U.S. patent application number 11/927318 was filed with the patent office on 2009-04-30 for combination-cell foam floating island.
This patent application is currently assigned to Fountainhead L.L.C.. Invention is credited to Bruce G. Kania, Frank M. Stewart.
Application Number | 20090107039 11/927318 |
Document ID | / |
Family ID | 40581031 |
Filed Date | 2009-04-30 |
United States Patent
Application |
20090107039 |
Kind Code |
A1 |
Kania; Bruce G. ; et
al. |
April 30, 2009 |
COMBINATION-CELL FOAM FLOATING ISLAND
Abstract
A floating island comprising a combination-cell thermoplastic
foam. In a preferred embodiment, the invention is a floating island
comprising: an island body comprising at least a first portion that
comprises a combination-cell thermoplastic foam and having a
cavity; and a bedding material that is disposed in said cavity;
wherein said combination-cell thermoplastic foam is buoyant in
water and permeable to gas and water.
Inventors: |
Kania; Bruce G.; (Shepherd,
MT) ; Stewart; Frank M.; (Bozeman, MT) |
Correspondence
Address: |
ANTOINETTE M. TEASE
P. O. BOX 51016
BILLINGS
MT
59105
US
|
Assignee: |
Fountainhead L.L.C.
Shepherd
MT
|
Family ID: |
40581031 |
Appl. No.: |
11/927318 |
Filed: |
October 29, 2007 |
Current U.S.
Class: |
47/65.5 |
Current CPC
Class: |
A01G 9/00 20130101 |
Class at
Publication: |
47/65.5 |
International
Class: |
A01G 9/02 20060101
A01G009/02 |
Claims
1. A floating island comprising: an island body comprising a
nonwoven plastic fiber matrix, said island body having a central
cavity and a bottom having a plurality of holes; a shaped liner
having a plurality of liner holes; a plurality of wicking cups that
connect each said hole to each side liner hole, each said wicking
cup having an outer layer and a central portion; and a growth
medium that is disposed in said shaped liner and in each said
central portion.
2. The floating island of claim 1 wherein said island body is
comprised of a nonwoven thermosetting or thermoplastic fiber
matrix.
3. The floating island of claim 1 wherein said growth medium is a
wicking composition.
4. The floating island of claim 3 wherein said growth medium
comprises a hydrophilic polymer foam and a plurality of organic
materials.
5. The floating island of claim 1 wherein said outer layer
comprises a combination-cell foam.
6. The floating island of claim 1 wherein said shaped liner
comprises a combination-cell foam.
7. A floating island comprising: an island body comprising at least
a first portion that comprises a combination-cell thermoplastic
foam and having a cavity; and a bedding material that is disposed
in said cavity; wherein said combination-cell thermoplastic foam is
buoyant in water and permeable to gas and water.
8. The floating island of claim 7 further comprising: a second
portion that comprises a matrix.
9. A floating island comprising: a buoyant matrix layer comprising
a combination-cell thermoplastic foam; a grass sod layer that is
disposed on said buoyant matrix material.
10. The floating island of claim 9 further comprising: a nonwoven
matrix layer that underlies said buoyant matrix material.
11. The floating island of claim 9 wherein said buoyant matrix
layer is selected from the group consisting of: a thermoplastic
polymer shape, a thermoplastic polymer foam shape, and a
combination of the shapes.
12. A fastening assembly comprising: at least two fastening pins,
each of said fastening pins comprising a substantially U-shaped,
stiff body having legs having notches; and a connecting cable that
connects said fastening pins.
13. A fastening unit comprising: a substantially U-shaped, stiff,
planar body having a substantially flat top and legs having
notches.
14. A combination comprising: a first floating island an island
body comprising a first combination-cell thermoplastic foam portion
and a first matrix portion; a second floating island comprising a
second combination-cell thermoplastic foam portion and a second
matrix portion; and the fastening unit of claim 12 wherein one
fastening pin is embedded in said first matrix portion and a second
fastening pin is embedded in said second matrix portion.
15. A combination comprising: a buoyant matrix layer comprising a
combination-cell thermoplastic foam; a grass sod layer that is
disposed on said buoyant matrix material; a nonwoven matrix layer
that underlies said buoyant matrix material; and the fastening unit
of claim 14 embedded at least two of said layers.
16. A floating island comprising: an island body that comprises a
first combination-cell thermoplastic foam portion and having a
cavity; a bedding material that is disposed in said cavity; a top
cover that comprises a second combination-cell thermoplastic foam
portion that is disposed on said island body; wherein said
combination-cell thermoplastic foam portions are buoyant in water
and permeable to gas and water.
17. A floating island comprising: an island body comprising a
matrix top, a matrix bottom and matrix sides and having an interior
portion; and a scrap material that is disposed in said interior
portion, said scrap material comprising a combination-cell
thermoplastic foam portion; wherein said combination-cell
thermoplastic foam portion is buoyant in water and permeable to gas
and water.
18. A floating island comprising: an island body comprising a first
matrix layer, a second matrix layer and a third matrix layer; and a
gas-trapping insert that is disposed between two of said layers,
said gas-trapping insert being fabricated from a material selected
from the group consisting of a combination-cell thermoplastic foam
and a solid thermoplastic; wherein said combination-cell
thermoplastic foam portion is buoyant in water and permeable to gas
and water.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to floating islands. In particular,
the invention relates to combination-cell foam floating
islands.
[0002] The background art is characterized by U.S. Pat. Nos.
5,224,292; 5,528,856; 5,766,474; 5,980,738; 6,086,755; and
6,555,219 and U.S. patent application Nos. 2003/0051398;
2003/0208954; 2005/0183331; the disclosures of which patents and
patent applications are incorporated by reference as if fully set
forth herein.
[0003] Background art floating planters have four major
deficiencies that are overcome in preferred embodiments of the
present invention. Some background art planters are predominantly
covered by materials that prevent or restrict plant growth. For
example, the invention described by Tepper (U.S. Pat. No.
6,086,755) comprises a top floatation layer that is manufactured
from a conventional buoyant foam such as a foamed plastic. This
material is not suitable for plant growth; therefore, this
invention requires cutouts to be installed through the foam layer,
and plants can only grow through the cutouts. With the Tepper
invention, only a portion of the top surface area of the planter is
available for plant growth, which reduces the total plant growing
capacity of the structure.
[0004] Other background art planters use hollow buoyant pipes that
are installed around the perimeter of the structure to provide
buoyancy. For example, Waterlines Solutions of the U.K. utilizes
sealed polypropylene tubes around the perimeter of its floating
planters to provide buoyancy. This method of providing buoyancy
tends to be fragile (e.g., subject to failure by impact from boats
and pressure from freezing ice) and expensive.
BRIEF SUMMARY OF THE INVENTION
[0005] The purpose of the invention is to provide an economical
floating island. Some embodiments of the invention comprise a
material (combination-cell thermoplastic foam) that has not been
used in the background art. This material has several beneficial
properties that require the use of multiple materials in the
background art. The material provides buoyancy via the closed
cells, water wicking and water adsorption via the open cells; it is
penetrable by plant roots and resistant to chemical and sunlight
degradation. When used under pockets of bedding soil, it prevents
loss of soil while supporting root growth and providing buoyancy.
The formulation of the combination-cell foam can be varied so as to
produce a variety of foam products from the same resin stock,
thereby reducing manufacturing costs.
[0006] Some embodiments of the invention are specifically designed
to maximize the use of scrap materials, thereby reducing production
costs and also converting waste products into environmentally
beneficial products. Fastening devices have been improved over the
background art to be more economical, stronger, and more
efficient.
[0007] Utilization of combination open/close celled foam as a
comprehensive one-material floating island solution allows for
simplified, less expensive mass production. This, in combination
with features like enhanced ultraviolet (UV) light protection,
provides for a higher quality, more consistent product.
[0008] In summary, this disclosure describes improvements to the
background art floating island technology embodied in products
manufactured by Floating Island International, LLC, of Shepherd,
Mont. The improvements described in this disclosure result in lower
production costs for floating island products that perform as well
or better than background art production models. The improvements
include changes in construction materials and fabrication
methods.
[0009] In a preferred embodiment, inexpensive and durable floating
(buoyant) islands are made by replacing background art
thermosetting (e.g., polyurethane) foam with thermoplastic (e.g.,
polypropylene, polyethylene, or ethylene vinyl acetate) foam. In
preferred embodiments, the thermoplastic foam is comprised of a
combination of open and closed cells, which provide benefits that
are not present in foams that are comprised of either open cells
alone or closed cells alone. Thermoplastic foams that contain both
open and closed cells are preferably produced by an extrusion
process that is similar to the ones used to produce both open cell
foam and closed cell foam. By adjusting the manufacturing
conditions such as foaming gas injection volume, extrusion
temperature, and extrusion pressure, a portion of the gas bubbles
break as they expand within the curing polymer, thereby producing
open cells. The remaining portion of the gas bubbles remain intact
as they expand, thereby producing closed cells. An example of a
manufacturer of this "combination-cell" material is Nomaco
Corporation of Zebulon, N.C. The open cells can absorb and wick
water, and they allow easy penetration by plant roots and stems.
The closed cells are gas-filled, thereby reducing the total weight
of the sheet, and providing buoyancy when the material is
submerged. The ability to include open and close cells in the same
material at whatever ratio is desired eliminates several
manufacturing operations that would otherwise be required to
achieve a desired buoyancy in combination with an appropriate gas
and water exchange rate within the body of a floating island.
[0010] In another preferred embodiment, the growth medium is
contained by an underlayer of permeable foam sheeting. The sheeting
is preferably comprised of thermoplastic (e.g., polypropylene,
polyethylene, or ethylene vinyl acetate) foam. The pore spaces
comprising the thermoplastic foam comprise a combination of open
and closed cells.
[0011] In another preferred embodiment, the buoyancy and outer
covering materials are rendered more resistant to degradation by
sunlight and other environmental effects by the utilization of
inert thermoplastic materials. In this embodiment, the buoyancy and
outer covering materials are comprised of thermoplastic or
thermoplastic foam. Both of these materials are relatively inert
compared to other materials, such as thermosetting polymers. Inert
materials do not react chemically with reactive materials such as
water or petroleum products; therefore, they do not degrade when
exposed to these materials. In addition, thermoplastic materials
are generally more resistant to sunlight-caused degradation than
thermosetting materials.
[0012] In another preferred embodiment, the entire island body is
comprised of combination-cell thermoplastic foam. This embodiment
is both buoyant and penetrable by plants.
[0013] In another preferred embodiment, the capillary wicking tubes
of previous embodiments have been made more effective and less
expensive by utilizing novel, pre-manufactured wicking cups filled
with wicking growth medium.
[0014] In yet another preferred embodiment, the matrix is rendered
self-buoyant and more durable by incorporating thermoplastic
polymer shapes (shapes may include threads, rods, strands, tubes,
strips, etc.) or thermoplastic polymer foam shapes. The shapes are
preferably melted or bonded together with a binder to form a
matrix. Thermoplastic foams may alternately be used in place of
polyurethane foam to provide adhesion between matrix layers and/or
buoyancy for the island. These shapes are preferably produced by an
extrusion process, wherein plastic pellets are softened by
increasing temperature and shear forces within a mechanical
extruder. An expansion gas such as compressed iso-butane is
injected into the softened plastic within the extruder. The
softened plastic exits the extruder in a continuous stream through
a nozzle. As the plastic exits the nozzle, the gas within the
plastic expands and forms bubbles, producing closed cell foam. The
foam cools sufficiently to set within a few seconds after exiting
the nozzle. Although extrusion machines typically produce a
continuous outlet stream, individual "shots" of foam may be
produced by means of a shuttle valve that alternately shunts the
stream of soft plastic back and forth between two or more
outlets.
[0015] In another preferred embodiment, internal buoyancy is
integrated within the island body by extruding uncured
thermoplastic foam into the porous matrix. Examples of suitable
thermoplastic foams include polyethylene, polypropylene and
polyester foams. In this embodiment, the thermoplastic material
expands and sets around at least some of the fibers of the matrix
to form a volume of non-permeable closed cell foam within the
island body. The density of the thermoplastic foam may be adjusted
by varying the chemical formula of the resin, or by varying the
application parameters such as the volume of expansion gas, the
extruder temperature, and the extrusion rate. Practical densities
of cured thermoplastic foam for the islands range from about 0.5 to
about 25.0 pcf. By selecting a thermoplastic resin that has a lower
melting temperature than the polyester fibers of the matrix, the
molten thermoplastic foam can be injected into the matrix without
melting the polyester fibers. For example, a molten polyethylene
foam at a temperature of 110 degrees C. can be injected into a
polyester matrix that has a melting point of 150 degrees C.
[0016] In yet another preferred embodiment, uncured thermoplastic
foam is continuously extruded onto a continuous layer of matrix
that passes in front of the thermoplastic extrusion nozzle on a
moving production line. The thermoplastic foam expands and sets to
form a continuous strip of buoyant foam that is bonded to the
matrix. The lengths of foamed matrix bodies are preferably cut into
individual island shapes in a subsequent manufacturing operation.
Optionally, two or more layers of matrix may be stacked with
uncured foam introduced between them during the production
operation, resulting in a multi-layer matrix with foam between the
layers after the foam cures. In this configuration, the foam
provides adhesion between joining layers as well as buoyancy.
[0017] In a further preferred embodiment, holes or strips are
precut into the matrix, and molten thermoplastic foam is extruded
into the precut voids, where it expands and sets. This technique
may be preferred in cases where injecting the molten foam directly
into the matrix results in poor quality foam due to the matrix
fibers causing the foam bubbles to break during the expansion
process, which could result in a less preferred foam that absorbs
water and loses buoyancy.
[0018] In another preferred embodiment, pre-manufactured
thermoplastic foam cylinders or other prismatic shapes are
installed into precut cylindrical or other holes within the matrix,
where they are retained by either a friction fit, or by melting, or
via a mechanical pin device. In yet another preferred embodiment,
pre-manufactured lengths of extruded foam rods or "noodles" are
laid lengthwise between multiple layers of matrix, and the assembly
is bonded by melting or by means of an adhesive or an adhesive foam
or a mechanical pin device to form a "sandwich" with internal
buoyancy provided by the foam noodles.
[0019] In another preferred embodiment, relatively small diameter
foam noodles are pre-manufactured, and then used to form a buoyant
matrix by bonding the noodles together via controlled melting, or
by applying suitable adhesive such as latex binder, or by
mechanically tangling the fibers to form a nonwoven blanket, or by
weaving the fibers to form a woven blanket or by use of an adhesive
foam, like polyurethane. Islands made from the buoyant matrix of
this embodiment require less additional buoyancy in the form of
discrete pieces of buoyant foam, and may be adequately buoyant for
some island applications without any additional buoyancy
components. The minimum diameter of commercially available noodles
is approximately 1/4-inch, but smaller diameter noodles (e.g., 0.05
inch) are technically feasible and may be preferred for making
buoyant matrix. One example of a manufacturer of 1/4-inch diameter
polyethylene foam rods is Nomaco Corporation of Zebulon, N.C.
[0020] Buoyancy tests preformed by the applicants indicate that
matrix made from ethylene vinyl acetate and polypropylene (without
binder additives) is buoyant, while matrix made from polyester
fibers with latex binder is not buoyant. Thus, nonwoven matrix made
by melting the fibers together is buoyant; nonwoven matrix made
with latex binder is not buoyant. If the fibers are made of foamed
polymer, then the matrix is more buoyant than if it is made with
the same material that is not foamed.
[0021] In another preferred embodiment, an inexpensive means is
used to join buoyant units to the matrix. The inexpensive means
preferably incorporates novel mechanical fastening pins.
[0022] Furthermore, modular units may be joined laterally or
vertically by inexpensive mechanical fasteners, thereby providing a
means for a standard-size product to be modified to any desired
thickness and/or surface area.
[0023] In yet another preferred embodiment, scrap materials (both
thermoplastic and thermosetting materials) are incorporated into
the island body, thereby reducing costs and providing environmental
benefits. This can be achieved by putting irregular shapes of scrap
matrix or foam of any polymer type into a predetermined shape and
either bonding with the adhesive means previously described, or
sandwiching the scrap between non scrap sheets of nonwoven matrix,
or alternatively, by passing scrap through a mechanical device,
like a wood chipper, and producing a homogenous material
characterized by a high level of surface area. This material is
then used as a filler within predetermined island module shapes.
Alternatively, this material can be baled much like straw or hay.
Depending on the level of buoyant polymer that makes up the
homogenous mix, such bales may be appropriately buoyant, or may
require added levels of buoyancy.
[0024] In another preferred embodiment, wicking and buoyancy are
incorporated into a single (e.g., thermoplastic) material that
comprises a combination of open and closed cells, thereby reducing
both material and construction costs, while improving floating
island efficiency.
[0025] The buoyant foam that provides adhesion between layers as
well as buoyancy for the structure is preferably comprised of an
inert thermoplastic polymer, thereby reducing material costs and
improving durability. In a first embodiment, conventional
thermosetting polyurethane foam is used to bond the top, bottom,
and sides of the matrix together, and closed cell or
combination-cell thermoplastic foam (optionally, scrap foam) is
used as a filler in the interior island space to provide
inexpensive buoyancy for the floating island. In a second
embodiment, thermoplastic foam is used exclusively to provide both
adhesion and buoyancy for the floating island. If combination-cell
thermoplastic foam is used, then plant roots can penetrate it.
[0026] A single type of material (thermoplastic foam) is preferably
used for several purposes on a floating island, by varying the
volumes and ratio of the open and closed cells that are produced
during the extrusion of the foam material, thereby reducing
material costs. For applications in which the primary objective is
to maximize long-term buoyancy and root penetration is not required
(e.g., injected buoyant units), then closed cell foam is preferred.
Closed cell foam does not absorb water, and it has the most
preferred long-term durability of thermoplastic foam varieties. For
applications where wicking and water absorption are the primary
objectives and buoyancy is not important (e.g., as a growth medium
additive), open-cell foam is acceptable and may be less expensive
to obtain than other foam types. For applications where wicking,
buoyancy and root penetration are required (e.g., for submerged
wicking cups), the combination-cell foam that contains a mixture of
open and closed cells is preferred. The same thermoplastic resin
stock may be used to produce all three varieties of foam.
[0027] Gas-impermeable inserts of various shapes (e.g., sheet or
saucer-shaped) may be manufactured into the floating island body
below waterline. These inserts trap gases on their undersides,
thereby providing renewable, long-term buoyancy to the island.
[0028] In a preferred embodiment, the floating islands are
manufactured so as to provide both aerobic and anaerobic zones
within the same island. This renders the floating islands useful
for a wide range of biological remediation applications.
[0029] By incorporating closed cell foam scrap within the body of a
floating island, three objects are accomplished: more buoyancy,
trapped gas at random within the island, and the creation of zones
that can allow gas and water passage. This multiplicity of aerobic
and anaerobic zones still allows for water to filter through the
island, exposing aerobic and anaerobic microbes to various
nutrients within the water. Applicants have learned that scrap foam
and/or scrap or commercial quality combination open/close cell foam
may be used at specific ratios and achieve the blend of buoyancy
(based on close cell foam) with filtration, (based on open cell
foam) to provide both buoyancy and appropriate filtration,
inexpensively.
[0030] The required percentage of closed cell foam for an island is
determined by the buoyancy requirements for the island. The closed
cells within the foam are filled with trapped gas, and therefore
provide buoyancy when submerged. Open cells within the foam become
saturated with water when submerged, and do not provide buoyancy.
For example, consider an island that is one foot thick, and having
a foam component that is required to provide a buoyancy of 10
pounds per square foot of island surface area. Lightweight foam
that is comprised entirely of closed cells provides about 60 pounds
of buoyancy per cubic foot (pcf) of foam; therefore, 10 pounds of
buoyancy will require about (10 lb./60 pcf)=0.17 cubic foot of
closed cell foam per cubic foot of island matrix. In other words,
the matrix must comprise 17% closed cell foam by volume. However,
if the foam is combination-cell foam that is comprised of cells
that are 50% closed and 50% open, then the matrix must contain
twice as much combination-cell foam by volume (2.times.17%=34%) to
achieve the required buoyancy of 10 pounds per square foot of
island surface area, because the buoyancy is only provided by the
closed-cell fraction of total cells within the foam. Similar
calculations can be made for any combination of island thickness,
desired buoyancy, and foam.
[0031] Gas impermeable inserts, in addition to being buoyant, may
be shaped (e.g., in an upside down saucer shape) to trap bio-gas or
other introduced gas underneath them, providing another low-cost
buoyancy feature. All of these inexpensive buoyancy improvements
reduce the need to rely on polyurethane, an expensive and
potentially hazardous material. Instead of utilizing polyurethane
for both buoyancy and adhesion, it can be used more sparingly, if
at all.
[0032] In a preferred embodiment, the invention is a floating
island comprising: an island body comprising a nonwoven plastic
fiber matrix, said island body having a central cavity and a bottom
having a plurality of holes; a shaped liner having a plurality of
liner holes; a plurality of wicking cups that connect each said
hole to each side liner hole, each said wicking cup having an outer
layer and a central portion; and a growth medium that is disposed
in said shaped liner and in each said central portion. Preferably,
said island body is comprised of a nonwoven thermosetting or
thermoplastic fiber matrix. Preferably, said growth medium is a
wicking composition. Preferably, said growth medium comprises a
hydrophilic polymer foam and a plurality of organic materials.
Preferably, said outer layer comprises a combination-cell foam.
Preferably, said shaped liner comprises a combination-cell
foam.
[0033] In another preferred embodiment, the invention is a floating
island comprising: an island body comprising at least a first
portion that comprises a combination-cell thermoplastic foam and
having a cavity; and a bedding material that is disposed in said
cavity; wherein said combination-cell thermoplastic foam is buoyant
in water and permeable to gas and water. Preferably, the floating
island further comprises: a second portion that comprises a
matrix.
[0034] In yet another preferred embodiment, the invention is a
floating island comprising: a buoyant matrix layer comprising a
combination-cell thermoplastic foam; a grass sod layer that is
disposed on said buoyant matrix material. Preferably, the floating
island further comprises: a nonwoven matrix layer that underlies
said buoyant matrix material. Preferably, said buoyant matrix layer
is selected from the group consisting of: a thermoplastic polymer
shape, a thermoplastic polymer foam shape, and a combination of the
shapes.
[0035] In a further preferred embodiment, the invention is a
fastening assembly comprising: at least two fastening pins, each of
said fastening pins comprising a substantially U-shaped, stiff body
having legs having notches; and a connecting cable that connects
said fastening pins. In another preferred embodiment, the invention
is a fastening unit comprising: a substantially U-shaped, stiff,
planar body having a substantially flat top and legs having
notches.
[0036] In another preferred embodiment, the invention is a
combination comprising: a first floating island with an island body
comprising a first combination-cell thermoplastic foam portion and
a first matrix portion; a second floating island comprising a
second combination-cell thermoplastic foam portion and a second
matrix portion; and a fastening unit disclosed herein wherein one
fastening pin is embedded in said first matrix portion and a second
fastening pin is embedded in said second matrix portion.
[0037] In another preferred embodiment, the invention is a
combination comprising: a buoyant matrix layer comprising a
combination-cell thermoplastic foam; a grass sod layer that is
disposed on said buoyant matrix material; a nonwoven matrix layer
that underlies said buoyant matrix material; and a fastening unit
disclosed herein embedded in at least two of said layers.
[0038] In another preferred embodiment, the invention is a floating
island comprising: an island body that comprises a first
combination-cell thermoplastic foam portion and having a cavity; a
bedding material that is disposed in said cavity; a top cover that
comprises a second combination-cell thermoplastic foam portion that
is disposed on said island body; wherein said combination-cell
thermoplastic foam portions are buoyant in water and permeable to
gas and water.
[0039] In another preferred embodiment, the invention is a floating
island comprising: an island body comprising a matrix top, a matrix
bottom and matrix sides and having an interior portion; and a scrap
material that is disposed in said interior portion, said scrap
material comprising a combination-cell thermoplastic foam portion;
wherein said combination-cell thermoplastic foam portion is buoyant
in water and permeable to gas and water.
[0040] Further aspects of the invention will become apparent from
consideration of the drawings and the ensuing description of
preferred embodiments of the invention. A person skilled in the art
will realize that other embodiments of the invention are possible
and that the details of the invention can be modified in a number
of respects, all without departing from the concept. Thus, the
following drawings and description are to be regarded as
illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0041] The features of the invention will be better understood by
reference to the accompanying drawings which illustrate presently
preferred embodiments of the invention.
[0042] FIG. 1 is an exploded perspective view of a preferred
embodiment of the invention that comprises wicking cups and a
shaped liner for preventing the loss of growth medium.
[0043] FIG. 2 is a side cross-section view of the embodiment of
FIG. 1, after the island parts have been assembled and plants have
become established.
[0044] FIG. 3 is a side cross-section view of another embodiment of
a floating island that comprises lost-cost materials.
[0045] FIG. 4 shows a side cross-section view of another low-cost
embodiment of a floating island in which the island body is
comprised entirely of thermoplastic foam.
[0046] FIG. 5 is a side cross-section view of yet another low-cost
embodiment of a floating island.
[0047] FIG. 6 is a perspective view of a preferred embodiment of a
fastening assembly.
[0048] FIG. 7 is a perspective view of a preferred embodiment of a
fastening assembly.
[0049] FIG. 8 is a side cross-section view of an embodiment of a
floating island that comprises a thermoplastic foam top cover, in
which the thermoplastic foam is comprised of both open and closed
cells.
[0050] FIG. 9 is a side cross-section view of a preferred
embodiment of a floating island that is comprised of a significant
percentage of scrap material.
[0051] The following reference numerals are used to indicate the
parts and environment of the invention on the drawings: [0052] 1
island body [0053] 2 wicking cups [0054] 3 shaped liner [0055] 4
matrix [0056] 5 central cavity [0057] 6 cutout holes [0058] 7 outer
layer [0059] 8 central portion [0060] 9 growth medium [0061] 10
plants [0062] 11 roots [0063] 12 water body [0064] 13 thermoplastic
foam [0065] 14 bedding mix [0066] 17 grass sod layer, sod layer
[0067] 18 buoyant matrix material, buoyant matrix layer [0068] 19
coarse nonwoven matrix material [0069] 20 fastening assembly [0070]
21 fastening pins [0071] 22 connecting cable [0072] 23 notches
[0073] 24 fastening unit [0074] 26 thermoplastic foam top cover,
top cover [0075] 27 matrix top [0076] 28 matrix bottom [0077] 29
matrix sides [0078] 30 scrap matrix [0079] 31 scrap open cell foam
[0080] 32 scrap closed cell foam [0081] 33 scrap combination-cell
foam [0082] 40 floating island [0083] 42 bedding pocket [0084] 44
liner holes
DETAILED DESCRIPTION OF THE INVENTION
[0085] Referring to FIG. 1, a preferred embodiment of floating
island 40 is illustrated that comprises island body 1, wicking cups
2 and shaped liner 3 for preventing the loss of growth medium.
Island body 1 is preferably further comprised of a nonwoven
thermosetting or thermoplastic fiber matrix 4 that has central
cavity 5 and bottom cutout holes 6. Wicking cups 2 are preferably
comprised of outer layer 7 and central portion 8. Central portion 8
is preferably filled with growth medium that has been formulated to
have wicking ability.
[0086] An example of a suitable growth medium is BIOMIX.RTM.
manufactured by Floating Island International of Shepherd, Mont.
BIOMIX is a mixture comprising a hydrophilic polymer foam and a
plurality of organic materials such as peat and bark.
[0087] Outer layer 7 is preferably comprised of thermoplastic
polymer foam that has been manufactured specifically to have a
combination of open cell and closed cell pore spaces within the
polymer material (to comprise a combination-cell foam). The ratio
of open to closed cell pores is set during the manufacturing
process so that outer layer 7 has the ability to wick water via
capillary action while retaining growth medium inside central
portion 8. Shaped liner 3 is preferably comprised of thermoplastic
polymer foam similar in composition to the material of outer layer
7. Shaped liner 3 preferably fits inside of island body 1, has
liner holes 44 in its lower surface and is filled with growth
medium 9.
[0088] Referring to FIG. 2, a side cross-section view of FIG. 1 is
presented, showing a floating island 40 after the island parts have
been assembled and plants 10 have become established. Wicking cups
2 are preferably installed into island body 1 via bottom cutout
holes 6. Shaped liner 3 is preferably installed into central cavity
5 of island body 1. Shaped liner 3 is preferably filled with growth
medium 9, and plants 10 are shown growing in growth medium 9. In
this embodiment, roots 11 of plants 10 have grown through bottom of
shaped liner 3, but growth medium 9 is retained within the interior
of shaped liner 3. Water is transported upward via capillary action
from water body 12 through outer layer 7 and central portion 8 of
wicking cups 2, as shown by the arrows. This water then spreads
laterally throughout growth medium 9 that is situation within
shaped liner 3, and becomes available to plants 10.
[0089] FIG. 3 is a side cross-section view of another embodiment of
a floating island that comprises lost-cost materials. As shown in
FIG. 3, island body 1 is preferably comprised of matrix 4, pieces
of thermoplastic foam 13 with a combination of open and closed
cells, plants 10 and optional bedding pocket or cavity 42 filled
with bedding mix 14. The pieces of thermoplastic foam 13 are
preferably both buoyant in water and permeable to gases and water.
One or more pieces of thermoplastic foam 13 may also act as a
barrier to prevent particles of bedding mix 14 from falling through
the bottom of bedding pocket 42. The pieces of thermoplastic foam
13 are preferably comprised of materials that are either thread- or
sheet-shaped. The pieces of thermoplastic foam 13 are preferably
penetrable by plant roots and can protect the roots from fish
grazing if placed at the bottom surface of island body 1. Because
the pieces of thermoplastic foam 13 are buoyant, they reduce the
need for other buoyancy means. They also have a large internal
surface area that is may be colonized by beneficial microbes. In a
preferred embodiment, the microbes that colonize the interior of
the pieces of thermoplastic foam 13 metabolize excess nutrients in
the water and produce gases during metabolism. This metabolism has
two benefits: water quality is improved as the nutrients are
removed, and the gases provide ongoing buoyancy to island body
1.
[0090] Referring to FIG. 4, another low-cost embodiment of floating
island is presented in which island body 1 is comprised entirely of
thermoplastic foam 13. In this embodiment, island body 1 may be
fabricated by injecting uncured thermoplastic foam into a mold, and
allowing it to form a combination of open and closed cells during
curing within the mold. The ratio of open and closed cells may be
varied between different zones within the island body. For example,
some zones may be made more buoyant by extruding foam with a higher
than average percentage of closed cells; other zones may be made
more hydrophilic by extruding foam with a higher than average
percentage of open cells. The ratio of open to closed cells may be
varied by using multiple extrusion devices (with different
open/closed cell ratio outputs) simultaneously to make a single
island. Alternately, the ratio of open to closed cells may be
varied by using a single extruder, by varying the operating
conditions of the extrusion process (e.g., by varying the volume
and pressure of the expansion gas). Also shown are optional bedding
pockets 42, which may be molded into island body 1 and filled with
bedding mix 14. This embodiment is well suited for mass
production.
[0091] Referring to FIG. 5, another low-cost embodiment of floating
island 40 is presented. In this embodiment, island body 1 is
comprised of grass sod layer 17, buoyant matrix material 18 and an
optional layer of nonwoven matrix material 19. The soil within sod
layer 17 traps rising gas bubbles that are generated within island
body 1, or otherwise are introduced into island body 1 (e.g., by an
aerator). Optional nonwoven matrix layer 19 provides an extended
zone for plant root growth, in which the roots are protected from
grazing by fish or other animals. This option may be desirable for
applications where islands with large plants are deployed in ponds
containing animals that eat the plant roots.
[0092] Buoyant matrix layer 18 may be comprised of: (a)
thermoplastic polymer shapes (threads, sheets, or solid molded
piece), which are buoyant, or (b) thermoplastic polymer foam
shapes, which are very buoyant, or a combination of (a) and (b).
Foam comprises trapped gas bubbles and is therefore more buoyant
than shapes made from the same material that do not contain gas
bubbles. In addition to providing buoyancy to island body 1,
buoyant matrix layer 18 traps soil particles, thereby preventing
the loss of soil from sod layer 17.
[0093] Referring to FIG. 6, a preferred embodiment of fastening
assembly 20 is presented. In this embodiment, fastening assembly 20
is comprised of two or more fastening pins 21 and connecting cable
22. Fastening pins 21 are preferably formed of any suitably stiff
and durable material such as aluminum, stainless steel, mild steel,
or nylon. Connecting cable 22 is preferably made from any suitable
strong and durable material such as stainless steel cable or nylon
rope. This device is preferably used to connect two or more
floating islands 40 together laterally, thereby effectively forming
a large island. Fastening assembly 20 is preferably installed by
pushing fastening pin 21 into the side of an island. Notches 23 in
pin 21 catch the strands of the matrix material and lock fastening
pin 21 into place. Another fastening pin 21 that is part of
fastening assembly 20 is pushed into a second floating island,
thereby attaching the two islands.
[0094] Referring to FIG. 7, a preferred embodiment of fastening
unit 24 is illustrated. This device may be used to join vertically
stacked layers of island body material, to attach additional
buoyant units from below, or to attach accessories such as wind
powered aerators to the surface of floating island 40. Fastening
unit 24 is preferably made from any suitable stiff and durable
material such as aluminum, stainless steel, mild steel or nylon.
The device is preferably made so that it can be pushed into island
body 1 by either hand pressure or foot pressure.
[0095] Referring to FIG. 8, an embodiment of floating island 40 is
shown that comprises thermoplastic foam top cover 26, which is
preferably comprised of a thermoplastic foam having both open and
closed cells. In this embodiment, island body 1 is preferably
comprised of matrix 4 and thermoplastic foam top cover 26. Top
cover 26 preferably provides sunlight protection to matrix 4 while
allowing plants 10 to penetrate it. In this embodiment, top cover
26 is preferably pre-manufactured in sheet form and attached to
matrix 4 by polymer adhesive or mechanical fasteners (not shown).
Alternately, top cover 26 may be pre-manufactured in a shaped form
to enable it to fit closely over the rounded shape of the top of
matrix 4, by extruding the uncured foam resin into a shaped mold
for curing during the manufacturing process.
[0096] Referring to FIG. 9, a preferred embodiment of floating
island 40 is presented that is comprised of a significant
percentage of scrap material. In this embodiment, island body 1 is
comprised of matrix top 27, matrix bottom 28 and matrix sides 29.
The interior portion of the island body 1 is preferably filled with
pieces of scrap material that include scrap matrix 30, scrap open
cell foam 31, scrap closed cell foam 32, and scrap combination-cell
foam 33. Additional scrap material is preferably attached to island
body 1 as shown. In this embodiment, buoyancy for the island body 1
is provided by scrap closed cell foam 32 and scrap combination-cell
foam 33. The pieces of scrap matrix 30 and scrap open cell foam 31
provide a growth medium for the roots of plants 10, and they also
provide additional surface area for growing beneficial
microbes.
[0097] Many variations of the invention will occur to those skilled
in the art. Some variations include a shaped liner and wicking
cups. All such variations are intended to be within the scope and
spirit of the invention.
[0098] Although some embodiments are shown to include certain
features, the applicant(s) specifically contemplate that any
feature disclosed herein may be used together or in combination
with any other feature on any embodiment of the invention. It is
also contemplated that any feature may be specifically excluded
from any embodiment of the invention.
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