U.S. patent application number 12/245239 was filed with the patent office on 2009-01-29 for method and process for collecting and processing recyclable waste.
Invention is credited to Marvin Acey, Jeffery A. Ashby, Charles Jongert, John Sasine.
Application Number | 20090029074 12/245239 |
Document ID | / |
Family ID | 37679375 |
Filed Date | 2009-01-29 |
United States Patent
Application |
20090029074 |
Kind Code |
A1 |
Sasine; John ; et
al. |
January 29, 2009 |
METHOD AND PROCESS FOR COLLECTING AND PROCESSING RECYCLABLE
WASTE
Abstract
Recyclable plastic film is efficiently collected for recycling
at stores or other locations by compacting the plastic film as
layers in plastic/cardboard bales. The plastic/cardboard bales can
be formed using existing cardboard balers that stores typically
already have for baling recyclable cardboard. In one embodiment,
the plastic/cardboard bales are preferably formed with a bottom
layer of cardboard, a middle layer of the recyclable plastic film,
and a top layer of cardboard. The layered structure can be modified
to omit one of the cardboard layers or to add additional plastic
film and cardboard layers.
Inventors: |
Sasine; John; (South Jordan,
UT) ; Jongert; Charles; (Sandy, UT) ; Acey;
Marvin; (South Jordan, UT) ; Ashby; Jeffery A.;
(Taylorsville, UT) |
Correspondence
Address: |
Workman Nydegger;1000 Eagle Gate Tower
60 East South Temple
Salt Lake City
UT
84111
US
|
Family ID: |
37679375 |
Appl. No.: |
12/245239 |
Filed: |
October 3, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11299442 |
Dec 12, 2005 |
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12245239 |
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11166516 |
Jun 24, 2005 |
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11299442 |
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60617971 |
Oct 11, 2004 |
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Current U.S.
Class: |
428/2 |
Current CPC
Class: |
B65D 85/07 20180101;
B65D 2565/385 20130101; B65F 1/1426 20130101; B65F 9/00 20130101;
B30B 9/30 20130101; B65B 13/20 20130101 |
Class at
Publication: |
428/2 |
International
Class: |
B65D 71/00 20060101
B65D071/00 |
Claims
1. A bale formed of cardboard and recyclable plastic, comprising: a
layer of recyclable plastic film, the layer of recyclable plastic
film comprising first and second opposing surfaces, wherein the
layer of recyclable plastic film comprises a plurality of used
plastic bags and plastic sheets and has a thickness of at least
about three inches; a first layer of cardboard in contact with the
first surface of the layer of recyclable plastic film, the first
layer of cardboard having a thickness of at least about twelve
inches; and a second layer of cardboard in contact with the second
surface of the layer of recyclable plastic film such that the layer
of recyclable plastic film is sandwiched between the first layer of
cardboard and the second layer of cardboard, the second layer of
cardboard having a thickness of at least about three inches;
wherein the layer of recyclable plastic film, the first layer of
cardboard, and the second layer of cardboard are compactly bound
together to facilitate transportation and storage.
2. A bale as defined in claim 1, wherein the layer of recyclable
plastic film comprises from about 10% to about 70% of the bale
thickness.
3. A bale as defined in claim 1, wherein the layer of recyclable
plastic film has a thickness of from about nine inches to about
eighteen inches.
4. A bale as defined in claim 1, wherein the top layer of cardboard
comprises at least about six inches of cardboard.
5. A bale as defined in claim 1, wherein the top layer of cardboard
comprises at least about twelve inches of cardboard.
6. A bale as defined in claim 1, wherein the bale has a thickness
of about forty-eight inches.
7. A bale as defined in claim 1, wherein each of the first layer of
cardboard and the second layer of cardboard have a sufficient
thickness such that a bale of similar or greater weight can be
stacked thereupon, with the layers of cardboard and plastic
positioned perpendicular to gravity, without the bale losing
structural integrity.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. Utility application
Ser. No. 11/299,442, entitled METHOD AND PROCESS OF COLLECTING AND
PROCESSING RECYCLABLE WASTE, filed on Dec. 12, 2005; which is a
continuation of U.S. Utility application Ser. No. 11/166,516,
entitled: "METHOD AND PROCESS OF COLLECTING AND PROCESSING
RECYCLABLE WASTE," filed on Jun. 24, 2005, which is incorporated
herein by reference. This application also claims the benefit of
U.S. Provisional Application No. 60/617,971, filed Oct. 11, 2004.
All of these applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. The Field of the Invention
[0003] The present invention relates to the field of recycling.
More particularly, the present invention relates to methods of
collecting and processing recyclable plastic film waste through the
formation of bales including both plastic and cardboard.
[0004] 2. The Relevant Technology
[0005] The field of plastic recycling is increasingly important as
the use of plastic wrap and plastic film bags permeate more and
more aspects of retail sales as well as the shipping and packaging
industry. For example, plastic shopping bags are well known to the
general public as they are the predominant method for consumers to
carry groceries and other purchased goods from a store. An even
greater volume of plastic film, however, is generated for product
packaging and distribution. For example, pallets of goods are
frequently wrapped with large sheets of shrink wrap plastic to keep
the content of the pallet from shifting or falling during transit.
Another example is clothing distribution, wherein each garment is
typically transported wrapped in its own plastic sleeve. Some
estimates are that plastic bags on apparel account for over 60% of
plastic waste at retail department stores.
[0006] With this proliferation of plastic wrap and plastic bags
into the shipping and packaging industry, there is a need to
recover this material out of the waste stream in an efficient and
effective manner. Stores that aggressively collect and recycle
waste plastic wrap and plastic bags separate from other garbage
frequently save hundreds of dollars per month in the cost of trash
hauling. Still, the storage, baling, shipping, and processing of
the plastic is extremely inefficient under current methods.
[0007] At stores and distribution centers, for example, one
conventional method of collecting plastic waste film for recycling
is to stuff plastic into other large plastic bags and toss them
somewhere in the facility in a haphazard fashion, for example on
top of other bales or bins. For transportation, the bags are thrown
into the back of a truck for transportation. Both of these methods
are extremely inefficient uses of space.
[0008] Because of these challenges, the majority of plastic wrap
and plastic bags are disposed of as waste. Not only does this add
to pollution and more quickly fill landfills, but the plastic film
fills on-site trash receptacles very quickly. Because waste is
typically paid for by volume, i.e. the number of waste containers
hauled off, the large volume of plastic film that is disposed of in
on-site trash receptacles represent a significant cost. In
addition, waste plastic film has a recycling value that is
unrealized when the plastic film is disposed of in garbage.
[0009] Despite the challenges in collecting recyclable plastic
film, uses for recyclable plastic are quickly expanding. For
example, recycled plastic is now used in plastic garbage can
liners, landfill liners, agricultural film, and composite lumber
products for picnic tables, park benches, porches, and walkways
where rot-resistant wood-like products are desired. Shipping
containers, carpet materials, and hard plastic containers are also
more and more frequently made with recycled plastic film. This
increased demand for products made from recycled plastic is fueling
an increased demand for the collection of recyclable plastic.
[0010] In addition, recent increases in the cost of raw petroleum
have led to a dramatic increase in the cost of plastics for plastic
products. As a result, the per pound value of collected recyclable
plastic has also increased dramatically. This adds to the demand
for the collection of recyclable plastic.
[0011] Nevertheless, the volume of plastic that is collected for
recycling remains considerably lower than is feasible. One key
imitation on the use of recyclable plastic is that plastic film is
difficult and costly to collect. For example, consumers using small
plastic bags rarely return them to a source whereby they can be
recycled. In addition, shrink wrapped plastic and garment bags at
department stores are often discarded rather than collected. In
particular, garment bags and shrink wrapped plastic at department
stores and warehouse stores are often discarded because the volume
of space required to store all the plastic accumulated within the
store becomes too expensive to dedicate to that purpose. Although
there are feasible methods for collecting plastic film, such as
dedicated plastic compactors and balers, these devices are too
expensive and the volume of space that must be dedicated to storing
pre-compacted plastic is usually impractical for most
businesses.
[0012] By analogy, efforts at recycling cardboard have been much
more successful. Cardboard recycling is performed at retailers, for
example, by using large cardboard balers to compact waste cardboard
and form the waste cardboard into bales for storage and
transportation to cardboard recycling facilities. Cardboard balers
are generally not used for plastic recycling, however, because they
are much too large for the volume of plastic that is dealt with.
Cardboard balers are typically designed to form forty-eight inch
tall bales. The amount of loose plastic it would take to form a
forty-eight inch tall bale simply cannot be stored by most, if not
all, retailers. As a result, unlike cardboard, for which there is
an efficient recycling infrastructure, there is currently no
effective method for collecting large volumes of recyclable
plastic.
[0013] In addition, plastic and cardboard cannot be mixed for
recycling. This is because they are completely different materials
that are recycled by very different processes. There are also no
efficient methods to separate plastic and cardboard since the value
of either material does not justify the labor. For this reason, it
is well known that the presence of plastic film in a cardboard bale
leads to rejection of the entire bale such that it is discarded
rather than recycled.
[0014] Accordingly, it would represent an advance in the art to
provide systems and methods to more efficiently and less
expensively collect and process recyclable plastic for use in
downstream recycling processes.
BRIEF SUMMARY OF THE INVENTION
[0015] The present invention relates to the collection of
recyclable plastic film in bulk form. As noted above, the disposal
or collection of plastic film from large retail stores, discount
warehouses, and distribution centers has heretofore presented a
significant cost to companies that made it inefficient or
impractical. This difficulty in recovering recyclable plastic film
results in the waste of a significant amount of otherwise
recyclable plastic and reduces profits for those that do collect
and recycle the plastic film.
[0016] These problems are overcome by the herein disclosed methods
for the collection of plastic film within plastic/cardboard bales
formed through novel methods of using balers such as conventional
cardboard balers. In general, a plastic/cardboard bale is formed of
layers of cardboard encompassing one or more layers of plastic.
Thus, an amount of plastic insufficient to form a bale by itself is
combined with one or more cardboard layers and compacted in a
plastic/cardboard bale. As a result of these improved methods, a
locale can use a cardboard baler not only to form cardboard bales,
but also to form plastic/cardboard bales.
[0017] Accordingly, a first example embodiment of the invention is
a method for collecting recyclable plastic. The method generally
includes: providing a cardboard baler; placing a first layer of
cardboard in the baler; placing a layer of recyclable plastic film
in the baler on top of the first layer of cardboard, wherein the
layer of recyclable plastic film has a thickness of at least about
three inches; and operating the cardboard baler to form a bale
formed of plastic and cardboard.
[0018] Another example embodiment of the invention is also a method
for collecting recyclable plastic. This method generally includes:
providing a cardboard baler; compacting a first layer of cardboard
in the baler; compacting a layer of recyclable plastic film in the
baler on top of the first layer of cardboard, wherein the layer of
recyclable plastic film comprises a plurality of used plastic bags
and/or plastic sheets and has a thickness of at least about three
inches to about thirty-six inches; and compacting a second layer of
cardboard over the plastic layer, whereby a bale is formed of
plastic and cardboard, wherein the bale has a thickness of from
about twenty-four inches to about sixty inches.
[0019] Yet another example embodiment of the invention is a bale
formed of cardboard and recyclable plastic. The bale generally
includes: a layer of recyclable plastic film, the layer of
recyclable plastic film comprising first and second opposing
surfaces, wherein the layer of recyclable plastic film comprises a
plurality of used plastic bags and plastic sheets and has a
thickness of at least about three inches; and a first layer of
cardboard in contact with the first surface of the layer of
recyclable plastic film, wherein the layer of recyclable plastic
film and the first layer of cardboard are compactly bound together
to facilitate transportation and storage. A second layer of
cardboard can formed on and in contact with the second surface of
the recyclable plastic film layer. Other cardboard and plastic film
layers can also optionally be included in the bale.
[0020] These and other objects and features of the present
invention will become more fully apparent from the following
description and appended claims, or may be learned by the practice
of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] To further clarify the above and other advantages and
features of the present invention, a more particular description of
the invention will be rendered by reference to specific embodiments
thereof which are illustrated in the appended drawings. It is
appreciated that these drawings depict only typical embodiments of
the invention and are therefore not to be considered limiting of
its scope. The invention will be described and explained with
additional specificity and detail through the use of the
accompanying drawings in which:
[0022] FIG. 1 illustrates a cardboard bale according to the prior
art;
[0023] FIG. 2 illustrates a plastic/cardboard bale according to one
embodiment of the invention;
[0024] FIG. 3 illustrates a plastic/cardboard bale according to
another embodiment of the invention;
[0025] FIG. 4 illustrates the insertion of recyclable plastic film
into a cardboard baler for forming a plastic/cardboard bale
according to embodiments of the invention;
[0026] FIG. 5 illustrates a plastic/cardboard bale formed in a
cardboard baler according to embodiments of the invention;
[0027] FIG. 6 illustrates a series of plastic/cardboard bale
stacked for storage according to another embodiment of the
invention;
[0028] FIG. 7 illustrates a bin for storing recyclable plastic
prior to its compacting in a plastic/cardboard bale according to
another embodiment of the invention; and
[0029] FIG. 8 illustrates another bin for storing recyclable
plastic prior to its compacting in a plastic/cardboard bale
according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Reference will now be made to the figures wherein like
structures will be provided with like reference designations. It is
understood that the drawings are diagrammatic and schematic
representations of presently preferred embodiments of the
invention, and are not limiting of the present invention nor are
they necessarily drawn to scale.
[0031] In the following description, numerous specific details are
set forth in order to provide a thorough understanding of the
present invention. It will be obvious, however, to one skilled in
the art that the present invention may be practiced without these
specific details. In other instances, well-known aspects of
cardboard balers and recyclable plastics have not been described in
particular detail in order to avoid unnecessarily obscuring the
present invention.
[0032] Referring now to FIG. 1, a conventionally formed cardboard
bale 100 includes a compacted single layer 102 of cardboard. As
depicted, the compacted cardboard bale 100 is bound together by
bands 104 to keep the cardboard bale 100 in a compacted state.
Cardboard bale 100 can be formed by a cardboard baler as generally
depicted in FIG. 4 or any other suitable baler or device used to
compact cardboard. Typically, the majority of the individual pieces
of cardboard that form cardboard bale 100 come from the same
product distribution activities that generate most recyclable
plastic film.
[0033] As previously noted, it has been conventionally held that
cardboard cannot be mixed with plastic film in collecting materials
for recycling. More particularly, the chemical and mechanical
processes for recycling cardboard and plastic film cannot work if
both are present. It has therefore been axiomatic that cardboard
bales, such as bale 100, cannot contain any plastic film or the
whole bale must be discarded. This is because not only can the
materials not be mixed in recycling processes, but the cost of
separating plastic film from cardboard is too high for
cost-effective recycling. As a result, mixed cardboard and plastic
bales have heretofore been discarded as waste.
[0034] Contrary to this conventional thinking, however, it has been
surprisingly found that plastic film can be effectively combined
with cardboard in forming a combined cardboard and plastic film
bale. As generally depicted in FIG. 2, one embodiment of such a
combined cardboard and plastic film bale 200 incorporates a first
layer 204 of cardboard, a layer 202 of plastic film, and a second
layer 206 of cardboard. The plastic film layer 202 is in effect
sandwiched between the two cardboard layers 204, 206. The compacted
plastic/cardboard bale is bound together by bands 208.
[0035] It can be readily seen in FIG. 2 how a significant amount of
plastic film has been compacted to a very small space in the
plastic/cardboard bale. In addition, it is also apparent that a
significantly less amount of plastic is used in this
plastic/cardboard bale than if the entire bale were formed of only
plastic film. Thus, because a smaller amount of plastic film can be
compacted in a single bale, the plastic can be disposed of in a
timely fashion from a single location. In contrast, if the plastic
were required to fill the entire bale, it would require many days,
weeks, or even months to fill a single bale, requiring great
expense to store a significant amount of uncompacted plastic.
[0036] Although it is preferred to have cardboard layers both above
and below the plastic film layer, other embodiments of the
invention may use only a single cardboard layer on one side of a
plastic film layer. Alternatively, a plastic/cardboard bale may
have numerous layers. For example, FIG. 3 illustrates several
plastic film layers 256, 260, 264 sandwiched between several
cardboard layers 254, 258, 262, 266 to form a plastic/cardboard
bale having a thickness 252. Of course, one skilled in the art, in
view of the disclosure herein, could configure a plastic/cardboard
bale with any number of layers of plastic and cardboard. The
limiting factor is that the thickness of each plastic layer and the
number of such plastic layers must be cost effective. This use of
numerous plastic film layers may be preferable in locations where
there is little storage space for loose plastic or cardboard and so
it is desirable to frequently compact the on hand loose plastic and
cardboard in multiple layers.
[0037] With reference now to FIG. 4, a conventional cardboard baler
400 is used to form plastic/cardboard bales according to
embodiments of the invention. Using conventional cardboard balers
greatly reduces the cost to retailers and distributors that already
have the balers on-site in that they do not have to acquire another
machine nor do they have to store two machines, one for cardboard
and one for plastic. The construction and operation of conventional
cardboard balers, such as for example cardboard baler 400, is well
known in the art and will not be described in great detail herein.
Most conventional balers are designed to form 48 inch, 60 inch, or
72 inch bales.
[0038] Generally, it can be seen that cardboard and plastic can
each be inserted through a top opening 402 while a gate 404 is in
the open position. In the illustration, a series of bags 302
containing plastic film have been inserted into the baler. Although
not visible in the illustration, a layer of compacted cardboard of
preferably twelve to eighteen inches is already formed below the
uncompacted plastic bags 302. After the gate 404 is closed, the
baler 400 can then be operated to compact the plastic bags 302 into
a compacted plastic film layer over the previously compacted
cardboard layer. It is preferably to load and compact several
cycles of plastic bags, for example eight to twelve, to form an
ideally sized plastic film layer. For example, a preferred plastic
film layer will be from about nine inches to about eighteen inches
in thickness.
[0039] After the plastic film layer is formed, an operator
preferably inserts a cycle of cardboard and then operates baler 400
to compress a layer of cardboard over the plastic film layer. This
top layer may be formed over several load cycles and preferably has
a thickness of twelve to eighteen inches. Finally, the finished
bale is bound, preferably with wire in contrast to conventional
plastic bands, to keep it compacted and then ejected from the baler
400. Preferably the bales have two wires at each end to further
bind the bales. FIG. 5 illustrates a completed and bound bale 200
seated within the bottom portion of baler 400. Alternatively, as
illustrated in FIG. 3 and previously discussed, multiple layers of
plastic film can be formed within a single bale and top or bottom
cardboard bales can be omitted. These embodiments are less
preferred, however.
[0040] Referring now to FIG. 6, forming stacks of plastic/cardboard
bales 200A-C is important in the recycling industry because it
allows for economy of storage and transport efficiency. Completed
plastic/cardboard bales 200A-C are typically stored for a time at
distribution and recycling centers, as seen in FIG. 6, stacked on
top of one another to conserve space. During transport to these
locations, bales are typically stacked on top of one another on a
flat-bed trailer. As the trailers travel, turn corners, bounce,
etc., the need for increased stability is important as bales shift
and tend to lose their structural integrity. The weight of these
bales is often over one thousand pounds, accentuating the tendency
of the bales to shift and lose structural integrity.
[0041] The structure of the inventive bales is particularly
beneficial in that having cardboard layers 204A-C, 206A-C sandwich
plastic layers 202A-C forms structural bookends that allow the
bales to maintain form and be transported safely and effectively.
In other words, whereas the plastic layers are not strong enough to
effectively stack perpendicularly on their own, the cardboard end
layers provide excellent structural integrity so the bales can be
stacked perpendicular to gravity without collapsing. The top and
bottom cardboard layers 204A-C, 206A-C therefore preferably each
have a thickness of at least about twelve inches to provide good
support, but as few as six inches or even three inches may also be
used in some embodiments.
[0042] In addition, the cardboard ends of the plastic/cardboard
bales allow the bales to be tightly secured by straps tightened by
a winch on a flat-bed trailer without the force of the straps
breaking the bales part.
[0043] Accordingly, one embodiment of the invention is a method of
transporting or storing plastic/cardboard bales by stacking two or
more plastic/cardboard bales, wherein each of the bales has a
cardboard layer, perpendicular to the stack, on each end of each
bale such that the bales do not lose structural integrity and do
not collapse. Such cardboard layers preferably have a thickness of
least about three inches, more preferable at least about six
inches, still more preferably at least about twelve inches.
[0044] In addition to providing structural support, the top and
bottom cardboard layers 204A-C, 206A-C also help contain loss of
debris when the bales 200A-C are transported on an open flat-bed
trailer. Cardboard is less likely to pull loose in the wind than
plastic and so having cardboard at the end pieces reduces the
likelihood of plastic being pulled loose. The cardboard layers are
also beneficial when the bales are stored on the ground in that the
cardboard absorbs water, reducing the amount of water entering the
plastic.
[0045] One example process of implementing the invention involves
first gathering recyclable plastic film to a single location. Such
plastic may include plastic generated on-site, for example plastic
shrink wrap or plastic garment bags removed from clothing prior to
sale. Plastic may also be gathered from other locations. For
example, a collection location may have a plastic bag collection
program wherein consumers can return their small plastic grocery or
shopping bags for recycling. In addition, plastic bags can be
collected throughout a community, such as at local schools, to
promote recycling and thereby provide the double effect of
providing a revenue stream for the store (sales of recyclable
plastic) and by generating community goodwill.
[0046] The gathered plastic film must then be stored for a brief
period of time. Storing recyclable plastic according to one
embodiment of the invention includes providing a specially designed
collection area. As seen in FIGS. 7 and 8, such a collection area
may be for example a tall narrow ball bin 280, 300 similar to those
currently used to store large rubber balls and the like. Within a
ball bin 280, 300 a plurality of single plastic bags 302, such as a
garbage bags, are filled with shrink wrap and other accumulated
plastic. The plastic bags 302 are preferably themselves recyclable
plastic film bags having other recyclable plastic film therein.
[0047] A ball bin 280, 300 can be conveniently located near a
cardboard baler so that bags 302 of plastic film can be stored
vertically to minimize occupied floor space. The ball bins can also
be formed or placed on a pallet 288 or wheeled dolly so it can be
moved as desired. In the embodiment of FIG. 7, the ball bin 280 can
have a lightweight frame 282, for example formed of PVC. The
depicted ball bin has a funneled top opening 290 and plurality of
bungee cords or ropes 286 that keep bags 302 from falling out. For
storage, the plastic bags can be either tossed in through the
funneled top opening or pushed between the movable bungee retainer
cords 286. The bags can then be removed for compacting by pulling
them through the movable bungee retainer cords 286. In the depicted
embodiment of FIG. 8, in another example the ball bin also be a
metal cage having top and bottom openings where the plastic bags
302 can be tossed in and removed.
[0048] The bags of plastic are preferably stored in a ball bin
until it is completely full. That volume of plastic is then loaded
into the baler over a series of compacting cycles to make a
plastic/cardboard bale. It has been determined that one bin of
approximately 4 feet in width, 4 feet in depth, and ten feet in
height can hold the plastic generated over two to three days by a
typical large retail store or discount warehouse.
[0049] It is preferable to make each plastic layer as thick as
possible to reduce the number of plastic/cardboard bales. Fewer
plastic/cardboard bales is preferable since it reduces the number
of bales that need to be specially handled. It is estimated that
large retail stores using a ball bin as describe herein to store
plastic film will generate approximately one plastic/cardboard bale
for every eight or nine cardboard bales.
[0050] Upon formation of a plastic/cardboard bale, such as for
example plastic/cardboard bale 200 or plastic/cardboard bale 250.
The plastic/cardboard bale can then be stored on-site until it is
shipped to a plastic and cardboard processing center, optionally
via other distribution locales such as returns centers. Because,
the plastic film has been compacted in the plastic/cardboard bales,
it takes up the less space in a trailer or other transportation
vehicle as a similar weight of loosely gathered plastic film.
[0051] At the downstream plastic and cardboard processing center
the bale is separated into its constituent parts, for example first
cardboard layer 204, plastic layer 202, and second cardboard layer
206. Because the plastic film in the plastic/cardboard bale is
contiguous, the compact plastic layer can be easily and readily
removed and isolated for recycling. Thus, neither the plastic nor
the cardboard is contaminated by the other.
[0052] Cardboard balers typically form bales that are about
forty-eight inches tall, about sixty to seventy-two inches wide,
and about thirty inches deep. A single plastic layer, in turn, may
comprise from about three inches to about thirty-six inches or more
in height. Alternatively, the layer of plastic film can be
described as being at least about 5% of the bale thickness, more
preferably from about 10% to about 70% of the bale thickness. While
less than about 3 inches, or less than about 5%, can be used in
embodiments of the invention, unless the price per pound for
recyclable plastic film becomes very high it is significantly less
financially feasible to process a bale to collect such a relatively
small volume of plastic. In addition, having at least about 30%
cardboard in each bale helps ensure sufficient rigidity for bale
stability and containment or plastic.
[0053] A lower cardboard layer will preferably be from about 5% to
about 95% of the bale thickness, more preferably about 75% of the
bale thickness. The optional top cardboard layer is preferably
thinner than the bottom cardboard layer such that it can be more
easily removed when the bale is disassembled. A top cardboard layer
thickness of about three to twelve inches, more preferably about
six inches to about nine inches, is therefore preferred. Although
not necessary, the use of the top cardboard layer is preferred as
it helps keep the bale more compact and intact than it would be if
plastic film were on the top of the bale.
[0054] Of course, the denotations of top and bottom are
interchangeable and the bales can be formed in an inverse manner to
that described hereinabove.
[0055] Various approaches can be used to track the weight of
plastic film that is pressed into each plastic/cardboard bale. One
efficient manner of keeping track of the volume of plastic that is
compacted in each bale is simply to measure the thickness of each
plastic layer and multiply that thickness times other known
constants such as the dimensions of the bale to determine an
approximate plastic volume. This number is particularly helpful for
use in determining the value of the plastic that has been
recovered.
[0056] For example, it is currently known that every three inches
of compacted plastic film in a 60'' by 48'' by 30'' bale weights
about 50 pounds. A 72'' by 48'' by 30'' bale, in turn weights about
65 pounds. Thus, upon the formation of the bale the thickness of
the plastic film layer can be approximately measured in inches and
a weight estimate can be made.
[0057] Alternatively, the thickness of the plastic film layer can
be estimated as a fraction of the bale thickness. Regardless, the
entire bale can also be weighed so that the correct fractional
portion of the load is assigned to the plastic film layer. Past
measurements of separated bales as well as the known densities of
plastic and cardboard can be used to create tables that indicate
any adjustments to these estimates if more precise estimates are
desired.
[0058] At the plastic and cardboard processing center, the whole
bales can be again weighed. After the bales are broken open and the
plastic is separated from cardboard the plastic can once more be
weighed to get a final accurate measurement of the recovered
plastic film. Of course, not all of these measurements may be
necessary depending upon the accuracy and tracking that is
desired.
[0059] After sorting the cardboard and plastic, each of the
cardboard and plastic can be baled separately and shipped either on
truck or rail car to paper and plastic consuming manufacturers
throughout the country.
[0060] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes which come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *