Note: Descriptions are shown in the official language in which they were submitted.
,
FLAT FOLDED BOTTOM SELF OPENING STYLE BAG AND METHOD OF MANUFACTURE
Priority Claim
This application claims priority to co-pending US provisional patent
application
62/405,396, filed on October 7, 2016.
Field of Disclosure
A new gusseted self-opening style bag with a unique bottom construction is
disclosed,
the bag manufactured via a new manufacturing process.
Background
The statements in this section merely provide background information related
to the
disclosure and do not necessarily all constitute prior art.
The prior art includes a bag known as an SOS bag. Opinions differ on what SOS
abbreviates, though it is commonly considered an abbreviation of Self Opening
Style. Other
interpretations of SOS include Self Opening Sack, Self Opening Square, and
Self Opening Satchel.
Regardless, an SOS bag as described herein is generally understood to be a
gusseted bag
including front and back panels joined by gussets, where the bag may be opened
from a flat
folded orientation to reveal a substantially flat rectangular bottom. When the
bag is opened,
the gussets may be unfolded and serve as side walls that, in conjunction with
the front and back
panels of the bag, as well as the rectangular bottom, define the general
structure of the bag. A
ubiquitous SOS bag of the prior art might include, by way of illustrative
example, a simple
single-layer brown paper lunch sack.
In the packaging industry, it is common for the top of the SOS bag to be
filled with
consumer goods, followed by the closure of the top of the bag to contain the
goods. This
closure can be done in a variety of manners, including applying adhesive or
other seal to the
top of the bag and rolling the bag closed to complete a top seal of the bag.
In other applications,
a reclosure apparatus, such as a resealable zipper profile with complementary
interlocking
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CA 2981792 2017-10-06
features or a hook and loop type reclosure mechanism, for example, may be
mounted atop the
bag. In other applications, a heat or ultrasonic seal could be applied across
the top of the bag.
Rectangular bottom, gusseted bags made substantially of plastic material exist
in the art,
though those bags are substantially distinct from the bags of this disclosure,
specifically in that
they are not traditional SOS bags. For example, some rectangular bottom
gusseted bags of the
prior art, such as those manufactured on box pouch machines, are not made from
a gusseted
tube. Rather, they are from one or more webs of material that are folded and
sealed together
into the general shape of a bag. These prior art bags are folded, heat sealed,
and then trimmed
to give flush edges around the folds and seams of the gussets, side walls, and
bottoms, creating
substantial waste. One of skill in the art will appreciate the numerous
distinctions between a
patch-style bag and a bag that will be disclosed herein.
Summary
This section provides a general summary of the disclosure, and is not intended
to
provide a comprehensive disclosure of its full scope or all of its features.
This disclosure includes method of manufacturing a new SOS bag including, as a
preliminary step, providing a gusseted tube of indefinite length. In a series
of steps, the
gusseted tube may be cut, trimmed, folded, and sealed to create a unique
bottom for an SOS
bag. The bottoms of the front panel and the rear panel may be cut so as to
permit the inward
folding of the bottoms of the gussets of the gusseted tube, such that the
bottoms of the gussets
overlap. A front panel of the gusseted tube may then undergo a trimming and
folding and heat
sealing, followed by the rear panel of the gusseted tube undergoing a trimming
and folding and
heat sealing. Other sealing mechanisms and a variety of bag material
constructions are
disclosed.
The disclosure additionally includes bags manufactured by the method disclosed
herein,
as well as SOS bags having the unique construction disclosed herein.
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Brief Description of the Figures
The drawings described herein are for illustrative purposes only of selected
embodiments and not all possible implementations, and are not intended to
limit the scope of
the present disclosure.
Figure 1, which shows prior art, is a perspective view of a conventional SOS
bag, this
bag open and resting upright on its bottom.
Figure 2, which also shows prior art, is a view of the conventional SOS bag of
Figure 1,
this particular view showing the bag folded and laying down, with the bottom
of the bag visible.
Figure 3 shows an embodiment of the creation of the gusseted tube of material
into
which a bag of the disclosure will be made, this figure showing an embodiment
of sealing of the
overlap of the bag panel.
Figure 4 shows an embodiment of a gusseted tube of material of an indefinite
length.
Figure 5 shows an embodiment of a die cut layout of an unfolded bag of the
disclosure,
this layout showing a step cut top.
Figure 6 shows an embodiment of a die cut layout of an unfolded bag of the
disclosure,
this layout showing a Z cut top.
Figure 7A shows a view of the gusseted tube of Figure 4, including details of
cut lines
and fold lines on the front panel at the bottom end of the tube, in a step of
an embodiment of
the bag manufacturing process.
Figure 78 shows an alternate view of the gusseted tube of Figure 7A, including
details of
cut lines and fold lines on the rear panel at the bottom end of the tube, in a
step of an
embodiment of the bag manufacturing process.
Figure 8 shows the gusseted tube of Figures 7A and 7B, viewed from the bottom,
including details of inward folding of the gussets, in a step of an embodiment
of the bag
manufacturing process, where the gusseted tube is substantially flat.
Figure 9 shows the configuration and presentation of the gusseted tube of
Figure 8 in a
T shape to a sealing apparatus, including details a first sealing region, in a
step of an
embodiment of the bag manufacturing process.
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_
..
Figure 10 shows the trimmed and folded front bottom flap of the gusseted tube
of
Figure 9, including details of two additional regions of sealing, in a step of
an embodiment of
the bag manufacturing process.
Figure 11 shows the trimmed and folded rear bottom flap of the gusseted tube
of Figure
10, including details of additional heat sealing, in a step of an embodiment
of the bag
manufacturing process, this final step completing the assembly of the gusseted
tube into a bag
of the disclosure.
Figure 12 shows an embodiment of a series of completed bags of the disclosure
as
displayed on retail shelving for viewing by consumers.
Corresponding reference numerals indicate corresponding parts throughout the
several
views of the drawings.
Detailed Description
The following description of various embodiments is merely exemplary in nature
and is
in no way intended to limit the invention, its application, or its uses. Areas
of applicability will
become apparent from the description provided herein.
A new SOS bag with a unique bottom closure, as well as a method of making the
same,
is disclosed. A typical SOS bag 100, as seen in Figure 1, includes a front
panel 102, a back panel
104, and two gusseted side panels 106 joining the front and back panels, to
create a tube
having an inside and an outside. A length of tube may be folded and sealed at
one end to create
a bottom 108, thereby forming an SOS bag. The unfolded, open end of the tube
may be
referred to as the top 110 of the bag or the open end of the bag. The SOS bag
of Figure 1 is
unfolded and opened upright, while the SOS bag of Figure 2 is folded
substantially flat. A bag of
the disclosure will resemble the prior art SOS bag of Figures 1 and 2, with
the distinction that
the bottom of the bag of the disclosure includes a unique construction
manufactured via a
unique method, as will now be explained.
A bag of the disclosure may be constructed from a gusseted tube of material of
indefinite length.
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The tube, and hence the bag, may be constructed of a variety of materials,
including but
not limited to a multi-layer construction. A multi-layer construction, for
example, may include
plastic film on the inner-most layer on the inside of the bag. Other layers
may include printed
paper, such as printed clay coated paper, one or more additional film layers,
including an
exterior film layer, a kraft paper layer, and a variety of other layers of
material. Various other
layers known to those of skill in the art of construction of multi-layered
bags may be
implemented to make a bag as disclosed herein.
Where the multi-layer construction includes an inner plastic film layer and a
middle
paper layer, those layers may be adhered together via a hot melt adhesive.
Where the multi-
layer construction includes an outer plastic film layer and a middle paper
layer, those layers
may also be adhered together via a hot melt adhesive. Where the SOS bag is
multi-layered, the
layers may themselves be adhered together in a variety of manners, including a
flood coat of
hot melt adhesive between the layers.
In an embodiment, a film layer may be adhered to any adjacent layer via
laminating the
film to said layer. For example, an inner plastic film layer may be laminated
to a middle clay
coated paper layer, and an outer film layer may be laminated to said middle
clay coated paper
layer.
The tube may, in an embodiment, be a single layer of plastic material, or
alternatively a
web of multi-layered plastic may be laminated together to form an effectively
single ply such
that the individual layers are not distinguishable or separately manipulable.
This is distinct from
the, for example, multi-layered construction that includes an inner plastic
film layer, a middle
kraft paper layer, and an outer printed clay coated paper layer, where each of
those layers is
still recognizable and distinct, and might be at least partially independently
manipulated via bag
manufacturing machinery.
In an embodiment of an effectively single ply plastic laminate, an inner layer
of woven
oriented polypropylene may be laminated to an outer layer of reverse printed
oriented
polypropylene to make an effectively single layer web of material. Reverse-
printed is
understood to mean a substantially transparent or translucent plastic film
that has been printed
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with backwards text and/or imagery that is visible through the plastic film
such that the text
and/or imagery is legible, i.e. not backwards, when viewed from the side of
the film opposite
from where it has been printed. Alternatively, an inner non-woven plastic film
layer and an
outer reverse printed plastic layer may be laminated together to form an
effectively single layer
web of material. Additionally, a single ply of plastic film may be used to
make a bag as disclosed
herein. Where heat seals are used, as opposed to seals effected via glue or
hot melt adhesive,
a plastic-to-plastic bond may be used, where one plastic film or layer would
be bonded to an
adjacent plastic film or layer.
These non-limiting examples and others are fully embraced by the scope of this
disclosure as the construction material into which a bag of the disclosure is
made by the
methods disclosed herein.
The gusseted tube of indefinite length into which a bag of the disclosure may
be made
can be created in a variety of ways. In an embodiment, a substantially
continuous sheet of
material having a consistent width and an indefinite length may be fed along a
machine and by
its length and manipulated and folded onto itself across its width to create
an overlap of
material. At the overlap, the material may be sealed to itself to create a
tube of material. This
folding may include folding to create gussets that run the length of the
material to create the
gusseted tube, where the folding of the gussets may happen before, after, or
in substantial
synchronization with the sealing of the material.
Where the sheet of material is fed along a machine, the material may be fed,
for
example, from a spool of material, or from an apparatus that creates plastic
sheeting from raw
plastic materials such as pellets. Or, in another embodiment, the material may
be fed from a
series of spools and laminated together to turn a multi-layer construction
into an effectively
single layer construction.
Figure 3 shows an example of a method of creating a gusseted tube 200.
Specifically,
Figure 3 shows a portion of material that has been folded to create gussets
202 as well as a
heat sealing apparatus 300 operating on a machine where the tube is moving in
a first direction
302 relative to the stationary heat sealing apparatus. In this embodiment, the
seal is being
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created by selective application of hot air via a nozzle 304 onto an inner
edge 204 of the
material as the tube 200 moves in the first direction 302. As the tube
continues along the
machine in the first direction, the now at least slightly molten plastic
material that comprises
the inner edge 204 of the material is pressed against a corresponding outer
edge of material
206 to provide compression and thereby adhere the two edges together and
create an overlap
208, which may be referred to as a side seam. The pressing may be effected by,
for example, a
roller 306 in close proximity to a hot air nozzle. The tube may be manipulated
in this method via
various subsequent rollers 308 known in the art of bag manufacturing. In this
way, the tube 200
may be completed, and the side seam 208 runs the length of the tube and is
substantially
parallel to the folds that define the front and back panels and the gussets.
It should be noted
that the selective hot air is applied in this embodiment to the inner edge of
the overlapping
material and not to the outer edge of material being overlapped, as the outer
edge in this
example is adjacent to the flat folded gussets. If the hot air was to be
applied to the outer edge,
being adjacent to the flat folded gussets, then, depending on various factors
including the
construction of the material and the geometry of the gussets relative to the
side seam, the
manufacturer runs the risk of undesirably heat sealing the gussets, resulting
in a non-functional
gusset and bag.
In an alternative embodiment, the material may be cut into planar segments of
material
of substantially equal lengths and then folded and sealed along an overlap to
create side seams
as individual tube portions, as opposed to being sealed along an overlap in a
sheet of indefinite
length which is then separated into individual tube segments.
Figure 4 shows an embodiment of a gusseted tube 200 of indefinite length that
may be
used to create a bag of the disclosure, this figure including detail of an
embodiment of a side
seam 208, including a side seam created via the aforementioned selectively
applied hot air
sealing method.
Although hot air sealing has been described, other sealing mechanisms may be
used at
various points of the manufacture of the bag of the disclosure. For example,
ultrasonic sealing,
also known as ultrasonic welding, is a method of applying high-frequency
ultrasonic acoustic
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,.
vibrations to a substrate to create a solid-state weld between two surfaces.
This can be done
selectively via an ultrasonic horn in combination with an anvil and wheel as
the substrate
moves in a lateral direction past the ultrasonic welding station. In another
embodiment, a
conventional heat bar may be used in some instances. A heat bar may be a
heated element,
often in the shape of a linear mass, such as a bar, to apply heat directly to
a surface, thereby
causing a brief molten state to a plastic material. In either instance,
pressure in the form of, for
example, a rolling mechanism could be used to press two surfaces together when
one or more
has received a sealing application to provide a snug seal between the
surfaces. In another
embodiment, a hot melt adhesive may be used to seal two surfaces, where a hot
melt is an
adhesive applied between surfaces that may then be pressed together. These and
other
mechanisms known in the art for sealing two surfaces of material are embraced
by this
disclosure.
Bags of the disclosure are manufactured in part via a new bottom closure
process that
will be described hereinafter. However, the top of the bag may vary based upon
the desires of
the bag customer. The bag customer may be a dog food manufacturer, for
example, who might
want the top of the bag in one type of configuration or another. A flush cut
bag is understood
to mean a bag where the upper edges of the bag are substantially flush. In a
flush cut bag,
where the SOS bag is open and resting with the bottom of the bag on a
horizontal surface, the
upper edges of the bag generally define a horizontal plane parallel to the
bottom of the bag. A
step cut bag, by comparison, includes a first panel of a first height, gussets
of a second height
slightly shorter than the first panel height, and a second panel of a third
height, slightly shorter
than the gusset height. A Z cut bag, includes a first panel of a first height
and a second panel of
a second height, where the transition between the two panels along the gussets
is a single
diagonal cut that, when the tube and gussets are folded flat, resembles a Z or
backwards Z,
depending on which gusset is being viewed. Flush cut, step cut, and Z cut are
all known terms to
those of ordinary skill in the art with respect to gusseted bags. These and
other tops, including
those suitable for accepting various closure and reclosure apparatuses, are
all embraced by this
disclosure.
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_
The gusseted tube of Figure 4 includes a front panel 210 and a back panel 212,
joined by
two gussets 214, the tube having an interior cavity 216. Although in this
figure a front and back
have been assigned such that the seam is on the back panel, this disclosure is
not intended to
be so limiting.
Figure 5 shows a step cut die cut pattern suitable for use in manufacturing a
bag of the
disclosure, and Figure 6 shows a Z cut pattern suitable for use in
manufacturing a bag of the
disclosure. Where die cutting of the top of the bag is desirable, in an
embodiment the die
cutting of the material occurs before the folding and sealing of the material
into the gusseted
tube of indefinite length. In this way, where a step cut or Z cut is to be on
the final product bags,
the gusseted tube of indefinite length will include a series of equally spaced
apart die cuts
corresponding to the unfolded die cut patterns of Figures 5 and 6.
Alternatively, the die cutting
of the tops of the bags may occur after each gusseted tube is cut into
individual segments. In
another embodiment, the die cutting may occur before the creation of the
gusseted tube, at
intermittent distances on a continuous length of material. In yet another
embodiment, the die
cutting may occur before the creation of a gusseted tube on individual panels
of material that
may then be formed into gusseted tubes.
It should be understood that die cutting of the patterns seen in Figures 5 and
6 is not
intended to be limited strictly to literally die cutting of the material.
Indeed, all cutting or other
mechanisms for separation of the grayed areas shown in Figures 5 and 6, and
cutting to
produce other tops of bags, are embraced by this disclosure. Further, the
dimensions and ratios
seen in Figures 5 and 6 are not meant to be so limiting, as these figures are
embodiments
intended to show various configurations of the top of the bag. A bag of the
disclosure may have
any suitable width, length, height, etc. and still be embraced by the claims.
Specifically, in Figures 5 and 6, an area of material 400 into which a bag of
the disclosure
will be formed may receive one or more cuts to create a section of material to
be removed 404
to generate the specific respective cut of the top of the eventual SOS bag.
These figures
additionally show fold lines that will eventually define the future front
panel 404, the future
back panel 406, and future gussets 408 of the bag. A region of future
overlapping section 410 is
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,
_
also present, as seen in Figure 3, which will include a portion of overlapping
that results in the
side seam that will define the gusseted tube of the disclosure. A future
bottom fold line 412
that defines portions of the material that will eventually make the bottom of
the bag runs the
width of the area of material 400 is also shown in Figures 5 and 6.
Gusseted tubes as described herein include a bottom end that undergoes
manipulations
and sealings to create the bag of the disclosure, where the top end of the
tube is the location
that the cut pattern of Figures 5 or 6, when applicable, would reside. The
bags may be cut into
segments of gusseted tubes which will then be manipulated and sealed to create
the SOS bag of
the disclosure. Where a flush cut is desired, cutting of the tube of
indefinite length into
individual segments will create the flush top of the bag.
An exemplary method of manufacturing a bag of the disclosure will now be
described.
In a preliminary step, a section of gusseted material as previously described
herein is provided.
Turning further to the figures, Figures 7A and 7B show an exemplary cut
pattern for the
bottom of the segment of gusseted tube 200. In a first step, the bottom 218 of
the gusseted
tube may be die cut according to the pattern seen in Figures 7A and 7B, where
Figure 7A shows
a view of the front of the gusseted tube and Figure 7B shows a view of the
rear of the gusseted
tube.
Figure 7A, more specifically, shows the outer surface of the bottom of the
panel of the
gusseted tube that will become the front panel of the bag of the disclosure.
In this embodiment,
two parallel front flap cuts 220 of equal length 228 are made on the bottom
edge 222 of the
panel, equidistant from the outer edges 224 of the front panel, near the
center of the width of
the panel. Figure 7A also shows, by way of hashed lines, a front flap fold
line 226. This front flap
fold line 226 will be the fold about which a front flap is folded inwardly
towards the center of
the bottom of the gusseted tube as a part of the creation of the bottom of the
bag in future
steps.
Figure 7B is a view of the gusseted tube 220 of Figure 7A, but showing the
outer surface
of the bottom of the panel of the tube that will become the rear panel of the
bag of the
disclosure. In this embodiment, two parallel rear flap cuts 232 of equal
length 234 are made on
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the bottom edge of the panel 236 near the outer edges 238 of the bottom of the
panel,
equidistant from the outer edges of the back panel. Figure 7B also shows, by
way of hashed
lines, a rear flap fold line 240. This rear flap fold line will be the fold
about which the rear flap is
folded inwardly toward the center of the bag, after the front flap has been
folded inwardly, to
complete the bottom of the bag. These rear flap cuts 232 run from the bottom
edge 236 of the
tube towards, but do not meet, in this embodiment, the rear flap fold line
240. Thus the
distance 242 of the rear flap fold line 240 from the bottom edge of the panel
236 is slightly
greater than the length 234 of the rear flap cuts 232. The rear flap cuts seen
in Figure 7B, create
the structure of the flat bottom display 230 and, together with the rear flap
fold line and the
bottom edge of the rear panel of the tube, define the outer edges of the flat
bottom display
230. The rear flap fold line 240 may be the same distance from the bottom edge
236 of the rear
panel as the front flap fold line 226 is from the bottom edge 222 of the front
panel.
It should be noted that where the terms "front" and "rear" are used herein,
these need
not necessarily be the literal front or back of the bag. These terms are
merely being used herein
to aid in describing the various steps of making the bag of the disclosure.
Figure 8 shows the gusseted tube 200 of Figures 7A and 7B, including details
of a second
step in the manufacturing process, as viewed from the bottom of the tube, this
step including
the inward folding of the gussets 214 along gusset bottom fold lines 242 to
create inwardly
folded gussets 280 on the bottom of the tube. This second step where the
gussets are inwardly
folded towards each other into the interior of the tube leaves two portions of
the bottom of the
tube unfolded. The two parallel front flap cuts of equal length on the bottom
edge of the panel
define a front flap trim region 244 that remains unfolded in this step, and
the two parallel rear
flap cuts of equal length near the outer edges of the bottom of the panel
define the flat bottom
display 230 that also remains unfolded in this step. The gusset bottom fold
lines are the same
distance from the bottom edge of the gussets as the panel fold lines are from
the bottoms of
their respective panels.
As can be seen in Figure 8, the bottom edges of the inwardly folded gussets at
least
partially overlap to create a gusset overlap region 246. This gusset overlap
region, the benefits
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of which will be explained hereinafter, is achieved as a result of the front
flap fold line 226,
designated by hashed lines in Figure 8, being located at a distance 248 from
the bottom edge of
the gusseted tube that is slightly greater than half the distance 250 across
the front panel of the
gusseted tube.
The two parallel front flap cuts of equal length on the bottom edge of the
panel enable
the inward folding of the gussets to create the gusset overlap region 246.
Without the front flap
cuts, the overlap region would, at its tip, create a challenge in folding of
the material or perhaps
a difficult physical configuration to overcome. These cuts allow the easy
inward folding by
eliminating any gusset overlap at the edge of the flap, were the front flat
trim region 244
resides.
As a result of the gusset folding as seen in Figure 8, a front flap 252 and a
rear flap 254
are defined. Thus, the front flap 252 is the portion of the folded gussets and
front panel beyond
the front flap fold line 226 away from the interior of the bag. The rear flap
254 is the flat
bottom display 230 and two small regions of folded rear panel 258 of the
gusseted tube beyond
the rear flap fold line 240, designated by hashed lines in Figure 8, away from
the interior of the
bag. The gussets are inwardly folded in Figure 8 along gusset bottom fold
lines 242. The two
flap fold lines 240, 226 and the two gusset bottom fold lines 242 together
define the
circumference and shape of the rectangular bottom of the SOS bag of the
disclosure. Additional
measurements show in Figure 8 will be discussed hereinafter.
After the folding step of Figure 8, a third step is seen in Figure 9, where
the gusseted
tube 200 is presented to a sealing apparatus in a T shape in a sealing
direction 274. In this way,
in an embodiment, the bottom 218 of the SOS bag, the front flap 252, and the
rear flap 254, are
substantially parallel and horizontal and represent the top of a capital T,
while the remainder of
the folded gusseted tube that represents a large portion of the body of the
bag of the
disclosure makes up the vertical portion of the T, where the tube is inverted
with the bottom
up and the top edge of the bag 276 aimed downwardly. In an embodiment, the
steps of the
manufacturing process, including the formation of the gusseted tube, take
place in a first
direction, where the tube moves down a manufacturing line bottom first, where
the bottom is
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the bottom of the eventual SOS bag. At some point, including in an embodiment
after the
folding as seen in Figure 8, the gusseted tube is manipulated by machinery
into the T shape and
rotated ninety degrees. In this way, the gusseted tube is now approaching the
sealing
apparatus gusset-first in a sealing direction 274, as indicated in Figure 9.
Figure 9 shows the configuration and presentation of the gusseted tube of
Figure 8 in a
T shape to a sealing apparatus, including details of a first sealing region
278, designated by a
hash-lined area. In a fourth step of an embodiment of the bag manufacturing
process, the front
flap trim region is at least partially removed from the tube, via cutting
along the front flap trim
line 256, for example, giving the front flap a substantially isosceles
trapezoid shape. In cutting
off the front flap trim region 244, as seen in Figure 8, the length 264 of the
front flap 252 is
made at least slightly shorter than the length 260 of the bag, which is the
length between the
front flap fold line 226 and the rear flap fold line 240. In this way, when
the front flap 252 is
folded inwardly and sealed into the bottom of the SOS bag, the front flap trim
region 244 is
removed and the length 264 of the front flap has been shortened to accommodate
the length
260 of the bottom of the bag.
In an alternate embodiment of the fourth step, the front flap trim region 244
may be
folded about the front flap trim line 256 onto the gusset overlap region 246
to create a front
flap 252 that is at least slightly shorter than the length 260 of the bag. In
this way, the fourth
step of this embodiment of the disclosed method may be to bring the front flap
down to a
length 264 that is at least partially shorter than the length of the gussets
and thus the length of
the bag, so as to enable a folding of the flap in a manner similar to that
when the front flap trim
region is removed.
Figure 9 additionally shows a first heat seal region 278 of the bottom 218 of
SOS bag,
the first heat seal region 278 being on the front flap 252, parallel to and in
proximity to the
front flap fold line 226. The first heat seal region may optionally abut the
front flap fold line. In
a fifth step, a heat seal may be applied to the first heat seal region 278 via
the previously-
described hot air mechanism, for example, where the bag, in a T shape, is
being moved gusset-
first in the sealing direction 274, down a machine line and a stationary hot
air nozzle applies
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selective hot air to a portion of the front flap 252 in the first heat seal
region 278 in conjunction
with a folding of the front flap 252 about the front flap fold line 226, and a
roller or other
compression mechanism applies pressure to the outside of the folded front flap
to adhere the
now at least partially molten plastic of the front flap to the inwardly folded
gussets 280 to
complete a front flap seal. In an alternate embodiment, the first heat seal
region may run along
the front flap fold line, effectively applying heat to both the front flap and
the inwardly folded
gussets to effect the seal. In another embodiment, the heat seal may only be
applied to the
inwardly folded gussets onto which the front flap is folded. The results of
this fifth step is the
configuration of the gusseted tube seen in Figure 10.
Figure 9 and the first heat seal region 278 demonstrate the importance of the
previously-discussed gusset overlap region 246. This gusset overlap region is
unique in the art
with respect to plastic bag constructions and at least partially enables the
SOS bag of the
disclosure to be made by the method disclosed herein. If the gusset overlap
region was not
present in the bags of the disclosure, the heat seal method disclosed herein
would not result in
a functional bag. As detailed in an embodiment herein, the heat seal is
applied across the width
of the front flap, which is then folded along the front flap fold line. In
this way, the gusset
overlap region folds over onto itself and is sealed to itself. If, instead,
there was no gusset
overlap region such that the two bottom edges of the gussets remained some
distance apart
when inwardly folded to create a gap therebetween, then a heat seal applied
across the width
of the front flap would be applied within that gap to the interior of the
gusseted tube material.
Then, when the front flap is folded inwardly, the portion of the material on
the front flap in that
gap that has received a hot air heating, for example, would fold onto and seal
against a portion
of the interior of the bag. The result of such a heat seal is a non-functional
bag that does not
have a proper SOS opening. That failure is overcome by virtue of having a
gusset overlap region
where the heat seal may be applied so that the front flap may fold inwardly
without sealing
itself to the interior of a panel of the bag.
Figure 10 shows the gusseted tube 200 of Figure 9, still in a T shape at a
sealing
apparatus, when viewed from the end of the tube that will become the bottom of
the bag, the
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front flap 252 having been folded and sealed as previously discussed about the
front flap fold
line in a front flap folding direction 282. Figure 10 further shows a second
heat seal region 284
and a third heat seal region 286, each heat seal region designated by hash-
lined areas in Figure
10, as well as the rear flap fold line 240 and a rear flap trim line 270.1n a
sixth step, the rear flap
is trimmed along the rear flap trim line 270 to remove a rear flap trim region
272, which is the
region of the rear flap 254 beyond the edge of the rear flap trim line and out
to the bottom
edge 236 of the rear flap. Similar to the management of the front flap trim
region 244, the
purpose of this sixth step is to bring the rear flap into a length 262 that
aligns with the length
260 of the bottom of the bag, as seen in Figure 8. The rear flap trim line 270
is parallel to the
rear flap fold line 240 and runs the entire width 266 of the display area 230
of the rear flap 254,
such that cutting along this line will trim off the rear flap trim region 272.
Referring again to
Figure 8, the distance 262 of the rear flap cut line to the rear flap fold
line is up to just below
the distance between the rear flap fold line and the front flap fold line 260,
which is the length
of the final assembled bottom of the bag. In this embodiment the bottom edges
of the trimmed
rear flap may come close to but not quite meet the front flap fold line.
The second heat seal region 284 is a region of heat sealing parallel to and in
the general
vicinity of the rear flap fold line 240, and may be analogous to the first
seal. This second heat
seal region, as seen in Figure 10, may be on the rear flap 254 near the rear
flap fold line 240. In
an alternate embodiment, the second heat seal may run along the rear flap fold
line, effectively
applying heat to both the rear flap and the inwardly folded gussets to effect
the seal. In another
embodiment, the heat seal may only be applied to the inwardly folded gussets
onto which the
rear flap is folded.
The third heat seal region 286 is, in an embodiment, the final region of heat
sealing and
is on the rear flap 254 parallel to and in the general vicinity of the rear
flap trim line 270,
running the length of the bottom edge 236 of the rear flap.
In a seventh step, a second heat seal is applied in the second heat seal
region 284 via
the previously-described hot air mechanism, for example, where the bag is
being moved
gusset-first in the sealing direction 274, down a machine line and a
stationary hot air nozzle
CA 2981792 2017-10-06
applies selective hot air to the second heat seal region 284 in conjunction
with a folding of the
rear flap 254 about the rear flap fold line 240 onto the inwardly, folded
gussets 280, the gusset
overlap region 246, and the previously-folded front flap 252, and a roller or
other compression
mechanism applies pressure to the outside of the folded rear flap to adhere
the now at least
partially molten plastic of the rear flap to the inwardly folded gussets and
front flap.
In an eighth step, a third heat seal is applied in the third heat seal region
286 via the
previously-described hot air mechanism, for example, where the bag is being
moved gusset-
first in the second direction 274, down a machine line and a stationary hot
air nozzle applies
selective hot air to the third heat seal region 286. Here, the rear flap 254
has previously been
partially folded onto the inwardly folded gussets 280 and front flap 252 in
the seventh step, and
a roller or other compression mechanism applies pressure to the rear flap near
the rear flap
trim line 270 to adhere the now at least partially molten plastic of the rear
flap to the inwardly
folded gussets and front flap, thereby completing the construction of a bag of
the disclosure.
Preferably the side seam of the gusseted tube is on the front panel and thus
the front
flap. This permits a clean, uninterrupted surface for display on the bottom of
the bag, whereas
a rear flap with a side seam running down it could create issues with printing
and appearance.
The completed gusseted bag of the disclosure, as seen now from the bottom in
Figure
11, having undergone the previous steps, including the folding of the rear
flap 254 about the
rear flap fold line 240 in a rear flap folding direction 288, may now continue
past the heat
sealing mechanism to be prepared for shipment to a consumer, for example. Bags
of the
disclosure may be filled and stacked on shelving with the bottom flap
outwardly visible towards
consumers, an embodiment of which can be seen in Figure 12.
In an optional step, before the front flap is folded over onto the overlapped
gussets and
sealed thereto, the gusset overlap region may itself be heat sealed, for
example by applying hot
air to the overlapping bottom gusset via a hot air nozzle and compressing it
to the overlapped
bottom gusset via one or more rollers. In this way, in conjunction with the
other seals applied in
subsequent steps, the bottom of the bag may be substantially sealed for
applications where a
siftable material, such as flour, could be introduced into the bag and not
escape around the
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overlapped gussets and out the sides of the bottom of the bag.
An SOS bag of the disclosure manufactured via the foregoing method will now
resemble
the prior art SOS bag of Figures 1 and 2, with the distinction that the bottom
of the bag of the
disclosure includes a unique construction manufactured via a unique method.
In an embodiment of a heat sealing mechanism of the disclosure, each heat
sealing
mechanism includes a nozzle for selectively applying hot air to a portion of
the material and a
subsequent roller to apply pressure to push two portions of material together
to create the
heat seal. In this mechanism, there is a direction which the material travels,
while the heat
sealing mechanism remains stationary, for example as one of a plurality of
stations on a
manufacturing line.
Where hot air heat sealing is used, the heat applied to the substrate will
vary based on
several factors, including the speed of manufacture in bags per minute and the
material being
heat sealed. The pressure required to effectuate the heat seal by pressing the
at least partially
molten material onto another substrate will also be determined by the speed of
manufacture of
the bags, the material being sealed, and the temperature of the hot air. The
specific settings for
the heat, speed, pressure, etc. may be calibrated on an individual basis on
each machine and
will vary from one machine to another, and from one process to another.
Generally, though,
hot air heat sealing stations may operate at a temperature range of 100 to
1,500 degrees
Fahrenheit, although to make bags relatively quickly a higher range of 500 to
1,500 degrees
may be preferred. Specific tolerances will vary by machine and substrate, but
can typically
fluctuate 25 degrees above or below the ideal conditions for bag manufacture
and still make a
quality product, based on a desired bag manufacturing speed. Many modern
machines can
manufacture bags at a rate of 60 to 80 large bags, such as those capable of
holding bulky dog
food, per minute, with higher end machines producing up to 100 per minute. As
the speeds
increase, so will the heat of the hot air and the corresponding pressure of
the rollers. With bags
moving faster down an assembly line, the hot air must be increased to
compensate for the
reduced time of exposure of the substrate to the hot air. The same may be said
for any
compression rollers, which might need additional pressure as bags move faster
past the hot air
17
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_
..
sealing station.
Similarly, where ultrasonic welding takes place as a part of the manufacturing
process,
the desired speed of manufacturing of the bags will govern the vibration
frequency and
pressure between the horn and anvil for each bag. Where an ultrasonic station
must operate
more quickly, the vibration frequency and pressure may be increased.
Additionally, where the
substrate demands, the specific settings of the ultrasonic welding station or
stations.
It will be appreciated by those of skill in the art that the various steps
disclosed herein
may be conducted by machinery in one or more manufacturing machines, and those
machines
may include a variety of tracks, wheels, rollers, and other known bag
manufacturing machine
components, including mechanisms to transfer the bag along the machine from
beginning to
end and between individual stations, such as sealing stations. Indeed, one
could manufacture a
bag of the disclosure at least partially by hand, escorting the gusseted tube
from one station to
another, such as individual sealing machines, or by making the bag of the
disclosure on one or
more manufacturing machines. All possible configurations of bag manufacturing
machines that
could be conceived by one of skill in the art that assemble a bag of the
disclosure or practice
the method of this disclosure are thus embraced by this disclosure, and this
disclosure should
not be limited to a single manufacturing machine with only the stations
described herein.
The embodiment showing the location of the rear flap cuts as near, but not at,
the outer
edges of the back panel, is in part due to the nature of the material from
which the gusseted
tube may be constructed. Plastic film, by its nature, has memory as a
property. By memory, it is
understood that plastic film wants to return to its original planar structure
and doesn't provide
the crisp, clean ninety degree folds that a paper material, for example, might
provide. So where
the gusseted bag is constructed of a substantially plastic material, such as
for example an
effectively single ply constructed by laminating an inner woven oriented
polypropylene layer
with a reverse printed oriented polypropylene film layer, long folds of this
material will not
have totally crisp ninety degree folds that retain their shape at the same
level as a paper bag,
such as the brown paper lunch sack discussed earlier herein. Because plastic
has memory, the
various folds of the gusseted tube and additionally the finished product
gusseted SOS bag of
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the disclosure will not be sharp bends, but rather very subtle curves at the
folds. Even after
folding along a crease, the plastic material will try, even if only slightly
so, to curve back into a
plane. When folding the flat bottom display about the rear flap fold line and
sealing it to
complete the bottom of the bag, having the outer edges of the bottom display
flush with outer
edges of the bottom of the bag might not result in as effective of a seal
because of the memory
of the plastic at those bends of the gussets into the bottom of the bag. The
die cut outer edges
of the flat bottom display in that instance might not adhere to the rest of
the bottom of the bag
while the folded plastic is attempting to return to a planar shape. Instead,
by having the rear
flap cuts near, but not at, the outer edges of the back panel of the tube, the
outer edges of the
bottom display may be tightly sealed against the bottom of the bag, resulting
in a more
complete seal. Ideally, in order to achieve the largest display area possible,
one would like to
have the rear flap cuts align with the folds that separates the bottoms of the
gussets from the
back panel, but plastic memory prevents this level of efficiency.
Thus a method of manufacturing a new flat bottom SOS bag has been disclosed,
including the preliminary step of providing a gusseted tube of indefinite
length. In a first step,
the bottom of the gusseted tube may be cut on the bottom of the front and back
panels to
provide two parallel front flap cuts of equal length, near the center of the
width of the panel,
and two parallel rear flap cuts of equal length near the outer edges of the
panel. In a second
step, the gussets are inwardly folded folded towards each other into the
interior of the tube to
at least partially overlap. In a third step, the gusseted tube is presented to
a sealing apparatus
in a T shape in a sealing direction, the tube having a front flap and a rear
flap. In a fourth step, a
portion of front flap maybe cut off or folded. In a fifth step, a heat seal
may be applied to a first
heat seal region on the front flap in conjunction with an inward folding of
the front flap. In a
sixth step, a portion of the rear flap may be cut off or folded. In a seventh
step, a second heat
seal may be applied to a second heat seal region on the rear flap in
conjunction with an at least
partial inward folding of the rear flap. In an eighth step, a third heat seal
may be applied to a
third heat seal region on the rear flap in conjunction with the completed
inward folding of the
rear flap.
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_
Additionally, a new SOS bag is disclosed. Bags of the disclosure may include a
gusseted
bag having a front and back panel joined by gussets, where the bottom of the
SOS bag includes
a pair of inwardly folded gussets, and inwardly folded front and back flaps to
create a folded
bottom. The bags disclosed herein may have a substantially rectangular flat
bottom rear flap
heat sealed to the inwardly folded front flap and inwardly folded gussets at
the bottom of the
bag. The gussets may overlap beneath the front flap and rear flap. The front
flap and/or rear
flap may be trimmed and/or cut to bring them into a length less than that of
the gussets. A bag
may include a plurality of heat seals about the bottom of the bag closure,
including a series of
substantially parallel hot air seals between the front flap and the inwardly
folded gussets,
and/or the rear flap and the inwardly folded front flap and/or gussets.
Bags of the disclosure provide several advantages over conventional bags of
the prior art.
For example, in the packaging of pet food, bags of the disclosure have various
specific benefits.
Pet food, including dry dog food, can be a greasy and heavy product. In the
past, the packaging
industry had embraced the use of paper-based or paper composite bags for dog
food. However,
at as the size of the bag, and thus the weight and volume of the dog food
contained therein,
increased, consumers and retailers were met with more frequent failures of the
bag integrity,
resulting in loss of product, mess in the retail environment, and negative
consumer experiences.
As the industry shifted away from paper-based bag construction, woven oriented
polypropylene became more favored, due to its substantially improved strength,
particularly its
resistance to puncture. Dog food became increasingly stored in bags
constructed of a ply of
woven oriented polypropylene (OPP) laminated with a layer of reverse printed
plastic film, with
the woven OPP on the inside of the bag against the food. These bags, by virtue
of the
construction material, in some instances provided less flexibility and less
opportunity for
attractive printing. Many of these large woven OPP were rolled and heat sealed
on the bottom,
which did not provide an attractive or particularly useful area for the dog
food company to print.
Large, heavy bags of pet food (or other goods) tend to lay on their sides in a
retail environment,
giving increased value to the bottom of the bags for printing.
Bags of the present disclosure, however, attempt to overcome the failures of
the art.
CA 2981792 2017-10-06
Bags disclosed herein allow the printing of logos and other information to
attract consumers on
the bottom of the bag in a clean, consistent manner on a substantially
congruent surface. Bags
can be stored laying down with the bottom-out and facing consumers, allowing
for more
product to be stored on shelves. Additionally, the rectangular bottoms of the
bags, paired with
the gusseted shape of a traditional SOS bag body, will allow tighter stacking
of bags of product,
both on top of each other and in adjacent columns of product. These and other
advantages
associated with the bags of the present disclosure will be apparent to those
of ordinary skill in
the art.
Certain terminology is used herein for purposes of reference only, and thus is
not
intended to be limiting. For example, terms such as "upper", "lower", "above",
and "below"
refer to directions in the drawings to which reference is made. Terms such as
"front", "back",
"rear", "bottom" and "side", describe the orientation of portions of the
component within a
consistent but arbitrary frame of reference which is made clear by reference
to the text and the
associated drawings describing the component under discussion. Such
terminology may include
the words specifically mentioned above, derivatives thereof, and words of
similar import.
Similarly, the terms "first", "second" and other such numerical terms
referring to structures do
not imply a sequence or order unless clearly indicated by the context.
When introducing elements or features and the exemplary embodiments, the
articles
"a", "an", "the" and "said" are intended to mean that there are one or more of
such elements
or features. The terms "comprising", "including" and "having" are intended to
be inclusive and
mean that there may be additional elements or features other than those
specifically noted. It
is further to be understood that the method steps, processes, and operations
described herein
are not to be construed as necessarily requiring their performance in the
particular order
discussed or illustrated, unless specifically identified as an order of
performance. It is also to be
understood that additional or alternative steps may be employed.
The foregoing description of the embodiments has been provided for purposes of
illustration and description. It is not intended to be exhaustive or to limit
the invention.
Individual elements or features of a particular embodiment are generally not
limited to that
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particular embodiment, but, where applicable, are interchangeable and can be
used in a
selected embodiment, even if not specifically shown or described. The same may
also be varied
in many ways. Such variations are not to be regarded as a departure from the
invention, and all
such modifications are intended to be included within the scope of the
invention as well as all
equivalents thereof.
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