U.S. patent application number 09/765176 was filed with the patent office on 2001-06-07 for method and apparatus for enhancing evacuation of bulk material shipper bags.
Invention is credited to Wilcox, Donald E..
Application Number | 20010002675 09/765176 |
Document ID | / |
Family ID | 27372161 |
Filed Date | 2001-06-07 |
United States Patent
Application |
20010002675 |
Kind Code |
A1 |
Wilcox, Donald E. |
June 7, 2001 |
Method and apparatus for enhancing evacuation of bulk material
shipper bags
Abstract
A bag is modified to include an air input port that allows
inflation of an interply region of the bag. As the interply region
inflates, an inner ply rises and becomes an advancing wall, raising
the bulk material level in the bag, inclining the bottom of the
bag, and pulling excess material away from the drain port all at
the same time. In another embodiment, the bag is made with half the
initial number of layers folded in half to create the upper and
lower plies and the non-fold edges are bonded. Where corner drain
ports are used, the bag can be arranged so that an interlayer bond
parallel to the fold is parallel to a diagonal of a tote in which
the bag sits and so that the interlayer bond is opposite the drain
port to enhance bag evacuation. An additional optional feature of
the invention is the inclusion of an integral filling conduit or
snout on the top of the bag, a mouth of which acts as a fill port
to ease filling of the bag. Junctures can be created in the
interply region to guide its inflation. The invention can also be
applied to fitted bags.
Inventors: |
Wilcox, Donald E.;
(Rochester, NY) |
Correspondence
Address: |
Steven R. Scott
Eugene Stephens & Associates
56 Windsor Street
Rochester
NY
14605
US
|
Family ID: |
27372161 |
Appl. No.: |
09/765176 |
Filed: |
January 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09765176 |
Jan 18, 2001 |
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09237819 |
Jan 27, 1999 |
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60072815 |
Jan 28, 1998 |
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60072816 |
Jan 28, 1998 |
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Current U.S.
Class: |
222/95 ;
222/386.5; 222/389; 383/109; 383/3; 383/41 |
Current CPC
Class: |
B65D 77/06 20130101;
B65D 88/62 20130101; B67D 7/0244 20130101; B67D 7/0255
20130101 |
Class at
Publication: |
222/95 ;
222/386.5; 222/389; 383/3; 383/41; 383/109 |
International
Class: |
B65D 035/28 |
Claims
I claim:
1. A method of enhancing evacuation of a multiple-ply bag of the
pillow bag type, the pillow bag including a seam at least partially
about a circumference of the bag and including at least two upper
plies and at least two lower plies, the plies being of
substantially identical dimension and being sealed together at
respective edges by the seam, regions between the upper plies being
sealed off from respective regions between the lower plies, the
pillow bag containing a bulk material and including an exit port
through which the bulk material can flow from the bag, the method
including the steps of: connecting a region between two plies of
the multiple-ply bag to a source of pressurized air; emptying the
viscous contents of the bag through the exit port; and allowing
pressurized air from the source of pressurized air to inflate the
region between the two plies when enough of the contents of the bag
has been emptied that a pressure exerted on an inner of the two
plies by the pressurized air is greater than a pressure exerted on
the inner of the two plies by the contents, the inner of the two
plies thereby urging the contents toward the exit port of the
bag.
2. The method of claim 1 wherein the method further includes
placing the bag in a rigid container before pumping so that an exit
port of the bag is aligned with a hole in the rigid container.
3. The method of claim 2 wherein the step of providing includes
using a bag that is substantially larger than the rigid container
so that excess bag material is present when the bag is filled and
is in the rigid container.
4. The method of claim 3 wherein the step of providing further
includes arranging the bag so that more excess bag material is
disposed away from the bag exit port.
5. The method of claim 2 wherein the bag plumps as the region
between the two lower plies fills with air until a portion of the
bag is visible above the rigid container and the method further
includes using the visible portion of the bag as an indicator that
the bag is substantially empty.
6. The method of claim 1 wherein the step of pumping includes
connecting the bag to a source of pressurized air, the pressurized
air having a desired pressure the value of which depends on a yield
strength of a material used to make the plies, a total thickness of
the plies, and a smallest diameter of the bag when the bag is
expanded.
7. The method of claim 1 wherein the step of providing includes
forming an air input conduit and the step of pumping includes:
connecting a first end of the air input conduit to a lower region
of the bag so that air traveling through the conduit can enter a
region between the two lower plies; and connecting a second end of
the air input conduit to a source of pressurized air.
8. The method of claim 1 wherein the step of allowing is performed
when the contents have reached a predetermined level.
9. The method of claim 1 wherein the bag is arranged in the rigid
container such that folds of excess material from collapse of the
emptying bag are pulled taut as the region plumps, thereby at least
significantly delaying blockage of the exit port by bag
material.
10. An arrangement enhancing output of viscous contents of a bag
including: an air input port formed on a multiple-ply bag, the
multiple-ply bag including a plurality of plies of substantially
identical perimetral extent, at least one edge of each ply being
joined to at least one respective edge of another ply, the air
input port being connectable to a source of pressurized air; an
interply region between two plies of the plurality of plies of the
bag with which the air input port is in fluid communication so that
the interply region can fill with pressurized air from a source of
pressurized air when a source of pressurized air is connected to
the air input port; a drain extending from an interior of the bag
to an exterior of the bag allowing contents of the bag to be
emptied when present; a portion of the bag acting as a bottom of
the bag; and an inner of the two plies having a bottom part at
least partially overlying the bottom of the bag and being arranged
so that an increasing portion of the bottom part of the inner ply
can become a wall part of the inner ply substantially non-parallel
to a the bottom of the bag to increase a depth of the bulk material
remaining in the bag.
11. The arrangement of claim 10 wherein the air input port is
attached to a first end of an air input conduit and a second end of
the air input conduit can be connected to the source of pressurized
air.
12. The arrangement of claim 10 wherein the plies include upper
plies and lower plies, the upper plies and the lower plies being
joined at respective edges to form a seam along at least a portion
of a circumference of the bag, the bag thus formed being a pillow
bag.
13. The arrangement of claim 10 wherein the source of pressurized
air provides air at a pressure less than a desired pressure
determined according to the formula 2 p desired t D ,where .tau. is
a yield strength of a material used to make the plies of the bag, t
is a total thickness of the plies, and D is a smallest diameter of
the bag when it is expanded.
14. The arrangement of claim 10 wherein the bag is formed so that
the bonded edges of the plies lie in a vertical plane when the bag
is in use, opposite side edges of the plies being bonded from top
edges to bottom edges, and the bag further includes: a diagonal
seam extending from a point along each side edge to a respective
point along the top edge; an unbonded portion of the top edge
between the points at which the diagonal seams meet the top edge;
the diagonal seams defining edges of an integral filling conduit of
the bag and the unbonded portion of the top edge being a mouth of
the integral filling conduit.
15. The arrangement of claim 10 wherein the bag is a fitted bag cut
from a length of a gussetted web of multiple-ply bag material and
sealed on its ends, the sealed ends partly defining the interply
regions.
16. A method of using the bag of claim 10 including the steps of:
connecting a first end of an air input conduit to the air input
port of the bag after the bag has been filled with bulk material;
connecting a second end of the air input port to the source of
pressurized air so that pressurized air can travel through the air
input conduit to the interply region; and allowing pressurized air
to enter into fluid communication with the interply region via the
air input conduit and the air input port so that a bottom portion
of the inner ply can urge the bulk material toward an exit port of
the bag.
17. The method of claim 16 wherein the bag is arranged in a rigid
container and the exit port of the bag is substantially
peripherally disposed in a bottom of the rigid container and the
predetermined level is a level at which the bottom portion of the
inner ply can assume a slope toward the exit port.
18. The method of claim 16 wherein the bag is disposed in a rigid
container and the exit port of the bag is disposed in a wall of a
rigid container adjacent a bottom of the rigid container and the
predetermined level is a level at which the bottom portion of the
inner ply can assume slope toward the exit port.
19. The method of claim 16 wherein the step of connecting the
second end is performed during a setup of the bag in the rigid
container.
20. The method of claim 16 wherein the step of connecting the
second end is performed when the bulk material reaches a level at
which pressurized air can inflate the interply region and cause the
inner ply to urge the bulk material toward the exit port.
21. The method of claim 16 wherein the step of allowing is
performed when a pressure exerted on the inner ply by the
pressurized air is greater than a pressure exerted on the inner ply
by the bulk material.
22. A method of enhancing evacuation of a multiple-ply, bulk
material-filled bag including a plurality of plies substantially
identical to each other in dimension, at least one edge of each ply
being joined to a respective edge of at least one other ply, the
method including the steps of: connecting a region between two
plies of the bag to a source of pressurized air, one of the two
plies being an inner ply and another of the two plies being an
outer ply; and inflating the region between the two plies with
pressurized air from the source of pressurized air, the region
extending under the bulk material, the pressurized air causing the
inner ply of the two plies to urge the bulk material toward an exit
port of the bag.
23. The method of claim 22 wherein the step of inflating occurs
automatically when a pressure exerted on the inner ply by the
pressurized air is greater than a pressure exerted on the inner ply
by the bulk material.
24. The method of claim 22 wherein the bag is a pillow bag
comprising at least two top plies and at least two bottom plies,
the top and bottom plies being joined at edges of the plies, and
the region is between two of the bottom plies.
25. The method of claim 22 wherein the step of connecting includes
connecting an air input conduit to a source of pressurized air, the
conduit being attached to the bag so that the pressurized air can
penetrate to the region between the two plies.
26. The method of claim 22 wherein the bag is a pillow bag with an
equator at which edges of at least two upper plies of the pillow
bag are joined to respective edges of at least two lower plies and
the region is between two of the at least two lower plies.
27. The method of claim 22 wherein the step of inflating induces a
slope in the inner ply so that a portion of the inner ply near the
exit port is lower than a portion of the inner ply distant from the
exit port.
28. A method of using the arrangement of claim 10 including the
steps of: filling the bag with viscous contents; connecting the air
input port to a source of pressurized air; and opening the drain to
allow the viscous contents to exit the bag, a portion of the inner
of the two plies farthest from the drain port and highest relative
to the bottom of the bag plumping in response to pressurized air
from the source of pressurized air, the plumping portion of the
inner ply thereby pulling the bottom part of the inner ply and
causing it to increase its slope so that the increasing portion of
the bottom part of the inner ply becomes the wall part.
29. A method of enhancing drainage of viscous contents of a
multiple-ply bag, the bag including at least two plies all of
substantially identical dimension, the method including the steps
of: pulling an inner ply of two plies of the bag; changing part of
the inner ply from being part of the bottom of the bag to being a
movable wall a portion of which is substantially perpendicular to
the bottom of the bag; moving the movable wall toward a drainage
port of the bag; and urging viscous contents of the bag toward the
drainage port.
30. The method of claim 29 further including providing an interply
region defined by the two plies of the bag and connecting the
interply region to a source of pressurized air before pulling,
changing, moving, and urging.
31. The method of claim 30 further including inflating the interply
chamber by exposing the interply region to pressurized air from the
source of pressurized air and opening an exit port of the bag so
that, when a pressure balance on the inner ply created by the
contents and the pressurized air allows, air enters the interply
region.
32. The method of claim 31 wherein tension in the plies defining
the interply region increases as the interply region fills with
air, an upper portion of the interply region filling first and
pulling up on the inner ply, thereby achieving the steps of
pulling, changing, moving, and urging.
33. A method of making the arrangement of claim 10 including the
steps of: providing at least two layers of material; cutting the
layers of material to a first size and to a shape having at least
four sides; folding the layers of material in half to form a fold
delineating the layers into at least four plies with at least four
sides each, the plies including at least two upper plies and at
least two lower plies, the region being located between two of the
lower plies; bonding the plies to one another along respective
sides; forming a fill port through the upper plies so that viscous
contents can be introduced into an interior of the bag; and forming
the air input port so that air can be introduced into the interply
region, the interply region lying between the at least one inner
ply and the at least one remaining lower ply.
34. The method of claim 33 wherein the step of bonding includes
bonding respective non-fold sides of the plies to each other and
the method of making further includes bonding at least the upper
plies to one another to form a seam substantially parallel to the
fold, the seam and the bonded non-fold sides thereby sealing the
interply region.
35. The method of claim 34 wherein the seam includes upper and
lower plies and lies substantially along the fold.
36. The method of claim 33 wherein the step of forming the air
input port includes forming the air input port through all but at
least one inner ply of the lower plies.
37. The method of claim 33 wherein the step of forming the air
input port includes inserting the air input port between two plies
of the bag at a location that will become seam so that the air
input port is in fluid communication with the interply region and
with an exterior of the bag.
38. The method of claim 37 wherein the air input port is a
multiple-ply tube with interply bonds at ends of the air input
port.
39. A system for evacuating semi-flowable bulk material from a
multi-ply bag arranged within a shipping container, the system
comprising: an air input passageway extending to an interply region
of the bag that extends under liquid contained within bottom plies
of the bag supported on a bottom of the container; the interply
region of the bag being configured to contain pressurized air
accumulating initially in regions remote from a drain means for the
bag and to exclude the pressurized air from substantial upper
regions of the bag; and the bag being configured and located within
the container so that pressurized air within the interply region
counteracts liquid pressure within the bag to raise a ply of the
bag against the bulk material in regions remote from the drain
means, thereby urging bulk material toward the drain means and
increasing bulk material depth so that folds of material collecting
from bag collapse ride on the surface of the bulk material, the
surface of the bulk material being maintained at a level above the
drain means by the raised ply of the bag in the interply region,
thereby preventing blockage of the drain means by the folds of
material.
40. The system of claim 39 further including an integral filling
conduit of the bag defined by: side seams of the bag including side
edges of the plies bonded to each other; diagonal seams extending
from the side seams to top edges of the plies and defining side
edges of the integral filling conduit, the top edges including top
edges of back plies and top edges of front plies; portions of the
back ply top edges that are bonded to each other; portions of the
front ply top edges that are bonded to each other; and a mouth of
the integral filling conduit providing access to an interior of the
bag between the bonded portions of the back and front ply top
edges, the mouth extending between points at which the diagonal
seams meet the top edges.
41. The system of claim 39 wherein the interply region extends
above a top of the container when the bag is nearly empty, thereby
acting as a bag empty indicator.
42. The system of claim 39 wherein the plies defining the interply
region are held together at junctures that guide the manner in
which air accumulates at locations in the interply region remote
from the drain means.
43. The system of claim 42 wherein said junctures are mechanically
created by physically pressing the plies defining the interply
region together.
44. The system of claim 43 wherein shaped elements are pressed
downward against the plies defining the interply region to create
said junctures.
45. The system of claim 44 wherein said shaped elements are
attached to the drain means.
46. The system of claim 42 wherein said junctures are created using
adhesives to join the two plies defining the interply region
together.
47. The system of claim 42 wherein said junctures are created using
heat sealing to join the two plies defining the interply region
together.
48. A combination of a shipping container and a multi-ply bag
arranged within the container for holding a semi-fluid material
within the multi-plies of the bag for shipment with the container,
the combination comprising: an air inlet arranged in communication
with an interply region of the bag extending below an equator of
the bag and underneath the material contained within the bag; seams
of the bag being configured to contain within the interply region
low pressure air pumped into the interply region and to
substantially exclude the low pressure air from a top region of the
bag; and the interply region being arranged to be balloonable in
regions remote from a drain means for the bag so that air pressure
ballooning the interply region of the bag counteracts material
pressure applied in a bottom region of the bag to displace the
material toward the drain means.
49. The combination of claim 48 wherein the bag is arranged within
the container so that the interply region has more ballooning
capability remote from the drain means than adjacent the drain
means.
50. The combination of claim 48 wherein the container has an open
top when the material is being evacuated, and the ballooning bag
extends above the container top to provide a visual indication that
the bag is nearly empty.
51. The combination of claim 48 wherein the ballooning of the bag
commences when a material level within the bag is low enough so
that low pressure air within the interply region can displace the
material toward the drain means.
52. The combination of claim 48 wherein the plies defining the
interply region are held together at junctures that guide the
manner in which air accumulates at locations in the interply region
remote from the drain means.
53. The combination of claim 52 wherein said junctures are
mechanically created by physically pressing the plies defining the
interply region together.
54. The combination of claim 53 wherein shaped elements are pressed
downward against the plies defining the interply region to create
said junctures.
55. The combination of claim 54 wherein said shaped elements are
attached to the drain means.
56. The combination of claim 52 wherein said junctures are created
using adhesives to join the two plies defining the interply region
together.
57. The combination of claim 52 wherein said junctures are created
using heat sealing to join the two plies defining the interply
region together.
58. In a bulk material shipping container lined with a bag having a
drain for withdrawing semi-fluid contents from the bag, a method of
keeping the drain flooded with contents being withdrawn, for more
completely emptying the bag, the method comprising: applying low
pressure air to an interply region of the bag extending below an
equator seam of the bag and below the contents within the bag; and
prearranging the bag within the container to provide ballooning
room opposite the drain for the interply region so that as a
contents level within the bag lowers, air pressure balloons the
interply region of the bag opposite the drain and displaces the
contents toward the drain and keeps the drain flooded with the
contents until the bag is nearly empty.
59. The method of claim 58 further including regulating the low
pressure air to a desired pressure the value of which depends of a
yield strength of a material used to make the plies, a total
thickness of the plies, and a smallest diameter of the bag when the
bag is expanded.
60. The method of claim 58 further including using the bulk
material displaced by the interply region to keep bag material from
clogging the drain during withdrawal of the bulk material.
61. The method of claim 58 wherein the interply region is seamed to
exclude the interply region substantially from upper regions of the
bag above an equator of the bag.
62. The method of claim 22 wherein: the plies have top, bottom, and
side edges; all plies are bonded along each side edge from top to
bottom; all plies are bonded along non-intersecting diagonal seams
extending from a point along respective side edges to respective
points along the top edge, the diagonal seams defining edges of an
integral filling conduit of the bag; and a mouth of the integral
filling conduit along a portion of the top edge extending between
the points at which the diagonal seams meet the top edge, the mouth
including back layers of material bonded to each other and front
layers of material bonded to each other.
63. The method of claim 34 wherein the bag orientation is changed
so that the upper plies are back plies and the lower plies are
front plies, and the step of forming the fill port includes the
steps of: bonding the plies to each other along diagonal seams each
terminating at one end in a respective one of two opposite bonded
non-fold sides at a point between the seam substantially parallel
to the fold and a non-fold side opposite the fold, the diagonal
seams each terminating at another end along the non-fold side
opposite the fold, the diagonal seams thereby defining edges of an
integral fill conduit of the bag; removing flaps of material
extending from the diagonal seams to respective corners of the
plies; bonding the back plies to each other along at least a
portion of the non-fold side opposite the fold; and bonding the
front plies to each other along at least a portion of the non-fold
side opposite the fold; the bonded back plies and bonded front
plies defining a mouth of the integral fill conduit providing
access to an interior of the bag, the mouth thereby being the fill
port of the bag.
64. The combination of claim 48 wherein the seams of the bag
include side seams along opposite edges of the bag and diagonal
seams extending from the side seams to a top of the bag to define
an integral conduit of the bag, a mouth of the integral conduit
extending between points at which the diagonal seams intersect the
top of the bag.
65. A container bag having at least two lower plies, which
container bag is drained via a top discharge means, comprising: an
air-tight interply region formed between the two lower plies; an
air input passageway extending to the interply region for pumping
air into the interply region; and junctures between the two lower
plies within the interply region guiding the manner in which air
entering the interply region accumulates.
66. A container bag as described in claim 65 wherein said junctures
cause air entering the interply region via the air input passageway
to accumulate first at locations remote from a drain means.
67. A container bag as described in claim 65 wherein said junctures
are mechanically created by physically pressing the plies defining
the interply region together.
68. A container bag as described in claim 67 wherein shaped
elements are pressed downward against the plies defining the
interply region to create said junctures.
69. A container bag as described in claim 68 wherein said shaped
elements are attached to the drain means.
70. A container bag as described in claim 65 wherein said junctures
are created using adhesives to join the two plies defining the
interply region together.
71. A container bag as described in claim 65 wherein said junctures
are created using heat sealing to join the two plies defining the
interply region together.
Description
RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of copending
allowed parent application Ser. No. 09/237,819, filed on Jan. 27,
1999, the disclosure of which is herein incorporated by reference,
which parent application claims the benefit of U.S. Provisional
Applications Nos. 60/072,815 and 60/072,816, both filed on Jan. 28,
1998, which provisional applications are further incorporated by
reference herein.
TECHNICAL FIELD
[0002] The invention relates to bags used for shipping bulk
materials such as granular materials, powders, liquids, pastes, and
other flowable and semi-flowable bulk materials. Specifically, the
invention relates to devices and arrangements for evacuating the
bags.
BACKGROUND OF THE INVENTION
[0003] In the bulk material shipping industry, where plastic bags
in totes, such as plastic totes, are used to ship quantities of
liquids, pastes, granular materials, powders, and other flowable
and semi-flowable bulk materials, substantial quantities of the
bulk material can be left in the bag when the bag has been nearly
completely evacuated. This is true even where pumps are connected
to the drain ports of the bags, and is especially true of more
flow-resistant bulk materials, such as drywall paste and
mayonnaise. This problem with bulk material shipper bags is created
when the bag is evacuated and collapses, which leaves folds of bag
material in the tote. When the excess folds are on the bottom near
the drain, they can be sucked against the drain port, stalling the
pump.
[0004] To reduce the amount of bulk material wasted by being left
in the bag, prior inventors have tried several approaches. One
approach is to incline the bottom of the bag toward the drain port
by tilting part or all of the base of the shipping container or
even tilting the entire shipping container, plastic tote and all.
This approach can be complicated and inefficient since it requires
mechanical apparatus to tilt the container if it is not done
manually. Additionally, since this approach does little, if
anything, to hold the bag in place within the rigid container, the
bag can slide when the bottom of the container is tilted. The
sliding bag can block the drain port, which prevents removal of
further bulk material from the bag and can cause pump stalling.
[0005] Another approach is to use a special structure in the bag or
in the rigid container to squeeze the residual contents out of the
bag. In the case of special structures in the bag, one arrangement
stiffens the bag near the drain port using battens or other
stiffeners that add to the cost of the bag. Another arrangement
adds a special chamber to the bag that can be filled with
pressurized air to squeeze the contents from the primary chamber.
This arrangement requires the addition of material to the bag
solely for the purpose of squeezing the contents of the primary
chamber, which increases cost and complexity of manufacture and is
inelegant. Additionally, there is no way to prevent pump stalling
by excess folds of bag material from blocking the drain port at low
bulk material levels. Squeezing the bulk material from the bag in
this manner also requires relatively high pressure. To resist the
high pressure, reinforced bag material or external
pressure-resistant containers must be used that are more expensive
than conventional bags and containers.
[0006] In the case of special structures in the rigid container,
prior inventors have used piston arrangements, rollers, and other
external squeezing arrangements. A more passive special rigid
container is the pressure-resistant container discussed above.
These clearly add significant cost and complexity to the rigid
container. Though blockage of the drain port by excess bag material
is not as prevalent in these arrangements as it is in arrangements
using inflatable chambers, neither is there a way to prevent such
blockage.
[0007] Another technique for reducing blockage of the drain port is
to leave the plunging arrow used to puncture the shipper bag
through the drain port extended into the bag. When the bag is
evacuated, the plunging arrow presents itself as an obstacle to
blockage of the drain port. This delays or reduces the amount of
blockage, but a significant amount of bulk material is still left
in the bag.
[0008] Another prior art device, known as an antivacuum device, can
be attached to the drain port to reduce and/or delay blockage of
the drain port. The antivacuum device is a cylinder that extends
into the bag interior from the drain fitment. A plurality of holes
are cut in the sides of the cylinder so that bulk material can flow
through the holes if the main opening of the cylinder is blocked by
folds of bag material. While this does reduce or delay blockage of
the drain port and the amount of wasted bulk material, a
significant amount of bulk material is left behind. Additionally,
the antivacuum device undesirably increases the cost and complexity
of bag manufacture.
[0009] A disadvantage of all prior attempts to enhance evacuation
of shipper bags and reduce wasted bulk material is that they
generally require human intervention during evacuation. Prior
arrangements cannot simply be hooked up and allowed to operate
until all bulk material that can be has been evacuated. Rather, a
human attendant must do something during evacuation to initiate the
evacuation enhancement.
[0010] With the disadvantages of the prior art, there is a need for
a simple, inexpensive, and elegant way to enhance shipper bag
evacuation. There is also a need for a liquid shipper arrangement
that avoids or at least significantly delays sucking of excess bag
material against the input of the drain port or other drain means
for the bag. An enhanced-evacuation shipper bag that does not
require human intervention during evacuation is also needed.
[0011] An additional problem with pillow-type shipper bags is that
they generally lack a filling conduit or snout that would enhance
ease of filling the bags. Typically, pillow bags include fitments
in their tops for filling the bags through fill hoses that can be
connected to the fitments. This arrangement is meant for users who
can pump bulk material into the bag through the fill hoses.
However, many users either do not want or cannot pump their bulk
material and instead pour their bulk material into bags, such as
open-top pillow bags and fitted bags equipped with snouts. Open-top
pillow bags tend to be more difficult to close than snout-equipped
fitted bags and are more susceptible to contamination, but
snout-equipped fitted bags are more expensive than open-top pillow
bags. In addition, prior attempts to incorporate snouts into
pillow-type bags have failed for one reason or another.
Consequently, there is a need for bags that solve the problems
associated with shipper bag evacuation as enumerated above and
that, optionally, include a snout for easy filling of the bag.
SUMMARY OF THE INVENTION
[0012] My invention takes advantage of existing shipper bag
construction to provide an inflatable chamber that enhances
evacuation of shipper bag contents without requiring human
intervention during evacuation. In one embodiment, I add an air
input port and conduit to the lower half of a pillow bag opposite
the drain port. The input port allows inflation of an interply
region between two lower plies of the pillow bag using low pressure
air. The air input conduit is preferably connected to a source of
pressurized air at the outset of evacuation. The interply region
inflates as the bulk material is removed from the bag through the
drain port. As the interply region inflates, the inner ply or plies
rise near the air input port so that the part beneath the bag
contents in that area effectively lifts the fluid and becomes an
advancing wall. Unlike prior arrangements, however, the advancing
wall doesn't squeeze the bag contents out the drain port. Rather,
the advancing wall simply inclines the bottom of the bag a little
at a time and raises the level of the bag contents so that the
drain port is always completely covered by bulk material. Because
the level of the contents is kept above the drain port until very
near the end of evacuation, folds of material that collect as the
bag collapses float or ride on the surface of the bulk material and
do not block the drain port. Additionally, the inner ply is kept
taut at all times by the air pressure, pulling the bag material
away from the drain port and further preventing or at least
significantly delaying drain port blockage. The combination of the
drain port and the plumped interply region also holds the bag in
place so that it does not slide around in the container if the
container is moved.
[0013] In another embodiment, I slightly modify the construction of
a pillow bag to enhance the performance of the inflatable chamber.
Here I use half the initial number of layers of material as in
conventional pillow bags, fold them in half to form the upper and
lower plies, and bond the non-fold edges of the plies. Depending on
particular needs, I can leave the fold unbonded, bond all plies
together very near the fold, bond the layers on the fold, or bond
one set of plies parallel to the fold at an advantageous location.
This adds little to the cost and complexity of manufacture, yet can
greatly improve performance of my invention. To enhance performance
of this embodiment when it includes a corner drain port, I rotate
the bag 45.degree. relative to the tote upon insertion of the bag
in the tote so that the bond defining the interply regions is
parallel to a diagonal of the tote.
[0014] An additional optional feature of my invention is the
incorporation of an integral filling conduit, which I prefer to
call a snout, into evacuation-enhancing pillow-type bags. I have
found a way to include a snout on such pillow bags without
significantly increasing cost or difficulty of manufacture. When
used in my inflatable, evacuation-enhancing pillow bag, I prefer to
form seals between the plies of the bag: one along the side(s) of
the bag opposite the drain port and one along the side(s) including
(and nearest to) the drain port. The seal opposite the drain port
is preferably formed at a point on the side of the bag below the
snout. The amount of bag material leading to the drain on either
side of the seal is preferably substantially equal, though the
exact position can vary depending on the particular application.
The other seal is at the midpoint of the bag. The air input port is
formed just below the seal opposite the drain. The result of this
configuration is a minimization of bulk material left in the bag
when no more bulk material can be discharged, significantly
increasing the amount of bulk material evacuated from the bag, thus
saving the user bulk material, time, and money. I take two or more
rectangular layers of material and bond their edges into a shape
that will yield a bag with a snout, such as a rectangle with the
long base of a trapezoid on one side. Flaps of material are left
next to the sides of the trapezoid, and I cut these off to
facilitate handling and filling of the bag. Alternatively, I can
use one or more rectangular layers of material folded in half, then
bond their edges along the sides to form the same
trapezoid/rectangle shape. In this alternative, the fold lies on
the side of the rectangle opposite the long base of the trapezoid
and may not need to be sealed, depending on the particular
application and the desires of the user. A drain can be included in
one side of either variation of the bag to allow discharge of the
bag's contents.
[0015] With the sides of the evacuation-enhancing snout bag thus
sealed, it is ready for use. As with the other forms of my
evacuation-enhancing pillow-type bulk material shipper bags, I
position the bag in a rigid container, such as a plastic shipping
tote, so that the seams lie at the midpoints of opposing sides of
the container. Alternatively, I can position the bag so that the
seams lie in the corners of the tote, depending on the particular
needs of the user. The position of the seams must be taken into
account when making the bag, however, to ensure adequate material
for proper sizing of the bag. With the bag positioned as desired, I
then attach the snout to a source of bulk material, preferably
using a spanner bar, and fill the bag. When the bag is full, I
remove the snout from the spanner bar (if used), tie it off, and
ship it. My invention thus provides a much less costly snout bag
than prior art arrangements.
[0016] Another variation of my invention is intended for use with
top discharge systems for container bags. In these systems, the
container bag is emptied via its open top or an opening in its top
rather than by a bottom drain. Numerous methods can be used for
this purpose; however, the most common are dip tubes, hoses, or
other drain means that rest with their input ends under or on top
of the material to be discharged. A suction pump is often used in
conjunction with these methods to drain the contents of the bag;
however, gravity acting via a siphon can also be used.
[0017] Of the methods listed in the preceding paragraph, the dip
tube is the most popular. It will generally be inserted straight
downward through the open top of the bag, an upper fill port, or
some other opening located in the approximate center of the upper
bag surface, but can be angled downward so that its input end is
close or adjacent to the bottom of the bag at a side or corner of
the bag. In this situation, one of the bag configurations
previously described could be used to help facilitate removal of
bag contents. However, whether a dip tube or some other top
discharge method is used, I have discovered that it is beneficial
to hold the upper ply of the two bottom plies down in the vicinity
of the input end to facilitate the pooling of material in this
location and to help avoid clogging of the input end with excess
bag material.
[0018] Various means can be used to hold the two lower plies
together. This can be accomplished via mechanical means, including
the use of a properly designed input end for the drain means or
other physical structures to press the upper ply down against the
lower ply along appropriate junctures. It can also be accomplished
by bonding the two plies together via heat seals, adhesives,
double-sided adhesive tapes, or other means along the desired
junctures. In the usual case, the input end of the drain means
being used is positioned so as to evacuate material from the bottom
of the bag at a location close to its center. Thus, for most
purposes, I have found it advantageous to create junctures between
the bottom plies at locations and in a manner calculated to
gradually urge the contents of the bag to a central drain area
where the input is located as the interply region inflates. This
can be done by creating junctures that encourage symmetrical
filling of the interply regions at the bottom of the bag beginning
at the periphery of the bag and moving gradually inward towards its
center as the bag contents are emptied. However, the methods
described herein are versatile and can be used in numerous ways to
facilitate the top discharge of container bags.
[0019] All of my embodiments overcome all the disadvantages of the
prior art discussed above. I enhance evacuation of the bags while
keeping costs low and achieving a level of elegance of use. An
additional benefit is that, when the interply region is
substantially fully inflated, a portion of the bag rises out of the
rigid container and acts as an indicator that the bag is empty. My
bag and system can be used in any system that uses bags in rigid or
semi-rigid containers where the bag has an inflatable portion with
at least two plies. This includes any bulk material shipping system
using, for example, closed-top pillow bags, open-top pillow bags,
and fitted bags. Typically such bags will be drained via a drain
port, dip tube, or other drain means with an input in, at, or near
the bottom of the container. I do not employ external bladders,
tilting bottoms, stiffening battens, or a pressure-resistant outer
container as do prior art devices. Instead, I take advantage of the
structure of the bags to form an inflatable air chamber between the
plies of the bags using edge and other seals, bonds, or seams, the
air chamber extending beneath some or all of the contents of the
bag. My invention can be used with liquids, powders, pastes, or any
other suitable bulk materials. Additionally, evacuation enhancement
occurs automatically as bag contents level decreases so that no
human intervention is required between setup and take down of the
bag.
DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A is a schematic view of a filled pillow bag according
to an embodiment of the invention.
[0021] FIGS. 1B and 1C are schematic views of the bag of FIG. 1A in
alternative orientations.
[0022] FIGS. 1D and 1E are schematic views of the invention applied
to a fitted bag in different orientations.
[0023] FIG. 2A is a schematic view of a filled pillow bag according
to another embodiment of the invention.
[0024] FIGS. 2B and 2C are schematic views of the bag of FIG. 2A in
alternative orientations.
[0025] FIG. 3 is a schematic view of the pillow bag of FIG. 1A
filled and in a plastic shipping tote according to one aspect of
the invention.
[0026] FIG. 4 is a cutaway schematic view of the filled bag and
plastic tote of FIG. 3.
[0027] FIG. 5A is an enlarged schematic view of the juncture of the
air input port and air input conduit shown within the dashed circle
area in FIG. 4.
[0028] FIG. 5B is an enlarged schematic view of the juncture of the
preferred air input port and the bag as shown in FIG. 8.
[0029] FIG. 6 is a cutaway schematic view of the bag and plastic
tote of FIG. 4 after a substantial portion of the contents of the
bag have been evacuated and the interply region has inflated.
[0030] FIG. 7 is a schematic view of the pillow bag of FIG. 2A
filled and in a plastic shipping tote according to an aspect of the
invention.
[0031] FIG. 8 is a cutaway schematic view of the filled bag and
plastic tote of FIG. 7.
[0032] FIG. 9 is a cutaway schematic view of the bag and plastic
tote of FIG. 8 after a portion of the contents of the bag have been
evacuated and the interply region has inflated.
[0033] FIG. 10 is a cutaway schematic view of the bag and plastic
tote of FIG. 8 after a substantial portion of the contents of the
bag have been evacuated and the interply region has inflated.
[0034] FIG. 11 is a schematic side view of two layers of material
used to make the invention according to an aspect of the invention
yielding the bag shown in FIG. 2A.
[0035] FIG. 12 is a schematic side view of the two layers of
material shown in FIG. 11 after they have been folded.
[0036] FIG. 13 is a schematic side view of the two layers of
material shown in FIG. 12 after the non-fold edges have been
bonded.
[0037] FIGS. 14-16 are schematic top views of the layers of
material shown in FIGS. 11-13.
[0038] FIGS. 17 and 18 are schematic top views of the layers of
material shown in FIGS. 11 and 12 as used in a variation of the
invention resulting in the bag shown in FIG. 19.
[0039] FIG. 19 is a schematic top view of the layers of material
shown in FIG. 13 according to the variation of the invention of
FIGS. 17 and 18.
[0040] FIG. 20 is a schematic top view of two layers of material
used to make the invention according to an aspect of the invention
yielding the bag shown in FIG. 1A.
[0041] FIG. 21 is a schematic top view of the layers of FIG. 20
after they have been folded or cut and stacked and the non-fold or
non-cut edges have been bonded.
[0042] FIG. 22 is a schematic top view of the layers of FIG. 21
after the fold or cut edge has been bonded.
[0043] FIGS. 23-25 are schematic side views of the layers shown in
FIGS. 20-22.
[0044] FIGS. 26-31 are schematic side views of the invention in use
illustrating the manner in which the interply regions inflate as
bag contents are evacuated.
[0045] FIG. 32 is a schematic front view of the pillow bag form of
the invention with an integral fill conduit according to another
aspect of the invention.
[0046] FIG. 33 is a top schematic view of two exemplary pieces of
material used to form a two-ply version of the invention shown in
FIG. 32.
[0047] FIG. 34 is a schematic view of the bag of FIGS. 32 and 33 as
it appears when filled.
[0048] FIG. 35 is a close-up of the air input conduit of the bag of
FIGS. 32-34.
[0049] FIG. 36 is a cross section of the bag of FIG. 32 taken along
the line 36-36.
[0050] FIG. 37A provides a schematic view of a the bottom of a bag
illustrating a first configuration for placement of interply
junctures.
[0051] FIG. 37B provides a schematic view of the bottom of a bag
illustrating a second configuration for placement of interply
junctures.
[0052] FIG. 37C provides a schematic view of the bottom of a bag
illustrating a third configuration for placement of interply
junctures.
[0053] FIG. 37D provides a schematic view of the bottom of a bag
illustrating a fourth configuration for placement of interply
junctures.
[0054] FIG. 37E provides a schematic view of the bottom of a bag
illustrating a fifth configuration for placement of interply
junctures.
[0055] FIG. 37F provides a schematic view of the bottom of a bag
illustrating a sixth configuration for placement of interply
junctures.
[0056] FIG. 38 is a cutaway schematic side view of a bag embodiment
in a plastic shipping tote with a dip tube configured to
mechanically create an interply juncture by holding the top ply of
the interply region in place against the bottom ply.
[0057] FIG. 39A is a schematic view from above the sixth
configuration for placement of interply junctures, showing its
inflating bottom ply shortly after the process of draining the
bag's contents has begun.
[0058] FIG. 39B is a schematic view from above the configuration
illustrated in FIG. 39A somewhat later in the process of draining
the bag's contents.
[0059] FIG. 39C is a schematic view from above the configuration
illustrated in FIG. 39B after more of the bag's contents have been
evacuated.
[0060] FIG. 39D is a schematic view from above the configuration
illustrated in FIG. 39C after most of the bag's contents have been
evacuated.
DESCRIPTION OF THE INVENTION
[0061] My invention can be applied to most bulk material shipper
bags including closed pillow bags, snorkel-top pillow bags,
open-top pillow bags, and fitted bags. Bulk material shipper bags
commonly include at least two edge seals (heat seal, tie off, or
other type) on opposite sides or ends of the bag. Optionally, they
can have a seal around the full perimeter of the bag. In most
cases, I prefer to form seals down the edges of the layers of
material used to make the bag. I generally add a third seal to
connect the two edge seals, if such a third seal is not already
present. This third seal can be another edge seal or an internal
seal or interply bond through the plies on one side of the bag. The
seal should be placed roughly opposite the drain port at a distance
of one half the smallest dimension of the container or more away
from the drain port. The third seal should also be somewhere above
the floor of the container, preferably at or above the midplane of
the container.
[0062] A fourth seal completes an inflatable air chamber in the
interply region, and I add a fourth seal if it is not already
present. One way to form the fourth seal is to use the weight of
the bag contents, such as by placing the fold on the bottom of the
container, so that the contents hold the plies together in a
quasi-seal. Alternatively, a physical seal can be formed connecting
the two edge seals positioned under the contents or on the opposite
side of the contents from the third seal. Other seals can also be
employed, or the seals can be combined into one or more continuous
seals, but the four seals discussed above are the minimum required.
The connection to the air chamber can be made at any point in the
air chamber, but the air chamber inflates sooner and grows larger
if the connection is made higher in the container.
[0063] Referring to the accompanying Figures and using closed-top
pillow bags as an exemplary embodiment, my invention comprises a
multiple-ply bag 10 that is formed with an air input port 14 and an
air input conduit 15 that allow air 6 from a source of pressurized
air 2 to enter an inflatable air chamber formed in an interply
region 204, 205 of the bag 10, lying between an outer ply 202, 212
and an inner ply 201, 211, when certain conditions are met. The bag
10 is preferably of the pillow type and can be made with some
variations, though my preferred embodiments show the best
performance. A fill port 11 is generally included through the upper
plies 24, and a drain or exit port 12 may be formed in the lower
plies 25 in a manner consistent with the state of the art to allow
appropriate connections to be made while preventing leakage. For
closed-top pillow bags, the fill port 11 includes a fitting onto
which a cap can be placed to seal the bag after filling. For
snorkel-top bags, the fill port 11 is the opening of the snorkel
and must be held open with a spanner bar on a fill head until the
bag is filled, at which point the spanner bar is removed and the
snorkel is tied off to close the bag. For open-top bags, the fill
port 11 is simply the opening left by the absence of a top. For
closed-top bags, I prefer to have the fill port 11 centrally
located in the upper plies 24 so that it sits in the center of the
top of the filled bag 10. While the drain port 12 can be formed
anywhere in or near the bottom 4 of the bag 10, I prefer to form
the drain port 12 so that it will sit near the bottom 4 in one of
the sides of the filled bag 10. While I generally show the bag 10
as having two upper plies 24 and two lower plies 25, my invention
can be used in a bag 10 that uses more plies. Also, while I show
the plies as being rectangular, they can have any suitable shape
that allows my invention to perform in a satisfactory manner. Where
I speak of bonds and seams, these can be made in any manner
consistent with the art, though I prefer to use heat sealing to
create the bonds and seams for simplicity of manufacture and cost
reduction. Further, the terms "upper" and "lower" are not meant to
limit the orientation of the bag in use but are used to aid in the
description of the exemplary embodiment.
[0064] In one form of my invention, best seen in FIGS. 1A, 3-6, 20,
22, 23, and 25, I form the bag 10 by taking four layers of plastic
and bonding their edges together to form seams 16-18 and 192. The
four layers can be made from two rectangular layers 20, 21 cut in
half as shown in FIGS. 20 and 23 and stacked as shown in FIG. 25.
The top two layers become upper plies 24 of the bag 10 and carry
the fill port 11. The other two become lower plies 25 of the bag 10
and carry the drain port 12. The seams 16-18 and 192 form an
equator seam of the bag 10 that seals an upper interply region 203
between the upper plies 24 of the bag 10 from a lower interply
region 204 between the lower plies 25 of the bag 10. The equator
seam is the equivalent of the four seams discussed above. The air
input port 14 in this embodiment is formed in the lower plies 25
and allows access to the lower interply region 204. I prefer to
form the air input port 14 by placing it between the lower plies 25
across what will be one of the seams before the plies are bonded as
shown in FIG. 5B. Alternatively, the input port 14 can be cut from
the outer ply 212 as shown in FIG. 5A and can include a fitting
similar to that used in drain ports in the art.
[0065] The air input port 14 can be kept sealed using a piece of
air-tight flexible material, such as plastic film, and another
piece of material, such as an elastomeric band, to hold the
air-tight material on the air input port 14. The outside end of the
air input port 14 can include a fitting for easier attachment of
the air input conduit 15. The air input port 14 itself can be
constructed from one or more plies of the same material used to
make the bag 10. Where more that one ply are used, the plies should
be bonded together at the ends of the air input port 14. In use,
the air input conduit 15 can be held on the air input port 14 using
an elastomeric band because of the low pressures within the joint
between the air input port 14 and the air input conduit 15.
[0066] In a variation of the first embodiment best seen in FIGS.
20-25, I form the pillow bag 10 from two layers 20, 21 of material
cut into rectangles and fold the layers 20, 21 in half to form four
rectangular plies 201, 202, 211, 212. As they appear in the FIGS.,
the left halves of the layers 20, 21 become the lower plies 25 and
carry the exit port 12, while the right layers become the upper
plies 24 and carry the fill port 11. After folding the layers 20,
21, I bond the non-fold edges of the plies together to form seams
16-18 which make a partial equator seam on the bag 10. Here,
opposing seams 16, 18 are the first and second seams discussed
above, and the intermediate seam is the second seam. The fold side
19 of the bag 10 can be treated in one of three ways: the layers of
material can be bonded to each other along the fold 19 in an
interlayer bond 191; the layers can be bonded at the fold so that a
seam or interply bond 192 can be formed with all four plies along
or near the fold; or the layers can be bonded parallel to the fold
in a top interlayer bond 23, but some distance away from the fold
19. Any of these three treatments of fold side 19 is the equivalent
of the fourth seam discussed above.
[0067] The bag 10 can be oriented with the equator seam horizontal,
as shown in FIGS. 1A and 2A, or vertical, as shown in FIGS. 1B, 1C,
2B, and 2C. In the vertical orientation, the bag can be arranged
with the vertical seals 16, 18 at the midpoints of the sides of the
container 1 as seen in FIGS. 1B and 2B. For bags using corner drain
ports, I prefer to place the vertical seals 16, 18 at the corners
of the container 1, as seen in FIGS. 1C and 2C, when I orient the
equator seam or partial equator seam vertically.
[0068] Where I bond the layers 20, 21 along the fold, best
illustrated in FIGS. 21 and 24, I form the interlayer bond 191
before folding. The interlayer bond 191 completes the equator seam
and seals the upper interply region 203 from the lower interply
region 204 in the completed bag 10. In both of these variations, I
still form the air input port 14 in the lower plies 25 to allow
access to the lower interply region 204.
[0069] In another variation, I prefer to bond the layers of
material parallel to the fold and between the fold and the fill
port 11 so that the interlayer bond 23 is a boundary of two
interply regions 205, 206 of different dimensions. (See, e.g.,
FIGS. 2A, 2B, 2C, 7-19 and 26-31). In those embodiments, the larger
of the interply regions is a trans-fold interply region 205 that
extends away from the fill port 11 on the top of the filled bag 10,
down the side of the filled bag 10, along the bottom 4 of the
filled bag 10, and up the lower halves of the non-fold sides of the
filled bag 10 to the partial equator seam including seams 16-18. In
this case, the plies are continuous from the interlayer bond 23 to
the seam 17 opposite the fold line, but I will still refer to the
upper portions of the plies as "upper plies" and to the lower
portions of the plies as "lower plies" for the sake of simplicity.
I prefer to form my air input port 14 to allow access to the larger
interply region 205, preferably in one of the seams 16, 18 between
the interlayer bond 23 and the fold line 19. Alternatively, the air
input port 14 can be cut through the outer ply 202 in the top of
the bag 10 and include a fitting. To further enhance performance of
the invention, I form diagonal seams 26, 27 from the exit side of
the bag 10 to the sides extending between the exit side and the
fold side. The seams join all four plies and form two pieces or
flaps 28, 29 of extra material that can be trimmed away.
[0070] My invention can be applied to typical multiple-ply fitted
bags, as shown in FIGS. 1D and 1E, in much the same fashion as I
apply it to pillow bags. The typical fitted bag will be cut from
nested gussetted tubes of bag material. Adjacent cut gusset edges
will be sealed to form the top and the bottom of the bag, each with
gusset lines that are visible when the bag is filled, as is known
in the art. The bottom seals are made on the individual plies prior
to nesting, as is also known in the art. Of course, what I refer to
as the top and bottom of the bag can be sides of the bag if the
user wishes to change the bag's orientation. For a fitted bag with
gusset lines on the top and bottom, the plies on the top have
already been sealed to form interply bond 16. I apply additional
interply bonds 17, 192 down opposite corners of the bag to define
the interply regions. In a fitted bag with the gussets on the
sides, I form one interply bond 16' along a top edge, another
interply bond 17' on one gusset lined side from a corner at the end
of the first interply bond to the lower opposite corner, and I use
the sealed cut gusset edges of the other gusset lined side as a
third interply bond 192' to define the interply regions. These
three interply bonds 16', 17', and 192' are the equivalents of the
interply bonds 16, 17, and 192 of FIG. 1D. The air input port
passes through one of the interply bonds 16, 16', 17, 17', 192,
192'. Additional interply bonds can be added to enhance evacuation
in much the manner described above.
[0071] In use, I place one of my bags 10 in a rigid container 1,
such as a plastic tote, and align its exit port 12, if present,
with a hole in the tote. In many cases, this is best accomplished
by using a cassette to hold the bag 10 during insertion and
filling. The cassette is configured to hold the bag as it fills so
that a minimum of bag material is trapped in the container during
filling, which could reduce the shipped amount of bulk material.
The cassette is typically made of an inexpensive, lightweight
material, such as cardboard, and is particularly useful with
closed-top pillow bags. With closed-top pillow bags, I place the
bag 10 on its cassette in the bottom of the container 1, attach a
fill hose, and fill the bag 10 with bulk material or viscous
contents 5, the bag 10 unfolding as it fills. For best evacuation
results with bags using corner drain ports, I place the bag 10 in
the tote so that the side of the bag 10 opposite the drain port 12
is parallel to a diagonal of the tote (a 45.degree. rotation of the
bag 10 relative to the tote). I also situate the bag 10 so that
there is more bag material near the air input port side of the
tote. Once the bag 10 is full, I seal the fill port 11 in whatever
manner is appropriate for the particular type of bag 10 used. The
filled bag 10 and plastic tote 1 are then shipped to a customer,
who connects the drain port 12, if present, to a drain conduit 13
and starts using the contents 5, beginning evacuation of the bag
10. For some contents 5, the customer also attaches a pump 3 to
draw the contents 5 from the bag 10. Other bulk materials 5 do not
require a pump 3 and can simply be allowed to exit the bag 10 under
the influence of gravity. For open-top bags and other bags without
drain ports, the contents 5 can be drained using a hose, dip tube
or other drain means connected to a pump 3 or acting as a
siphon.
[0072] The air input conduit 15 can be connected to a source of
pressurized air 2 at any time, though I prefer that it be connected
during initial set up at the site of bag evacuation after the exit
port 12 is connected to the drain conduit 13 or other drain means
is in place. The customer could also wait to connect the air input
port 14 until the contents 5 had reached a particular level or
until it became difficult to evacuate, but this requires human
intervention that my invention intends to eliminate. Connecting the
air input conduit 14 to the source of pressurized 2 air at any time
other than initial setup is less efficient than my preferred choice
of connecting the air input port 14 at initial set up since the
alternatives require the customer to go back to the bag 10 to
connect the air input conduit 15, check the level of the contents
5, monitor difficulty of contents evacuation, and/or wait until the
pump 3 stalls.
[0073] The source of pressurized air preferably provides enough
pressure for my invention to work, yet not so much as to burst the
bag 10. I have found that the pressure required varies with the
strength of the bag and as the inverse of the bag size. Bag
strength is, of course, directly proportional to the total
thickness of the plies of the bag and the strength of the bag
material. The particular pressure p.sub.desired of the air provided
by the source of pressurized air 2 will thus vary depending on the
particular material strength .tau. of the bag (I prefer to use
yield strength), total thickness t of the bag's plies, and the
smallest diameter D of the bag when the bag is expanded and can be
approximated using the formula 1 p desired t D .
[0074] For a typical shipper bag-in-box arrangement, this formula
indicates that the source of pressurized air 2 preferably should
provide air at a pressure of no more than from about 1 psig to
about 5 psig. I prefer to use a pressure in the range of from about
0.05 psig to about 0.5 psig (about 0.2 psig, for example), which
works quite well for the typical arrangement, using an intermediate
bulk container in the 300 gallon range and using a total film
thickness of about twelve thousandths of an inch (mils). Whatever
pressure is used, as long as it does not exceed the value given by
the formula above, it will be far less than the pressure required
by the prior art for the same container size and total ply
thickness. A pressure regulator can be used to ensure that the
appropriate pressure is maintained. The source 2 can be
depressurized shop air or can be a separate source, such as a
compressor or fan.
[0075] My invention begins to more noticeably enhance evacuation
when the level of the contents 5 drops to a point where air 6 can
enter the interply region 204, 205. Using the lower interply region
204 of the equator-seamed pillow bag 10, air 6 begins to enter the
interply region 204 when the pressure exerted on the inner ply 211
by the air 6 is greater than the pressure exerted on the inner ply
211 by the contents 5 of the bag 10. Using the trans-fold interply
region 205, the interply region 205 fills in a much more complex
manner that depends in part on exactly how the bag 10 is positioned
and filled in the tote 1, as well as the particular location of the
air input port 14.
[0076] With particular reference to FIGS. 8-10 and 26-31, for the
preferred connection of the air input port 14 to the interply
region 205, the interply region 205 fills as the contents 5 of the
bag 10 are evacuated. Initially, the top part of the outer ply 202,
212 balloons or plumps up and the top part of the inner ply 201,
211 urges the contents 5 to move away from the side wall as seen in
FIG. 9, much like a wedge. As the bag contents level continues to
drop, it is urged farther and farther from the side wall.
Eventually the bag contents level drops enough and the interply
region plumps enough that the bottom part of the inner ply 201, 211
is pulled up and toward the drain port 12 as seen in FIGS. 9, 10,
and 28-31.
[0077] The plumping of the interply regions 204, 205 of both
variations has numerous effects. First, the bottom 4 of the bag 10
above the interply region 204, 205 effectively gradually becomes a
moving wall portion 31 of the bag 10 that urges the contents 5
toward the drain port 12 in the direction indicated by the arrows
in FIGS. 6, 9, 10, and 27-31. In the process of becoming the moving
wall portion 31, the bottom 4 of the bag 10 inclines, allowing
gravity to act on the contents 5 for a reduction in the amount or
material retained in the bag 10 when no more material can be
removed.
[0078] Because the volume of the bag 10 interior is effectively
reduced by the moving wall portion 31, the level of the bag
contents 5 in the remaining interior is kept above the top of the
drain port 12 until nearly all of the contents 5 have been
evacuated. In ordinary shipper bags, evacuation of the contents
without allowing air into the interior of the bag causes the bag to
collapse, yielding piles and folds of material floating on the free
surface of the contents. The drain port of the ordinary shipper bag
can become blocked by the folds and piles of bag material when the
contents level drops below the top of the drain port. Drain port
blockage can cause pump stalling and trap a significant amount of
bag contents within the bag. However, the inflation of the interply
region 205 of my shipper bag significantly delays or eliminates
this blockage by keeping the level of the contents 5 above the
drain port 12 longer. As the interply region 204, 205 inflates, it
also pulls any folds 30 of the inner ply 201, 211 taut to reduce
the number of folds 30. The elimination of folds 30 of the inner
ply 201, 211 further reduces the risk of stalling the pump 3 since
it prevents or at least significantly delays the folds 30 from
being sucked against the drain port 12. This eliminates the need
for antivacuum devices and leaving the plunging arrow extended to
prevent suction of the folds 30 against the drain port 12.
Alternatively, my invention enhances the effectiveness of
antivacuum devices and extension of the plunging arrow if they are
still employed. As an added benefit particularly shown in FIG. 10,
the plumped bag 10 extends considerably above the top of the tote
when the bag 10 is nearly empty so that it acts as a bag-empty
indicator.
[0079] To summarize the preferred operation of the invention with
particular reference to FIGS. 26-31, prior to discharge of the bag
contents, I connect the air chamber to a source 2 of low pressure
air just sufficient to lift the contents 5 (less than one psig for
a four-foot container). During discharge of the contents 5, the
inner ply 211 of the air chamber, mostly interply region 205, moves
the contents 5 to the drain port 12 so that the bag 10 is
completely or nearly completely evacuated without human attendance.
The air 6 expands the air chamber until a force balance is reached
with the weight of the bulk material 5 (this can also be expressed
as a pressure balance between air pressure and bulk material
pressure on the inner ply). Since the air chamber extends down the
wall of the container and under the bulk material 5, it pushes the
bulk material 5 away from the wall as it inflates. As the volume of
the bag contents 5 diminishes, the air chamber continues to expand
by inflation.
[0080] The air chamber and the bag 10 are configured so that the
air chamber expands to the greatest extent in a region of the
container away from the drain 12, thus forcing the contents 5
toward the drain 12. As the chamber expands, the increased area on
which the air pressure acts increases the force exerted on the bulk
material 5 by the inner ply(ies) 201, 211 of the bag. The force
reaches a maximum when the bag is nearly completely evacuated, at
which point the bag material would normally obstruct the drain 12.
However, the bulk material 5 at the drain 12 floats adjacent bag
material above the drain 12, preventing the bag material from
blocking the drain 12 and trapping bulk material 5 in the bag.
Additionally, the inflation of the air chamber pulls the bag
material taut so that the drain 12 remains unobstructed.
[0081] The fitting of the drain 12 is locked in the container and
seals through the bag plies 201, 202, 211, 212. This anchors or
ties the bag 10 down at one point in, at, or near the floor of the
container 1. This also limits the inflation of the air chamber at
and around the drain port 12. The air chamber is also configured so
that its expansion pulls the layers 201, 202, 211, 212 of the bag
taut. When the volume of bulk material 5 left in the bag 10 is
insufficient to float the bag material above the drain 12, this
tension helps to prevent the bag material from closing off the
drain 12. The air chamber is optimally configured so that, near the
end of evacuation, all the remaining bulk material 5 is lifted off
the floor of the container 1, above the level of the drain 12. This
allows the bulk material 5 to flow down into the drain 12 as if it
were in a funnel. The bulk material 5 can be used as a fourth
quasi-seal, as seen in FIGS. 26-31. If the bulk material 5 is used
as a fourth quasi-seal, then air seeps under the bulk material 5
and expands into air chambers, including interply region 206, on
both sides of the bulk material 5 formed in the main air chamber by
the presence of the bulk material 5. This action pulls the bag
layer in front of the drain up at an angle, providing a gap for
flow of the remaining bulk material 5 to the drain port.
[0082] I can also include an integral filling conduit 110 in my
exemplary embodiment of an evacuation enhanced pillow bag 10', as
particularly shown in FIGS. 32-36. I also refer to the integral
filling conduit as a snout. With respect to this aspect of the
invention, I make reference to my U.S. Pat. No. 6,120,181, issued
Sep. 19, 2000, entitled Pillow Bag with Integral Filling Conduit,
the disclosure of which is hereby incorporated by reference. This
form of my invention is very similar in its construction and use to
that shown in FIGS. 2A, 2B, 2C, 7-19 and 26-31. To make my bag with
a snout, I prefer to start with two pieces of material 100', 100"
very much as described above and stacked so that, when folded in
half, one half of each piece of material 100', 100" forms a back
layer or ply 101', 101", and the other half of each piece of
material 100', 100" forms a front layer or ply 102', 102".
Alternatively, the back and front layers can each be their own
separate pieces of material rather than halves of larger pieces of
material. Preferably, the layers of material 100', 100" are
rectangular. I then take the two back layers 101', 101" and bond
them together to form a rear interlayer or interply bond 23', which
is similar in location and function to the top interlayer bond 23
mentioned above. I also form the rear snout interlayer bond 111'. I
insert an air input conduit 15' between the back layers 101', 101"
to allow access to a back interply region 120 between the back
layers 101', 101" as seen particularly in FIG. 35. The back
interply region 120 is similar in form and function to the smaller
interply region 206 described above.
[0083] Next I take the two front layers 102', 102" and bond them
together to form a front interlayer or interply bond 108, as well
as the front snout interlayer bond 111". I then bond all four
layers 101', 101", 102', 102" together to form the sides and base
of the rectangle and the sides of the trapezoid with seams or seals
16', 18', 26', 27'. Depending on the particular application of the
bag, I can also seal along the fold line 19'. If this is done
before the pieces of material 100', 100" are folded, then an
interply bond 191' is formed between the pieces of material 100',
100". If this is done after the pieces of material 100', 100" are
folded, or if this is done where each layer 101', 102', 101",102"
is its own piece of material, then an interply bond 192' is formed
between all four layers 101', 102', 101", 102". I form the drain
port 12' in the front layers 102', 102".
[0084] The seams 16', 18', 26', 27', the rear interlayer bond 23',
and front interlayer bond 108 define the back interply region 120
and a front interply region 130. While I prefer to include the
front interlayer bond 108 to improve performance of the enhanced
snout bag 10', it can be left out, in which case the fold 19' is
used to delineate the two interply regions 120, 130 in much the
same way as the variation of my enhanced pillow bag of FIGS. 2A,
2B, 2C, 7-19 and 26-31, and the bulk material 5 acts to seal the
regions from each other.
[0085] The rear and front interply bonds 23', 108, along with the
side seams 16', 18', 26', and 27', define an inflatable air chamber
in the back and rear interply regions 120, 130. The air chamber
extends from the back interply bond 107 down the side of the bag
10', under the contents of the filled bag 100', and up the opposite
side of the bag 10' to the front interply bond 108. When a user is
ready to discharge the contents of the filled bag 10', he or she
connects the air input conduit 15' to a source of pressurized air.
As the contents of the bag 10' are discharged, the air chamber
inflates, expanding the interply regions 120, 130. The inflation of
the air chamber pulls up on the inner ply 101", 102" along the side
and bottom of the bag 100'.
[0086] Here, as shown particularly in FIG. 9, I prefer to arrange
the bag 10' with the edge seams 16', 18', 26', and 27' in the
corners of the rigid container 1' and the drain port 12' protruding
from a hole in the rigid container 1'. Once the bag 10' is filled,
the air input conduit 15' runs up between the side of the bag 10'
and the side of the container 1' and over the edge of the container
1'.
[0087] Prior to discharge of the bag contents, I connect the air
chamber to a source of low pressure air just sufficient to lift the
contents (preferably less than one psig for a four-foot container).
During discharge of the contents, the inner ply 101', 102' of the
air chamber moves the contents to the drain 12' so that the bag 10'
is completely or nearly completely evacuated without human
attendance. The air expands the air chamber until a force balance
is reached with the weight of the fluid (this can also be expressed
as a pressure balance between air pressure and fluid pressure on
the inner ply). Since the air chamber extends down the wall of the
container and under the fluid, it pushes the fluid away from the
wall as it inflates. As the volume of the bag contents diminishes,
the air chamber continues to expand by inflation.
[0088] The air chamber and the bag are preferably configured so
that the air chamber expands to the greatest extent in a region of
the container away from the drain, thus forcing the contents toward
the drain. As the chamber expands, the increased area on which the
air pressure acts increases the force exerted on the fluid by the
inner ply(ies) of the bag. The force reaches a maximum when the bag
is nearly completely evacuated, at which point the bag material
would normally obstruct the drain. However, the fluid at the drain
floats adjacent bag material above the drain, preventing the bag
material from blocking the drain and trapping fluid in the bag.
Additionally, the inflation of the air chamber pulls the bag
material taut so that the drain remains unobstructed.
[0089] The drain fitting is locked in the container and seals
through the bag plies. This anchors or ties the bag down at one
point in, at, or near the floor of the container. This also limits
the inflation of the air chamber at and around the drain port. The
air chamber is also configured so that its expansion pulls the
layers of the bag taut. When the volume of fluid left in the bag is
insufficient to float the bag material above the drain, this
tension prevents the bag material from closing off the drain. The
air chamber is optimally configured so that, near the end of
evacuation, all the remaining fluid is lifted off the floor of the
container, above the level of the drain. This allows the fluid to
flow down into the drain as if it were in a funnel. The fluid can
be used as a fourth quasi-seal. If the fluid is used as a fourth
quasi-seal, then air seeps under the fluid and expands into
chambers on both sides of the fluid formed in the main air chamber
by the presence of the fluid. This action enhances the evacuation
by pulling the bag layer in from the of drain up at an angle. This
angle provides a gap for flow of the remaining fluid to the drain
port.
[0090] The variations illustrated in FIGS. 37A through 39D can be
advantageously utilized with top discharge systems for container
bags. All are based on methods for holding the two lower plies 25
together at junctures that serve to force the contents of the bag
gradually towards the region where the input for some top discharge
means will be located as the interply region 204 inflates. The two
lower plies 25 can be mechanically held together as illustrated in
FIG. 38. In this configuration, a dip tube 300 is provided at its
input end 301 with an extension 301A terminating in a ring-shaped
member 301B that is pressed downward against the two lower plies 25
to create the juncture 302 illustrated. Junctures 302 of numerous
types can be mechanically created by utilizing shaped members that
are held down by their own weight, are held down by pressing from
above, hold the two lower plies 25 together by connectors fastened
through both plies, are held down by connectors fastened through
the bottom of the container, or are held down or together by other
means. Alternatively, the two lower plies 25 can be bonded to each
other using heat seals, adhesives, adhesive tapes, or other means
to accomplish this purpose. However, no matter what method is used,
such inflation guide junctures 302 will differ from the seals and
bonds previously discussed in that they are not primarily intended
to form borders and boundaries for an air-tight interply region to
be filled. Instead, they act within such an interply region to
guide the manner in which it inflates. Where the input is centrally
located, such inflation guide junctures 302 will hold the two lower
plies 25 together in a manner that encourages symmetrical filling
of the lower interply region 204, beginning at the periphery of the
bag 10, and moving gradually inward towards its center as its
contents are emptied.
[0091] One configuration for placement of such inflation guide
junctures 302 when a top discharge method is being used to drain a
bag from its center is illustrated in FIG. 37A. In this example,
the inflation guide junctures 302 form a ring-like configuration.
The inflation guide junctures 302 are centrally located in FIG. 37A
and thereby define a depressed drain area (denoted generally in the
drawing figures by arrow 303). In the configuration illustrated,
air will enter the area surrounding drain area 303 at the bottom of
bag 10 and initially work its way inward from the outside,
eventually filling in the entire area exterior to drain area 303.
The ring-like configuration illustrated in FIG. 37A is indicative
of a general configuration type characterized by an exterior line
surrounding an interior zone into which drain means such as a dip
tube 300 with input end 301 can be inserted. This exterior line
could be square, triangular, or polygonal. It can also be broken or
intermittent such that its interior is not sealed off from the
other portions of the bottom of the bag 10. It will still act to
conserve and create an interior zone, drain area 303, that will
remain substantially depressed. The bag 10 will inflate from the
outside towards this interior zone, causing the contents of the bag
10 to drain inward to drain area 303 for efficient removal.
[0092] Another general form or configuration for such junctures is
illustrated in FIG. 37B. In this configuration, the inflation guide
junctures 302 radiate from drain area 303. Radial arrangements seem
to encourage the most even and symmetrical filling of the areas
exterior to drain area 303 and are, therefore, preferred. Radial
juncture arrangements can be combined with ring-like juncture
arrangements, as illustrated in FIGS. 37E and 37F. Other
representative configurations for the positioning of inflation
guide junctures 302 are illustrated in FIGS. 37C and 37D. The
configuration illustrated in FIG. 37C has been found to be the most
advantageous in terms of its cost, effectiveness, and ease of
construction. An inflation sequence for the configuration of FIG.
37F is illustrated in FIGS. 39A through 39D and is generally
representative of the manner of inflation for the radial inflation
guide juncture configurations described. The configurations
illustrated are not, however, exhaustive. Numerous configurations
can be utilized to urge bag contents towards a desired location,
whether at the center or side of the container, as the bag contents
are drained and the interply region 204 between lower plies 25 is
inflated.
Parts List
[0093] 1 Rigid/plastic container/tote
[0094] 2 Source of pressurized air
[0095] 3 Pump
[0096] 4 Bottom region of bag and container/tote
[0097] 5 Contents of bag; bulk material contents; bulk material;
viscous or semi-flowable contents
[0098] 6 Air in interply region
[0099] 10 Multiple-ply bag
[0100] 10' Snout bag; pillow bag with integral fill conduit
[0101] 11 Fill port
[0102] 12, 12' Drain port; exit port; drain
[0103] 13 Drain/exit conduit
[0104] 14, 14' Air input port
[0105] 15, 15' Air input conduit
[0106] 16-18 Interply bonds
[0107] 16' Second main seam of snout bag
[0108] 18' First main seam of snout bag
[0109] 19, 19' Fold
[0110] 20 Upper/top layer
[0111] 21 Lower/bottom layer
[0112] 23 Top interlayer bond
[0113] 23' First/back interlayer bond of snout bag; first/back
interply bond of snout bag
[0114] 24 Upper plies
[0115] 25 Lower plies
[0116] 26 Diagonal seam
[0117] 26' First diagonal seam of snout bag
[0118] 27 Diagonal seam
[0119] 27' Second diagonal seam of snout bag
[0120] 28, 28' Flap; extra piece of material
[0121] 29 Flap; extra piece of material
[0122] 30 Folds of material resulting from bag
collapse/evacuation
[0123] 31 Moving wall portion of inner ply(ies)
[0124] 100', 100" Pieces of material of snout bag
[0125] 101', 101" Back layers of material of snout bag; back plies
of snout bag
[0126] 102', 102" Front layers of material of snout bag; front
plies of snout bag
[0127] 108 Second/front interlayer bond of snout bag
[0128] 191, 191' Interlayer bond along fold
[0129] 192, 192' Interply bond along fold
[0130] 201 Upper/Top inner ply; top part of inner ply
[0131] 202 Upper/Top outer ply; top part of outer ply
[0132] 203 Upper/Top interply region
[0133] 204 Lower interply region
[0134] 205 Larger interply region; trans-fold interply region
[0135] 206 Smaller interply region
[0136] 211 Lower inner ply; bottom part of inner ply
[0137] 212 Lower outer ply; bottom part of outer ply
[0138] 300 Dip tube
[0139] 301 Dip tube input
[0140] 301a Dip tube extension
[0141] 301b Shaped member
[0142] 302 Juncture
[0143] 303 Drain area
* * * * *