Note: Descriptions are shown in the official language in which they were submitted.
CA 02552129 2012-01-25
INSULATION HAVING A THERMAL ENHANCEMENT MATERIAL
AND METHOD OF MAKING SAME
Background
Loose-fill fibrous insulation can be pumped or blown into an attic, wall or
wall cavity
of a building such as a residential home. Various materials can be added to
the fibrous
insulation to reduce settling and static discharge, as well as to reduce the
amount of dust
formed during installation. Conventional systems for forming an insulation
product from a
loose-fill fibrous insulation, and/or the use of a liquid binder dispersion or
water to activate a
powdered adhesive, are discussed in U.S. Patent Nos. 4,710,480, 4,804,695,
5,641,368 and
5,952,418.
Conventional systems for forming an insulation product from loose-fill
insulation
typically present various disadvantages. For example, conventional systems
often suffer
from partial or complete blockage of an adhesive nozzle and/or a blowing hose
through
which the loose-fill insulation is blown. In addition, conventional systems
typically employ a
relatively high moisture content such as 50% of the dry weight of the
preinstalled insulation,
to enable proper adhesion between the insulation and the substrate. Such
relatively high
moisture content can cause mold-related problems such as mold growth on a
paper facing of
a wallboard. In addition, drying the installed insulation product having a
relatively high
moisture content can take a relatively long period of time such as two or more
days. Such a
prolonged drying period can slow down the installation process and contribute
to the overall
inefficiency thereof.
Conventional systems which use sprayed cellulose loose-fill insulation
typically
employ a high moisture content to ensure adhesion of the insulation in a
cavity. For
example, cellulose insulation typically contains water in an amount of 30% to
50% by weight
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of the insulation. This amount of moisture corresponds to about 2 to 3 pounds
of water in
the installed insulation per standard eight foot high wall cavity, i.e., a
cavity defined by a
construction of 8 foot high, nominal 2 by 4 inch framing members (actual 1.5
inch by 3.5
inch) on 16 inch centers. The term "on centers" refers to the distance between
the centers
of the framing members. This amount of moisture can cause the installation to
have a drying
time of 2 to 3 days or longer in a dry climatic region such as Denver,
Colorado. That is, a
wallboard typically should be installed after 2 to 3 days or longer to reduce
the potential for
mold growth. In more humid regions such as Florida, the drying time is
typically
considerably longer. Longer drying times typically exist when the insulation
is installed in a
deeper cavity structure.
A dry powdered adhesive can be added to a cellulose insulation material prior
to the
addition of water to reduce the amount of water used to enable the cellulose
to adhere to a
wall cavity, as disclosed in U.S. Patent No. 4,773,960. However, the moisture
content of the
insulation soon after installation typically remains relatively high, for
example, as much as
15% water or more.
Furthermore, cellulose insulation typically has a relatively high moisture
storage
capacity, which can extend the drying period of the cellulose insulation. ASTM
C739 which
sets forth the specification for a cellulose loose-fill insulation material,
allows a moisture
sorption rate as high as 15%. ASTM C764 which sets forth the specification for
an inorganic
fiber loose-fill material, allows for a moisture sorption rate of only up to
5%.
In addition, it can be difficult to form an insulation product having an
acceptable R-
value from a loose-fill cellulose material due to the inherent density and
thermal
characteristics of the cellulose material.
In conventional systems which employ an insulation material having a
preinstalled
moisture content less than that used in cellulose insulation, the insulation
typically does not
sufficiently adhere to particular conventional linings of wall cavities
causing collapse and
lower productivity.
Other systems for installing loose-fill insulation into vertical wall cavities
employ a
retaining means such as netting or cardboard baffles to retain the loose-fill
insulation during
blowing. Installing the restraining means typically requires additional labor,
for example, as
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much as an extra day of labor, and can substantially add to the cost of
installing the
insulation.
Summary of Invention
According to one aspect, a method of forming a nodular insulation material
suitable
for installation in a cavity is provided, comprising:
propelling fibrous nodules at a substrate, wherein the fibrous nodules
comprise glass
fibers, wherein a majority of the nodules has a maximum dimension of about one-
half inch,
and
contacting the nodules while the nodules are being propelled, with a solution
comprising water and a water soluble binder to produce coated nodules, wherein
the coated
nodules form an insulation on the substrate,
wherein the insulation comprises a thermal enhancement material.
According to another aspect, an insulation product is provided comprising
fibrous
nodules comprising glass fibers, wherein a majority of the fibrous nodules has
a maximum
dimension of about one-half inch, and wherein the fibrous nodules are coated
with a solution
comprising water and a water soluble binder, wherein the insulation product
further
comprises a thermal enhancement material.
Detailed Description
A nodular insulation product can be formed by propelling fibrous nodules
coated with
a binder solution at a substrate on which the insulation is to be formed. The
coated nodules
can adhere to the surface(s) of the substrate and to other nodules to form the
installed
insulation product. The nodular fibrous insulation can be effective for
providing thermal
and/or acoustical insulation, and can be formed to comply with various
existing and newly
proposed building code requirements.
The nodular insulation material includes a thermal enhancement material in
addition
to the fibrous nodules. When incorporated into the nodular insulation
material, the thermal
enhancement material is effective to reduce the rate of heat transfer through
the nodular
insulation material. For example, the thermal enhancement material can be
effective to
reduce the rate of heat transfer under normal operating conditions, for
example, at room
temperature, and/or under conditions where temperatures are relatively high,
for example,
during a fire. The thermal enhancement material can be effective to improve
the insulation
characteristics of the nodular insulation material and/or the fire rating of
such material.
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In an exemplary embodiment, the use of the fibrous nodules can enable the just-
installed insulation to resist slumping and/or collapse. This in turn can lead
to the formation
of an insulation product having improved structural strength after the
insulation is sufficiently
dried. As used herein, the term "just-installed" refers to a time period
within one hour of
installation of the insulation product. For example, the insulation material
can typically
become sufficiently dry within one hour, more preferably within one-half hour,
to enable
determination of properties of a sample of the insulation product. For
example, in one
embodiment, the insulation can have a moisture content of about 5% to 20%
after one-half
hour. This period of time can depend on, for example, temperature, humidity,
the
permeability of surrounding materials, the amount of water initially present,
and/or the airflow
around the insulation. While it can sometimes take as long as one-half hour
for the
insulation material to be sufficiently dry for measurement, in some cases it
can take a
relatively short period of time such as 10 minutes.
The use of the fibrous nodules can result in an insulation product having good
thermal insulation performance, good airflow resistance, a relatively low
density, a relatively
low moisture weight to facilitate drying, and/or a relatively fast
installation time. For example,
the resulting nodular fibrous insulation can have a low moisture sorption
potential that is
sufficient to decrease drying time and mold growth. The nodular fibrous
insulation can also
have relatively high thermal insulation performance at a relatively low
density to enable a
variety of R-values (thermal resistance values) in standard wall cavity
depths.
The substrate at which the fibrous nodules can be propelled can include any
material
on which an insulation product is capable of being formed. For example, the
substrate can
include at least one surface and preferably a plurality of surfaces, at
predetermined angular
orientations. In an exemplary embodiment, the substrate can include at least
one surface of
a wall, floor or ceiling cavity in a residential or commercial building. In a
preferred
embodiment, the substrate can include a surface of a wall cavity at least
defined by two
framing members (such as beams, studs, etc.) and a rear backing surface. The
framing
members can be formed from any suitable material including, for example, wood
and/or
metal such as steel. The rear backing surface can be formed from any suitable
material
such as, for example, oriented strand board. The framing members can have any
suitable
dimensions, for example, nominal 2 by 4 inches or nominal 2 by 6 inches, and
can be about
8 feet long or longer. The spacing interval between the framing members can be
any
suitable length to enable application of a spray-on insulation therebetween,
such as about 16
inches on center or wider, preferably about 16 or about 24 inches on center.
In an
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exemplary embodiment, the substrate can include a standard wall cavity. As
used herein,
the term "standard wall cavity" refers to a cavity formed by standard 2 by 4
inch studs, 8 feet
high and 16 inches on center.
The nodular fibrous insulation can be formed at least from fibrous nodules
bound
together with a binder. The fibrous nodules can have any shape such as a
generally random
shape, and can be generally spherical in shape having one or more radii. The
fibrous
nodules can be relatively small in size, and preferably the nodules can be
smaller in size
than relatively large-sized clumps of insulation material used in conventional
systems. As a
result of using relatively small-sized nodules, the nodules can be greater in
number than the
relatively large-sized clumps used in conventional systems. For example, the
maximum
dimension of the fibrous nodules can be about three-quarters (3/4) inch,
preferably about
one-half (1/2) inch, more preferably about one-quarter (1/4) inch. As used
herein, the term
"maximum dimension" of a nodule refers to the longest of the width, length,
thickness or
diameter of such nodule.
The size of the nodules can depend on, for example, the thermal insulation
performance desired, the desired R-value and density of the installed
insulation, the size and
shape of the volume to be insulated, and/or the relevant building code
requirements. In an
exemplary embodiment, the maximum dimension of a majority of the nodules,
preferably at
least about 70%, more preferably at least about 80%, and most preferably at
least about
90%, can be about one-half inch. In a preferred embodiment, the maximum
dimension of a
majority of the nodules, preferably at least about 70%, more preferably at
least about 80%,
and most preferably at least about 90%, can be about one-quarter inch.
The nodular fibrous insulation can also contain, in addition to the fibrous
nodules,
particles that are larger than such fibrous nodules, hereinafter referred to
as "clumps".
Preferably, the nodular fibrous insulation can be substantially free of such
clumps or has
only a small amount of clumps. For example, such clumps can adversely affect
the
properties of the insulation by reducing thermal performance, producing voids
in the
insulation, detracting from the appearance of the insulation by making the
surface thereof
less uniform, and/or by being pulled out more easily during scrubbing of the
insulation.
Thus, in an exemplary embodiment, the insulation can be formed in a manner
which results
in the reduction or substantial removal of clumps therefrom.
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The dimensions of the nodules can be measured by any suitable technique such
as,
for example, using a plurality of stacked screen sieves containing various
screen mesh sizes
to segregate the nodules; spreading out a sampling of the nodules on a
horizontal flat
surface and physically measuring each nodule within the sample with a tape
measure; using
various air flow resistance methods to correlate nodule size with air flow
resistance readings;
and/or using sonic energy measurements through samples to correlate sound
energy with
nodule size.
Conventional, relatively large-sized clumps typically do not provide the
desired
uniformity and aesthetically pleasing surface appearance to meet inspection
standards
and/or regulations, and to ensure consistent thermal performance. In addition,
use of such
clumps can lead to a relatively high occurrence of nozzle plugging, and can
also hinder
adequate wetting with a binder solution.
While not wishing to be bound by any particular theory, it is believed that
the
relatively small size of the fibrous nodules can provide various advantages in
comparison
with conventional, larger-sized clumps. For example, the fibrous nodules can
increase
adhesion between the installed insulation and various substrates such as wall
cavity
surfaces. Use of the fibrous nodules can also improve adhesion between the
nodules
themselves.
Use of the fibrous nodules can, for example, reduce or prevent the occurrence
of
clogging of a nozzle and/or hose through which the nodules are blown during
application of
the insulation. By reducing or avoiding such clogging, the amount of cleanup
necessary can
be reduced and/or the rate of application of the insulation can be increased.
For example,
the flow rate of the dry nodules ejected from a blowing machine can be from
about 10 to
about 50 Ibs/min, more preferably about 20 to about 30 Ibs/min. The amount of
time it takes
to fill a cavity with the insulation product can depend on at least the volume
of the cavity.
For example, the amount of time it takes to fill a standard wall cavity can be
from about 5 to
about 30 seconds, for example as long as about 20 to about 30 seconds, or as
short as
about 5 to about 15 seconds. As used herein, the term "standard wall cavity"
refers to a
cavity formed by standard 2 by 4 inch framing members, 8 feet high and 16
inches on
center. The relatively small size of the nodules can improve wetting thereof
by the binder
solution. The insulation formed from the nodules can have good thermal and
acoustical
performance and an aesthetically pleasing surface appearance. The use of the
nodules can
also improve the consistency of the R-value of the insulation.
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In an exemplary embodiment, the insulation formed from the fibrous nodules can
have a reduced amount of gaps, voids and/or bridges formed from the nodules,
as a result of
the use of the relatively smaller sized nodules. Reducing the amount of gaps,
voids and/or
bridges present in the installed product can minimize heat transfer by
convection. Use of the
nodules can also result in increased uniformity in filling the framing faces
of a cavity.
For example, the relatively small-sized nodules can enable filling around
obstructions
in building cavities such as electrical boxes, wiring and plumbing, thereby
providing a
substantially uniform and substantially void-free fill. In addition, the
relatively small-sized
nodules can allow the installer to maintain substantial surface flatness and
uniformity in the
insulation product after excess material is removed from the cavity framing
faces. In
addition, the fibrous nodules can form a more structurally uniform insulation
product, for
example, a substantially structurally uniform product.
Use of relatively small-sized and lightweight fibrous nodules can enable the
insulation
to have a relatively low density while still maintaining an acceptable thermal
resistivity or R-
value. As used herein, the term "R-value" refers to the thermal resistivity
multiplied by the
installed thickness of the insulation. For example, the insulation can have a
thermal
resistivity of from about 3.4 to about 4.0 hour-ft2- F/(Btu-inch) over an
installed density of
about 0.8 to 1.0 Ibs/ft3 (PCF). This corresponds to an R-value of from about
12 to about 14
hour-ft2- F/Btu in a nominal 2 by 4 inch cavity (3.5 inch actual cavity
depth). Alternatively,
the insulation can have a thermal resistivity of from about 4.0 to 4.6 hour-
ft2- F/(Btu-inch)
over an installed density of about 1.5 to 1.8 Ibs/ft3. This corresponds to an
R-value of from
about 14 to about 16 hour-ft2 F/Btu in a nominal 2 by 4 inch cavity (3.5 inch
actual cavity
depth). Maintaining a relatively low density can enable the insulation to be
cost-competitive
with low cost cellulose material and other similar materials. The low density
of the
installation can also facilitate reduction of drying time.
The fibrous nodules can contain additives such as, for example, an anti-static
agent,
a de-dusting oil, a hydrophobic agent such as a silicone, a biocide, a
fungicide and/or a fire
retardant. In conventional systems, the use of a hydrophobic agent such as
silicone has
been found to necessitate the use of an additional amount of adhesive. The use
of the
fibrous nodules as described herein can enable a hydrophobic agent to be used,
for
example, without necessitating the use of an excessive amount of adhesive. The
fungicide
can include, for example, benzimidazole 2-(4-thiazolyl), available under the
trade name
Irgaguard F3000 from Ciba Specialty Chemicals, Inc., located in Tarrytown, New
York.
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The fibrous nodules can include inorganic fibers formed from a material that
is
effective to provide, for example, thermal and/or acoustical insulation. For
example, the
inorganic fibers can be formed from glass fibers, slag wool, mineral wool,
rock wool, ceramic
fibers, carbon fibers, composite fibers and mixtures thereof. Preferably, the
inorganic fibers
can have a relatively small diameter, and more preferably can at least be
formed from glass
fibers having a relatively small diameter.
Inorganic fibers having a relatively small diameter can provide an improved
degree of
infrared radiation absorption and scattering capability because the inorganic
fibers can have
a higher surface area per mass ratio in comparison with fibrous materials
formed from larger
fibers. In addition, inorganic fibers having a relatively small diameter can
be effective to
create small pockets of still air which can be effective to reduce solid
material conduction
through the fibers.
The inorganic fibers can have any dimensions suitable for providing thermal
and/or
acoustical insulation. For example, the inorganic fibers can have an average
diameter of
about 3 microns or less, preferably about 2.5 microns or less, more preferably
about 2
microns or less, more preferably about 1.5 microns or less, and most
preferably about 1
micron or less. In an exemplary embodiment, the inorganic fibers can have
relatively low
moisture absorption and adsorption potential, for example, preferably less
than about 5%
moisture gain by weight. Such low moisture sorption potential can enable
faster drying and
can limit moisture storage capacity which can in turn reduce mold growth.
The nodular insulation material includes a thermal enhancement material in
addition
to the inorganic fibers used to form the nodules. As used herein, the term
"thermal
enhancement material" refers to a material that, when incorporated into the
nodular
insulation material, is effective to reduce the rate of heat transfer through
the nodular
insulation material. The reduction of the rate of heat transfer can be
achieved under normal
conditions, for example, at room temperature, and/or at much higher
temperatures, for
example, temperatures reached during a fire. The thermal enhancement material
can be
effective to improve the insulation characteristics of the nodular insulation
material and/or the
fire rating of such material. For example, the nodular insulation material can
have a fire
rating of at least one hour under the standard set forth in ASTM El 19-05a,
andl preferably at
least two hours. The contents of ASTM El 19-05a are herein incorporated by
reference.
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The thermal enhancement material can include, for example, an opacifier
material, a
reflective material, a phase change material, an intumescent material, a
material which is
effective to reduce the rate of air flow through the insulation, or a
combination thereof. In an
exemplary embodiment, the thermal enhancement material is not necessarily
limited to
having the characteristics of only one of the above types of materials, but
the thermal
enhancement material can be a multifunctional material which possesses the
characteristics
of two or more of the above types of materials.
For example, the thermal enhancement material can include an opacifier
material
which is effective to reduce the rate of heat transfer through the nodular
insulation material
by scattering and/or absorbing thermal radiation energy. In an exemplary
embodiment, the
thermal enhancement material can be effective for reducing the rate of
infrared radiation
transfer through the nodular insulation material. The thermal enhancement
material can
include a reflective material that is effective to reduce the rate of heat
transfer by reflecting
radiation, for example, back to surroundings or to adjacent surfaces and/or
materials. The
thermal enhancement material can include a phase change material which
undergoes a
phase transition, for example, from solid to liquid or liquid to solid, under
specific
temperature conditions. The phase transition temperature can depend on, for
example, the
particular materials used to form the phase change material and/or the
geometry of the
material. By changing phases under certain temperature conditions, the phase
change
material can be effective to reduce the overall rate of heat transfer through
the nodular
insulation material. The thermal enhancement material can include an
intumescent material
which is capable of increasing in volume upon exposure to heat while reducing
the rate of
heat transfer through the insulation. The thermal enhancement material can
include a
material which reduces the rate of air flow through the insulation, which in
turn can reduce
the rate of heat transfer through the insulation.
For example, the thermal enhancement material can include a phenolic binder,
polyvinyl acetate, aluminum powder, carbon black, expandable graphite, borate,
phosphate
such as polyammonium phosphate, aluminum trihydrate, clay, mica, vermiculite,
talc,
magnesium carbonate (magnesite), magnesium oxide, colloidal silica, colloidal
alumina,
fumed silica, precipitated silica, aluminum silicate hydroxide (pyrophyllite),
alumina silicate
such as amorphous alumina silicate (for example, perlite), aerogel such as a
silica aerogel,
or a combination thereof.
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The thermal enhancement material can be employed in an amount effective to
provide beneficial thermal properties to the nodular insulation material. The
specific amount
can depend on, for example, the type of thermal enhancement material employed,
the
manner in which the thermal enhancement material is incorporated into the
nodular
insulation material, and the type of materials used to form the nodular
insulation material.
The thermal enhancement material can be in any suitable form which allows such
material to be incorporated in the nodular insulation material. In an
exemplary embodiment,
the thermal enhancement material can be in a form which facilitates the
substantially even
distribution of the material in the insulation material, for example, in the
form of particles.
The thermal enhancement material can include particles having an average
particle size and
dimensions that permit substantial even distribution of such material in the
nodular insulation
material.
The thermal enhancement material can be incorporated into the nodular
insulation
material using any suitable technique. For example, the thermal enhancement
material can
be incorporated into the nodular insulation material in a manner that permits
substantially
uniform distribution of the thermal enhancement material in the nodular
insulation material.
For example, the thermal enhancement material can be present in the binder
solution that is
contacted with the fibrous nodules. Additionally or alternatively, the thermal
enhancement
material can be propelled at the substrate with the fibrous nodules. For
example, the
thermal enhancement material can be added to the nodules or flow of nodules
prior to
propelling same, and/or can be used as a starting material during the
formation of the
nodules. Additionally or alternatively, the thermal enhancement material can
be propelled at
the substrate separately from the fibrous nodules, for example, in a flow that
is separate
from the flow of fibrous nodules. In an exemplary embodiment, a substantially
uniform
distribution of the thermal enhancement material can be obtained by employing
such
techniques, which can in turn lead to improved thermal performance.
The fibrous nodules can be formed by processing a fibrous source material
containing the inorganic fibers. In an exemplary embodiment, the fibrous
source material
can be provided in the form of a substance or a plurality of particles which
is/are relatively
large in size, and such substance or particles can be reduced in size to form
the fibrous
nodules.
CA 02552129 2006-07-14
For example, the fibrous source material can be provided in any form suitable
for
being reduced to relatively small-sized nodules. The fibrous source material
can include, for
example, a fibrous blanket such as a fiberglass blanket in which the glass
fibers are bonded
together with a cured resin, a blanket of virgin fiberglass, or combinations
thereof.
Additionally or alternatively, the fibrous source material can include virgin
blowing wool
which is substantially free of a binder. The fibrous source material can
contain at least one
additive such as, for example, an infrared blocking agent, an anti-static
agent, a silicone, a
lubricating oil, an anti-fungal agent, a biocide, a de-dusting agent such as a
hydrocarbon, a
pigment or colorant and/or filler particles. Prior to applying a binder
solution to the fibrous
nodules, the nodules can have an organic content of from about 0.1 to about 10
wt. percent,
for example, from about 2.0 to about 10 wt. percent, as measured by the loss
on ignition test
set forth in ASTM C764.
The fibrous nodules can be formed using any suitable process and equipment. In
an
exemplary embodiment, a system for forming the nodules can include an
apparatus for
reducing the size of a fibrous source material to form the nodules, and an
exit screen having
a plurality of openings of a pre-selected size which is effective to
substantially control the
size of the nodules exiting from the system.
For example, a hammer mill can be used which can tear and shear fibrous
particles
or a fibrous sheet, and can roll such particles into generally irregular
spherical or rounded
nodules. The hammer mill can keep most particles in the mill until they reach
a pre-selected
size. An additive can be added to the material during processing in the hammer
mill such
as, for example, an infrared barrier agent, an anti-static agent, an anti-
fungal agent, a
biocide, a de-dusting agent, a pigment and/or colorant. Alternatively, a
slicer-dicer
apparatus can be used which can cut or shear a sheet of fiberglass insulation
into smaller
particles, for example, into cube-like particles.
The size of the plurality of openings of the exit screen can be pre-selected
to yield a
desired nodule size. The size of the plurality of openings can depend on, for
example, the
type of fibrous source material that is used, and the manner in which the
nodules are
processed. In an exemplary embodiment, for fiberglass material, the plurality
of openings
can be substantially square-shaped and range in size from about 1 to about 3
inches to
produce particles that range in size from about 1/8 inch to about 3/4 inch. In
a preferred
embodiment, an exit screen can be used which includes a pattern of 2 inch by 2
inch
substantially square openings or 2 inch diameter substantially circular
openings. Such an
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exit screen can produce, for example, particles containing nodules having a
maximum
dimension of 1/4 inch.
A binder solution can be applied to the nodules which can enable the nodules
to
adhere to a substrate at which the nodules are propelled. The binder solution
can also
enable the nodules to adhere together to form an insulation product on and/or
above the
substrate. The binder solution can include, for example, a water-soluble
binder and water.
The binder solution can be provided as a premixed solution, or the binder
solution can be
produced by adding water and a binder material to a tank and optionally
stirring the resulting
mixture. The binder material can be provided in the form of a concentrated
solution or a
powder. In the case a powdered binder material is used, the mixture can be
stirred for a
longer period of time to ensure proper mixture of the materials. The mixture
can optionally
be heated to at least room temperature.
The binder used to form the binder solution can include any material that
enables the
nodules to substantially adhere to the substrate surface and to other nodules,
and can
include, for example, resin solids. Preferably, the binder can provide
sufficient adhesion to
reduce or prevent settling, collapsing or slumping of the installed
insulation. The binder can
include a liquid-soluble binder, preferably a water-soluble binder. For
example, the binder
can include a water-soluble polymer, resin or oligomer, such as a water-
soluble partially
hydrolyzed polyester oligomer, polyvinyl acetate, polyvinyl pyrilidone,
polyvinyl alcohol or
mixtures thereof. In an exemplary embodiment, the binder can include a
partially hydrolyzed
polyester oligomer such as S-14063 and/or SA-3915 available from Sovereign
Specialty
Chemicals located in Greenville, South Carolina. The S-14063 resin contains
23% to 36%
solids, and can be mixed with water, for example, at a water to binder ratio
of about 0.5:1 to
about 2:1, preferably about 1:1. The SA-3915 adhesive contains 10% to 15%
solids and can
be used without further addition of water.
The binder solution can optionally include at least one additive such as, for
example,
an anti-freezing agent, a viscosity modifying agent, a biocide, a pigment.
The binder can be present in the binder solution in an amount that enables the
nodules to substantially adhere to the substrate surface and to other nodules.
Preferably,
the binder can be present in an amount which provides sufficient adhesion to
reduce or
prevent settling, collapsing or slumping of the installed insulation. For
example, the binder
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can be present in an amount from about 10% to about 50%, preferably from about
10% to
about 20%, based on the volume of the binder solution.
After installation and drying of the insulation, the binder can be present in
the dried
insulation product in an amount of less than about 6 wt. percent, preferably
from about 2 wt.
percent to about 6 wt. percent, more preferably from about 2 wt. percent to
about 4 wt.
percent, most preferably about 3 wt. percent, on an oven dry basis, for
example, of an
installed product having an installed density ranging from about 0.8 to about
1.0 PCF. As
used herein, the terms "oven dry basis" and "oven dry" refer to the material
in question being
measured while being substantially free of moisture. In addition, as used
herein, the terms
"ambient dry basis" and "ambient dry" refer to the material in question being
measured after
equilibriating to ambient conditions, in which case the material can contain
an amount of
moisture during measurement.
The nodules can be contacted with the binder solution to produce coated
nodules.
The term "coated nodules" encompasses nodules which are partially or
substantially entirely
coated with the binder solution. The binder solution can be present at an
outer region of the
coated nodules, for example, at the surface of the coated nodules. The nodules
can be
contacted with the binder solution while the nodules are being propelled. For
example, the
nodules can be contacted with the binder solution while the nodules are
ejected from a
nozzle or at a time thereafter but prior to the nodules contacting the
substrate.
The coated nodules can be used to form an insulation product in a wall cavity.
To
ensure complete filling of the cavity, the coated nodules can be applied in an
amount such
that the insulation overflows from the cavity. For example, the installed
insulation can
extend past the face of the frame which defines the cavity. Thereafter, excess
insulation
material can be removed, rolled and/or compressed, for example, to
substantially level the
insulation with the face of the frame defining the wall cavity. Leveling the
insulation can
enable a wall board or other facing board to be installed substantially flush
with the face of
the frame. In an exemplary embodiment, excess insulation can be removed
without rolling
or compressing the insulation.
The insulation formed from the nodules and binder solution can be installed
using
any system suitable for applying a fibrous insulation onto a substrate. For
example, the
insulation can be applied using a commercially available blowing system such
as a system
specifically designed for cellulose blowing.
13
CA 02552129 2006-07-14
In an exemplary embodiment, the nodules can be provided to a hopper of a
blowing
machine. The blowing machine can mix the nodules with air and eject such
mixture as a
rapidly moving air suspension from an outlet. A hose can be connected to the
outlet and
convey the nodules to the substrate on which the insulation is to be formed.
Any suitable
hose can be used, for example, a hose as long as 300 feet having a diameter
from about 2.5
inches to about 4 inches.
The hose can have a nozzle attached to an end thereof through which the
nodules
are ejected. A handle can be provided to assist an operator to hold and aim
the nozzle
during application of the nodules. The nozzle can have at least one jet spray
tip for
contacting the binder solution with the nodules near the exit end of the
nozzle, preferably at
or past the exit end. In an exemplary embodiment, two or three jet spray tips
can be used
opposite each other across a moving stream of suspended nodules. For example,
an
exemplary jet spray tip which can be used is available under the trade name
Unijet (25
degree or 65 degree spray), available from Spraying Systems Co. located in
Wheaton,
Illinois. Other exemplary nozzles which can be used are described in, for
example, U.S.
Patent Nos. 5,641,368 and 5,921,055. A pump such as an adjustable rate pump
can be
connected to a tank containing the binder solution to provide the binder
solution at a pre-
selected flow rate and pressure to the jet spray tips of the nozzle through
one or more
flexible hoses. The flow rate and pressure of the binder solution is
preferably pre-selected to
enable adequate coating of the nodules with the binder solution.
An excessive amount of insulation material can be formed on the substrate, and
such
excessive insulation can be removed using any suitable means. For example, an
amount of
insulation material can be removed to substantially align the insulation
product with the
framing members that define the cavity in which the insulation product is
formed. The use of
the relatively smaller sized nodules can enable removal of excessive material
while
maintaining a substantially smooth, even surface of the insulation product.
For example, a powered scrubber including a rotating brush-like device can be
used
to reduce or remove the excess insulation. The powered scrubber can span two
adjacent
wall studs. Water or other liquid is preferably not used with the powered
scrubber. In
conventional insulation systems, the rotating action of the powered scrubber
can lead to
damage of the insulation such as the tearing of large chunks of the insulation
from the cavity.
The use of the powered scrubber with the insulation formed by the present
methods can
reduce or avoid the occurrence of the tearing of large chunks of the
insulation from the
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CA 02552129 2006-07-14
cavity. This can be a result of, for example, a higher degree of tackiness
between the
nodules, the smaller size of the nodules, and/or the reduction of voids in the
insulation
product.
The just-installed insulation product can have a relatively low moisture
content, which
can in turn contribute to reducing drying time and/or minimizing the potential
for mold growth.
For example, the coated nodules can have a moisture content of less than about
25 wt.
percent, preferably less than about 20 wt. percent, more preferably less than
about 15 wt.
percent, more preferably less than about 10 wt. percent, based on the dry
weight of the
nodules. For example, the water present in the just-installed insulation can
be from about 10
wt. percent to about 30 wt. percent, preferably from about 10 wt. percent to
about 20 wt.
percent, based on the dry weight of the nodules.
The moisture content in the just-installed insulation product can be less than
about
2.0 lbs of water per standard wall cavity. For example, the moisture content
can be less
than about 0.75 Ibs, more preferably less than about 0.50 Ibs, and most
preferably less than
about 0.25 lbs of water in a standard wall cavity, for example, for an
installed insulation
product having an R-value of 13 and an oven dry density from about 0.8 to
about 1.0 PCF.
Alternatively, the moisture content can be less than about 2.0 Ibs, more
preferably less than
about 1.5 Ibs, and most preferably less than about 0.50 lbs of water in a
standard wall cavity,
for example, for an installed insulation product having an R-value of 15 and
an oven dry
density from about 1.5 to about 1.8 PCF.
While not wishing to be bound by any particular theory, Applicants believe
that the
weight of water in a standard wall cavity or other unit volume can be an
accurate indicator of
the amount of time needed to sufficiently dry the insulation. For example, the
amount of
water in a standard wall cavity or other unit volume may be a more accurate
indication of
drying time than, for example, the moisture content percentage in the
insulation, since drying
time is typically dependent on the total amount of water present. In this
regard, the moisture
content percentage is with respect to the weight of the material itself, and
does not
necessarily indicate the total amount of water present.
The resultant coated nodules of inorganic fiber insulation can contain binder
solids in
an amount of less than about 6 wt. percent, preferably less than about 4 wt.
percent, and
more preferably less than about 3 wt. percent, based on the dry weight of the
nodules, for
installed densities ranging from about 0.8 to about 1.0 PCF.
CA 02552129 2006-07-14
The insulation product can have a density preferably of about 3 PCF or less,
more
preferably about 2 PCF or less and most preferably about 1 PCF or less. The
density can
depend to some extent on the R-value desired. The R-value of the insulation
product can
be, for example, from about 12 to about 16. For example, in a standard wall
cavity, the dried
installed insulation product can have a density from about 0.8 to about 1 PCF
and an R-
value of about 13, or a density from about 1.5 to about 1.8 PCF and an R-value
of about 15.
The relatively low density and low moisture content of the insulation product
can result in
reducing the cost and improving drying time in comparison with conventional
systems.
In an exemplary embodiment, the distance the nodules are propelled can be
selected
to achieve a predetermined density of the nodular insulation material.
For example, the nozzle can be held at a particular distance from the
substrate in order to
achieve a predetermined density of the nodular insulation material.
Several examples and ranges of parameters of preferred embodiments of the
present invention have been described above, but it will be apparent to those
of ordinary skill
in the insulation field that many other embodiments by manipulation of the
parameters can
be employed. For example, although only a few different resin binders are
specifically
disclosed, there are many soluble binders that can function in the above
disclosed invention
to produce the useful result of having sufficient tack value. While most of
the above
discussion involves using the present invention in generally vertical wall
cavities, this
insulation product can be used to insulate attics or any suitable area.
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