Note: Descriptions are shown in the official language in which they were submitted.
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NON-PROVISIONAL PATENT APPLICATION
FLEXIBLE INDEPENDENT MULTI-LAYER CONTAINER
AND
METHOD FOR FORMING
Inventor
Charles W. True
5747 Larkin St.
Houston, Texas 77007
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FLEXIBLE INDEPENDENT MULTI-LAYER CONTAINER AND
METHOD FOR FORMING
FIELD OF THE INVENTION
[0001] This invention relates to the field of flexible multi-layer containers
and methods
for making the flexible multi-layer containers. The flexible multi-layer
containers are used
for transport and storage of flowable materials generally of container sized
volumes, but can
be used with smaller volumes. The flexible containers are readily foldable and
can be
unfolded and used to convert normally dry containers used in shipping into wet
or flowable
material containers or they may be used as stand alone containers. The
flexible multi-layer
containers are for retention and delivery of flowable materials and have
independent layers
which are freely movable between each other and are sealed off from each
otlzer, but have
seals formed at fittings which are attached to these containers for filling,
discharge, sainpling,
etc. These independent layers are generally sealed off from each other as the
containers of
this field of invention provide secondary containment of their content from
leaking out
and/or contamination within by penetration. Further in this field of invention
these
containers and fittings are readily reuseable/recyclable.
BACKGROUND OF THE INVENTION
[0002] The prior art has been in search of flexible containers for use in the
shipment and
storage of flowable materials, such as liquids, slurries, etc. and methods for
making them
which do not leak or fail in use and can be re-used multiple times. Some such
prior art
containers have been used solely for storage in stationary locations, which is
a less rigorous
use, because stationary use does not have the dynamic loading forces caused by
motion in the
shipping process on the flexible materials and the interface between the
flexible materials
and fittings mounted to these flexible containers. However, even stationary
storage has
dynamic loading forces caused by the liquid pulses of loading and unloading of
these
stationary flexible containers. These loading forces have caused prior art
tanks to leak or fail.
[0003] The prior art has resorted to many different processes for solving the
leak
problems associated with these flexible tanks. In some cases the prior art
tanks or containers
used heat-welding technology for sealing the containers and attaching the
fittings to the
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flexible bodies of the containers. The problem of using heat welding is that
it requires
precise application of heat and pressure for a period of time and inust be
done in a very
controlled environment. The order of difficulty of all these variables in the
process of heat
welding goes up dramatically in relation to the number of layers of inaterial
that is being heat
welded at one time. If the heat welding process generates too much heat at the
surface layer
being welded the plastic material can become crystallized and become brittle
wliich can
cause failure of the weld and the container. If the heat welding process
generates too little
heat at the mid-layers being welded the plastic materials may not be
sufficiently welded and
the defective weld fails and the tank leaks. These defects in many cases would
not be evident
at the time of manufacture, but would become obvious when the container was
loaded or
shipped and the container fails completely or leaked product being shipped.
[0004] Other prior art has attempted to add chemical welding to the heat and
pressure
welding process of flexible materials used in the formation of flexible tanks
and for attaching
the fittings to the containers and tanks, but this has proved to be as
unsuccessful as just the
heat and pressure welding. These failures occur especially when the prior art
containers are
subjected to violent hydraulic motion, which is encountered in fluid shipments
of containers.
It should be realized that the containers are not baffled and the fluid inside
can have full
range of motion inside such containers, which can be 40 feet long and can
produce great
pressure on the flexible containers.
[0005] Further the prior art discovered that even if all the cliemical, heat
and pressure
variables were perfect, failure to form a weld in the flexible container
materials and securing
the fitting could still occur because of body oil of workers, dust, powder or
even light
difference over the surfaces to be welded could cause failure.
[0006] The prior art provided mechanical members in addition to the welding
process
whether chemical and/or heat and pressure welding to form a seal for the
securing the
container and tank at the point where the fittings are mounted. In these
applications the
flexible materials were sealed about the hole made in the flexible materials
where the fitting
was to be inserted into the container and then the fitting was mechanically
clamped on to the
flexible tank or container. The sealed flexible materials about the hole did
not rely on the
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mechanical clamping to seal the multiple layers about the hole nor did the
mechanical
clapping prevent the flexible materials forming the multiply layers from
preventing
movement creep in the flexible containers when they were filled and the
flexible materials
stretched or expanded because of filling or motion.
[0007] In yet other prior art flexible containers the fittings were created
with specialized
collars which could have the various layers of the flexible material being
used for forming
the flexible containers fitted about the collars both above and below and then
chemically
and/or heat and pressure welded to seal the fitting in place on the flexible
tank or container.
These welds of flexible material to more rigid materials of these collars
created not only the
typical problems of chemical, heat and pressure welds, but also stress razor
points at the
interface between the collar and the layers of materials being used in the
flexible tank or
container. These stress razor points produced failures when loading and/or
discharging these
tanks and containers, plus having failures during shipment thereof caused by
dynainic wave
actions in these flexible containers or tanks. Further these specialized
collars tended to be
some wliat rigid and hindered folding of the flexible containers for shipment.
[0008] The prior art in an effort to overcome some of these leak problems, at
the fittings
in flexible containers especially in severe operating conditions, attempted to
develop
additional special fitting, such as concentric cord and wire reinforced
"doilies" about fittings
which are used with flexible containers. These reinforced "doilies" then were
chemically
and/or heat and pressure welded to bind the flexible materials of various
layers of flexible
containers to these doilies. Finally, a metal clamp down was provided with
fastener meinbers
who were fastened into the fitting, but not into the flexible materials of the
flexible
containers. This prior art was designed to provide hard non-compressible
members to clamp
down upon for a secure hold. This prior art was aimed at the problem of
movement creep or
"pulling out" of the flexible materials from the fittings. It never the less
did not solve the
problem of the failures of the flexible materials at the interface between the
flexible materials
and the more rigid fittings which occurred because of the wave action and
other causes in the
transport of these flexible containers and which occur at the time of loading
and/or
discharging from these containers.
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[0009] Ot11er prior art just formed a chemical weld and/or heat and pressure
seal about
the place in the wall of the flexible materials of the container and then put
a fitting there
through and attached the fitting with a screw down collar clamp. The screw
down collar
clamp attached the fitting securely about the chemical weld and/or heat and
pressure seal
already formed. However this type of fitting mount was subject to failure
because of motion
creep or out ward pulling forces which are generated by the stretching of the
flexible
materials used in the walls of the containers as they are filled or as motion
waves are created
in these containers shipment.
[0010] In addition to the above, the prior art used a flexible container of
various materials
having both the flexible material and reinforced material to prevent leaks so
that when
failures occurred in one layer of material, it did not get out of the
container. Some of these
flexible materials had woven fibers put into the inner layers of the flexible
materials used to
form layers of a flexible container, but these fibers created voids and
provided friction points
against the otlier smooth layers of flexible material. These voids and
friction points caused
creases and tucks in the smooth layer materials and became stress razors or
pinching points
for causing pinholes in the smooth layers of the flexible materials. Once a
hole was formed
then the woven fiber provided channels to allow the product to leak to other
layers of the
container or the container to leak.
[0011] The prior art has also tried using very thick flexible materials for
providing
strength, but these materials added weight to the containers and were not very
flexible.
Further these very thick flexible materials had a tendency to not fold out or
fill smoothly and,
if they did not, then stress pinches in the flexible material would cause
these materials to
have pin whole leaks through them. Once a leak occurs and the fluid product
gets passed the
thick flexible materials, which was provided for strength, the pressure of the
fluid is
transferred through to the next layer of flexible materials, which can lead to
failure of the
container. Further, if a thin walled flexible material of less than 15 mills
thickness was used
with a very thick flexible material as the inner layer then when this type
container is
discharged the pump suction at its intake can suck this thin walled flexible
material into the
intake and cut or damage that flexible material which would prevent the
container further
use.
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[0012] Also the prior art used thick single flexible materials with re-
enforcing materials
built into the single flexible layers with compression seals and chemical
welds to make tanks,
but these tanks are very lleavy and the re-enforcing materials are bound
together with the
tank materials to be come one layer of materials. In addition to being heavy
these type tanks
provided no environmeiital containment and the failure of the single wall was
complete
failure of these taiiks. Also these tanks were in additional to being heavy,
they were
inflexible and could not be folded back on themselves for shipping multiple
tanks in a
shipping container.
[0013] As the prior art has added technology to solve these problems in multi
layer
flexible containers, the method of their manufacture became more complicated
and more
expensive. In many cases the added technology did not solve the problems of
container
failures in either shipment or static storage.
[0014] In addition to environmental containment problems, these prior art
containers had
recyclability problems because the fittings were so integrated into the
materials, which might
have been recyclable, that it was prohibitively expensive to recycle them.
[0015] The increases in shipping cost has demanded that the prior art flexible
containers
be easily folded and tightly packed to get as many folded containers shipped
as possible to a
site and then filled to save on the increasing costs of transportation. These
prior art tanks
with the bulky fitting and thick reinforced materials were not tightly
foldable and were
expensive to ship, which has made them less desirable.
[0016] The prior art did not recognize that the energy passed through the
surface of
flexible materials as these flexible tanks are moved and transported nor did
they recognize
the handling energies which are created upon filling and discharging materials
from these
flexible containers. As these fitting are directly in the path line of the
energy being passed
through the surface of the flexible container materials, many failures
occurred at the
interfaces between the flexible material and the fitting.
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OBJECTS OF THIS INVENTION
[0017] The object of this invention is to create a flexible multi-layer
container and to
create a method for making a flexible multi-layer container for use in
shipment and storage
of flowable materials, such as liquids, slurries, mashes, etc which do not
leak or fail in use
and can be re-used repeated times.
[0018] Also an object of this invention is to provide a flexible container
which may serve
as a stationary tank or container and handle the dynamic loading forces caused
by liquid
pulses created during loading and unloading of these flexible multilayer
containers with out
leaking or failing.
[0019] Yet another object of the method of this invention is to use chemical
and/or heat
welding process on these coinpressible and elastic flexible material in their
formation where
as few layers are welded at once as possible. In a preferred embodiment, only
one layer of
the material is chemically and/or heat welded at once in the formation of
these flexible
containers for the prevention of crystallized materials being formed and for
obtaining a good
seal. At the point where the fittings are inounted through the walls of the
flexible containers,
no welding occurs between the compressible and elastic flexible materials and
the fittings,
which eliminates any crystallized materials formation. At these points only a
compression
seal is formed to fix the fitting in place and seal the compressible elastic
flexible materials to
form a flexible container, therefore brittleness does not occur and the
compressible flexible
material maintains it full range of flexibility.
[0020] Also an object of the method of this invention is to provide simplified
steps for
the formation of this flexible container which provide relatively easy control
of the variables
which can cause a chemical and/or heat weld to fail, such as body oil of
workers, dust,
powder, etc. and at the same time provide a method which provides a flexible
container not
subject to failure in its operation.
[0021] Yet another object of this invention is the formation of containers
which can be
used in the shipment of liquids and which can handle or withstand the violent
hydraulic
forces caused by the motion, which is encountered in shipping fluid in
flexible containers.
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This invention can endure the forces produced in shipment of a 40 foot flexile
container
without baffles therein.
[0022] Still a further object of this invention is a flexible container with
fitting provided
througlz the compressible elastic flexible multiple layer materials of the
flexible container of
this invention which do not have to have special collars for chemical or heat
welding them to
form seals for securing the fittings and for forining a seal between the
multiple layer
materials at the fitting for forming a flexible container with fittings.
[0023] A still further object of this invention is a flexible container with
fitting provided
through the compressible elastic flexible multiple layer materials of the
flexible container of
this invention which do not have specially prepared coils or ridge materials
against which
fittings can be mechanically clainped to hold the flexible materials against
movement creep
or pulling out motions by the flexible materials of these containers.
[0024] It is the object of this invention to provide fittings which have
flanged surfaces for
1lolding the compressible elastic flexible multiple layer materials of the
flexible containers of
this invention with sufficient force to have the compressible elastic flexible
multiple layer
materials form compression seals for sealing the fittings and the multiple
layers of material
for forming a flexible container. Further these flanges may have surfaces
which assist in
holding the inultiple layers against motion creep or pulling the flexible
material out of the
flanged surfaces forming the compression seal. Also to assist against motion
creep or pulling
out of the flanged surfaces by inultiple layers forming the compression seal
are fasteners
which pass through the multiple layers being held as a compression seal and
are used with
the flanges for tightening down the flanges for forming the compression seal
between the
flanges and the multiple layers.
[0025] Another object of this invention is to allow the smooth filling out of
the internal
layers of the flexible materials before fully engaging the next layer of
flexible materials so
that no stress razors or pinching points occur to eliminate the cause of hole
formation in the
smooth layers of the flexible materials and then driving the next layer of
smooth flexible
material to expand smoothly, driven by the layer below it after it is smoothly
expanded with
in its elastic liinits.
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[0026] Still a further object is to provide the outer most layer with a
reinforcing fiber
layer for abrasion resistance and having the smoother layers inside it so that
if a failure
occurs internal of the multiple smooth layers of material the reinforcing
fiber layer will not
serve as a channel to allow the product to leak to the other layers of the
container or
propagate tank failure or leaking.
[0027] It is the object of this invention to use relatively thin layers of the
compressible
elastic flexible material layers, but not so thin that a compression seal may
not be fonned and
not so thick as to cause or allow the movement to creep or pulling out forces
to cause the
failure of the materials and to cause leaking of the flexible container at its
fittings.
[0028] Also an object of this invention is to use multiple layers of
relatively thin
compressible elastic flexile materials to form these containers and to achieve
the strength of a
thick single flexible material with re-enforcing materials built into it. By
using these
independent layers in tight mechanical relationship with each other, the
container formed
with these multiple layers of compressible elastic flexible materials achieve
superior strength
without becoming inflexible. These tanks or containers are easily folded back
on themselves
for shipping multiple tanks in a shipping container. Further these multiple
layered containers
provide environmental containment by being composed of multiple layers should
one layer
develop a leak as well.
[0029] Also an object of this invention is to provide a flexible container
that is recyclable
because its fittings are easily reinoved for reuse and are not bounded to the
flexible multiple
layers but the fitting seal the multiple layers to provide secondary
containment against leaks
in this flexible container at the fitting and the independent layers provide
containment
throughout the flexible container.
[0030] Still a further object of this invention is to provide a highly
flexible container
which is relatively inexpensive and which is not bulky and easily folds into a
small space for
being shipped to a location for filling.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The flexible multi-layer contairier and the methods for making the
flexible multi-
layer container of this invention may be practiced in certain physical forms
and arrangements
and adjustments of the variable parts herein described, but preferred
embodiments of which
will be described in detail in the specification and illustrated in the coming
drawings which
will form a part hereof.
[0032] FIG. 1 is a drawing of the flexible inulti-layer container of this
invention,
containing flowable materials, formed from independent layers freely movable
between each
other and sealed off from each other with the at least one fitting formed
there through for
forming compression seals with the compressible and elastically flexible multi-
layer
materials at the at least one fitting.
[0033] FIG. 2 is a top drawing view of the flexible multi-layer container of
this
invention, void of flowable materials therein, formed from independent layers
freely movable
between each other and sealed off from each other with the at least one
fitting formed there
through for forming compression seals with the compressible and elastically
flexible multi-
layer materials at the at least one fitting.
[0034] FIG. 3 is a cross-section drawing of the flexible multi-layer container
of this
invention with at least a 1 st bag layer formed from a compressible and
elastically flexible
material smoothly expanded within elastic limits upon having received some
flowable
materials, but before causing the at least a 2nd bag layer to be expanded.
[0035] FIG. 4 is a cross-section drawing of the flexible multi-layer container
of this
invention with the at least a 2nd bag layer formed from a compressible and
elastically flexible
material sized relative to the at least 1 st bag layer formed from flexible
material for allowing
the at least lst bag layer to smoothly expanded within elastic limits and for
causing the 2nd
bag layer to be expanded with in its elastic limits upon the lst bag layer
expanding, upon
receiving flowable materials.
[0036] FIG. 5 is a cross-section drawing of the flexible multi-layer container
of this
invention with at least a 3rd bag layer formed from a flexible material having
strength and
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abrasion resistant properties sized relative to the at least lst and 2nd bag
layers for allowing
the 1 st and 2nd bag layers formed from flexible materials to smootl-Ay expand
within their
elastic limits and for causing the at least 3rd bag layer to be expanded
within its flexible limits
upon the 1 St and 2nd bag layers expanding, upon receiving flowable materials.
[0037] FIG. 6 is an exploded drawing of the flexible multi-layer container of
this
invention, showing the 1 St flanged member of the at least one fitting
internal of the at least 1 st
bag layer, and showing the 2nd flanged member of the at least one fitting
external of the 2nd
bag layer and showing the fasteners for passing through the aperture in the
15t and 2d flange
member and through the 1 st and 2nd bag layers for forming a compression seal
with the 1 St
and 2nd bag layers and holding 1 St and 2nd bag layers against movement creep
upon said
fasteners being fastened.
[0038] FIG. 7 is an exploded drawing of the flexible multi-layer container of
this
invention, showing the at least l St flanged member of the at least one
fitting internal of the at
least lst bag layer, and showing an at least 2nd bag layer and at least a 3rd
bag layer and the at
least 2nd flanged member of the at least one fitting external of the at least
3rd bag layer for
forming a compression seal with the lst, 2nd, and 3rd bag layers and holding
the lst, 2nd, and
3rd bag layer's against movement creep upon said fasteners being fastened.
[0039] FIG. 8 is a cross-sectional view taken througll FIGS. 1 and 7 of the at
least one
fitting with the fasteners fastened through the at least 1 st flanged member
and 2nd flange
member for forming a compression seal between the 1St, 2nd, and 3rd bag layers
and holding
the lst, 2nd, and 3'd bag layers against movement creep. This cross-section
also shows the
orifice in the at least one fitting for filling and emptying the flexible
multi-layer container.
[0040] FIG. 9 is a representational view of the 2nd flanged member of the at
least one
fitting member, showing the sufficient surface of the 2nd flanged member and
gripping
surface for holding the 15t, 2nd, and 3rd bag layers and forming a compression
seal and
holding of the lst, 2nd; and 3rd bag layers against movement creep.
[0041] FIG. 10 is a representational view showing the beginning steps of the
method of
this invention for forming flexible multi-layer containers for containing
flowable materials,
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formed from independent layers freely movable between each other and sealed
off from each
other starting with a tube of a compressible and elastically flexible
material.
[0042] FIG. 11 is a representational view sliowing the forming of a first seal
on one end
of the tube of FIG. 10 and indexing where the at least the 1 St flange of the
at least one fitting
is to be located and showing holes sufficient for the orifice of the fitting
and for leaving
elastic flexible material witli holes for fastener but in contact with the 1
st flange of the fitting
and the 1 St flange of the fitting held in place inside the tube of FIG. 10.
[0043] FIG. 12 is a representational view showing a second seal formed on the
other end
of the tube of FIG. 11 tube for forming at least a 1 St bag layer from the
tube of FIG. 10.
[0044] FIG. 13 is a representational view showing the beginning steps forming
a second
bag layer by placing the first bag layer of FIG. 12 inside a tube of a
compressible and
elastically flexible material.
[0045] FIG. 14 is a representational view showing the forming of a first seal
on one end
of the tube of FIG. 13 and indexing where the 1 St flange of the at least one
fitting is located to
align the hole sufficient for the orifice of the fitting and rerriaining
elastic material with holes
for fasteners but to be in contact with the material of the 1 st bag layer.
[0046] FIG. 15 is a representational view showing a second seal on the other
end of the
tube of FIG. 14 for forining at least a 2"d bag layer from the tube of FIG.
13.
[0047] FIG. 16 is a representational view showing the 2"d bag layer of FIG.
15, but
having tab members connected to the 2d bag layer and projecting there from.
[0048] FIG. 17 is a representational view showing the beginning steps for
forming a 3rd
bag layer by placing the 1 st and 2d bag layer of FIG. 16 inside a tube of a
flexible material
having strength and abrasion resistant properties sized relative to said lst
and 2d bag layers
for allowing the at least 1st and 2 d bag layers to smoothly expand within
their elastic limits
and for causing the 3rd bag layer to expand within its flexible limits.
[0049] FIG. 18 is a representational view showing the forming of a first seal
on one end
of the tube of FIG. 17 which attaches the tab members thereto and indexing
where the at least
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2"a flange of the at least one fitting is to be located and showing a hole
sufficient for the
orifice of the fittings and aligned with the at least 1St flange internal of
the at least 1St bag
layer and aligned with the remaining elastic material with holes for fasteners
but to be in
contact with the material of the 3rd bag layer.
[0050] FIG. 19 is a representational view showing a second seal on the other
end of the
tube=of FIG. 18 for forming at least a 3rd bag layer from the tube of FIG. 17
and attaching the
tab members thereto.
[0051] FIG. 20 is an exploded drawing of another embodiment of the flexible
multi-layer
container of this invention using co-extruded materials, showing the at least
1st flanged
member of the at least one fitting internal of the at least an interior bag
layer formed from a
compressible and elastically flexible material, and showing the at least 2"d
flanged member of
the at least one fitting external of the at least exterior bag layer formed
from a co-extruded
flexible material having strength and abrasion resistant properties and
showing the fasteners
for passing through the aperture in the 1st and 2"d flange member and through
the interior and
exterior bag layers for forming a compression seal and holding the interior
and exterior bag
layers against movement creep upon the fasteners being fastened.
[0052] FIG. 21 is an exploded drawing of the flexible multi-layer container of
this
invention using co-extruded materials, showing the at least l st flanged
member of the at least
one fitting internal of the at least interior bag layer, and showing an at
least interinediate bag
layer formed from a co-extruded compressible and elastic flexible material
between the
interior and exterior bag layers and the at least 2"d flanged member of the at
least one fitting
external of the at least exterior bag layer for forming a compression seal and
holding the
interior, intermediate and exterior bag layers against movement creep upon the
fasteners
being fastened there through.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] The present invention relates to flexible multilayer containers for
retention and
delivery of flowable materials having independent layers freely movable
between each other
and sealed off from each other by each independent layer being sealed to form
a bag with at
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least one fitting formed there through and compression seals formed with the
at least one
fitting formed there througli generally referred to at reference number 10 of
FIG. 1. In at
least one embodiment as shown in FIG. 1, the flexible multilayer container 10
is shown being
filled with a flowable material and with at least one fitting 11 positioned on
the top. In
FIG. 2 the flexible multilayer container 10 is shown void of flowable
materials but is shown
as see tlirough to show the independent layers as separate and freely movable
between each
other and sealed off from each other and have tabs 15. From FIG. 2 it can be
seen that each
bag layer is sized to allow it to smoothly expand within its elastic limits
and then engage the
next bag layer and also smoothly expand the next bag layer or layers, but
still be within the
elastic limits of all the bag layers. In FIG. 2 of this embodiment is shown a
lst bag layer 12, a
2"a bag layer 13, and a 3'd bag layer 14 with at least one fitting 11. These
bag layers must be
of sufficient thickness to give proper strength to a bag layer but not so
thick as to be
inflexible and not compressible. On the other hand no matter their strength
they can not be so
thin as to not be compressible for forming or acting as compression seals. To
better
understand this invention reference should be had to FIGS. 3, 4, and 5 which
show the
transition from FIG. 2 to FIG. 1 of this flexible multilayer container 10.
[0054] Referring to FIG. 3, the 1St bag layer 12 is formed from a compressible
and
elastically flexible material, such as polyethylene of 15 mils thickness,
having the ability to
expand within its elastic limits upon receiving flowable materials. This 1st
bag layer 12 as
shown in FIG. 3 is allowed to expand until it has smoothly expanded within its
elastic limits
prior to engaging the 2 d bag layer 13 as shown in FIG. 3. The 2"d bag layer
13 is
mechanically separate as an independent layer from the 1St bag layer 12. Thus
the lst bag
layer is formed as a smoothed walled container with no stress razors or
pinching points to
cause hole formation in this lst bag layer 12 because it does not engage the 2
nd bag layer 13
until it has fully formed as a smoothed walled container with in the 2nd bag
layer 13 before it
causes the 2"d bag layer to smoothly expand.
[0055] Referring to FIG. 4, the 2d bag layer 13 is formed from a compressible
and
elastically flexible material, such as polyethylene of 15 mils thickness,
having the ability to
expand within its elastic limits, but is sized to allow the lst bag layer to
smoothly expand
before it engages the 2"d bag layer 13 for then causing the 2"d bag layer 13
to smoothly
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expanded within its elastic limits upon being engaged by the 1" bag layer 12.
Thus the 2"a
bag layer 13 is formed as a smoothed walled container with no stress razors or
pinching
points to cause hole formation in the 2"d bag layer 13 because it does not
engage the 3ra bag
layer 14 until it has fully formed as a smoothed walled container within the
3d bag layer.
[0056] Referring to FIG. 5, the 3rd bag layer 14 is formed from a flexible
material having
strength and abrasion resistant, such as polypropylene woven fiber of 4oz. to
16oz. weight
thickness, and sized to allow the 2"d bag layer 13 to smoothly expand within
it elastic limits
and be guided by tabs 15 before it engages the 3rd bag layer 14 for then
causing the 3'd bag
layer 14 to smoothly expand within its limits upon being engaged by the 2nd
bag layer 13 for
forming a flexible inultilayer container 10. By each bag layer being expanded
within its
elastic limits into the next bag layer a flexible multilayer container 10 is
formed which can
handle violent hydraulic forces caused by motion in shipping fluids in these
flexible
containers as if they where made of much tliicker flexible materials, but yet
these flexible
containers are much lighter and more flexible containers which allows them to
be easily
folded into small space for being shipped to a location for filling.. Also
these flexible
containers are generally lighter than thicker walled flexible tanks.
[0057] These independent bag layers are formed from a compressible and
elastically
flexible material having the ability to expand within the elastic limits upon
receiving
flowable materials but must have at least one fitting 11 for receiving and
discharging
flowable materials. As shown in FIGS. 6 and 7, by these bag layers being
independent of
each other, there must be provision for mounting at least one fitting member
11 through each
independent bag layer and forming a seal between each of these bag layers at
the at least one
fitting 11 to prevent leaks and make these containers useable. Any seal formed
at the at least
one fitting member 11 in the at least 15t bag layer is also subject to
expansion within the
elastic limits of the flexible material upon receiving the flowable materials
which causes the
stresses or movement creep associated with those elastic forces on filling or
from violent
movement forces produced at the fitting on such a container. Further, the at
least 2"d bag
layer 13, as shown in FIGS. 6 and 7, is formed from a coinpressible and
elastically flexible
material sized relative to the at least 1 st bag layer 12 for allowing the at
least 15t bag layer 12
formed to smoothly expand within the elastic limits of the flexible material
upon receiving
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flowable materials and for causing the at least 2d bag layer 13 to be smoothly
expanded with
in its elastic limits also put stresses or movement creep associated with
those elastic forces
whether on filling or from violent movement forces produced in shipment on the
at least 2nd
bag layer 13 also. These forces of stress or movement creep are increased at
the at least one
fitting member 11 formed especially through the interface at least 1St and 2"d
bag layers 12
and 13 formed at the at least one fitting 11. In this embodiment, as shown in
FIG. 6, the at
least one fitting member 11 to deal with the forces of stress or movement
creep has a 1 st
flange member 16 internal of the at least 1 St bag layer 12 formed and a 2"d
flange member 17
external of the at least 2"d bag layer 13 formed for forming a compression
seal between the
flanges and the compressible and elastically flexible material. These flanges
16 and 17 have
apertures 18 through them for accepting fasteners 22 for compressing the
compressible and
elastically flexible material of the at least 1st and 2 d bag layer material
12 and 13, between
the 1 St and 2"d flange members 16 and 17 sufficiently for forming a
compression seal there
between and for sealing the at least one fitting member 11 in place and thus
forming a
flexible multi-layer container 10. As those skilled in the art of seals and
seal formation will
recognize, if the material to be used as a seal is not compressible enough it
will fail to form a
seal. If the material is compressible enough, but is under compressed or over
compressed the
seal to be formed will fail. Further in the seals of this invention formed in
this compression
state must also deal with movement creep, which is the tendency for these
elastically flexible
materials to pull out from these fittings when violent motion occurs in
shipment, which
generates dynamic pressure spikes applied across the planes or surface of
these elastically
flexible materials. So the forces used on the fasteners 22 to form these
compression seal
must be adjusted for these materials and their applications, and the preferred
range of 315
inch/lbs to 80 incli/lbs has been found to work, but a broader range of 400
inch/lbs. to 75
inch/lbs. has also been determined to work on most materials.
[0058] In yet another embodiment, this invention, as shown in FIG. 7, relates
to
including at least a 3rd bag layer 14 formed from a flexible material having
strength and
abrasion resistant properties and sized relative to the at least 1 St and 2"d
bag layers 12 and 13
for allowing the at least 1 St and 2"d bag layers 12 and 13 formed from
flexible materials to
smoothly expand within their elastic limits and for causing the 3rd bag layer
14 to expand
within its flexible limits. Also this invention relates to the at least one
fitting member 11
16
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having 1 St and 2"d flanged members 16 and 17 having sufficient flange surface
areas 19 and
20 for engaging the at least 1 St bag layer formed 12 from the inside surface
of the at least 1 st
bag layer 12 and sufficient flange surface 20 for engaging the at least 3d bag
layer 14 from
the external surface of the at least 3rd bag layer 14 to form compression
seals through the lst,
2"d, and 3'd bag layer 12, 13, and 14 at the at least one fitting member 11.
In some
embodiments as shown in FIGS. 8 and 9 the flanged surfaces 19 and 20 in
addition to having
sufficient flanged surfaces 19 and 20 to create compression seals and hold
against creep
movement, they may also have provided gripping surfaces 21 such as shown in
FIGS. 8 and
9 to aid in forming a compression seal and holding against creep movement of
the materials
at the fitting member 11 when fasteners 22 are tightened down. As shown in
FIGS. 8 and 9
the gripping surface 21 is concentric circular grooves or ridges, but as those
skilled in the art
would know many non-smooth surfaces could be used to form a gripping surface
to aid the
compression seal for holding the materials against creep movement.
[0059] These fasteners 22, are provided for passing through apertures 18 in
the flanges
16 and 17and holes 23 of the at least lst, 2"d, and 3rd bag layers 12, 13, and
14 for functionally
drawing the flanges 19 and 20 against the 15t, 2"d, and 3rd bag layers 12, 13,
and 14 to form
compression seals and for penetrating the lst, 2 d, and 3d bag layers 12, 13,
and 14 through
holes 23. Both the compression and penetrating as shown in FIG. 8 are used for
preventing
movement creep of the at least 15t, 2"d, and 3rd bag layers 12, 13, and 14
materials at the
compression seal formed at the at least one fitting 11. As those skilled in
the art of seals and
seal formation will recognize, if the material to be used as a seal is not
coinpressible enough
it will fail to form a seal. If the material is compressible enough, but is
under compressed or
over compressed the seal to be formed will fail. Further, the seals fornled in
this invention
must also deal with movement creep, which is the tendency for these
elastically flexible
materials to pull out from these fittings when violent motion occurs in
shipment or other
forces act on these materials. So the forces used on these fasteners 22 to
form these
compression seals inust be adjusted for the material used and the preferred
range of 315
inch/lbs. to 80 inch/lbs. with a broad range of from 400 inch/lbs. to 75
inch/lbs. has been
determined to work with most such materials.
17
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[0060] In some applications as shown in FIG. 2, where different inaterials are
used in the
bag layers having different surface frictions, as for example between the 2d
bag layer 13
made of polyethylene and 3rd bag layer 14 made of polypropylene, it has been
found that to
aid in the formation of smoothly expanding within elastic limits of 2"d bag
layer 13 without
forming stress razor or pinching points between the material of 3rd bag layer
14, that tabs 15
are provided on the 2d bag layer 13 and fastened to the 3d bag layer 14 for
guiding
aligmnent while the 2"d bag layer 13 is smoothly expanding within it elastic
limits. These
tabs 15 thus keep the 2"d bag layer 13 in rough alignment with the 3rd bag
layer 14 as the 2 d
bag layer 13 is smoothly expanding, but the 3rd bag layer 14 is still loose
around the 2d bag
layer 13 until it expands into the 3rd bag layer 14 for causing the 3rd bag
layer 14 to expand
within its flexible limits for forming a flexible multilayer container 10.
[0061] In yet another embodiment of this invention as shown in FIG. 20 at
least an
interior bag layer 24 is formed as at least a single bag layer which is
physically independent
from other bag layers, but interior bag layer 24 may be made of co-extruded
multiple layers,
which in FIG. 20 are represented as having two layers 25 and 26 of
compressible and
elastically flexible materials being used as an interior bag layer 24. Whether
a single layer of
co-extruded multiple layers or a single lst bag layer, these bag layers must
be subject to the
formation of a compression seal between the 1" flange member 16 and 2d flange
member 17
of the fitting 11. In that regard the combined thickness of the co-extruded
materials, which in
this embodiment are represented by layer 25 and 26, inust be in the broad
range of being no
less thick than 04 mils and no thicker than 80 mils with a preferred range of
no less thickness
than 06 mils and no thicker than 70 mils. Further these co-extruded materials
must be
capable of being sealed or welded to form a interior bag layer 24, so in many
embodiments
these layers 25 and 26 will be of relatively thin materials for forming a good
weld, but when
combined as co-extruded materials they will fall within the above ranges. Also
in this
embodiment there is at least an exterior bag layer 29 formed as at least as a
single layer
which is physically independent but may be made of co-extruded or woven
multiple layers,
which in FIG. 20 are represented as having two layers 30 and 31 of flexible
materials having
strength and abrasion resistance properties being used as an exterior bag
layer 29. Whether a
single layer of co-extruded multiple layers or a single bag layer they are
sized relative to each
other for allowing the interior bag layers 24 to smoothly expand within its
elastic limits and
18
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for causing the exterior bag layer 29 to expand within its flexible limits,
and allow at least
one fitting 11 to be formed through the interior and exterior bag layers 24
and 29 for forming
a compression seal between 1 St and 2"d flanges 16 and 17 for sealing the at
least one fitting 11
in place and for forming a flexible multi-layer container 10.
[0062] In yet other embodiment of this invention as shown in FIG. 21 at least
an
intermediate bag layer 32 is formed as at least a single bag layer which is
physically
independent from other bag layers, but the intermediate bag layer 32 may be
made of co-
extruded multiple layers, which in FIG. 21 are represented as having two layer
33 and 34 of
compressible and elastically flexible materials. Whether composed of an
interior bag layer
24, and an external bag layer 29 or having the intermediate bag layer 32 there
would be
provided at least one fitting member 11, which forms a compression seal about
these layers
for sealing these bag layers off from each other and mounting the at least one
fitting member
11.
[0063] From all the forgoing embodiments described it should be apparent that
these
flexible containers would be recyclable because their fittings 11 are easily
removed for re-use
by removing the fasteners 22 and simply mechanically separating the lst and
2nd flange
members 16 and 17 from the multiple layers, as there is no welding or chemical
fastening
between these 1 st and 2nd flange member 16 and 17 of fittings 11 and the
flexible multi-layer
bag materials. Further as the multiple bag layers are formed as independent
bags sealed off
from each other and sealed off from each other at the compression seals formed
through them
at the fitting 11 these flexible multilayer container provide environmental
contauunent
against leaks should one multiple bag layer fail.
[0064] At least one method embodiment for forming the flexible container 10 of
this
invention is shown in FIGS. 10 through 19. Starting at FIG. 10 with at least a
1st tube 35 of
compressible and elastically flexible material, a 1St seal 36 is formed on one
end of the tube
as shown in FIG. 11. Then in FIG. 11, it can be seen that a 1 s' flange member
16 of the at
least one fitting 11 is inserted and held for indexing of its orifice 37 and
fastener apertures 18
in 1 S{ flange member 16 are to be put through the 1 st tube 35 while one end
of the 1 st tube 35
is held open. After indexing on the 1St tube 35 for the position of the
orifice 37 through the
19
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lst flange member 16 and fastener apertures 18 positions, then holes are made
in the lst tube
35 at the indexed positions in the elastically flexible material in contact
witli the 1St flange
member 16 of the at least one fitting 11. Once the holes have been made the
lst flange
member 16 of the at least one fitting 11 is held in place against the inside
surface of the 1st
tube 35 about the fastener and orifice holes made at the indexed position as
shown in
FIG. 11. Then as shown in FIG. 12 a seal is formed on the other end 39 of the
Ist tube 35 of
the compressible and elastically flexible material for forming at least a Ist
bag layer 12.
Those skilled in the art will appreciate that the quality control of forming a
single weld
through as single tube will provide a higher quality seal and improve the
chance of not
having a weld failure. The next step, as shown in FIG. 13, is positioning the
Ist bag layer 12
into a second tube 40 of a compressible and elastically flexible material,
which tube is sized
to be larger than the lst bag layer 12. Then as shown in FIG. 14 forming a lst
seal 41 on one
end of the second tube 40 of a compressible and elastically flexible material,
and then
indexing on the second tube 40 for alignment with the position of the 1 st
flange menlber 16 of
the at least one fitting 11 both for aligning the orifice 37 and fastener
apertures 18 with those
of the at least 1 st bag layer 12. Once indexed, then making holes in the
second tube 40 at the
indexed positions sufficient for the orifice 37 of the 1 St flanged member 16
of the at least one
fitting 11 and fastener apertures 18 but leaving the elastically flexible
maternal in alignment
with the at least 1" bag layer 12 material about the orifice 37 and aperture
holes 18. Then, as
shown in FIG. 15, forming a 2"d seal on the other end 42 of the second tube 40
to form a 2d
sealed tube bag layer 13 sufficiently distant from the 1 St bag layer 12 to
allow the 1 st bag
layer 12 to smoothly expand within the 2"d bag layer within its elastic limits
and for causing
the 2"d bag layer to smoothly expand within it elastic limits when filled. In
some
embodiments of this method as show in FIG. 16 tabs 15 are attached to the 2nd
bag layer and
the at least 1 st and 2a bag layers 12 and 13 would be positioned, as shown in
FIG. 17 inside a
third tube 43 of material having strength and abrasion resistant propertied
and a flexile limit.
Then as shown in FIG. 18, indexing the third tube 43 material for the position
of l St flange
member 16 of the at least one fitting 11 for aligning the orifice 37 with the
apertures made in
the 1 st and 2"d bag layers 12 and 13. Once aligned and indexed, holes are
made in the 3rd tube
43 material at the indexed position for the orifice 37 and fastener apertures
18 of the Ist
flanged member 16 of the at least one fitting 11 and fastener apertures 18 but
leaving the 3ra
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tube 43 material in alignment with the 1 St and 2 nd bag layer 12 and 13
materials. Then one
end 44 of 3rd bag layer 14 is sealed which fixes tabs 15. Then as shown in
FIG. 19, the 3rd
tube 43 is sealed 45 which fixes tabs 15 and tube 43 is formed in to a 3rd bag
layer 14 about
the 1 st and 2"d bag layers 12 and 13 with sufficient distance from the at
least 1 St and 2"d bag
layers 12 and 13 to smoothly expand within each other and to smoothly expand
within the at
least 3rd bag layer 14 to expand the at least 3 bag layer 14 to its flexible
limits. Then as
shown in FIG. 19 the 2d flanged member 17 of the at least one fitting 11 is
held against the
outside surface of the at least 3rd bag layer 14 and fasteners 22 are inserted
through the
fastener apertures 18 in the lst and 2"d flanged member 16 and 17 and the at
least lst, 2"d and
3rd bag layers 12,13, and 14 for forcing the 1 St and 2 nd flanged members 16
and 17 having
flanged surfaces 19 and 20 of the at least one fitting 11 against the at least
1st, 2"d, and 3d bag
layer 12, 13, and 14 positioned between the 1 St and 2"d flanged surfaces 16
and 17 for
fastening the fasteners 22, for forming a compression seal there between and
for prevention
of movement creep of the at least lst, 2"d and 3rd bag layers 12, 13, and 14
at the at least one
fitting 11 for forming a flexible multi-layer container for retention and
delivery of flowable
materials. The range of fastening force can be from 75 inch/lbs to 400
inch/lbs, but as those
skilled in the art will appreciate it will vary within that range depending
upon the material
being used. It has been found that a range of from 80inch/lbs to 315 incli/lbs
will work with
polyethylene and polypropylene materials, but again depending on the
thicknesses and
weights of these materials falling between 04 mils to 80 mils and a preferred
range of 06 mils
to 70 mils and weights of 04 oz. to 16 oz. Also the 1 St and 2"d flanged
surface 19 and 20 must
have sufficient surface to provide a sufficient seating surface against the
bag layer materials
to form a compression seal, and if different flanged surfaces are used it may
vary the
fastening forces as those skilled in the art will appreciate.
[0065] From the above method it can be seen that when forming a seal on the
bag layers,
which can be a heat weld and/or chemical, the welds are formed with only one
layer of
material being welded at one time to provide the highest quality seal possible
and when a seal
is formed across multiple layers a compression seal is formed through these
bag layers. That
the fitting 11 being formed in the bag layers to fasten the at least one
fitting and the bag layer
off from each other and against creep movement of the bag layers is the
compression seal.
However, if a bag layer is formed of co-extruded materials with independent
layers these
21
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individual layers are very thin such that their collective layers are within
the range of 04mils
to 80mils or the preferred range of 06mils to 70mils then these co-extruded
materials may be
treated as a 1 St bag layer, but in fact they may be an interior bag layer,
intermediate bag layer,
and exterior bag layer.
[0066] While the referenced embodiments of the invention of this flexible
container and
the method for there formation has been disclosed it will be appreciated that
other
embodiments and process may be used without departing fonn the sprit of the
invention and
from the methods herein claimed.
22
