Note: Descriptions are shown in the official language in which they were submitted.
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MULTI-LAYER RECEPTACLE AND RESIDUE REMOVAL METHOD THEREFOR
BACKGROUND
The present invention broadly concerns receptacles for the storage and
transportation of selected items or materials. More specifically, the present
invention
concerns containers suited for holding liquid substances such as
agrochemicals,
which can be rinsed with a suitable solvent to remove residue in the interior
of the
container. The present invention also concerns a method of removing residue
from
the interior of a receptacle.
Packaging is a fundamental need in modern society. At its very essence,
packaging enables goods to be distributed over large geographical areas while
both
protecting and preserving the quality of the goods during their distribution
and
storage. Typically, packaging provides important information about the goods
it
contains, such as an explanation of the product, how the product is to be
used, and
legally pertinent information. Importantly, packaging can also provide a
significant
commercial advantage to companies who sell competing products. For example,
the
shape of a product's packaging and colors or illustrations appearing on the
packaging can be a significant marketing tool, especially when consumers
identify
certain packaging characteristics with a particular source or brand of goods.
As markets continue to diversify and the economy grows, packaging solutions
must continue to satisfy the economic, social and governmental requirements of
existing and emerging products. Since the product and its packaging are so
interdependent, meeting these demands requires more than just combining
available
materials to contain the goods. Rather, in today's commercial environment, a
well-
designed package requires the appropriate integration of structure,
aesthetics, style,
communication and legal elements specific to each product. Moreover,
successful
packaging solutions should be cost efficient and environmentally responsible.
Packaging solutions that are environmentally responsible will continue to be
an important driver in the discovery of new packaging materials and designs.
Of
particular importance is the advancement of environmentally responsible
packaging
for hazardous materials, such as agrochemicals, heavy metals, and organic
chemicals, which is strictly regulated by governments and agencies in various
countries, including the United States of America. Indeed, environmental,
safety,
and commercial pressures have triggered stringent regulatory requirements
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designed to reduce soil and groundwater contamination resulting from the
disposal
of partially filled containers or residue left in improperly rinsed
containers. As a
result, many hazardous materials manufacturers that are subject to these
disposal
schemes or have customers that are subject thereto, now consider the product
packaging and its disposal to be of equal importance to the product itself.
The agrochemical industry, for example, has developed strategies and
programs in effort to reduce the impact of their products on the environment.
For
example, agrochemical companies have made substantial advancements to place
their products in reusable packaging as well as to create recycling programs
to
systematically and efficiently refill the containers as incentives to use
these
programs. While these programs do lessen the amount of containers that need to
be
disposed, these containers cannot be used indefinitely. For example, the
integrity of
the packaging can deteriorate after sufficient use, rendering it unusable.
Additionally, and perhaps even more common, the names of agrochemical
manufacturers change over time for a variety of reasons such as mergers or
acquisitions. Also, product names change and even the packaging dimensions or
configurations are typically modified over time. As a result, potentially vast
quantities
of containers with the incorrect names, sizes, or configurations are no longer
useable
and are eventually disposed.
Despite the increasing use of reusable containers, many agrochemical
products must be packaged one-way or non-reusable containers. In fact, a
significant quantity of agrochemical products are packaged non-reusable
containers
because a large percentage of farms are too small to make practical use of
reusable
containers. These containers must also be properly cleaned prior to disposal
in
designated areas.
As may be appreciated from the foregoing examples pertaining to the
agrochemical industry, vast quantities of retired and one-way containers are
subject
to disposal regulations. In the US, for example, the Environmental Protection
Agency (EPA) has imposed and enforces regulations requiring that agrochemical
containers be rinsed by prescribed rinsing methods, such as the "pressure
rinsing"
and "triple rinsing", prior to their disposal. Pressure rinsing generally
involves use of
a special nozzle attached to the end of a hose while, triple rinsing simply
refers to
rinsing the pesticide container three times. Both of these rinsing methods
have been
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shown to remove more than 99% of pesticide residue remaining in the container
after it has been emptied.
Despite the advancements made thus far in packaging solutions and efforts to
employ reusable containers, there is still a need for improved packaging
design
features and materials that alleviate the environmental impact of agrochemical
products and other hazardous materials. In particular, there is a need for
containers
that can be more efficiently and effectively rinsed to better protect soil and
water
contamination and help users better comply with applicable disposal
regulations.
There is also a need to develop containers that use less disposal space in
designated sites. The present invention is directed to meeting these needs.
SUMMARY OF THE INVENTION
According to the present invention, then, there is provided a receptacle
having
an interior that is sized and adapted to receive and hold a selected
substance. The
receptacle comprises a container body surrounding the interior and having a
mouth
in communication therewith. The container body includes an inner layer formed
of a
first material that is soluble in the presence of a selected solvent and
having a first
thickness. The container also includes an outer layer supported by said inner
layer
and formed of a second material that is insoluble in the selected solvent of a
selected second thickness. The first thickness of said inner layer may be
greater
than the second thickness of said outer layer.
The inner layer is preferably substantially continuous and surrounds a
majority
of the container interior and may be formed of a material that is either hot
water
soluble or cold water soluble and that is also impervious to hazardous
substances.
For example, the inner layer maybe formed of polyvinyl alcohol. The outer
layer, on
the other hand, may be formed of polypropylene, polyvinylchloride, high
density
polyethylene, low density polyethylene, or polyethylene terephthalate.
The container may further be provided with a middle layer or tie layer
interposed between the inner layer and the outer layer. The middle layer may
be
formed of a material selected from the group consisting of polyvinyl acetate,
ethylene
polyvinyl acetate, polyamide, and ethylene vinyl alcohol.
Also contemplated herein is a method of removing chemical residue from the
interior of a container wherein the container interior is surrounded by an
inner
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sidewall layer formed of a water soluble material, said method comprising
contacting
the container interior with a sufficient quantity of water to dissolve said
inner sidewall
layer.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a representative receptacle having a sidewall
according to the present invention;
Fig. 2 is a perspective view, partially broken away, of the receptacle in Fig.
1,
showing the inner and outer sidewall layers;
Fig 3 is a cross-section of the receptacle shown in Fig. 2 taken about lines 3-
3
of Fig. 2;
Fig. 4 is a perspective view, partially broken away, of an alternate
embodiment of the according to the present invention; and
Fig. 5 is a cross-section of the receptacle shown in Fig. 4, taken about lines
5-
5 of Fig. 4.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
The present invention generally relates to a receptacle or container adapted
for the storage and transportation of selected materials or items, including
liquid, gel,
or solid substances. These selected items or materials can be either hazardous
or
non-hazardous substances. As will be appreciated from the description below,
the
container has particular utility for the storage and transportation of liquid
hazardous
substances such as agrochemicals. As used herein, a hazardous substance (or
dangerous goods) generally refers to a substance that is potentially toxic or
detrimental to human health or the environment. Such hazardous materials can
be
in the form of solids, liquids, or gels and include agrochemicals, poisons,
radioactive
materials, explosives, flammable or nonflammable gases, to name a few. Also as
used herein, the term "agrochemicals" generally refers to pesticides, such as
herbicides, insecticides, fungicides and other types of agricultural chemicals
that are
often potentially harmful materials and are commonly made in concentrated form
as
a solid, a liquid, a dispersion or a gel, for example.
One aspect of the container is the multilayer construction of the container
body, which is adapted to both safely contain hazardous substances and
facilitate
the removal of residue from the container interior prior to its disposal. The
multilayer
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construction is versatile and may be incorporated into a variety of containers
of
selected configurations including both reusable and one-way containers.
For the sake of simplicity, the container disclosed herein and shown in the
accompanying figures is in the configuration of a conventional jug and
described in
5 the context of liquid agrochemical products. However, it should be
appreciated that
the utility of the container is not limited to this configuration nor is it
limited to the
transportation and storage of the liquid agrochemical products. Other
container
configurations are also contemplated, such as trays, blister packages, tubes,
bulk or
mini-bulk tanks, or any suitable container for transportation and storage for
the
product selected.
With reference first to Figs. 1 and 2, a first representative receptacle is
shown
in the form of container 10 having the configuration of a conventional 2.5
gallon jug
typically used as a one-way container to transport and store a variety of
liquid
agrochemical products. Container 10 includes container body 20 surrounding
container interior 18, which is sized and adapted to receive and hold a
selected
substance, such as a liquid agrochemical product. Container 10 also includes a
bottle finish or mouth (not shown), which communicates with interior 18 that
is
sealable in a conventional manner with removable cap 14, as is known in the
art.
Container 10 may further be provided with handle 12 that is adapted to be
grasped
by a user's hand.
With continued reference to Fig. 2 and reference now to Fig. 3, container body
20 has a multilayer construction including an inner sidewall or inner layer 22
and an
outer sidewall or outer layer 24. As shown, inner layer 22 may be a continuous
layer
that is coextensive with outer layer 24, but the container body is not limited
to this
construction. For example, the inner layer need not be fully coextensive with
the
outer layer. However, since the inner layer is in direct contact with the
agrochemical
product once it is received in the container, it is preferably at least
substantially
continuous and surrounds at least a majority of the container interior.
Inner layer 22 may be formed of a material that dissolves or deteriorates when
in contact with a suitable solvent such as water, or when in contact with a
cleaning
solution comprising surfactants, soap, or combinations thereof. Preferably,
the
solvent used to dissolve or deteriorate inner layer 22 is either hot water or
cold
water. An inner layer material that is hot water soluble material generally
dissolves
or otherwise disintegrates in water having a temperature above about 50 C. On
the
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other hand, a selected inner layer material that is cold water soluble
dissolves or
otherwise disintegrates in water having a temperature below about 50 C and
preferably at a temperature between about 5 C and 35 C.
Representative materials which may be used to form the inner layer include
polyvinyl alcohol; polyethylene oxide; polyoxyethylene; cellulose derivatives;
sodium
polyacrylate; polylactic acid; lactic acid esters and ethers of polyvinyl
alcohol; lactic
esters and ethers of cellulosics; carrageenan; pectin; combinations of the
above; and
combinations of the above with starches. The cellulose derivative group could
consist of: methyl cellulose; methylhydroxyethyl cellulose;
methylhydroxypropyl
cellulose; hydroxypropyl cellulose; cellulose; cellulose monoacetate and
hydrophobically modified cellulose derivatives. The outer layer, on the other
hand, is
formed of a material that does not dissolve or disintegrate when in contact
with the
solvent selected to dissolve the inner layer and is preferably not water
soluble.
Representative materials which may be used to form the outer layer include
polypropylene, polyvinylchloride, high density polyethylene, low density
polyethylene,
and polyethylene terephthalate.
Inner layer 22 and outer layer 24 each should have a thickness suitable to
provide the container with the necessary structural integrity to hold the
container's
selected configuration during normal rigors of the transportation. Further,
outer layer
24 should be of suitable thickness to shield the inner layer from exposure to
the
environment as well as water or other solvents that would cause it to
deteriorate.
Inner layer 22 may have a thickness between about .01 mm and 4.0 mm, while
outer
layer 24 may have a thickness between about 1.0 mm and 4.0 mm.
The ratio of thickness of the inner layer to the outer layer may vary as
desired.
For example, as shown in Figs. 3 and 4, inner layer 22 is thicker than outer
layer 24.
More particularly, inner layer 22 has a selected first thickness "d,"
sufficient to be
freestanding and hold the container's selected configuration during normal
rigors of
the transportation and storage of the product it contains. Outer layer 24 is
bonded to
and supported by inner layer 22 and has a selected second thickness "d2" that
is
less than that of "di". Outer layer 24 provides additional rigidity to the
overall
container, while protecting inner layer 22 during shipment and storage of the
agrochemical product. In this configuration, outer layer 24 is frangible or
otherwise
lacks sufficient structural integrity to retain the selected configuration of
the container
and deforms under pressure without the support of the inner layer. Generally,
then,
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outer layer forms a continuous protective shell about inner layer 22.
Additionally,
outer layer 24 provides a substrate on which product labels may be adhered or
otherwise provided to identify the product and any required legal information.
Now that the construction of container 10 has been described in some detail,
it may now be appreciated how the multilayer construction facilitates the
removal of
residue that collects or otherwise builds up during the course of contact with
the
product. Once it is determined that container 10 is to be disposed and the
product is
used or otherwise removed from the container interior, the container must be
properly rinsed prior to disposal, particularly of the container is used for a
hazardous
substance. Since the inner layer is water soluble, it will begin to
deteriorate or
dissolve when in contact with water. Accordingly, if one chooses to employs,
for
example, the EPA triple rinsing procedure described in the Background, at
least
some of the inner layer will dissolve while performing triple rinsing steps.
As the
inner layer continues to dissolve or disintegrate, the layer, along with the
residue
adhered thereto will be flushed through the mouth or finish of the container.
It is
anticipated that the removal of the inner layer will achieve the effective
removal of
the residue thereon, and preferably at least 99.9999% of the chemical residue
in the
container interior.
After a sufficient amount or the entire inner layer has been removed, the
outer
layer or shell of the container will remain and ultimately be disposed of in
the landfill.
Since the outer layer is frangible and no longer supported by the inner layer,
it will
easily deform or collapse under an insignificant amount of pressure, thereby
reducing its size so as to take up less space in the disposal site than its
original
configuration prior to removal of the inner layer.
By way of example, container 10 described above may be used for the
storage and transportation of a herbicide containing mesotrione, which is the
active
ingredient for example, in a product marketed under the trademark Callisto
registered to Syngenta Crop Protection, Inc. located in Greensboro, North
Carolina.
A container having an inner layer formed of suitable material that is cold
water
soluble would preferably be used. This is because mesotrione would not impair
or
damage in the inner layer while stored therein. Alternatively, an inner layer
formed
of a hot water soluble material would be useful for storing a seed treatment
product
having thiamethoxam as an active ingredient such as the seed treatment product
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marketed under the trademark Cruiser also registered to Syngenta Crop
Protection, Inc.
With reference now to Figs. 4 and 5, a second exemplary embodiment of a
container according to the present invention is shown. Similar to container 10
shown
above, container 110 has a multilayer container body 120 that surrounds
container
interior 118. However, as shown here, container body 120 is formed of three
layers:
inner layer 122, outer layer 124, and tie layer or middle layer 126 located
therebetween. Middle layer 126 may be formed of a material suitable to assist
in
keeping the inner layer and the outer layer together. For example, middle
layer 126
may be formed of polyvinyl acetate, ethylene polyvinyl acetate, polyamide, and
ethylene vinyl alcohol.
As should be appreciated, the multilayer container body can be formed of a
plurality layers, and is not limited to the exemplary embodiments described
above
with reference to the figures. For example, the container body could be
provided
with multiple inner or outer layers and tie layers as needed to form a
suitable
receptacle or container for the selected material. Preferably though, the
inner layer
or layers are formed of a material that will dissolve or disintegrate in the
presence of
a suitable solvent to effectively remove residue in the interior of the
container. The
container contemplated herein may be formed by ordinary processes known in the
art such as co-extrusion, blow molding, injection molding, or any suitable
process.
From the foregoing, it may also be appreciated that the present invention
contemplates a method of removing residue located in the interior of a
container that
may be accomplished by the steps inherent in the described structure.
Generally,
the method includes contacting the interior of a container with a selected
solvent
adapted to dissolve or otherwise disintegrate at least a portion of the inner
layer or
sidewall that surrounds the container interior. The method includes repeated
rinsing
of the container interior sufficient to flush a portion of the inner layer of
the container
body and cause removal of the residue. This method can also cause accomplish
the
step of removing the interior support of the overall container configuration
such that
the remaining outer layer of the container body is collapsible under an
insignificant
amount of pressure.
Accordingly, the present invention has been described with some degree of
particularity directed to the exemplary embodiments of the present invention.
It
should be appreciated, though, that the present invention is defined by the
following
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claims construed in light of the prior art so that modifications or changes
may be
made to the exemplary embodiments of the present invention without departing
from
the inventive concepts contained herein.
