Note: Descriptions are shown in the official language in which they were submitted.
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Flowable Bag Filling System and Bag Therefor
[04] This invention relates to plastic bags made from plastic sheeting such as
those that
may be used for packaging pet foods, foodstuffs and other bulk products. More
specifically,
this invention relates to the use of these plastic bags in a unique seamless
configuration and
the process of manufacturing them. This invention also relates to the use of
these plastic bags
in a unique system which provides for filling and sealing the bags with bulk
contents such as
pet foods, foodstuffs, concrete, plaster, and the like, in an automated
process with a
substantially dust-free environment.
BACKGROUND OF THE INVENTION
[OS] Currently, most bags used for bulk contents are standard side-gusseted
plastic bags,
typically four to five mils thick and are filled from the top bag mouth, then
sealed (or sewn
closed) and palletized for shipping. Plastic bags of this variety are usually
made from
sheeting, as opposed to tubing and are highly desirable for bulk use such as
packaging
fertilizer; lawn maintenance products, seed bags, salt, kitty litter and so
on. Generally
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speaking, these bags are put up in larger sizes to handle loads from as little
as 5 pounds to as
much as 100 pounds.
[06] The primary reason that sheeting is used to form these bags is that they
may be
expertly printed in up to 6 colors with process-tone print quality on all
panels- front, back
and the two sides and, at times, the top and bottom. To make a prior art bag,
the printed
sheeting is folded over and formed into a layflat tube, the open side edges
are matched flush
atop one another in the machine direction, lap-sealed (a continuous heat
seal), gusseted on the
sides, then cut and sealed along a bottom edge to form a bag. This type of
high quality
printing is restricted on tube-type bags since they are printed independently
on the front and
the back panels while in a two-sided layflat configuration, before being
gusseted. Thus, print
registration from front to back is extremely difficult to hold. In the outer
portion of the
layflat surfaces that become the front and rear gusset panels of the side
gussets; it is
commonly understood that print copy on the front panel of a gusset should not
be attempted
_ to be registered with print copy on the back panel of a side gusset. A
further problem with
printing tube stock is that the number of colors available to each independent
surface is
reduced. Since most printing presses have a maximum of 6 print stations (6
colors), there are
only 6 color stations total that must be divided between the two surfaces,
front and back.
Thus, it is impossible to print 6-color process tone print quality on two
sides, which would
require a total of 12 stations: a set of 6 stations for each independent front
and back surface.
[07] When manufacturing a prior art lap seal bag, the two open edges are
matched and
externally sealed with about a'/4" "lap seal", sealing the two matched edges
together, thus
forming a tube. When later gusseting the bag, this lap seal seam is usually
registered on an
outer gusset edge since it naturally points outward anyway. After gusseting,
the bag is
formed by heat sealing the bottom edge and cutting the top-open bag mouth.
This is a fairly
common manufacturing process used in industry today. The '/4" lap seal seam
that protrudes
outward at the gusset edge may distort or interrupt the printing on the bag.
Generally
speaking, it is undesirable to print where a bag is going to be lap (heat)
sealed, as the ink
tends to build up on the lap sealer's heat elements when sealing along the
printed film edges.
But it is also undesirable to leave a lap seal strip unprinted and disrupt the
continuity of
attractive graphics. Thus, this becomes a predicament to the graphic artist,
the bag
manufacturer and the retailer.
[08] Most bags used with cement and concrete products and other heavy flowable
contents
are large multiwall paper bags with fill valves, like those commonly seen
palletized in home
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improvement centers throughout the U.S. They typically contain products, such
as 60#
mortar and concrete mix and 94# cement and concrete mix, sold to consumers for
use in
home garden and yard applications.. The chief reason paper valve bags are used
for these
applications is primarily due to per unit cost and productivity factors. Paper
valve bags cost
S more than standard, top-loading plastic bags, but the paper bags are much
faster to fill, thus
substantially improving productivity and output. There has been some limited
use of plastic
valve bags made from a woven polypropylene-especially in Europe-that do not
lower
productivity. But in the U.S. and other countries where paper is still
relatively inexpensive,
the polypropylene valve bags cost quite a bit more. One of the main reasons
they cost more
than traditional polyethylene top loading bags is because the equipment used
to manufacture
them is extremely expensive-as much as ten times that of a standard plastic
bag machine.
[09] As anyone experienced in the art knows, there are several problems
associated with
the prior art. In addition to the high cost, other disadvantages of paper
packaging include the
consumption of five times the storage space of plastic; the vulnerability of
cement and
concrete products stored in paper to weather conditions (especially rain), and
the
vulnerability of paper to pest infestations. In contrast, the superior
environmental qualities of
plastic are becoming commonly known to retailers and users throughout the
country and
would be desirable, if practical.
[10] Without question, if a plastic bag could be developed that could
eliminate the external
lap-sealed seam from sticking out and interrupting print graphics, it would be
highly desirable
in many applications. -Moreover, if a plastic valve bag and system could be
developed that
could replace the multiwall paper bags cost effectively, without reducing
productivity, it
would be highly desirable. In fact, if a plastic valve bag were developed that
could compete
favorably with standard top-fill plastic bags, that too would be highly
desirable.
BRIEF SUMMARY OF THE INVENTION
[11] A bag having an inwardly disposed seam is manufactured from a sheet of
plastic bag
material having two major surfaces and two parallel side edges. A first seam
seals the two
parallel side edges together at the same major surface with the side edges
disposed inwardly
of the tube to form the sheet of plastic bag material into a tube with
internal flap portions
extending interiorly of the tube. At least one seal across the tube is
provided for forming at
least a three-sided bag structure (and preferably two seals across the tube
for forming a closed
four-sided bag structure) whereby pressure in the interior of the bag acts
against the internal
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flap portions disposed inwardly of the tube to enhance the sealing of the
seam. The bag is
filled at an opening defined along the opposite side edges of the seam facing
inwardly of the
tube. Preferably, at least one additional second seam is placed at the opening
and configured
at substantial right angles to the first seam. This second seam extends at
least from the first
seam, joining the side edges inwardly of the bag to form an internal flap
portion for closing
the opening responsive to pressure in the interior of the bag. The at least
one additional
second seam is angularly disposed with respect to the first seam to form an
opening of
variable crosssection, preferably tapering from a wide crosssection at the
seam to the narrow
crosssection interior of the bag. A tapered conduit having a smaller forward-
most end and a
larger rearward end. is disposed within the opening of the decreasing
crosssection from the
first seam along the side edges into the interior of the tube. The bag opening
is placed over
the smaller forward-most end and held tight to the larger rearward end to fit
snugly along a
portion of the tapered conduit. The bag is filled through the tapered conduit.
Air and dust
from the filling process are vented. By providing pressure in the interior of
the bag and
1 S withdrawing the conduit, the filled bag is sealed The variable
crosssection opening is pulled
from the bag interior to form a pouring spout for metered discharge of the bag
contents.
[12] The problems associated with the prior art are overcome by the present
invention.
That is, the present invention eliminates the protruding lap seal seam and
eliminates the
requirement to seal atop the ink on printed surfaces. In appearance, it
literally creates an
attractive, seamless.bag, that is friendlier and more forgiving to graphic
artists, bag
manufacturers and retailers.
[13] The present invention also discloses a new kind of valve bag that is
suitable for
cement and concrete by-products packaging, costs less than paper and will not
sacrifice
productivity. Furthermore, the valve bag may be manufactured in a method that
allows the
valve to be pulled out into a pour spout, which is ideal for many types of
products such as
seeds, fertilizer and some bulk food products.
[14] In addition, the present invention discloses a method of making the
seamless bag and
the valve bag that can actually decrease bag machinery costs, making the new
method less
costly than its traditional counterpart.
[15] The present invention accomplishes these objectives by turning the lap
seal inside and
thus sealing it along an internal edge with the use of a cantilevered lap
sealing system. The
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cantilevered system is accompanied by an internal former that subsequently
gussets the bag
in a single internal operation. This method of making an internal lap seal
also eliminates the
need and cost of external post-gusseters.
[16] The most significant benefits of the unique manufacturing process, system
and bag
are elimination of the external lap seal, improved graphics, reduced equipment
costs, fill
valves suitable for filling with flowable contents, and dual-purpose valves
that serve as a
filling means and also as spouts. And most important, all of this can be
accomplished
without having a negative impact on the integrity of the product.
[17] The problems associated with the fill valve bags of the prior art are
overcome by the
present invention. The key to the solution is a high-productivity method that
allows for
immediate conversion of paper valve-bag filling systems to accommodate
inexpensive plastic
valve bag alternatives. The .bag and system of the present invention
accomplish that by using
- a method of affixing a plastic valve bag onto a unique fill nozzle in a high-
productivity
manner. As a result, the bag of the invention can outperform both paper
filling processes and
1 S top-fill plastic bag filling processes.
[18] The present invention also discloses a means of creating a dust-free
filling
environment. The system is adaptable to several valve bag styles and may be
automated as
well.
[19] The present invention accomplishes these objectives by using a conical
fill nozzle to
which a valve bag firmly affixes itself. The fill nozzle also uses a narrowed
tip to allow for
easier insertion of the bag valve. The filling process may incorporate an air
relief system that,
in combination with the other attributes, creates not only a dust-free filling
environment, but
concentrates air and dust removal from the bag being filled to a single
location behind the fill
nozzle.
[20] The most significant benefits of the unique filling method are the
ability to load as
quickly as paper, dust containment, and automation potential. All of which is
accomplished
without having a negative impact on the integrity of the product, and may be
used with
polyethylene bags that cost less than present day paper or woven polypropylene
bags.
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In accordance with one aspect, there is provided a bag having an inwardly
disposed
seam with a self sealing opening comprising in combination: a sheet of plastic
bag material
having first and second major surfaces and two parallel side edges; the sheet
of plastic bag
material formed into a tube with the first major surface of the plastic bag
material located on
the exterior of the tube and the second major surface of the plastic bag
material located on
the interior of the tube; a first seam joining the two parallel side edges
together at the first
major surface with the two parallel side edges disposed inwardly of the tube
with internal
flap portions extending interiorly of the tube; at least two seals across the
tube for forming a
four-sided bag structure having a sealed interior; and an opening defined
along the first seam
interrupting the seam at the first major surface with the two parallel side
edges adjacent the
opening disposed inwardly of the four sided-bag to form an internal flap
structure adjacent
the opening; whereby pressure in the interior of the bag acts against the
internal flap portions
disposed at the second major surface of the sheet of plastic bag material
adjacent the opening
and disposed inwardly of the four sided bag structure to cause the internal
flap portions to
move into a sealed relationship to seal the opening defined along the first
seam.
In accordance with another aspect, there is provided a process of filling a
bag having
an inwardly disposed seam comprising the steps of providing a bag manufactured
from
plastic sheet having two major surfaces and two parallel side edges and
including, a first
seam joining the two parallel side edges together forming a tube with the side
edges disposed
inwardly of the bag; at least two seals across the tube for forming a four
sided bag structure;
whereby pressure in the interior of the bag acts against the side edges
disposed inwardly of
the bag to close the seam; providing an opening defined along the first seam;
providing a
conduit; fitting the conduit into the opening; filling the bag through the
conduit and the
opening to exert pressure on the inside of the bag, whereby pressure in the
interior of the bag
Sa
acts at the first seam and opening to enhance closure of the first seam and
opening.
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BRIEF DESCRIPTION OF THE DRAWINGS
[21] Fig. 1 is a plan view of a gusseted seamless bag, which can include two
lap seals.
[22] Fig. 2 is a blown-up cross-sectional view of the gusseted film in the bag
of Fig. 1
[23] Fig. 3 is a perspective view of the bag in Fig. I with contents inside.
[24] Fig. 4 is a plan view of a valve bag of the present invention.
[25] Fig. 5 is a cross-sectional view of the gusseted film in the bag of Fig.
4.
[26] In Fig. 6 bag is a perspective view of the top portion of the bag in Fig.
3 after being
filled and illustrating the closure of the valve sleeve.
[27] Fig. 7 is a plan view of a valve bag in which the valve doubles as a pour
spout and
also showing an anti-dimpling effect at the bag bottom.
[28] Fig. 8 is a perspective view of the bag in Fig. 7 with the pour spout
pulled out.
[29] Fig. 9 is a plan view of the bag in Fig. 7 with an air ventilation system
along the
internal flap and with a with a die-cut handle.
[30] Fig. 10 is a top perspective view of the cantilevered manufacturing
process.
[31] Fig. 11 is a perspective view of a tapered fill nozzle of the present
invention.
[32] Fig. 12 is a plan view of a valve bag similar to that of the bag of Fig.
1.
[33] Fig. 13 is a perspective view of the bag in Fig. 12 snugly mounted on the
tapered fill
nozzle of Fig. I 1.
[34] Fig. 14 is a plan view of a variation on a valve bag also suitable for
mounting on the
tapered fill nozzle of Fig. 11.
[35] Fig. 15 is a perspective view of the tapered fill nozzle of Fig. 11 with
an air relief
system.
[36] Fig. 16 is a perspective view of the bag in Fig. 12 mounted in a magazine
feed system
that enables the user to quickly mount the bag onto a fill nozzle.
[37] Fig. 17 is a perspective view of a tapered fill nozzle, with a mounted
valve bag and a
U-shaped bag retaining means.
DETAILED DESCRIPTION OF THE INVENTION
[38] In Fig. 1, bag 10 has top 12, a bottom 14, left- and right-side gussets
16 and 16',
respectively, with left- and right-side center gusset creases 18 and 18',
respectively.
Extending inward approximately I/8" to 1/4", or a little more, from left-side
center gusset
crease 18 are internal flap edges 20 and 22 (the latter not shown as it lies
directly underneath
internal flap edge 20). Internal lap-sealed portion 24 (shaded portion) is the
narrow strip of
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material that lies in between left-side center gusset crease 18 and internal
flap edges 20 and
22 and runs continuously from bag top 12 to bottom 14. As viewed, the lap-
sealed portion 24
lies inside of bag 10 adjacent to left-side center gusset crease 18, and the
lap seal defining
left-side center gusset crease 18. With the lap seal facing inward, inside the
bag, the outer
surface of the bag has no ridges or seals pointing outward, as would be the
case with prior art.
[39) In Fig. 2, bag 10 is illustrated as having a front panel 26, a rear panel
28, a left-front-
side gusset panel 30, a left rear side gusset panel 32, a left-side center
gusset crease 18, a
right-front-side gusset panel 34, a right rear side gusset panel 36 and a
right-side center gusset
crease 18'. In between left-side center gusset crease 18 and internal flap
edges 20 and 22 is
internal lap-sealed portion 24. This lap-sealed portion may be a strip as
narrow as 1/8" or
may be wider. For the economy of using fewer raw materials, the narrow seal is
preferred,
unless of course, a wider, stronger seal were preferred due to heavier
contents. It is easy to
see that with the lap seal's disposition being inside the bag, the outer
surfaces appear to be
seamless, with no outwardly protruding edges or seals. Lap sealing in this
method naturally
1 S produces a center gusset crease, albeit, the crease may also be positioned
elsewhere on the
bag, for instance, on the right-side gusset or on a front or rear panel.
[40] In Fig. 3 bag 10 has been filled with a flowable material and sealed at
the top edge 12.
Left-side center gusset crease 18 is one continuous crease formed by the
internal lap-sealed
portion 24 (the latter not shown since it is inside bag 10). The outer
appearance of center
gusset crease 18 looks much like that of any other side gusset crease commonly
seen in
standard tube-type bags, that is, one clean, continuous fold.
[41] In Fig. 4 bag 40 has atop 42, a bottom 44, left- and right-side gussets
46 and 46',
respectively, with left- and right-side center gusset creases 48 and 48',
respectively. Both bag
top 42 and bottom 44 are sealed forming bag 40 into a pillow-like bag when
filled.
Extending inward from left-side center gusset crease 48 are internal flap
edges 50 and 52 (the
latter not shown as it lies directly underneath internal flap edge 50). ,
Internal lap-sealed
portion 54 (shaded portion) is a narrow sealed strip that lies adjacent to
left-side center gusset
crease 48 and spaced from internal flap edges 50 and 52, but runs continuously
only from bag
bottom 44 up to point 56, where it stops. Valve opening 58 is the unsealed
portion that lies
along left-side center gusset crease 48 in between point 56 and bag top 42,
and is suitable for
allowing entry of a fill nozzle much like those used to fill standard paper
valve bags. With
valve opening 58 positioned at the center gusset crease, it is easy and
natural for the user to
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find the valve opening 58 of bag 40 and mount it on a fill nozzle. In between
lap-sealed
portion 54 and valve opening 58, and internal flap edges 50 and 52, lie
internal flap portions
60 and 62 (the latter not shown as flap portion 62 lies directly under flap
portion 60) that run
continuously from bag top 42 to bag bottom 44. Typically, internal flap
portions 60 and 62
may extend inward, inside bag 40, about 2" to 3" depending upon bag size, but
could
certainly be more or less. Horizontal seal 64 begins at point 56 and runs
approximately
horizontally into internal flap portions 60 and 62. The area in between
horizontal seal 64 and
sealed bag top 42 forms a valve sleeve 65, which sleeve, along with valve
opening 58,
typically measures about the same overall circumference, or slightly greater,
as an existing
prior art fill nozzle. Thus, valve opening 58 and valve sleeve 65 may be
mounted onto a fill
nozzle with a reasonably snug fit, preventing leakage as the bag is filled,
and subsequently
collapsing upon itself after filling, so that the flowable material contained
inside will not leak
out. The intention of the present invention is not to specifiy the width of
the internal flap
portions that allow the formation of a valve sleeve, but to illustrate the
concept as one that is
viable with present day flowable filling machinery that use fill nozzles. The
internal flap
portion as shown is an integral portion of the same sheeting that has formed
the internal flaps
and the bag. It may also be accomplished by inserting a separate internal flap
portion and
sealing it to the bag top and to the internal lap seal 54 below point 56. Or,
it may even be
accomplished in much the same way, but with an external lap seal instead of an
internal lap
seal. Either manner could serve the same purpose. However, having the internal
portion as a
continuous part of the sheeting is the preferred manufacturing process, even
though it
requires using a bit more film and a bit more raw material. This manufacturing
process may
be improved upon by cutting away the unused internal flap portions that lie
below the
horizontal seal 64 and recycling that unused portion.
[42] In Fig. 5, bag 40 is illustrated as having a front panel 66, a rear panel
68, a left-front-
side gusset panel 70, a left rear side gusset panel 72, a left-side center
gusset crease 48, a
right-front-side gusset panel 74, a right rear side gusset panel 76 and a
right-side center gusset
crease 48'. In between left-side center gusset crease 48 and internal flap
edges 60 and 62 is
valve opening 58. The internal lap-sealed portion 54 is not shown as it lies
directly below
open valve portion 58 and is much like that of internal lap seal 24 of Fig. 2
in that it may be a
strip as narrow as 1/8" or wider. Valve sleeve 65 lies inward of valve opening
58. Horizontal
seal 64, though not shown, defines the lower extremity of valve sleeve 65. As
shown valve
sleeve 65 is made from integral portions of internal flap edges 60 and 62.
Alternatively, it
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may be an attached sleeve portion sealed to a top edge and the internal lap
seal as described
in Fig. 4.
[43] In Fig. 6, the top of bag 40 has been filled with flowable contents and
takes on its
natural parallelepiped or cubic disposition predetermined, in the most part,
by the bag's
dimensions. As seen, bag 40 includes a sealed top 42, a front panel 66, a left-
front-side
gusset panel 70, a left rear side gusset panel 72 and a left center gusset
crease 48, which is in
an unfolded disposition since bag 40 is filled with flowable contents. Upon
filling with
flowable contents, bag 40 has formed a top 78, which is made up of the two
upper portions of
front panel 66 and rear panel 68 (see Fig. 5), with valve opening 58 now
positioned inside the
upper folded left-side gusset region 80 and closed off. Upon filling with
contents, valve
sleeve 65 closes back upon itself into a layflat configuration, thus not
allowing the flowable
contents to escape, or leak out. The formation into a cubic disposition causes
valve sleeve 65
to close upon itself and also to pull downward and outward thus causing a
small stress dimple
69 at the junction of bag top 42 and internal flap edges SO and 52 (not
shown). Once
15_ palletized, bag 40 would be placed flat upon rear panel 68, thus making
top 78 an "end" of
the rectangular cube. It is important to note that the closure phenomena
explained herein is
even stronger in its palletized disposition since the pressure from the
contents pushes outward
on the valve sleeve, creating a more secure closure of the valve sleeve and
valve opening.
[44J In Fig. 7, the structure of bag 90 is much like that of bag 40 in Fig. 4
with a top 92, a
bottom 94, left- and right-side gussets 96 and 96', respectively, with left-
and right-side center
gusset creases 98 and 98', respectively. Both bag top 92 and bottom 94 are
sealed forming
bag 90 into a pillow-like bag when filled. Extending inward from left-side
center gusset
crease 98 are internal flap edges 100 and 102 (the latter not shown as it lies
directly
underneath internal flap edge 100). Internal lap-sealed portion 104 (shaded
portion) is a
narrow sealed strip that lies adjacent to left-side center gusset crease 98
and spaced from
internal flap edges 100 and 102, and runs continuously from bag bottom 94 up
to point 106,
where it stops. An improvement is made at point 106 by rounding the lap-sealed
edge as it
joins horizontal seal 114, thus eliminating a potential stress location and
also making valve
opening 108 easier to mount on a fill nozzle. Valve opening 108 lies along
left-side center
gusset crease 98 in between point 106 and bag top 92, and is suitable for
allowing entry of a
fill nozzle much like those previously described. In between lap-sealed
portion 104 and
valve opening 108, and internal flap edges 100 and 102, lie internal flap
portions 110 and 112
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(the latter not shown as flap portion 112 lies directly under flap portion
110) that run
continuously from bag top 92 to bag bottom 94. Beginning at point 106 and
running
approximately horizontally into the internal flap portions 110 and 112, is
horizontal seal 114
defining valve sleeve 115, which in combination with valve opening 108, is
mountable on a
fill nozzle. Top perforation line 116 is located on internal flaps 110 and
112, near the top of
valve sleeve 115, adjacent to bag top 92, and bottom perforation line 118 is
located near the
bottom of internal flap portions 110 and 112 adjacent to bag bottom 94. Top
perforation line
116 is sufficiently easy to tear so that a user may reach in and pull outward
on the
prefabricated valve sleeve 115, thus forming a pour spout as illustrated in
Fig. 8. Top
perforation line 116 also serves to eliminate the stress dimple (shown as 69
in Fig. 6) at the
top region, when it tears free upon filling with flowable contents. Likewise,
when bottom
perforation line 118 tears free upon filling with flowable contents, there
will be no stress
dimple along the bottom sealed edge either. Stress dimples do not appear to
affect the
integrity of the bag strength quality in most applications, but might if the
bags were filled
with extremely heavy contents and the internal flaps extend far into the bag.
In other words,
the narrower the internal flap, the less significant the stress dimple. Using
perforations at the
top and bottom regions of the internal flaps and eliminating the stress
dimples also improves
the outward appearance, since there is no distortion along a top or bottom
sealed edge.
Alternatively, creating a top pour spout or eliminating stress dimples can be
achieved by
placing cut lines on the internal flaps instead of top or bottom perforations.
A perforation
line also doubles as a means to maintain the integrity of the web of film as
it moves along in
the manufacturing process, whereas a cut line may tend to allow some web
distortion. The
perforation or cut line may also extend outward, past the internal flap and
into the gusset
panels to the outermost bag edges.With this design, the spout tends to become
larger.
[45] In Fig. 8, bag 90 is filled with flowable contents and sits upright much
like the bag in
Fig. 6. Valve sleeve 115 has been pulled outward and perforation line 116 (see
Fig. 7) has
severed, forming pour spout 120. Pour spout 120 was valve sleeve 115 when in
its internal
position (see Fig. 7), and is defined by top edges 122 and 122', and a bottom
edge 124. Top
edges 122 and 122' were the edges of valve sleeve 115 at perforation line 116
when the
sleeve was in its internal position. Bottom edge 124 is horizontal seal 114,
which has been
extracted from the interior of the bag to form a pour spout base. The pour
spout size is
determined by the overall height (or size) of the valve sleeve. Valves used in
many common
nozzle tilling applications are about 4" to 4.5" in circumference, and when
pulled out to form
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a spout, make a workable pour spout. Pull-out pour spouts as defined herein
also include
those that are part of an internally attached portion that is not part of an
internal flap.
[46] In Fig. 9, bag 140 is much like those in Fig. 4 and Fig. 7 with a top
142, a bottom 144,
left- and right-side gussets 146 and 146', respectively, and left- and right-
side center gusset
creases 148 and 148', respectively. Both bag top 142 and bottom 144 are
sealed, forming bag
140 into a pillow-like bag when filled. Extending above bag top 142 are handle
portions 143
and 147 (the latter not shown because it lies directly underneath handle
portion 143), which
portions have centrally located die-cut handles 145 and 149 (also not shown
because die cut
149 is cut upon handle portion 147 and lies directly below die cut handle
145). Handle
portions 143 and 147 are contiguous sections of film connected to front panel
1 S 1 and rear
panel 153 (the latter not shown because it lies directly below front panel 151
). Extending
inward from left-side center gusset crease 148 are internal flap edges 150 and
152 (the latter
not shown because it lies directly underneath internal flap edge 150).
Internal lap-sealed
portion 154 (shaded portion) is a narrow sealed strip that lies adjacent to
left-side center
gusset crease 148, is spaced from internal flap edges 150 and 152, and runs
continuously
from bag bottom 144 up to point 156, then stops. A second internal lap-sealed
portion 155 is
adjacent to internal flap edges 150 and 152, is spaced from left-center gusset
crease 148, runs
parallel to lap-sealed portion 154, and ends at point 157 where it joins
horizontal seal 164.
Throughout second internal lap-sealed portion 155 are intermittent breaks 167
in the seal to
allow air passage. These breaks typically are as narrow as 1/32" to as great
as 1/4". In
addition, intermittent breaks 169 are positioned throughout internal lap-
sealed portion 154 .
In between internal lap-sealed portion 154 and second internal lap-sealed
portion 155 lies a
mostly sealed-in internal region 160 created by the internal flaps themselves,
bounded by four
seals-bottom seal 144, internal lap seals 154 and 155 and horizontal seal 164-
with breaks
at 167 and 169 as previously described. When bags of the present invention are
filled with
flowable materials, it may be desirable to have a means to allow entrapped air
to escape from
portions other than the valve sleeves and valve openings. Thus, breaks 167 in
second internal
lap seal 155 allow air to escape into the sealed-in internal region 160 and,
subsequently, out
through breaks 169 in lap seal 154. This is a tortuous path because sealed-in
internal portion
160 is collapsed upon itself. Such a tortuous path is desirable in many cases
since it will
help prevent, or completely eliminate leakage of the flowable contents. A
tortuous path may
also be created by having perforation holes in the mostly sealed-in portion
instead of having
breaks in second lap seal 155. In such a bag, the handled top is suitable for
carrying and
11
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transporting as well as serving as a means to assist in pouring flowable
contents from the
pour spout (as illustrated in Figs. 7 and 8). It may be made in any variety of
styles and sizes.
While not essential, the air relief means serves as a means of allowing air
trapped inside
during the filling process, to escape from inside the bag, and allows the bag
to breathe in order
to avoid condensation build-up.
[47] In the top view of Fig. 10, layflat film sheet 170 moves between rollers
172 and 174
(the latter not shown because it lies directly under roller 172). The pressure
exerted between
rollers 172 and 174 holds film 170 in its layflat disposition. Upon leaving
rollers 172 and
174, layflat sheet 170 begins a fold-over process as it wraps around
cantilever arm 176.
Cantilever arm 176 is secured to base 178 and protrudes forward toward the
tube-to-be-
formed, which, at its extremity, is mounted with an internal former 180, an
edge turning
device 182 and internal lap sealer 184. Two gusseting fins 186 and 188 are
located on the
outside of former 180. As layflat sheet 170 folds over, which is accomplished
by any number
of prior art means, film edge 190 turns under until it is matched with film
edge 192. The
15. edges move together into edge turning device 182, thus turning the two
matched film edges
190 and 192 inward, pointing inside the tube-to-be-formed. The two inside film
edges 190
and 192 then move to internal lap sealer 184, are sealed together in an
internal disposition
and, as may be required for the various bag styles previously discussed, may
include the
interruption of seals to create valve openings or air relief breaks. At
location 194 a tube has
been formed from the film, and the gusseting operation is completed by the
internal former
180 and the two external gusset fms 186 and 188, as the film passes by.
Rollers 196 and 198
(the latter not shown because it lies directly under roller 196) maintain the
newly gusseted
film 200 in its predetermined gusseted disposition for further processing
downstream.
[48] The forming of the tube to create two turned-in matched edges for further
internal lap
sealing, may be accomplished in a number of ways. The novelty of what is
revealed herein is
not the exact methodology of doing this, but the requirement to do so on a
cantilevered
means. Internal formers are known in prior art, but have not been used in
accordance with a
cantilever process as described herein. The internal forming operation, may be
achieved by
the internal former being an integral part of the cantilever/lap sealing
system, or the internal
former may be independent of the sealing operation. But the internal sealing
must be
accomplished in a cantilevered fashion, regardless of whether the cantilever
extends out 5
inches or 5 feet.
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[49] In Fig. 11, tapered fill nozzle 210 is an extended hollow tube connected
to the filling
equipment (not shown) at its rear entry point 212. The front tube portion 214
of fill nozzle
210 tapers to a smaller diameter than at rear entry point 212, and ends with a
pointed tip 216,
suitable for easy insertion into a valve bag. Exit point 218, from which
flowable material will
flow into a bag when mounted on fill nozzle 210, is set back from pointed tip
216. Typically
this type of fill nozzle has about a 2" - 2.5" ID and is about 18" long for
concrete products
filling applications. The nozzle may be substantially smaller for small bags,
or substantially
larger for larger bags or bulkier flowable materials. For durability, fill
nozzles are usually
made of steel, but may be made of most any other type of material, such as
plastic or
aluminum, that can be formed into a tubular shape. As will be illustrated, the
use of a tapered
fill nozzle may include a nozzle that is tapered only along the front portion,
a mid portion or a
rearward portion, depending upon how far onto the fill nozzle a bag is to be
mounted.
[50] In Fig. 1 l, valve bag 230 has a top 232, a bottom 234, and left- and
right-side gussets
236 and 236', respectively, with left- and right-side center gusset creases
238 and 238',
respectively. Both bag top 232 and bottom 234 are sealed forming bag 230 into
a pillow-like
bag when filled. Extending inward from left-side center gusset crease 238 are
internal flap
edges 240 and 242 (the latter not shown because it lies directly underneath
internal flap edge
240). Internal lap-sealed portion 244 (shaded portion) is a narrow sealed
strip that lies
adjacent to left-side center gusset crease 238 is spaced from internal flap
edges 240 and 242,
and runs continuously only from bag bottom 234 up to point 246, then stops.
Valve opening
248 is the unsealed portion that lies along left-side center gusset crease 238
in between point
246 and bag top 232, and is suitable for allowing entry of the fill nozzle
shown in Fig. I 2. In
between lap-sealed portion 244 and valve opening 248, and internal flap edges
240 and 242,
lie internal flap portions 250 and 252 (the latter not shown because flap
portion 252 lies
directly under flap portion 250) that run continuously from bag top 232 to bag
bottom 234.
Typically, internal flap portions 250 and 252 extend inward about 2" to 3"
inside bag 230,
depending upon bag size, but could certainly extend to a greater or lesser
depth. Beginning at
point 246 and running approximately horizontally, but tapering upward into the
internal flap
portions 250 and 252 is horizontal tapered seal 254. The area in between
horizontal seal 254
and sealed bag top 232 forms a tapered valve sleeve 255, which sleeve along
with valve
opening 248 snugly fits around the front tapered portion 214 of the fill
nozzle of Fig. 11.
Valve opening 248 and valve sleeve 255 may be mounted onto a standard fill
nozzle with a
snug fit, or onto a tapered fill nozzle such as that of Fig. 1 with an even
greater secure, snug
13
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WO 03/000005 PCT/US02/18672
fit, thus preventing the flowable material from spilling out during the
filling process (which is
frequently a high-pressure operation). This tapered fit also keeps air and its
accompanying
flowable material dust particles from escaping, such as that which accompanies
cement and
concrete byproducts. A tapered valve sleeve as described herein clearly works
best in
combination with a tapered fill nozzle, as it will seat itself along the
entire valve surface to
the tapered nozzle surface underneath. However, the tapered valve sleeve is
also an
improvement when used with existing non-tapered fill nozzles.
[51] In Fig. 13, bag 230 is mounted onto fill nozzle 210 by pulling valve
opening 248 over
pointed tip 216, pulling forward (direction of arrows) and seating valve
sleeve 255 securely
on tapered front tube portion 214 (as illustrated now lies directly under
valve sleeve 255).
The tapered valve sleeve 255 of the present invention will typically be
tapered at the same
degree as the tapered fill nozzle front portion, which means both would have
about the same
circumference dimensions at any given point along the valve sleeve or fill
nozzle, once the
valve sleeve has been mounted on the fill spout. These matching tapers provide
an extremely
tight fit and can virtually eliminate the escape of even the smallest dust
particles. As shown,
horizontal tapered seal 254 provides the matched tapers that ensure the tight
fit on front tube
portion 214 so that the exit point 218 lies just past internal flap edge 240,
which also defines
the innermost edge of valve seal 255 at curved dotted line 241. When valve
sleeve 255 is
withdrawn from fill nozzle 210, it subsequently collapses upon itself, back
into its layflat
disposition, so that the flowable material contained inside will not leak back
out. The
intention of the present invention is not to specify the length and width of
the tapered valve
sleeve or the fill nozzle, but to illustrate the concept that the matched
circumferences of the
two tapered elements provide unique, valuable dynamics: 1) the superior
securing of a
tapered valve on a fill nozzle; 2) elimination of flowable material leakage
during the fill
process; and 3) elimination of dust contamination in the work environment.
[52] In Fig. 14, plastic valve bag 260 has a top 262, a bottom 264, and left-
and right-side
gussets 266 and 266', respectively, with left- and right-side outside gusset
folds 268 and 268',
respectively. Both bag top 262 and bottom 264 are sealed forming bag 260 into
a pillow-like
bag when filled. Situated in from the left-side outer gusset fold is an
overlapping edge 270
that extends outward from internal flap edge 272. Overlapping edge 270 has an
adjacent lap-
sealed portion 274 (shaded portion), a narrow sealed strip that runs
continuously from bag
bottom 264 up to point 276, then stops. Valve opening 278, the unsealed
portion of
14
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WO 03/000005 PCT/US02/18672
overlapping edge 270, lies in between point 276 and sealed bag top 262, and is
suitable for
allowing entry of a fill nozzle like that of Fig. 11. In between lap-sealed
portion 274 and
valve opening 278, and internal flap edge 272, lies external flap portion 280
and internal bag
wall portion 282 (not shown because it lies directly below external flap
portion 280).
External flap portion 280 and internal bag wall portion 282 run continuously
from bag top
262 to bag bottom 264. Typically, internal flap edge 272 extends inward from
overlapping
edge 270, about 2" to 3" inside bag 260, depending upon bag size, but could
certainly extend
to a greater or lesser depth. Horizontal seal 284, begins at point 276 and
runs approximately
horizontally, but tapers upward into internal bag wall portion 282.. The area
between
horizontal tapered seal 284 and sealed bag top 262 forms a tapered valve
sleeve 285. The
tapered sleeve, along with valve opening 278, typically measures about the
same overall
circumference, at any given point, as the circumference along the front
tapered portion of a
fill nozzle as described in Fig. 13. Thus, valve opening 278 and valve sleeve
285 mount onto
fill nozzle 210 with a highly snug fit, much like that of the bag described in
Figs. 12 and 13,
with the same results of setting a secure fit of the valve on the fill nozzle,
preventing leakage
of flowable materials during the filling process, and eliminating the escape
of flowable
material dust pauticles. Again, the intention of the present invention is not
to specify the
width of the internal bag wall portion or external flap portions that allow
the formation of a
valve sleeve, but to illustrate the concept as one that is viable with present
day flowable
filling machinery that uses fill nozzles.
(53] Moreover, the location of the overlapping edge may be all the way out to
the left-side
outer gusset edge, or further inward. The overlapping edge may even be rotated
about to be
positioned on one of the inner gusset panels or at a center gusset crease.
This type of valve
may also be created by inserting a separate internal flap portion, or
portions, and sealing it (or
them) to a bag top (such as 262) and to a lap seal (such as 274 below point
276) In such a
case there would be no need to have an internal bag wall portion. Either
manner serves the
same purpose. However, having the internal bag wall portion as a continuous
part of the
sheeting is the preferred manufacturing process for this style of bag. This
manufacturing
process may be improved upon by cutting away the unused internal flap portions
that lie
below the horizontal tapered seal 84 and recycling those unused portions. The
use of this
type of valve bag generally works well on the fill nozzle of the present
invention. Valve bags
of this variety with the valve openings positioned in the side gusset panels,
and preferably at
the center gusset crease, tend to be preferred overall as it is easier to find
the valve opening
CA 02451165 2003-12-18
WO 03/000005 PCT/US02/18672
and they have a stronger construction because the suspending of the bag and
valve on the fill
nozzle is more balanced and uses equal film material plies (two) on each side
of the valve
sleeve.
[54] In Fig. 15, tapered fill nozzle 290 is similar to that of Fig. 11 and is
an extended tube
connected to the filling equipment (not shown) at its rear entry point 292.
The front tube
portion 294 of fill nozzle 290 is not tapered and ends at exit point 298,
where flowable
material flows into a subsequently mounted bag. Securely positioned around
front portion
294 and exit point 298 is a second, larger, tapered tube 300 with a pointed
tip 296, suitable
for easy insertion into a valve bag. Air space 302, which allows the escape of
air and dust
upon pressurized filling operations, is located around the outer surface of
front portion 294
and the inner surface of tapered tube 300. With a bag mounting on fill nozzle
290, as in Fig.
13, any entrapped air and its accompanying dust exits in the direction of the
arrows, the
venting being placed back and away from the location of the workers loading
bags onto the
nozzles. Typically this type of fill nozzle combination has about a 2" - 2.5"
ID and a length
of about 18" for concrete products filling applications. This fill nozzle
combination may be
substantially smaller for small bags or substantially larger for larger bags
or bulkier flowable
materials. For durability, this combination could be made of steel, but may be
made of most
any type of material, such as plastic or aluminum, that can be formed into a
tubular shape.
The principle that is illustrated here is one that provides for an air escape
so that during the
filling process, any air that is used in the high pressure filling operations
will not be captured
and contained within the bag, such as happens in the fill processes typically
used with cement
and concrete products. With a high-pressure filling method in combination with
the secure
tight fit of the valve sleeve on a tapered nozzle, some form of air relief is
desirable. The
method of the invention primarily eliminates the need to have ventilation in
plastic bags so
that trapped air may subsequently escape. Further, the method directs the air
and dust escape
route backward into a concentrated area where it can be recaptured with a
vacuum system
and put back into the raw material silos. This concentrated air and dust
escape means can
also be accomplished by having an air relief tube inserted inside a fill
nozzle, such as that of
Fig. 11. Thus, the present invention provides a means of allowing for a
concentration of air
and dust to escape in a direction away from the front side of the nozzle where
an individual is
working as he/she mounts the bags and bag valves on the fill nozzle or is
monitoring an
automated process. For most applications having a high degree of dust levels
and air pressure
utilization in the fill process, this nozzle is the preferred version.
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(55] In Fig. 16, magazine holder 410 has a left side 412 , a right side 414
(not shown as it
opposes left side 412 ), a bottom panel 416 (not shown), a front panel 420 and
a rear panel
418 (not shown as it opposes front panel 420 ), with valve bag pack 422
(consisting of bags
of one of the styles previously disclosed) set vertically within the magazine
holder. Bag pack
422 is positioned within the magazine holder with all the underlying valve
openings and
valve sleeves registered inside the center gusset crease, (not shown) in the
upper front corners
434. Adjacent to edge 424 and running substantially along front panel 420 is
open slot 426
that allows for removal of a forward-most bag. As illustrated, forward-most
bag 428 is
partially extracted from magazine 410. Extracting a bag may be accomplished by
several
means. First, a worker may grasp forward-most bag 428 with his hand at the
upper front
corner 430 , pull it forward (arrow direction) and out through open slot 426
and subsequently
mount the underlying valve opening 432 and valve sleeve 434 on a nearby fill
nozzle 436.
Another means of extraction would be by the use of two suction cups that affix
themselves to
the front and rear bag panels (one to each panel) at the upper front corner
430 thus, grasping
the opposing panels at the upper front corner 430. In combination, the two
suction cups pull
the side gusset panels slightly open and then pull the bag forward and onto
the fill nozzle.
Other grasping operations may be used as well; the general principle is to
have bags mounted
in a conveniently positioned magazine for subsequent manual or mechanical
extraction.
Furthermore, the magazine may be positioned at a slight tilt so that gravity
causes the bags to
stay in an upright disposition. Or, a simple spring-loaded plunger means may
serve the same
purpose. The magazine may also be loaded from the side instead of the top. In
addition, the
bags may be maintained in a horizontal disposition prior to being placed in a
vertical
disposition on a fill nozzle.
[56] In Fig. 17, tapered fill nozzle 440 has a valve bag 442 mounted thereon
much like any
of the bags and fill nozzles described herein. Bag 442 is held in place with
pressure-actuated
retaining means 444, which, when actuated by electric eye 446, moves downward,
pins and
maintains the secure fit of bag 442 on nozzle 440. Retaining means 444 is "U-
shaped" at
base 445 so it fits the contour of the bag on the fill nozzle and faces back
at an angle, so that a
worker may conveniently place his/her hands at the top of bag 442 at top
forward point 448
while retaining means 444, when actuated, pins down bag 442 at top rear point
450 out of the
way of a worker's fingers and hands. In front of retaining means 444 is safety
stop 452 that
prevents the workers fingers or hands from going past as he/she slides the bag
442 onto fill
17
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nozzle 440. Typically retaining means 444 is metal with a rubber base. The
safety stop is
made of a somewhat flexible material, such as a hard rubber.
[57J The spirit of the present invention is to improve existing filling
operations of flowable
materials while enhancing dust control and improving productivity. Without
question, there
could be variations and modifications that may be considered, all of which
would be
considered as falling under the scope of the present invention.
[58J As of the time of the filing of this PCT application, actual bags
incorporating the
invention have been built. Typical lay flat dimensions of this bag include a
10 inch width and
a 21 inch length. On the side opposite the opening, the bag has a 2-inch
inwardly extending
seam. On the side having the opening, the bag has a 5-inch seam. The aperture
of the bag is
about 5 lineal inches in the lay flat configuration. The actual performance of
the bag is quite
surprising. When fabricated from thick plastic material, the bag can be blown
full of air and
seals itself. Further, once the bag has sealed itself, a 200-pound man can
stand on the bag
and the air inside the bag will not escape! The reader will understand that
the above
1 S dimensions can be varied by simple trial and error.
[59J In the following claims, the term "seam" will be reserved for joinder of
the two
parallel side edges of the tube material at the same major surface to form a
joinder of the bag
material. The term "seal".will refer to any joinder of the bag material,
including a seam.
18
