodiment of the present invention;
(0033] FIG. IS is a perspective view of a tube body having a plurality of
gussets
with an inner ply removed formed therein according to an embodiment of the
present
invention;
[0034] FIG. 16 is a perspective view of a tube body having a plurality of
gussets
and having a bag seal zone formed therein using an adhesive material according
to an
embodiment of the present invention;
[0035] FIG. 17 is a perspective view of a tube body having a slider zipper and
fin
combination applied thereto according to an embodiment of the present
invention;
[0036] FIG. 18 & 19, a perspective fragmentary view (FIG. 18), and enlarged
perspective fragmentary view (FIG. 19) of a slider zipper and fin combination
adhesively
connected to a multiwall bag according to an embodiment of the present
invention;
(0037) FIG. 20 is a fragmentary sectional view of a slider zipper and fin
combination adhesively connected to the bag seal zone of a multiwall bag taken
along
line 20-20 of FIG. 19 according to an embodiment of the present invention;
[0038] FIG. 21 is a perspective view of two substrates with an adhesive layer
being positioned between the two substrates so that complete lamination occurs
in the
bag seal zone when fornling a tube body in accordance with an embodiment of
the
present invention;
[0039] FIG. 22 is a sectional view of two substrates having an adhesive layer
positioned between the two substrates taken along line 22-22 of FIG. 21
according to
an embodiment of the present invention; and
(0040] FIG. 23 is a flow diagram of a method of producing a multiwall bag
according to an embodiment of the present invention
DETAILED DESCRIPTION
[0041] The present invention will now be described more filly hereinafter with
reference to the accompanying drawings, which illustrate preferred embodiments
of
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CA 02509057 2005-06-02
the invention. This invention may, however, be embodied in many different
forms and
should not be construed as limited to the illustrated embodiments set forth
herein.
Rather, these embodiments are provided so that this disclosure will be
thorough and
complete, and will fully convey the scope of the invention to those skilled in
the art.
Like numbers refer to like elements throughout. The prime notation, if used,
indicates
similar elements in alternative embodiments.
[0042] As illustrated in FIGS. 1-21, an embodiment of the present invention
._
advantageously provides a multiwall bag 20 of tubular form. The multiwall bag
20
includes an inner tube 37, an outer tube 35, a bag seal zone 21, a fin member
22, a
zipper track 24, a zipper block 34, a plurality of gussets 25, and an external
reinforcement 53 for the plurality of gussets 25, as shown in FIGS. 1, S, 8,
9, 14, and
18. The inner tube 37 preferably has at least one layer of a polymeric
material 41.
The inner tube 37 includes an inner front wall region 38 and an inner back
wall region
39 positioned to face opposite the inner front wall region 38 (see FIG. 3).
The outer
tube 35 preferably has at least one layer of paper material 46. The outer tube
35 is
positioned to substantially surround outer surfaces of the inner tube 37. The
outer
tube 35 has an open end region 31, a closed end region 32, an outer front wall
region
33, and an outer back wall region 34. The closed end region 32 is typically
initially in
an open position and is adapted to receive filling material F therethrough.
The closed
end region 32 is then sealingly closed to a closed position (see FIG. 9). The
outer
front wall region 33 is positioned between the open end region 31 and the
closed end
region 32 such as illustrated (see FIGS. 1-3). The outer back wall region 34
also is
positioned between the open end region 31 and the closed end region 32 and is
positioned to face opposite the outer front wall region 33.
[0043] External reinforcement 53 can include various types of reinforcements.
For
example, tape, ribbons, labels, clips, brads, or bands could be used. Other
suitable
types of external reinforcement means will be known to those of skill in the
art and
are to be considered within the scope of the present invention.
[0044] The bag seal zone 21 is formed adjacent the open end 31 of the outer
tube
35 (see FIGS. 1 and 3-4) so that the at least one layer of polymeric material
41 of
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inner surfaces of the inner front wall region 38 of the inner tube 37
abuttingly contacts
and seals to inner surfaces of the inner back wall region 39 of the inner tube
37.
[0045] The plurality of gussets 25 is preferably formed between the outer
front
wall region and the outer back wall region of the multiwall bag 20. At least a
first one
S of the plurality of gussets 25 is formed in a first region between the outer
front and
back wall regions so as to define a first outer side wall region. At least a
second one
of the plurality of gussets 25 is formed in a second region between the outer
front and
back wall regions so as to define a second outer side wall region. The second
side
wall region is positioned opposite the first outer side wall region. The
multiwall bag
20 further includes an adhesive material positioned adjacent the plurality of
gussets 25
to thereby define a plurality of sealed gussets 25. The plurality of sealed
gussets 25
increase drop and abuse resistance of the bag 20, reduce the risk of access to
contents
of a bag 20 by a pest, and reduce sifting of filling material when positioned
in the bag
20.
[0046) An external reinforcement 53 is advantageously positioned to overlie
each
of the plurality of sealed gussets 25. The external reinforcement 53 extends
past each
of the sealed gussets 25 to cover regions of the front and back wall regions
adjacent to
each of the sealed gussets 25. The external reinforcement 53 thereby enhances
the
strength and stiffness of each of the sealed gussets 25 and further reduces
the risk of
access to contents of the bag 20 by a pest.
[0047] The multiwall bag 20 can include a handle 55 that is attached to the
external reinforcement 53, as shown in FIGS. 1, 5, 8, 9, 14, and 18. The
handle 55
enables consumers to better handle the multiwall bag 20. The handle 55 can be
used
to pour the contents contained within the multiwall bag 20 out of the bag 20
or to
transport the multiwall bag 20 to another location.
[0048] The fin member 22 is preferably formed of a plastic material that can
be
connected to or attached to the bag 20 using a heat seal, such as shown in
FIG. 4. Use
of heat to adhere the fm member 22 to the bag 20 can be used when the
outermost ply
of the bag 20 is a polymeric material. The heat enables the polymers contained
with
the plastic material of the fin member 22 and the polymeric material to form
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CA 02509057 2005-06-02
adhesive bond between the two materials that enables the fin member 22 to
become
adhered to the bag 20.
[0049] As shown in FIGS. 5 and 6, the fin member 22 is forn~ed of a plastic
material and is connected to or attached to the bag seal zone 21. This
comlection or
S attachment, for example, can be on the outer surface of the outer tube 35
such as by
use of an adhesive material as illustrated or by attachment to one of the
inner layer 41
of the inner tube 37 or to any layers 42, 47, 48 therebetween (see FIGS. 2, S
and 7).
The fin member 22 extends substantially the entire lateral extent of and along
the
outer front and back wall regions 33, 34. The fin member 22 can include at
least a
pair of spaced-apart elongate fin strips 28, 29 positioned to face opposite
each other.
[0050] The zipper track 24 is connected to each of the pair of elongate fin
strips
28, 29 of the fin member 22. The zipper track 24 includes a first track strip
26 and a
second track strip 27. The first and second track strips 26, 27 are adapted to
be
positioned between an open position defined by the first and second track
strips 26, 27
being spaced apart to allow access to inner portions of the bag 20 and a
sealingty
closed position defined by the first and second track strips 26, 27 abuttingly
contacting each other to prevent ready access to the inner portions of the bag
20 (see
FIGS. 10-13). The zipper block 34 is slidably connected to the zipper track 24
to
allow the zipper block 34 to slidably move along the zipper track 24 and move
the
first and second track strips 26, 27 between the open position and the closed
position.
The fin member 22, the zipper track 24, and the zipper block 34 together and
in
combination define a slider zipper and fin combination.
[0051] According to another embodiment, construction for the multiwall bag 20
can be altered, for example, by forming a tube body 40 from a plurality of
layers of
material or by having the inner tube 37 and outer tube 35 as described above
as
understood by those skilled in the art. The tube body 40 has at least one
inner layer
41 of polymeric material and at least one outer layer 46 of paper material
positioned
to substantially surround outer surfaces of the inner layer 41 of polymeric
material.
The tube body 40 has a pair of opposing tube ends 31, 32. An outer front wall
region
33 is positioned between the pair of opposing tube ends. An outer back wall
region
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CA 02509057 2005-06-02
34 is positioned to face opposite the outer front wall region 33 and between
the pair of
opposing tube ends 31, 32.
[0052] The at least one layer 46 of paper material of the outer tube 35 can
include
a polymeric material layer that is positioned so that when the multiwall bag
20 is
S constructed, the polymeric material layer is the most external, or
outermost, layer.
[0053] As shown in FIG. 6, the multiwall bag 20 can include a pair of corner
clips
36 each connected to an opposite end of the zipper track 24 and to the fin
member 22.
,_
The corner clips 36, for example, advantageously help reduce the risk of
damage to
the zipper block 34 and can operate as a stop to the zipper block 34 at
opposing ends
of the zipper track 24.
[0054] The bag seal zone 21 preferably includes a heat seal at least
positioned
between the slider zipper and fin combination and outer surfaces of the outer
tube 35
so that inner surfaces of the polymeric material of the inner front wall
region 38 are
heatingly sealed to the inner surfaces of the polymeric material of the inner
back wall
region 39 (see FIGS. 4 and 9-13). When the bag 20 is filled from the closed
end (see
FIGS. 8-9), the heat seal enhances protection of the slider and zipper
combination by
operating as a stop region or constructive bottom for the filling material and
thereby
enhances filling performance of the bag 20. As will be understood by those
skilled in
the art, the heat seal preferably allows the inner surfaces of the inner front
wall and
inner back wall regions 38, 39 to pealingly separate and unseal the inner
surfaces of
the inner front and back wall regions 38, 39 without significant or
substantial damage
to the inner surfaces when initially opening the bag 20 through the slider
zipper and
fin combination (see FIGS. 10-13).
[0055] The bag seal zone 21 can be formed using an adhesive material to create
an
adhesive seal that is at least positioned between the slider zipper and fin
combination
and outer surfaces of the outer tube 35, as shown in FIGS. 18 - 20. When the
bag seal
zone 21 is formed using an adhesive material, inner surfaces of the polymeric
material
of the inner front wall region 38 are adhesively sealed to the inner surfaces
of the
polymeric material of the inner back wall region 39, as shown in FIGS. 17 and
20.
When the multiwall bag 20 is filled from the closed end region 32, the
adhesive seal
enhances protection of the slider and zipper combination by operating as a
stop region
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for the filling material, which enhances filling performance of the bag 20.
The
adhesive seal advantageously allows the inner surfaces of the inner front wall
and
inner back wall regions 38, 39 to pealingly separate and unseal the inner
surfaces of
the inner front and back wall regions without substantial damage to the inner
surfaces
thereof when initially opening the bag 20 through the slider zipper and fin
combination.
[0056] The multiwaIl bag 20 of an embodiment of the present invention also
advantageously provides anti-tampering properties to indicate whether the bag
20 has
already been opened. In the embodiments containing the bag seal zone 21, once
the
bag seal zone 21 has been opened initially as shown in FIGS. 10-13, the bag
seal zone
21 further remains unsealed even when the zipper block 34 is in the closed
position as
shown in FIG. 13. The inability to reseal the bag seal zone 21 as initially
sealed
indicates that initial opening has occurred and that tampering with the
opening of the
bag 20 may have occurred.
(0057] Various materials or chemical compounds can be used as the polymeric
material of the inner layer 41 (or plurality of layers 41, 42) the inner tube
37.
Preferably the polymeric material is selected from at least one of the
following:
polyethylene, polypropylene, nylon, ethylene vinyl acetate, ethylene vinyl
alcohol,
malefic anhydride grafted polyethylenes and propylenes, polyesters, and PTE.
The
polymeric material preferably enhances the effectiveness of the heat seal and
yet
reducing risk of damage to the polymeric material. Other suitable polymeric
materials will be known to those skilled in the art and are to be considered
within the
scope of the present invention. As understood by those skilled in the art, the
polymeric material is preferably formed by at least one of the following:
extrusion,
co-extrusion, lamination, and coating processes.
[0058] Oil and grease resistance is an important property for bags 20,
particularly
when containing various types of food products, including pet food. Oil and
grease
resistance protects the contents within the bag 20 from the outside, while
also
protecting the outside from the contents. In all embodiments of the present
invention,
the multiwall bag 20 can be constructed to provide oil and grease resistance
to the bag
20. The multiwall bag 20 can be constructed so the inner tube 37 further has a
second
13
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layer 42 formed of a grease resistant material (see FIG. 2). The second layer
42
preferably overlies the f rst layer 41 as illustrated. The at least one paper
layer 46 of
the outer tube 35 also can be a plurality of paper layers 46, 47, 48. The
outer tube 35
further includes at least one grease resistant barrier 48 associated with the
plurality of
paper layers 46, 47, 48. The second layer 42 of the inner tube 37 can be
constructed
from at least one of the following materials: nylon, rubber, vinyl, and
polymeric
materials. The grease resistant barrier 48 of the outer tube 35 can be
constructed by
using a grease resistant coating, applying a chemical to at least one of the
plurality ~f
paper layers 46, 47, 48 or providing a separate non-paper material layer 48.
j0059] The outer tube 35 can have a plurality of gussets 25 formed between the
outer front wall region 33 and the outer back wall region 34. At least a first
one of the
plurality of gussets 25 is preferably formed in a first region between the
outer front
and back wall regions 38, 39 so as to define a first outer side wall region.
At least a
second one of the plurality of gussets 25 is preferably formed in a second
region
between the outer front and back wall regions 38, 39 so as to define a second
outer
side wall region positioned opposite the first outer side wall region (see,
e.g., FIGS. 3-
4). The bag 20 further can have an adhesive material 49 positioned adjacent
the
plurality of gussets 25 so that when the heat seal is formed, the adhesive
material 49
also is repeated to thereby enhance sealing adjacent the gussets 25, such as
when
passing through the nip of a heat sealer as shown in FIG. 4, and thereby
define a
plurality of sealed gussets 25 to increase drop and abuse resistance of the
bag 20 by
strengthening the regions around the gusset and allowing the bag 20 to flex
when
contents are positioned therein. This enhanced sealing of the gussets 25 can
also
advantageously reduce the risk of access to contents of a bag 20 by a pest and
can also
reduce sifting of filling material when positioned in the bag 20.
[0060] The fm member 22 of the zipper and fin combination can include a fin
seal
zone associated with and positioned between the pair of fin strips 28, 29 and
positioned adjacent the open end 31 of the outer tube 35 proximal to the
zipper track
24. In all embodiments of the present invention, the fin seal zone preferably
includes
a score line 50 that is positioned between the fin strips 28, 29, as
illustrated in FIGS.
10 and 11. The score line 50 ensures that an initial opening of the zipper
track 24
14
CA 02509057 2005-06-02
allows the fin seal zone to be readily separated in the proper location to
provide
access to the filling material and inner contents of the bag 20. The score
line SO
provides another anti-tampering indication that the zipper track 24 has at
least been
initially opened.
S [0061] As another embodiment of the present invention, a multiwall bag 20 of
tubular form is advantageously provided. In this embodiment, the bag 20
preferably
includes an inner tube 37 that has least one layer of polymeric material that
includes
an inner front wall region 38 and an inner back wall region 39 positioned to
face
opposite the inner front wall region 38. The bag 20 also includes an outer
tube 35 that
contains at least one layer of paper material. The outer tube 35 is
advantageously
positioned to substantially surround outer surfaces of the inner tube 37. The
outer
tube 35 has an open end region and a closed end region that is initially in an
open
position. The closed end region is advantageously adapted to receive filling
material
therethrough, and then be sealingly closed to a closed position once filled.
The bag
20 also includes an outer front wall region that is positioned between the
open end
region and the closed end region. The bag 20 includes an outer back wall
region that
is also positioned between the open end region and the closed end region and
is
positioned to face opposite the outer front wall region.
(0062] The bag 20 includes a fin member 22 that is formed of a plastic
material
and connected to the outer front and back walls. The fin member 22 extends
substantially the entire lateral extent of and along the outer front and back
wall
regions of the bag 20. The fin member 22 advantageously includes at least a
pair of
spaced-apart elongate fin strips positioned to face opposite each other. A
zipper track
24 is also provided as a component of the bag 20. The zipper track 24 is
connected to
each of the pair of elongate fin strips of the fin member, 22. The zipper
track 24
preferably includes a first track strip and a second track strip. The first
and second
track strips can be adapted to be positioned between an open position and a
sealingly
closed position. The open position is defined by the first and second track
strips being
spaced apart to allow access to inner portions of the bag 20. The sealingly
closed
position is defined by the first and second track strips abuttingly contacting
each other
to prevent ready access to the inner portions of the bag 20.
CA 02509057 2005-06-02
[0063) The multiwall bag 20 also advantageously includes a zipper block 34
that is
slidably connected to the zipper track 24. The manner in which the zipper
block 34
and the zipper track 24 are connected allows the zipper block 34 to slidably
move
along the zipper track 24 and move the first and second track strips between
the open
position and the closed position. The fin member 22, the zipper track 24, and
the
zipper block 34 advantageously define a slider zipper and fin combination.
[0064] A multiwall bag 20 having reinforced gussets 25 is advantageously
provided as another embodiment of the present invention. The multiwall bag 20
preferably includes an inner tube 37, an outer tube 35, a fin member 22, a
zipper track
24, a zipper block 34, a plurality of gussets 25, and an external gusset
reinforcement
53.
[0065) The inner tube 37 preferably has at least one layer of polymeric
material
that includes an inner front wall region 38 and an inner back wall region 39.
The
inner back wall region 39 positioned to face opposite the inner front wall
region 38.
[0066] The outer tube 35 preferably has at least one layer of paper material
and is
positioned to substantially surround outer surfaces of the inner tube 37. The
outer
tube 35 has an open end region, a closed end region, an outer front wall
region, and an
outer back wall region. The closed end region is initially in an open position
and is
adapted to receive filling material therethrough, and then sealingly close to
a closed
position. The outer front wall region is advantageously positioned between the
open
end region and the closed end region. The outer back wall region is positioned
between the open end region and the closed end region and positioned to face
opposite the outer front wall region.
[0067] The fzn member 22 is preferably formed of a plastic material and is
connected to the outer front and back walls and extending substantially the
entire
lateral extent of and along the outer front and back wall regions of the
multiwall bag
20. The fin member 22 includes at least a pair of spaced-apart elongate fin
strips
positioned to face opposite each other.
[0068] The zipper track 24 is connected to each of the pair of elongate fin
strips of
the fin member 22. The zipper track 24 preferably includes a first track strip
and a
16
CA 02509057 2005-06-02
second track strip, which are adaptable to be positioned between an open
position
defined by the first and second track strips being spaced apart to allow
access to inner
portions of the bag 20 and a sealingly closed position defined by the first
and second
track strips abuttingly contacting each other to prevent ready access to the
inner
portions of the bag 20.
[0069] The zipper block 34 is slidably connected to the zipper track 24 to
allow the
zipper block 34 to slidably move along the zipper track 24 and move the first
and
second track strips between the open position and the closed position. The fin
member 22, the zipper track 24, and the zipper block 34 define a slider zipper
and fin
combination.
[0070] The plurality of gussets 25 is advantageously formed between the outer
front wall region and the outer back wall region. At least a first one of the
plurality of
gussets 25 is formed in a first region between the outer front and back wall
regions so
as to define a first outer side wall region. At least a second one of the
plurality of
gussets 25 is formed in a second region between the outer front and back wall
regions
so as to define a second outer side wall region positioned opposite the first
outer side
wall region. The multiwall bag 20 further includes an adhesive material
positioned
adjacent the plurality of gussets 25 to thereby define a plurality of sealed
gussets 25.
The sealed gussets 25 increase drop and abuse resistance of the bag 20, reduce
the risk
of access to contents of a bag 20 by a pest, and reduce sifting of filling
material when
positioned in the bag 20.
[0071 ) The external reinforcement 53 is advantageously positioned to overlie
each
of the plurality of sealed gussets 25. The external reinforcement 53 extends
past each
of the sealed gussets 25 to cover regions of the front and back wall regions
adjacent to
each of the sealed gussets 25 to thereby enhance the strength and stiffness of
each of
the sealed gussets 25 and further reduce the risk of access to contents of the
bag 20 by
a pest.
[0072] Another embodiment of a multiwall bag 20 having reinforced gussets 25
is
also advantageously provided. In this embodiment, the multiwall bag 20
includes an
inner tube 37, an outer tube 35, a plurality of gussets 25 that become sealed
through
the application of an adhesive material, and an external reinforcement 53. As
in all
17
CA 02509057 2005-06-02
embodiments containing the plurality of sealed gussets 25, the sealed gussets
2~
increase the drop and abuse resistance of the bag 20, reduce the risk of
access to
contents of a bag 20 by a pest, and reduce shifting of filling material when
the
material is positioned in the multiwall bag 20.
[0073] In all embodiments of the present invention, the plurality of gussets
25 can
be formed so that there is at least one less one ply of material 57 in at
least the first
and second outer side walls than in the outer and inner front wall regions,
33, 34, as
shown in FIG. 16. It is advantageous to remove at least one ply of material 57
when
forming the sealed gussets 25, as described herein, so that the adhesive 49
used to
form the gussets 25 can be melted sufficiently. Additional plies or layers can
be
removed, if necessary to sufficiently melt the adhesive 49. Inner or middle
plies are
preferably removed, when plies are required to be removed. When the bag 20 is
formed with the plurality of gussets 25, the gussets 25 increase the number of
plies
that the heat has to pass through. For example, with a three ply bag, when
gussets 25
are formed, the three plies become twelve plies within the cross-section of
the gusset.
Removable of one ply would reduce the number of total plies in the cross-
section of
the gusset to eight plies, instead of twelve.
(0074] As shown in FIGS. 1-21, in addition to the multiwall bottom fillable
bags
20, the present invention also advantageously provides a method of forming a
multiwall bag 20 having a zipper associated therewith. The method 60 of
forming the
multiwall bag 20 includes laminating a plurality of layers 41, 42, 46, 47, 48
of
material (block 61) (see FIGS. 3-4 and 14). Complete lamination can be used in
the
bag seal zone, as shown in FIG. 21, and as understood by those of ordinary
skill in the
art. Continuous lamination or the combination of complete and continuous
lamination
can also be used in the bag seal zone. The plurality of layers 41, 42, 46, 47,
48
preferably includes at least one layer 41 of polymeric material and at least
one layer
46 of paper material. Once the layers 41, 42, 46, 47, 48 of material are
laminated, the
layers 41, 42, 46, 47, 48 are formed into a tube body 40 (block 62). The at
least one
layer 41 of the polymeric material defines an inner surface of the tube body
40 and the
at least one layer 46 of paper material defines an outer surface of the tube
body 40.
The tube body 40 has a front wall and a back wall positioned to face opposite
the
18
CA 02509057 2005-06-02
front wall. An end portion of the inner surface of the front wall is sealed to
an
opposite facing end portion of the inner surface of the back wall to thereby
define a
bag seal zone 21 (block 63). A combination of a fin member 22, a zipper track
24
connected to the fin member 22, and a zipper block 34 connected to the zipper
track
24 is connected to the bag seal zone 21 (block 64). The finished or end
product
packaging can then be sent to a customer for bottom filling and bottom sealing
(block
65) or such filling and sealing of the bag 20 can be performed on site if
desired.
(0075] The method of forming the multiwall bag 20, for example, can be altered
by supplying layers of materials that are already laminated. If the materials
are
already laminated, then the tube body 40 can be formed without having to
laminate
the materials.
[0076] In addition to the steps described, the method of forming can include
applying an adhesive material 49 in regions of the tube body 40 between
peripheral
side edges of the front and back walls to form a plurality of gussets 25 in
the tube
body 40 extending between the front wall and the back wall to thereby define a
pair of
gusseted side walls. Heat can then be applied to at least one of the
respective end
portions 31, 32 of the front and back walls of the tube body 40 and
positioning the
inner surfaces of the respective end portions of the front and back walls to
abuttingly
contact each other so that the inner surfaces of the front and back walls
adhere to each
other and form a seal therebetween. The adhesive material 49 on outer surfaces
of
end portions of the pair of gusseted side walls is reactivated when heat is
applied to at
least one of the respective end portions of the front and back walls and
holding the
gusseted side walls to also form a seal in the gusseted side walls so that the
sealed
gusseted side walls can further define a portion of the bag seal zone 21 if
desired. For
example, as will be understood by those skilled in the art, the adhesive
material can be
applied to an outer surface of the tube body 40 and allowed to dry. The
adhesive
material can be reactivated during application of a heat seal such as in a
bottomer or
bottom forning machine as understood by those skilled in the art. End portions
of the
gussets 25 can then be sealed by use of the reactivated adhesive as the
gussets 25 pass
through a nip or nip region of a machine, which applies contact pressure on
the end
portions of the gussets 25.
19
CA 02509057 2005-06-02
(0077) The sealed end portion of the tube body 40 preferably includes a first
end
portion and a second end portion. The tube body 40 is preferably filled with a
filling
material F through the second end portion when the first end portion is sealed
so that
the bag seal zone 21 operates as a stop to flow of filling material into the
tube body 40
or as a constructive bottom (see FIG. 8). This, for example, can
advantageously
prevent contact of the filling material F within the tube body 40 with the
zipper track
24 and zipper block 34. The second end portion is then closed after the tube
body 40
is filled with a desired quantity of filling material F (see FIG. 9). '~
[0078] Embodiments of the present invention also provide an additional methods
of using or additional steps to the forming methods described herein. The
zipper
block 34, for example, can be positioned in an open position. The zipper track
24 is
then separated to provide access to inner portions of the tube body 40. Also,
separation of a fin seal zone can be performed by separating the fin strips
28, 29 along
a score line 50 such as formed with a laser or other device as understood by
those
skilled in the art. The inner surface of the front wall is then pealingly
separated from
the inner surface of the back wall in the bag seal zone 21 without causing any
damage
to the inner surfaces in the bag seal zone 21 (see FIGS. 10-13). This also
provides
direct access to the contents of the tube body 40.
[0079] For example, a method of using a bag 20 can advantageously include
filling
a bag 20 with product through a first end of the bag 20 and stopping the
product from
reaching a second end of the bag 20 by a bag seal zone 21 positioned adjacent
the
second end. The second end has at least a combination of a zipper track 24 and
a
zipper block 34 positioned on the zipper track 24, and more preferably a fin
member
22 connected to the zipper track 24 as well, connected to the second end so
that the
bag seal zone 21 operates as a constructive bottom to thereby enhance
protection of
the combination of the zipper track 24 and the zipper block 34 during filling.
[0080] A method of using a bag 20 can also include moving a zipper block 34
positioned on a zipper track 24 to a zipper block 34 open position. The zipper
track
24 is connected to a fin member 22, and the fin member 22 is connected to a
sealed
end of a bag 20 defining a bag seal zone 21. The fin member 22 has a fin seal
zone
positioned between the zipper track 24 and the bag seal zone 21. The method
can
CA 02509057 2005-06-02
further include separating the zipper track 24 to a zipper track 24 open
position,
separating the fin seal zone along a score line formed therein to provide
access to the
bag seal zone 21, and separating the bag seal zone 21 to thereby provide
access to
contents of the bag 20.
(0081] The combination of the fin member 22, the zipper track 24, and the
zipper
block 34 can be connected to the bag seal zone 21 by several methods. If the
outer
surfaces of the tube body 40 contain a polymeric material, then the
combination of the
fin member 22, the zipper track 24, and the zipper block 34 can be connected
by
forming a heat seal between the fin member 22 and the outer surfaces of the
tube body
40. Other methods of connecting the combination of the fin member 22, the
zipper
track 24, and the zipper block 34 can include at least one of the following:
applying
an adhesive material between inner surfaces of the fin member 22 and outer
surfaces
of the tube body 40 in the bag seal zone 21, adhering the fin member 22 to the
tube
body 40 between the at least one polymeric layer 41 and the at least one paper
layer
46, and adhering the fin member 22 to inner surfaces of the tube body 40.
Other
methods for connected the combination to the bag seal zone 21 will be known of
ordinary skill in the art and are to be considered within the scope of the
present
invention.
[0082] Several advantages exist with the present invention. As a first
advantage of
the present invention, the bag seal zone 21 of the multiwall bag 20 provides
users with
an indicator to determine if the bag 20 has already been open. This indication
alerts
consumers of possible tampering of with the bag 20. The bag seal zone 21 also
protects the zipper combination that is used to seal the multiwall bag 20.
[0083] As another advantage of the present invention, the multiwall bag 20 is
constructed in such a manner to prevent insects from being able to access the
contents
within the bag 20. The bag seal zone 21 and the adhesively secured gussets 25
provide additional protection so that insects will not be able to gain access
to the
interior of the bag 20.
[0084) From the foregoing it will be seen that the invention is well adapted
to
attain all of the ends and objects hereinabove set forth, together with other
advantages
that are obvious and that are inherent to the method and product. It will be
21
CA 02509057 2005-06-02
understood that certain features and sub-combinations are of utility and may
be
employed without reference to other features and sub-combinations. This is
contemplated by and is within the scope of the claims.
[0085] Because many possible embodiments may be made of the invention
without departing from the scope thereof, it is to be understood that all
matter herein
set forth or shown in the accompanying specification is to be interpreted as
illustrative
and not in a limiting sense. It should be apparent to those skilled in the art
that the
invention is susceptible to various changes without departing from the scope
of the
invention.
[0086] For example, various types of substrates with or without coatings can
be
used to form the tube body of the multiplayer bag. Suitable substrates and
coatings
will be known to one skilled in the art. The use of the bottom finable
multiplayer bag
with zipper combination can be used for many types of consumer end products,
such
as candy wrappers, food items, or any type of packaging that needs a strong
bag with
easy access to the contents of the bags.
22
