Note: Descriptions are shown in the official language in which they were submitted.
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SOUND ATTENUATION BUILDING MATERIAL AND SYSTEM
RELATED APPLICATIONS
This application claims benefit of U.S. Patent Application No. 12/077,951,
filed
on March 21, 2008, which claims the benefit of U.S. Provisional Patent
Application No.
60/919,509, filed on March 21, 2007, and of U.S. Provisional Patent
Application No.
60/961,130, filed on July 17, 2007, and of U.S. Provisional Patent Application
No.
61/002,367, filed on November 7, 2007, which are each incorporated by
reference herein
in their entireties. This application also claims benefit to U.S. Provisional
Patent
Application No. 61/081,949, filed on July 18, 2008, and of U.S. Provisional
Patent
Application No. 61/081,953, filed on July 18, 2008.
FIELD OF THE INVENTION
The present invention relates to building materials, and more particularly to
wallboard and other building materials comprising sound attenuation
properties.
BACKGROUND OF THE INVENTION AND RELATED ART
Several building materials are designed with sound attenuation or absorption
properties in mind as it is often desirable to minimize, or at least reduce,
the amount of
sound that can be heard across a partition. With respect to building
structures, building
materials such as wallboard, insulation, and often paint, are considered
materials that can
contribute to a reduction in sound.
Wallboard is a common utility or building material, which comes in many
different types, designs, and sizes. Wallboard can be configured to exhibit
many different
properties or characteristics, such as different sound absorption, heat
transfer and/or fire
resistance properties. By far, the most common type of wallboard is drywall or
gypsum
board. Drywall comprises an inner core of gypsum, the semi-hydrous form of
calcium
sulphate (CaSO4.% H20), disposed between two facing membranes, typically paper
or
fiberglass mats. Drywall may comprise various additives and fillers to vary
its properties.
The most commonly used drywall is one-half-inch thick but can range from one
quarter (6.35 mm) to one inch (25 mm) in thickness. For soundproofing or fire
resistance,
two layers of drywall are sometimes laid at right angles to one another.
Drywall provides
a thermal resistance, or R value, of 0.32 for three-eighths-inch board, 0.45
for half inch,
0.56 for five-eighths inch and 0.83 for one-inch board. In addition to
increased R-value,
thicker drywall has a slightly higher Sound Transmission Class (STC) rating.
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STC, part of ASTM International Classification E413 and E90, is a widely used
standard for rating how well a building material attenuates airborne sound.
The STC
number is derived from sound attenuation values tested at sixteen standard
frequencies
from 125 Hz to 4000 Hz. These transmission-loss values are then plotted on a
sound
pressure level graph and the resulting curve is compared to a standard
reference contour.
Acoustical engineers fit these values to the appropriate TL Curve (or
Transmission Loss)
to determine an STC rating. STC can be thought of as the decibel reduction in
noise that
a wall or other partition can provide. The dB scale is logarithmic, with the
human ear
perceiving a 10 dB reduction in sound as roughly halving the volume.
Therefore, any
reduction in dB is significant. The reduction in dB for the same material
depends upon
the frequency of the sound transmission. The higher the STC rating, the more
effective
the barrier is at reducing the transmission of most common sound frequencies.
Conventional interior walls in homes or buildings have opposing sheets of
drywall
mounted on a stud frame or stud wall. In this arrangement, with the drywall
panels
having a 1/2 inch thickness, the interior wall measures an STC of about 33.
Adding
fiberglass insulation helps, but only increases the STC to 36-39, depending
upon the type
and quality of insulation, as well as stud and screw spacing. As wallboard is
typically
comprised of several sheets or panels, the small cracks or gaps between
panels, or any
other cracks or gaps in the wall structure are referred to as "flanking
paths," and will
allow sound to transmit more freely, thus resulting in a lower overall STC
rating. For this
reason it is critical that all potential flanking paths be eliminated or
reduced as much as
possible.
Similarly, the Outdoor-Indoor Transmission Class (OITC) is the widely used
standard for indicating the rate of transmission of sound between outdoor and
indoor
spaces. OITC testing typically considers frequencies down to 80 Hz and is
weighted
more to lower frequencies.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides sound attenuating building
materials,
systems, and methods for attenuating sound. In one aspect, for example, a
sound
attenuating building material is provided. Such a building material can
include a core
matrix disposed on a facing material, where the core matrix includes a
plurality of
microparticles, and a binder configured to support the microparticles, and
wherein a side
of the core matrix is exposed to create an at least substantially exposed face
of the
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building material to increase sound attenuation by reducing reflections from
sound waves
impinging on the building material as compared to a control building material
lacking an
exposed face. The building material can further include an acoustically
transparent
material disposed on the exposed face of the building material. Such an
acoustically
transparent material can include a screen or mesh material. Additionally, in
some aspects
the building material can further include a rigid material associated with the
core matrix.
In one specific aspect, the rigid material is disposed within the core matrix.
A variety of microparticles are contemplated for inclusion in the core
matrixes of
the present invention. In one aspect, the microspheres are hollow. In another
aspect, the
microspheres are filled with an inert gas. In yet another aspect, the
microspheres are
made from fly ash.
The exposed face of the building material can include a variety of
configurations,
from relatively planar to substantially non-planar. For example, in one aspect
the
substantially exposed face has a plurality of protrusions extending from the
core matrix.
Such protrusions can vary depending on the intended properties of the building
material,
however in one aspect the protrusions are spaced in a predetermined pattern.
The present invention additionally provides a system for attenuating sound
using a
building material. Such a system can include a first building material, a
second building
material disposed in a substantially parallel orientation to the first
building material such
that the first building material and the second building material are
separated by a
distance to create a sound trap space, and wherein the first building material
comprises a
core matrix disposed on a facing material. The core matrix can include a
plurality of
microspheres and a binder configured to support the microspheres, wherein a
side of the
first building material core matrix facing the second building material is
exposed to create
an at least substantially exposed face of the first building material to
increase sound
attenuation by reducing reflections from sound waves impinging on the first
building
material as compared to a control building material lacking an exposed face.
In a more
specific aspect, a building structure can be located within the sound trap
space. In
another more specific aspect, the first building material is supported about a
first side of
the building structure and the second building material is supported about a
second side of
the building structure. In yet another more specific aspect the first building
material, the
second building material, and the building structure form a walled partition.
In some
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aspects, an insulation material can be disposed within the sound trap between
the first
building material and the second building material.
Numerous configurations for the second building material are contemplated. In
one aspect, for example, the second building material includes a core matrix
disposed on
a facing material, where the core matrix includes a plurality of microspheres
and a binder
configured to support the microspheres. In a specific aspect, a side of the
second building
material core matrix facing the first building material is exposed to create
an at least
substantially exposed face of the second building material to increase sound
attenuation
by reducing reflections from sound waves impinging on the second building
material as
compared to a control building material lacking an exposed face.
Alternatively, the side
of the second building material core matrix facing the first building material
can be
substantially covered.
The present invention additionally provides a method of attenuating sound with
a
building material. Such a method can include introducing sound waves into the
sound
trap as described herein, such that the sound waves are attenuated by passing
at least
partially through at least one of the first building material core matrix and
the second
building material core matrix. In a further aspect, the sound waves are
attenuated by
passing at least partially through both the first building material core
matrix and the
second building material core matrix. In yet another aspect, the sound waves
are at least
partially attenuated as a result of reduced reflections from the sound waves
impinging on
the exposed face of the first building material as compared to a control
building material
lacking an exposed face,
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully apparent from the following
description and appended claims, taken in conjunction with the accompanying
drawings.
Understanding that these drawings merely depict exemplary embodiments of the
present
invention they are, therefore, not to be considered limiting of its scope. It
will be readily
appreciated that the components of the present invention, as generally
described and
illustrated in the figures herein, could be arranged and designed in a wide
variety of
different configurations. Nonetheless, the invention will be described and
explained with
additional specificity and detail through the use of the accompanying drawings
in which:
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FIG. 1 illustrates a detailed perspective view of a building material in
accordance
with one exemplary embodiment of the present invention;
FIG. 2 illustrates a detailed perspective view of a building material in
accordance
with another exemplary embodiment of the present invention;
FIG. 3 illustrates a partial side cross-sectional view of an exemplary sound
attenuation system in the form of a walled partition formed in accordance with
one
exemplary embodiment, wherein the walled partition is formed from opposing
exemplary
building materials, and wherein the walled partition creates and defines a
sound trap;
FIG. 4 illustrates a partial side cross-sectional view of an exemplary sound
attenuation system in the form of a walled partition formed in accordance with
another
exemplary embodiment, wherein the walled partition is formed from opposing
exemplary
building materials, and wherein the walled partition creates and defines a
sound trap;
FIG. 5 illustrates a partial side cross-sectional view of an exemplary sound
attenuation system in the form of a walled partition formed in accordance with
still
another exemplary embodiment, wherein the walled partition is formed from
opposing
exemplary building materials, and wherein the walled partition creates and
defines a
sound trap;
FIG. 6 illustrates a detailed perspective view of a wallboard building
material in
accordance with one exemplary embodiment of the present invention, wherein the
building material comprises a microparticle-based core matrix, a multi-
elevational surface
configuration formed in one surface of the core matrix, and a facing sheet
disposed on an
opposing surface of the core matrix;
FIG. 7-A illustrates a detailed perspective view of a wallboard building
material in
accordance with another exemplary embodiment of the present invention, wherein
the
building material comprises a microparticle-based core matrix, a lath disposed
or
sandwiched within the core matrix, a multi-elevational surface configuration
formed in
one surface of the core matrix, and a facing sheet disposed on an opposing
surface of the
core matrix;
FIG. 7-B illustrates a detailed view of the building material of FIG. 7-A;
FIG. 8 illustrates a top view of a building material in accordance with still
another
exemplary embodiment of the present invention, wherein the building material
comprises
a patterned pillow-like multi-elevational surface configuration formed in the
exposed
surface of the core matrix;
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FIG. 9 illustrates a cross-sectional side view of the building material of
FIG. 8;
FIG. 10 illustrates a cross-sectional end view of the building material of
FIG. 8;
FIG. 11 illustrates a detailed side view of the building material of FIG. 6;
FIG. 12 illustrates a detailed side view of a building material having a multi-
elevational surface configuration in accordance with another exemplary
embodiment;
FIG. 13 illustrates a detailed side view of a building material having a multi-
elevational surface configuration in accordance with another exemplary
embodiment;
FIG. 14 illustrates a cross-sectional side view of a building material in
accordance
with another exemplary embodiment, wherein the building material comprises a
plurality
of strategically formed and located cavities or voids; and
FIG. 15 illustrates a building material configured for use as a finishing
material on
an exterior of a structure.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The following detailed description of exemplary embodiments of the invention
makes reference to the accompanying drawings, which form a part hereof and in
which
are shown, by way of illustration, exemplary embodiments in which the
invention may be
practiced. While these exemplary embodiments are described in sufficient
detail to
enable those skilled in the art to practice the invention, it should be
understood that other
embodiments may be realized and that various changes to the invention may be
made
without departing from the spirit and scope of the present invention. Thus,
the following
more detailed description of the embodiments of the present invention is not
intended to
limit the scope of the invention, as claimed, but is presented for purposes of
illustration
only and not limitation to describe the features and characteristics of the
present
invention, to set forth the best mode of operation of the invention, and to
sufficiently
enable one skilled in the art to practice the invention. Accordingly, the
scope of the
present invention is to be defined solely by the appended claims.
In describing and claiming the present invention, the following terminology
will
be used in accordance with the definitions set forth below.
The singular forms "a," "an," and, "the" include plural referents unless the
context
clearly dictates otherwise. Thus, for example, reference to "a wallboard"
includes
reference to one or more of such wallboards, and reference to "the binder"
includes
reference to one or more of such binders.
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For purposes of discussion and interpretation of the claims as set forth
herein, the
term "building material," as used herein, shall be understood to mean various
types of
products or materials incorporating a matrix of microparticles (e.g.,
microspheres)
adhered or bound together using one or more components, such as a binder of
some kind.
The building materials may comprise other additives, components or
constituents, such as
setting agents, foaming agents or surfactants, water soluble polymers, and
others. The
building materials may comprise many different types, embodiments, etc., and
may be
used in many different applications.
The term "microparticle," as used herein, shall be understood to mean any
naturally occurring, manufactured, or synthetic particle having an outer
surface, and in
some cases, a hollow interior. Generally, the microparticles referred to
herein comprise a
spherical or substantially spherical geometry having a hollow interior, known
as
microspheres. Other types of microparticles may include those made from wood,
ground
rubber, ground up plastic, sawdust, etc.
The term "core matrix," as used herein, shall be understood to mean the
combination of microparticles and other constituents used to form the support
matrix of
the building materials. The microparticles may be combined with one or more
binders,
additives, setting agents, etc.
The term "multi-elevational" shall be understood to describe at least one
surface
of the core matrix of the building material, wherein the surface has formed
therein a series
of peaks and valleys (or protrusions and recesses) to provide an overall
surface
configuration having different surfaces located in different elevations and/or
orientations.
The multi-elevational surface configuration may be arbitrarily formed or
patterned. In
addition, the multi-elevational surface may be defined by any arbitrary or
geometrically
shaped protruding and recessed components.
As used herein, the term "substantially" refers to the complete or nearly
complete
extent or degree of an action, characteristic, property, state, structure,
item, or result. For
example, an object that is "substantially" enclosed would mean that the object
is either
completely enclosed or nearly completely enclosed. The exact allowable degree
of
deviation from absolute completeness may in some cases depend on the specific
context.
However, generally speaking the nearness of completion will be so as to have
the same
overall result as if absolute and total completion were obtained. The use of
"substantially" is equally applicable when used in a negative connotation to
refer to the
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complete or near complete lack of an action, characteristic, property, state,
structure, item,
or result. For example, a composition that is "substantially free of particles
would either
completely lack particles, or so nearly completely lack particles that the
effect would be
the same as if it completely lacked particles. In other words, a composition
that is
"substantially free of' an ingredient or element may still actually contain
such item as
long as there is no measurable effect thereof.
As used herein, the term "about" is used to provide flexibility to a numerical
range
endpoint by providing that a given value may be "a little above" or "a little
below" the
endpoint.
As used herein, a plurality of items, structural elements, compositional
elements,
and/or materials may be presented in a common list for convenience. However,
these
lists should be construed as though each member of the list is individually
identified as a
separate and unique member. Thus, no individual member of such list should be
construed as a de facto equivalent of any other member of the same list solely
based on
their presentation in a common group without indications to the contrary.
Concentrations, amounts, and other numerical data may be expressed or
presented
herein in a range format. It is to be understood that such a range format is
used merely
for convenience and brevity and thus should be interpreted flexibly to include
not only the
numerical values explicitly recited as the limits of the range, but also to
include all the
individual numerical values or sub-ranges encompassed within that range as if
each
numerical value and sub-range is explicitly recited. As an illustration, a
numerical range
of "about 1 to about 5" should be interpreted to include not only the
explicitly recited
values of about 1 to about 5, but also include individual values and sub-
ranges within the
indicated range. Thus, included in this numerical range are individual values
such as 2, 3,
and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc., as well
as 1, 2, 3, 4,
and 5, individually. This same principle applies to ranges reciting only one
numerical
value as a minimum or a maximum. Furthermore, such an interpretation should
apply
regardless of the breadth of the range or the characteristics being described.
The present invention describes various utility materials formulated using a
plurality of microparticles. The present invention also describes a various
methods used
to produce or fabricate different utility materials, as well as various
applications for such
utility materials. The presently disclosed utility material, associated
wallboard
embodiments, and associated methods of making and using such utility materials
provide
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several significant advantages over prior related utility materials, such as,
e.g., wallboard
products, and particularly drywall, some of which are recited here and
throughout the
following more detailed description. First, the wallboard building material
provides
enhanced thermal properties. For example, in one aspect, the wallboard
building material
provides a much greater resistance to thermal heat transfer. Second, in
another aspect,
wallboard building material provides enhanced acoustical properties. For
example, the
wallboard building material disclosed herein, provides a significantly better
Sound
Transmission Class (STC) rating. Third, the present invention wallboard
building
material is stronger and lighter. These advantages are not meant to be
limiting in any
way. Additionally, one skilled in the art will appreciate that other
advantages may be
realized, other than those specifically recited herein, upon practicing the
present
invention.
Utility materials, as disclosed herein, are highly adaptable to a variety of
applications. Utility materials, due to their composition or makeup, can be
manipulated to
achieve different performance characteristics depending upon the intended
application for
use. For example, it is possible to control the porosity and density of the
microparticles to
achieve any level desired. This is useful in many applications, such as when a
sound or
thermal insulating utility material is desired.
In one aspect, for example, the present invention provides a building material
having an improved Sound Transmission Class rating and other beneficial
properties
(e.g., high resistance to thermal heat transfer) over conventional drywall.
The building
material may be configured as a shear panel, or as a wallboard panel, each
comprising a
core matrix formed of a plurality of hollow or solid, inert, lightweight
naturally occurring
or synthetic microparticles, as well as at least one binder or binder solution
configured to
support (e.g., bond or adhere) the microparticles together, and to form a
plurality of voids
present throughout the core matrix. The microparticles are thus interspersed
and
suspended in a composition, comprising at least the binder, and perhaps other
ingredients,
such as a surfactant or foaming agent. The binder may comprise an inorganic
binder
solution, an organic or latex binder solution, or a combination of an
inorganic binder
solution and an organic binder solution. The core matrix may also comprise
various
additives, fillers, reinforcement materials, etc. Depending upon the selected
composition,
the utility materials may be configured to exhibit certain physical and
performance
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properties in addition to acoustic attenuation properties, such as strength,
flexibility,
hardness, as well as thermal properties, fire resistant properties, etc.
In the case of a wallboard panel, the core matrix may be disposed about a
facing
material on one side or about one face, with the opposing side or face of the
wallboard
panel left uncovered, or at least partially uncovered to provide a rough,
porous surface
defined by the composition and configuration of the core matrix. In other
words, the
building material is configured with the core matrix at least partially
exposed. In the case
of a shear panel, the core matrix may be disposed about a facing material with
the
opposing side exposed. The facing material may be any useful material such as
paper,
cloth, polymer, metal, etc. Each of the components of the present invention
sound
attenuation building material and system, as well as other features and
systems, are
described in greater detail below.
The exposed surface of the core matrix has now been found to greatly increase
the
sound attenuation properties of the building material. Sound waves impinging
on the
exposed surface exhibit reduced acoustic reflection as compared to a building
material
lacking such an exposed surface. As a result, sound waves are more effectively
absorbed
and attenuated by the materials comprising the core matrix of the building
material.
With reference to FIG. 1, illustrated is a detailed perspective view of a
building
material formed in accordance with one exemplary aspect of the present
invention. As
has been described, the building material comprises an exposed face or side to
provide a
rough, porous surface. As shown, the building material 10 is in panel form,
similar to a
wallboard panel, having a size of approximately 4 ft. in width, and 8 ft. in
length, which is
the same size as most conventional wallboard products. Of course, building
material
sizes other than 4 ft. by 8 ft., as well as different thicknesses, are also
contemplated. The
building material 10 is shown as comprising a core matrix 14 disposed about a
single
facing sheet or layer, namely facing material 34. An exposed side 18 of the
core matrix
14 allows sound to be attenuated by the microparticles and binder with less
acoustic
reflection than would be seen if both sides of the building material 10 were
covered with
a facing material. In one aspect, the exposed side 18 of the core matrix 14
can face
inward as the building material is installed or mounted to a structure, such
as a stud wall,
with the facing membrane 34 facing out. In another aspect, the exposed side 18
of the
core matrix 14 is can face outward as the building material is installed or
mounted to a
structure, with the facing membrane 34 facing in.
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The core matrix 14 is comprised of a plurality of microparticles and at least
one
binder, wherein the microparticles are at least bound or adhered together, and
in some
cases bonded together, by the one or more binders to create a core matrix
structure having
a plurality of voids defined therein. The voids are formed from the point to
point contact
between the microparticles as secured in place by the binder. The
microparticles, as
bonded together, provide a significantly more rough surface than if the
building material
were to comprise an additional facing membrane. The presence of a rough,
porous
surface functions to significantly improve the sound attenuation properties of
the building
material by being able to better absorb sound as it attempts to pass through
the core
matrix.
The microparticles contemplated for use herein may comprise many different
types, sizes, shapes, constituents, etc. In one aspect the microparticles can
be
microspheres. In one aspect, the microparticles used in the present invention
building
material can have an average size ranging between about 10 and about 1500
microns. In
another aspect, the microparticles can have an average size ranging between
about 10 and
about 1000 microns. In yet another aspect, the microparticles can have an
average size
ranging between about 200 and about 800 microns. In yet another aspect, the
microparticles can have an average size ranging from about 300 to about 600
microns. In
a further aspect, the microparticles can have an average size ranging from
about 350
microns to about 450 microns. Furthermore, the microparticles can have a bulk
density of
from about 0.4 to about 0.6 g/ml, thus providing products that are much
lighter than
conventional building materials such as gypsum-based drywall or oriented
strand board
(OSB). The size of the microparticles may thus depend upon the application and
the
performance characteristics desired. However, the microparticles should not be
too large
so as to cause any binder disposed thereon to run off or to not be effective.
The size of the microparticles will also function to influence the
permeability of
the building material. The microparticles are intended to be compatible with
any binders,
additives, and/or facing sheets. In the case of hollow microparticles, the
shell thickness
may be kept to a minimum amount, provided the microparticles maintain
structural
integrity as desired in the core matrix material. In one aspect, the
microparticles can have
a shell thickness of less than about 30% of the diameter of the microparticle.
For
nonspherical microparticles, the diameter of the particle can be calculated
based on the
effective diameter of the particle, using the total area of the cross section
of the particle
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and equating such area to a circumferential area and determining the diameter
from that
value. In a further aspect, the shell thickness can be less than about 20 % of
the diameter
of the microparticle.
In one exemplary aspect, the microparticles may comprise hollow, inert,
lightweight naturally occurring, glass particles that are substantially
spherical in
geometry. One particular type of microsphere is sold under the trademark
ExtendospheresTM, which are manufactured and sold by Spear One Corporation. In
some
aspects a hollow interior can be beneficial in order to reduce the weight of
the building
material, as well as provide good insulating properties. In one aspect, the
microparticles
can be the naturally occurring hollow, inert, glass microspheres obtained from
a fly ash
byproduct. Such microspheres are often referred to as cenospheres. Cenospheres
may be
separated from other byproduct components present in fly ash and further
processed, such
as to clean and separate these into desired size ranges. Cenospheres are
comprised
primarily of silica and alumina, and may have a hollow interior that is filled
with air
and/or other gasses. They possess many desirable properties, such as a crush
strength
between 3000 and 5000 psi, low specific gravity, and properties that allow the
endurance
of high temperatures (above 1800 F). Although they are substantially
spherical in
overall shape, many are not true spheres, as many are fragmented, or comprise
unsmooth
surfaces caused by additional silica and/or alumina.
As was noted, microparticles or microspheres can include an amount of air or
other gasses within the hollow interior. Where possible, the composition of
the gaseous
material within the microsphere can optionally be selected so as to provide
enhanced
characteristics of the utility material. For example, the hollow interior can
include a
noble gas or other known insulating gasses, such as argon, to improve the
insulating
properties of the overall utility material.
In another aspect, the microparticles may comprise hollow, spherical
structures
manufactured from a synthetic material. One advantage of utilizing a synthetic
material
is the uniformity between microspheres, thus making their behavior and the
behavior of
the resulting core matrix and building material more predictable. However, in
some cases
these advantages may not be significant enough to justify their use, as
synthetic
microspheres are often expensive to manufacture. The use of naturally
occurring
microspheres over synthetic microspheres to form a building material may
depend on
several different factors, such as the intended application, and/or desired
performance
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properties or characteristics. In some applications, naturally occurring
microspheres may
be preferred while in others a synthetic type may be more desirable.
The core matrix materials of the present invention can include microparticles
in
any amount, depending on the intended properties of the resulting utility
material. In one
aspect, for example, microparticles can be present in the core matrix in an
amount
between about 25 and about 60 percent by weight of the total core matrix, in
wet mixture
form. In another aspect, the microparticles can be present in an amount
between about 30
and about 40 percent by weight. Other amounts are further contemplated,
particularly in
those aspects including other additives or fillers in the core matrix, such as
perlite, or
setting agents, such as Class C fly ash. It should be noted that fly ash, of
any type, can be
utilized as a filler material, and/or optionally as a source of cenospheres.
In one aspect,
Class C fly ash can be one or the only source of microspheres. Class C fly ash
can, in one
aspect, be included in a core matrix in an amount ranging from about 0.5 wt%
to about 50
wt%. In another aspect, it can be present in combination with synthetically
made
microspheres at a ratio of Class C fly ash to synthetic microspheres of about
1:15 to about
15:1. In yet another aspect, Class C fly ash can be present in an amount of
less than about
1/3 of the amount of microspheres. The Class C fly ash used can optionally
include
greater than about 80 wt% calcium aluminate silicates, and less than about 2
wt% lime.
As has been described, the present invention further comprises one or more
binders operable to couple together the microparticles, and to facilitate
formation of the
porous core matrix. The microparticles can be bound by any manner, including a
physical cementing arrangement, chemically binding microparticles, merging
boundaries
of microparticles, etc. In a specific aspect, the microparticles can be bound
by a physical
cementing arrangement, as held together in a matrix of binder, wherein the
binder adheres
or physically immobilizes the microparticles, but does not form covalent or
other
chemical bonding with the microspheres. The binder may cause the microspheres
to
adhere together, wherein the binder is allowed to dry if water based, or cured
in a high
temperature environment if non-water based. In one aspect, the binder may be
caused to
be cross-linked, wherein the binder functions to bond the microparticles
together and to
improve the water resistant properties of the building material.
The ratio of binder to microparticles may vary depending upon the building
material to be formed. A higher ratio of binder to microparticles will result
in a building
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material that is more solid and dense than one with a smaller ratio. A smaller
ratio of
binder to microparticles will result in a more porous building material.
Numerous binder materials are contemplated for use in aspects of the present
invention. It should be noted that any binder capable of binding a plurality
of
microparticles together into a core matrix should be considered to be within
the present
scope. Different binders may be selected as part of the composition to
contribute to the
makeup of the resulting building material and to help provide the building
material with
certain physical and performance properties. Both water-based and non-water-
based
binders are contemplated for use. Examples of general binder categories
include, but are
not limited to, thermoplastics, epoxy resins, curatives, urethanes,
thermosets, silicones,
and the like.
In one exemplary embodiment, the binder comprises an inorganic binder, such as
sodium silicates in one form or another, combined with an organic binder such
as
polyvinyl acetate copolymer or ethylene vinyl acetate. The ratio of these
binders may
vary. In one aspect, the ratio of inorganic binder to organic binder may be
about 7:1 to
about 10:1. Stated more generally, the inorganic binder may be present in an
amount
between 50 and 60 percent by weight of the total weight of the core matrix (or
about 20 to
about 36 wt% dry inorganic binder), in wet form (the binders comprise an
amount of
water, or are mixed with an amount of water), with the organic binder present
in an
amount between 5 and 15 percent by weight of the total weight of the core
matrix, in wet
form (or about 2 to about 6 wt% dry organic binder). The listed amounts can be
based on
the pure forms of the binder material (with the percent weight of the binders
in the total
core matrix discussed herein being reduced between 40 and 60 percent), e.g. on
pure
sodium silicate, or can be based on binder mixtures including optionally
water, similar
chemical forms, e.g. silicates, silicic acid salts, etc., and other additives.
As a non-
limiting example, a sodium silicate binder solution commercially sold includes
from
about 35 wt% to 40 wt% sodium silicate in solution. Furthermore, more than one
type of
inorganic and/or organic binder can be utilized simultaneously.
Numerous compositions of materials making up the core matrix are contemplated,
depending on the desired properties of the resulting utility material. In a
specific
embodiment, the core matrix composition can contain between 400 g and 600 g of
microspheres, mixed with between 600 g and 800 g of sodium silicate binder
solution,
and between 60 g and 100 g of ethylene vinyl acetate. Of course, other ranges
are
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possible, depending upon the application. For example, it may be desirable to
have
between 200 g and 1500 g of sodium silicate or other binder mixed with between
300 and
800 g of microspheres, mixed with between 20 g and 180 g of ethylene vinyl
acetate
copolymer. Other ratios and ranges of each of the components of various
compositions
are contemplated. Furthermore, more than one organic binder could be used, as
could
more than one inorganic binder.
In one specific example, the inorganic binder solution is present in an amount
about 55.5% by weight of the total weight of the core matrix in wet mixture,
with the
binder solution comprising sodium silicate and water. More specifically, the
inorganic
binder solution comprises sodium silicate present in an amount between about
40% and
about 60% by weight and water present in an amount between about 40% and about
60%
by weight. In many cases, the inorganic binder solution will comprises a 1:1
ratio of
sodium silicate to water. The sodium silicate may be pre-mixed and the
solution provided
in liquid, or the sodium silicate may be in powder form and subsequently mixed
with
water.
In one aspect, a latex or organic binder can be present in an amount about
7.4% by
weight of the total weight of the core matrix in wet mixture, and comprises a
ethylene
polyvinyl acetate (EVA) emulsion. The latex binder facilitates formation of a
flexible,
porous composition that is subsequently formed into the core matrix of the
wallboard.
One particular example of latex binder used is ethylene vinyl acetate (water-
based binder)
sold under the trademark Airflex (e.g., Airflex 420), which is manufactured
and sold by
Airproducts, Inc. This particular binder can be used to facilitate a flowable
and formable
formation of the core matrix, as well as to provide either flexible or semi-
rigid
compositions. The latex binder can be pre-mixed with water to be in liquid
form. The
latex binder comprises EVA present in an amount about 40% by weight, and water
present in an amount about 60% by weight. In one aspect, the latex binder can
range
from about 2.5 wt% to about 30 wt% of the total weight of the core matrix in
wet mixture.
In a further aspect, the latex binder can range from about 5 wt% to about 20
wt%. Non-
limiting examples of latex binders include those produced by Airflex
(including
specifically 323, 401, 420, 426), those produced by UCAR (specifically 154s,
163s),
conventional glues and pastes, those produced by Vinac (including XX2 10), and
mixtures
and combinations thereof.
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A water soluble polymer can be included in the core matrix formulation. The
water soluble polymer may be added to the core matrix composition already
dissolved in
water or in dried form. The function of the water soluble polymer is to serve
as a
stabilizer for any surfactant or foaming agent present in the mixture.
Specifically, the
water soluble polymer helps to stabilize the composition until the binder is
either cured or
cross-linked. Non-limiting examples of water soluble polymers that can be
included in
the formulation include those distributed by Airflex, such as polyethylene
oxide (e.g.,
WSR 301). The water soluble polymer can also function as a thickener and
prevent water
from running out of the mixture during core matrix formation. Such polymers
can be
useful to control the stiffness, flexibility, tear strength, and other
physical properties of
the building material, as well as to stabilize any surfactants, if present. In
some
embodiments, it may be desirable to eliminate, or at least significantly
reduce, the amount
of organic component in the core matrix composition. This is particularly the
case in the
event it is desirable that the building material comprise more enhanced fire
resistant
properties. The amount of organic component remaining in the core matrix
composition
may thus be dependent upon the particular application.
As has been described, and depending upon the type used, the binder may be
simply cured, with no cross-linking, or it may be cross-linked. By cross-
linking the
binder(s), a stronger more permanent physical coupling occurs between the
binder and the
microspheres. As such, the present invention contemplates using one or more
means to
effectively cross-link the binders. In one exemplary embodiment, the binders
may be
cross-linked by elevating the temperatures of the binders to a suitable
temperature for a
suitable period of time to effectuate polymerization and bonding. This may be
done using
conventional radiant heating methods, or it may be done using microwaves
applied
continuously or at various intervals, as well as with microwaves of different
intensities.
Using microwaves is significantly faster, and much more cost effective. In
addition,
cross-linking with microwaves functions to produce a stronger building
material as the
amount of binder actually cross-linked is increased. Additionally, depending
of the
particular binder used, chemical crosslinking agents can be utilized. Such
chemical
crosslikers are well known in the art.
Cross-linking within a building material provides significant advantages over
a
building material having a composition that is not cross-linked. For example,
with cross-
linking, the binders are made stronger, they do not absorb water as easily,
and the
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connection between microspheres is much stronger. In addition, the building
material
often weakens less over time. Other advantages may be realized by those
skilled in the
art. It should be noted, however, that there may be applications where cross-
linking is not
desirable, and where a non-bonded composition may be preferred.
The present invention further contemplates utilizing a surfactant or foaming
agent,
mixed with the binder and the microspheres to achieve a building material
having a
relatively low density. With respect to a foaming process, once ingredients
are combined,
they can be whipped or agitated to introduce air into the mixture, and then
dried.
Mechanical agitation or compressed air may be used to physically introduce air
into the
mixture and to create the foaming process. The foaming process effectively
causes
microparticles to be supported in a much more separated position with respect
to one
another as compared to a non-foamed composition. With the presence of the
foam, the
microparticles are suspended and are thus able to dry in more dispersed
configurations.
In another aspect, the suspension of the microspheres due to the presence of
the foaming
agents may also function to make certain core matrix compositions more
flowable or
pumpable, as well as more formable. Examples of suitable surfactants or
foaming agents
include, but are not limited to, anionic foaming agents, such as Steol FS406
or Bio-terge
AS40, cationic foaming agents, and non-ionic foaming agents, etc.
As a specific example, the core matrix material can include from about 25 wt%
to
about 60 wt% of microparticles based on wet formulation, where the
microparticles
having a size of from about 10 to about 1000 microns, from about 20 wt% to
about 36
wt% sodium silicate, and from about 5 wt% to about 15 wt% of a vinyl acetate.
Additional details regarding wallboard building materials are described in
related
copending U.S. Provisional Patent Application No. , filed September 25,
2008, and entitled "Wallboard Materials Incorporating a Microparticle Matrix"
(Attorney
Docket No. 2600-32683.NP.CIP2), and in related copending U. S. Provisional
Patent
Application No. , filed September 25, 2008, and entitled "Shear Panel
Building Material" (Attorney Docket No. 2600-32683.NP.CIP3), each of which is
incorporated by reference in its entirety herein.
The facing material may comprise many different types of materials or
combination of materials having diverse properties. In one exemplary aspect,
the facing
material can be a paper material similar to that found on various wallboard
products, such
as drywall or the wallboard incorporated by reference herein, as noted above.
In another
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exemplary aspect, the facing material can be a cloth, a polymer, or a metal or
a metal
alloy.
With reference to FIG. 2, shown is a building material formed in accordance
with
another exemplary embodiment of the present invention. The building material
110 is
similar in many respects to the building material 10 discussed above and shown
in FIG. 1.
However, building material 110 comprises a mesh membrane 154 disposed about
the
exposed side 118 of the core matrix 114, opposite the facing membrane 134. The
mesh
membrane 154 comprises a plurality of intersecting members forming a plurality
of grid-
like openings. The mesh membrane 154 functions to provide support and
stability to the
core matrix 114 similar to facing membrane 134, but still leaves a substantial
portion of
the core matrix 114 exposed on that side to maintain the rough, porous surface
of the
building material 110. The mesh membrane 154 may numerous different types of
materials, and the grid-like openings may be of many different sizes and
configurations.
In one aspect, the mesh membrane 154 may comprise a fiberglass or plastic mesh
or mesh-like material. This reinforcing mesh material gives flexural strength
to the
building material 110, and further supports the microparticles as they are
exposed on one
side of the building material 110 for the specific purpose of receiving and
dissipating
sound by absorbing sound waves and dampening vibration. The mesh membrane 154
may be made from glass, plastics (e.g., extruded plastics), or other
materials, depending
upon the particular application and need. The mesh membrane 154 may be bound
to the
core matrix 114 in a similar way as the facing membrane 134, or by any other
method
known in the art.
One significant advantage over conventional products is the ability for the
present
invention building material to attenuate or absorb sound. The Sound
Transmission Class
rating was found to be between 40 and 60 for a building material formed
similar to that
shown in FIGS. 1 and 2 (having a thickness of % inch), depending upon the
composition
of the core matrix, the thickness of the wallboard panel, and whether or not a
reinforcing
material was present. Conventional drywall, also '/2 inch thick, has an STC
rating of
about 33. In testing a building material based on the embodiments described
above, and
shown in FIGS. I and 2, it was discovered that a sound absorption of around
.89 . 10
could be reached. In addition, at 3000 Hz, noise reduction was between 55 and
65 dB.
At 2000 Hz, noise reduction was between 35 and 45 dB. At 1000 Hz, noise
reduction
was between 10 and 20 dB. In comparison, drywall had a noise reduction of 40
dB at
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3000 Hz; a noise reduction of 28 dB at 2000 Hz; and a noise reduction of 3 dB
at 1000
Hz. As can be seen, the building material is significantly better at absorbing
sound.
Besides its improved or enhanced sound attenuation properties, the present
invention building material provides many additional improved properties and
characteristics over conventional building materials, such as drywall, gypsum,
OSB. For
example, the present invention building material has a significantly lower
heat transfer
than conventional building materials. For example, in the building material
discussed
above and shown in FIGS. 1 and 2, a 400 C temperature gradient may be
achieved. In
one particular test, one side of the present invention building material was
heated to 100
C with no noticeable temperature increase on the opposite side after 2 hours.
This
temperature gradient may range or vary depending upon the makeup of the
composition,
such as the ratio of microspheres to binder, the type of binder(s) used, the
presence of a
reinforcing material, etc. as discuss herein. It can thus be seen that the
building materials
of the present invention exhibit excellent thermal properties. Using
standardized ASTM
testing, the building material was found to have a 20 C less heat transfer
under the same
testing conditions (e.g., time and temperature) than drywall. Tests have shown
that the
building material absorbs approximately .11 BTU, as compared to drywall which
absorbs
approximately .54 BTU. As such, the heat capacity, namely how much heat the
material
absorbs, is enhanced using a microsphere-based core matrix. The thermal
resistance, or
R-value, of the same building material has been discovered to be between 2 and
3 for a V2
inch thick panel, as compared to drywall, which is .45 for a %2 inch thick
panel.
The same building material described above was additionally discovered to be
between 20% and 30% lighter than drywall. For example, a 4x8 panel weighs
about 39
lbs, compared with a similarly sized drywall panel which weighs approximately
51 lbs. A
4x12 drywall panel weighs approximately 80 lbs, compared with a present
invention
wallboard building material, which weighs approximately 60 lbs.
In addition to weighing less, it has been discovered that the same building
material
is between 10% and 20% stronger than drywall. In one example, various tests
revealed
that the building material will break between 170 lbs and 180 lbs in a flexure
strength
test. In comparison, drywall typically breaks around 107 lbs. The panels used
in these
tests were of comparable size and thickness. In an edge hardness test, the
building
material averaged approximately 15 lbf, while drywall tested at 11 lbf. In a
nail pull test,
the building material tested an average of 99 lbf, while gypsum tested at 77
lbf.
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The building material of the present invention may further comprise a rigid
material or a reinforcing member configured to provide enhanced
characteristics in one or
more areas as compared with the exemplary building material of FIGS. 1 and 2.
In one
exemplary embodiment, the building material may comprise a rigid material
disposed
within the core matrix (sandwiched therein), or between the outer surface of
the core
matrix and a facing material. The rigid material may be configured to
reinforce or
enhance one or more properties or characteristics of the building material.
For example,
the rigid material may be configured to reinforce against (or improve the
resistance of)
sound transmission, heat transfer, or a combination of these. The rigid
material may also
be configured to enhance the overall strength of the building material. The
rigid material
may comprise various types of materials, such as metals, woven or nonwoven
fibers or
fiber sheets, plastic films, etc., and may comprise any necessary thickness.
The present invention also provides systems and methods for improving and
enhancing the noise reduction across a walled partition using a sound trap.
Such a sound
trap can be created by disposing present invention building materials about a
building
structure such as a stud or other wall, wherein the opposing building
materials create the
sound trap configured to absorb sound and to significantly reduce sound
transmission
across the wall. In this configuration, opposing exposed surfaces would be
positioned to
face one another. The sound attenuation system may be formed by a number of
properly
situated present invention building materials having a number of
configurations. As such,
those specifically presented herein are not intended to be limiting in any
way.
In general, sound waves entering the sound trap are attenuated by the
associated
building materials with varying degrees of acoustic reflection, depending on
the
configuration of the sound trap and the building materials used. As has been
described,
the exposed surface of the core matrix greatly increases the sound attenuation
properties
of the building material. Sound waves impinging on the exposed surface exhibit
reduced
acoustic reflection as compared to a building material lacking such an exposed
surface.
As a result, sound waves are more effectively absorbed and attenuated by the
materials
comprising the core matrix of the building material. For a sound trap having
surrounded
by building materials having exposed faces, sound attenuation is increased by
all the
building materials in the sound trap. For sound traps utilizing a first
building material
having an exposed face on one side and a second building material having a
facing
material opposite the exposed face of the first building material, sound may
be attenuated
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primarily by the exposed face of the first building material while the facing
material of
the second building material functions to reflect sound waves into the exposed
face of the
first building material. Thus for both configurations, sound waves are trapped
and
effectively attenuated between the building materials.
In an alternative embodiment, a sound trap can be constructed using two facing
building material panels, each containing the core matrix material as
described herein
sandwiched between two facing material layers. The facing material layers can
be made
from a variety of materials, as has been described herein, such as paper,
cloth, metal and
metal alloys, polymeric materials, and combinations thereof.
With reference to FIG. 3, illustrated is a sound attenuation system 200 in
accordance with one exemplary embodiment of the present invention, wherein the
sound
attenuation system creates and defines an exterior walled partition 204. The
sound
attenuation system 200, and the exterior walled partition 204, comprises a
first building
material 210 supported about a first side of building structure, such as an
exterior stud
wall (not shown), and a second building material 310 supported about a second
side of the
building structure opposite the first building material 210. In this case the
second
building material is a shear panel having a rigid material disposed therein.
The first and
second building materials are supported or mounted to the building structure
in
accordance with practices commonly known in the art.
The first building material 210 comprises a wallboard panel, and has a core
matrix
214 disposed about a facing membrane 234, with one side 218 of the core matrix
exposed, or at least substantially exposed. The exposed side 218 of the core
matrix faces
inward, and is placed against the components making up the stud wall, with the
facing
membrane 234 facing outward. The second building material 310 comprises a
shear
panel, and has a core matrix 314 disposed between a first facing membrane 334
formed of
a metal, such as aluminum, and a second facing membrane 354 formed of a paper
material. Optionally, the wallboard building material 210 and/or the shear
panel building
material 310 may comprise a rigid material 374 sandwiched between the core
matrix 314
of the shear panel building material 310.
Mounted in this configuration on the stud wall, the wallboard building
material
210 and the shear panel building material 310 function together to provide and
define a
volume of space or sound trap 284, extending between the inner surfaces of
each building
material within the building structure. This sound trap is intended to resist
the
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transmission of sound waves across the walled partition 204 in either
direction as these
are caused to be absorbed more efficiently by the core matrix 214, facilitated
by the
exposed rough surface 218 of the wallboard building material 210. Sound waves
originating indoors and traveling through the wallboard building material 210
toward the
shear panel building material 310 are partially absorbed and partially
deflected by the
shear panel building material 310. Those sound waves that are deflected travel
towards
the exposed side 218 of the core matrix 214 of the wallboard building material
210 where
they encounter the rough, porous surface of the exposed side 218. Due to the
rough,
porous configuration, much of the sound is absorbed into the core matrix and
attenuated.
The core matrix 314 of the shear panel building material 310 also contributes
to the
absorption and attenuation of the sound as well. As such, the sound
attenuation system
200, and particularly the walled partition 204, provides both a higher STC and
OITC
rating over exterior walled partitions formed from conventional drywall and
OSB
material. Adding insulation to the present invention walled partition would
further
enhance the STC and OITC ratings over a walled partition of drywall, OSB and
insulation.
FIG. 4 illustrates a sound attenuation system 400 in accordance with one
exemplary embodiment of the present invention, wherein the sound attenuation
system
creates and defines an interior walled partition 404. The sound attenuation
system 400,
and the interior walled partition 404, comprises a first building material 410
supported
about a first side of a building structure, such as an interior stud wall (not
shown), and a
second building material 510 supported about a second side of the building
structure
opposite the first building material 410 to define sound trap 484. The first
building
material 410 is similar to the first building material 210 of FIG. 3, which
description
above is incorporated here. The second building material 510 is also similar
to the first
building material 210 of FIG. 3, but is different in that wallboard building
material 510
comprises a core matrix 514 disposed between a first facing sheet 534 and a
second
facing sheet 554. In other words, no side of the core matrix 514 of the second
building
material 510 is exposed, but rather covered. The sound absorption and
attenuation
properties of the sound attenuation system 400 are enhanced by the direct and
deflected
sound waves penetrating the exposed side 418 of the first wallboard building
material
410, where they are dampened and at least partially absorbed by the core
matrix 414, the
sound waves being trapped in the sound trap 484.
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FIG. 5 illustrates a sound attenuation system 600 in accordance with one
exemplary embodiment of the present invention, wherein the sound attenuation
system
600 also creates and defines an interior walled partition 604. The sound
attenuation
system 600, and the interior walled partition 604, comprises a first building
material 610
supported about a first side of building structure, such as an interior stud
wall (not
shown), and a second building material 1710 supported about a second side of
the
building structure opposite the first material 610 to define sound trap 684.
First and
second building materials 610 and 1710 are similar to one another, with each
comprising
a core matrix 614 and 1714, respectively, and each having an exposed side 618
and 1718,
respectively. Both exposed sides 618 and 1718 operate to receive and absorb
sound, thus
trapping a substantial portion of the sound waves within the sound trap 684,
and
preventing their transmission out of the sound trap 684. As such, the sound
attenuation
system comprises a significantly higher STC rating than a walled partition
with standard
drywall.
In each of the above exemplary sound attenuation systems, sound is designed to
penetrate the outer layers or membranes of the various building materials and
to become
trapped in the created sound trap, thus significantly reducing sound
transmission across
the walled partition, whether the partition is an interior or exterior wall.
It should be
noted that the sound trap can also be created and defined about a ceiling or
any other
partition, as will be recognized by those skilled in the art. Sound waves that
enter the
sound trap are attenuated by their acting on and penetrating the exposed side
of at least
one of the building materials. The rough, porous surface of the exposed core
matrix
functions to reduce deflection and transmission of the sound waves, with the
core matrix,
as a whole, operating to at least partially absorb and dampen the sound waves
that were
not deflected. The thickness of the core matrix of the building materials will
affect the
noise reduction or sound transmission properties, as will the composition,
density, and
configuration of the core matrix.
It is contemplated that any combination of present invention building
materials
may be used on either side of a building structure to create and define a
sound trap,
including the various embodiments disclosed in the applications incorporated
by
reference herein. In addition, it is contemplated that the present invention
building
materials may be manufactured in accordance with that taught in the
applications
incorporated herein.
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In some aspects the core matrix can be constructed to further enhance the
sound
attenuating properties of the building materials. In one aspect, the present
building
material comprises an exposed face or side to provide a rough, porous surface.
In
addition, the present building material comprises an exposed core matrix
surface having a
multi-elevational surface configuration formed therein.
As shown in FIG. 6, the building material 710 is in panel form, similar to a
wallboard panel, having a size of approximately 4 ft. in width, 8 ft. in
length and %2 in. in
thickness, which is the same size as most conventional wallboard products. Of
course,
other sizes such 4 ft. by 8 ft. sizes, as well as different thicknesses is
also contemplated.
The building material 710 is shown as comprising a core matrix 714 disposed
about a
single facing sheet or layer, namely facing material 734. The other side 718
of the core
matrix 714 is exposed, thus exposing a portion of the configuration of
microparticles and
binder. The exposed surface of the core matrix provides and defines a rough,
porous
surface that is designed and intended to better attenuate sound. In one aspect
the exposed
side 718 of the core matrix 714 is intended to face inward as the building
material is
installed or mounted to a structure, such as a stud wall, with the facing
membrane 734
facing out. In another aspect the exposed side 718 of the core matrix 714 is
intended to
face outward as the building material is installed or mounted to a structure,
with the
facing membrane 734 facing in.
FIG. 6 further illustrates the exposed side 718 of the core matrix as
comprising a
multi-elevational surface configuration. The purpose of providing a multi-
elevational
surface configuration formed about one surface, particularly the exposed
surface, of the
core matrix is at least twofold; 1) to significantly further enhance the sound
attenuation or
damping properties of the building material, namely to ensure acoustic
isolation and
absorption over a wide range of frequencies; and 2) to enhance the flex
strength of the
building material by eliminating shear lines. As will be described below, many
different
multi-elevational surface configurations are contemplated herein. Those
skilled in the art
will recognize the benefits of providing a series of peaks and valleys about a
surface to
create different surfaces located in different elevations, as well as
different surfaces
oriented on different inclines, particularly for the specific purpose of
attenuating sound.
Sound waves incident on these different elevational and/or oriented surfaces
are more
effectively attenuated.
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In the specific embodiment shown, the multi-elevational surface configuration
comprises a waffle pattern, with a plurality of protruding members 718, having
a square
or rectangular cross-section, defining a plurality of recesses 726. This
series of peaks and
valleys effectively creates a plurality of surfaces (in this case horizontal
surfaces 730 and
734) that are located in different elevations about the overall surface of the
core matrix
714. In addition, the protruding members 718 may be configured to provide
surfaces
oriented at different angles (in this case, the protruding members 718 also
define several
vertically oriented surfaces 738).
It is further contemplated that a separate mesh facing sheet may or may not be
disposed over the exposed multi-elevational surface of the core matrix 714. If
used, the
mesh facing sheet is preferably configured to be flexible to conform to the
multi-
elevational surface configuration.
FIGS. 6 and 14 further illustrate the building material 710 as comprising a
plurality of cavities or air pockets 746 strategically formed and located
throughout the
core matrix 714, and designed to reduce the overall weight of the building
material
without significantly affecting the strength or other properties of the
building material.
Preferably the cavities 746 are randomly located throughout the core matrix
714, but they
may also be arranged in a pre-determined pattern. The cavities 746 may be
formed in
accordance with any known method during the manufacture of the building
material.
Essentially, the cavities 746 function to define a plurality of voids or air
pockets within
the core matrix 714 at various locations. The cavities 746 may be sized to
comprise a
volume between about 0.2 and about 200 cm3, and preferably between about 5 and
about
130 cm3. These not only help to reduce weight, but also help to increase the
overall R
value due to the dead air space. In addition, these help to further attenuate
sound as these
provide additional surfaces that function to absorb sound waves rather than
transmit them.
With reference to FIGS. 7-A and 7-B, shown is a building material formed in
accordance with another exemplary embodiment of the present invention. The
building
material 810 is similar in many respects to the building material 810
discussed above and
shown in FIG. 6. However, building material 810 comprises a lath 854 disposed
or
sandwiched within the core matrix 814. The lath 854 comprises a plurality of
intersecting
members 856 forming a grid having a plurality of openings 858. The lath 854
functions
to provide support and stability to the core matrix 814, as well as additional
strength. In
addition, the lath 854 increases the mass of the building material 810, which
reduces the
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potential for vibration, thus contributing to the sound attenuation properties
of the
building material 810. The lath 854 may comprise many different types and
configurations, with the grid and openings being of different sizes and
configurations.
The lath 854 shown in FIG. 7 is not intended to be limiting in any way.
In one aspect, the lath 854 may comprise a metal, fiberglass, or plastic mesh
or
mesh-like material. This reinforcing lath material provides strength to the
building
material 810, and further supports the microspheres. The lath 854 may also be
made from
glass, plastics (e.g., extruded plastics), or other materials, depending upon
the particular
application and need.
With reference to FIGS. 8-10, illustrated is a building material 910 formed in
accordance with another exemplary embodiment of the present invention. In this
embodiment, the building material 910 comprises a core matrix 914 having a
first surface
918. Formed in the first surface 918 is a multi-elevational or nonplanar
surface
configuration in the form of a repeating pattern of pillow-type protrusions,
thus providing
multiple different surfaces or surface areas in multiple different elevations.
The
protrusions may be any desired size, configuration and height. Therefore,
those shown in
the drawings are intended to be merely exemplary.
With reference to FIG. 11, illustrated is a side view of the building material
710 of
FIG. 6, having a multi-elevational surface configuration in the form of a
repeating waffle-
type pattern. The waffle-type configuration extends between the perimeter
edges of the
building material, and defines a plurality of protrusions 722 and recesses
726. FIG. 14
illustrates a cross-sectional view of a building material wherein the building
material 710
comprises a plurality of strategically formed and located cavities or voids
746 in the core
matrix 714.
FIG. 12 illustrates a detailed side view of another exemplary building
material
1010 comprising a core matrix 1014 having a first surface 1018, wherein the
first surface
1018 has formed therein a multi-elevational surface configuration comprising a
repeating
pattern of first protrusions 1022 in the form of pyramids or cones, and a
repeating pattern
of second protrusions 1024 having an arbitrary shape. The second protrusions
1024 are
shown as comprising a primary base protrusion having a square cross-section,
upper
secondary protrusions 1023, and lateral secondary protrusions 1025, each
having a
pyramid or cone shape. First and second protrusions 1022 and 1024 define
recesses 1026.
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While the present invention is not intended to be limited to any particular
shape of
protrusions, FIG. 12 illustrates that arbitrary shapes are at least
contemplated.
FIG. 13 illustrates a detailed side view of another exemplary building
material
1110 comprising a core matrix 1114 having a first surface 1118, wherein the
first surface
1118 has formed therein a multi-elevational surface configuration comprising a
repeating
pattern of first protrusions 1122 and recesses 1126, wherein these form an egg
carton-type
pattern.
FIGS. 8-13 thus illustrate several different multi-elevational surface
configurations. These, however, are not meant to be limiting in any way.
Indeed, one
skilled in the art will recognize other configurations and/or patterns that
may be used to
accomplish the designs of the present invention.
EXAMPLES
The following examples illustrate embodiments of the invention that are
presently
known. Thus, these examples should not be considered as limitations of the
present
invention, but are merely in place to teach how to make the best-known
compositions and
forms of the present invention based upon current experimental data.
Additionally, some
experimental test data is included herein to offer guidance in optimizing
compositions and
forms of the utility material. As such, a representative number of
compositions and their
method of manufacture are disclosed herein.
EXAMPLE 1 - TESTING OF UTILITY MATERIAL OF CENOSPHERES AND
SODIUM SILICATE
A mixture of Cenospheres of the form of ExtendospheresTM and sodium silicate
were combined and allowed to dry and form a fire-resistant insulating material
Extendospheres of a 300-600 micron diameter size range were combined with
sodium
silicate solution (0 type from PQ corporation) in a 1:1 weight ratio. The wet
slurry was
poured into a cavity around the turbine and allowed to dry. It formed a
hardened mass of
extendospheres and sodium silicate. The material was tested with an Ipro-Tek
single
spool gas turbine. The tests showed that the material has a high insulation
capacity, and
the ability to withstand heat. The insulation was exposed to temperatures of
up to 1200
C. However, it was found that when the material is exposed directly to flames
for periods
of more than a few minutes, it cracks and blisters and begins to lose physical
strength.
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EXAMPLE 2 - FORMATION OF MOLD TO FORM WALLBOARD
In one aspect, the utility material can be wallboard panels. The panels can
optionally be formed by exposing an uncured wallboard to microwaves. Such
formation,
as well as general wallboard formation, can utilize a mold. An example of a
mold can be
made up of a vinylester resin mold having top and bottom pieces. To form the
vinylester
resin mold, a wood mold is first constructed.
To form the vinylester resin mold, an outer mold of wood is attached to the
base
of the wood mold using double sided tape. Any releasable binder or means of
attaching
can be alternatively used. A resin mixture is formed of 97.5 wt% vinylester
resin mixed
with 2.5 wt% methyl ethyl ketone peroxide (MEKP) catalyst. Microspheres of the
form
of Extendospheres and the resin mixture are added in a 1:1 ratio to form a
core mixture.
The core mixture is mixed well using a stirring device that was mounted in a
drill such as
you would use to mix paint. Mix time was about 3 minutes. The core mixture is
poured
into the prepared wood mold and distributed to cover the full mold, including
all corners.
The mixture is gently smoothed out, although not pressed into the mold using
short
dropping, manual shaking, mechanical vibration, and spreading tools such as
trowels. The
mixture is not pressed into the wood mold as pressing it can decrease the
porosity of the
resulting vinylester resin mold and can make it unusable. The mixture is cured
at room
temperature until it is rigid and strong to the touch. The curing time is
typically about
three hours. The porous vinylester resin mold is then carefully removed. The
resulting
vinylester resin mold has a cavity 11.625 inches by 15.25 inches by 0.5 inches
deep, with
a 0.375 inch wall around the outside edge. A top piece for the vinylester
resin mold is
formed using the same procedure and results in a mold in a rectangle having
dimensions
of 12.375 inches by 16 inches by 0.5 inches deep.
EXAMPLE 3 - PREPARATION OF WALLBOARD USING MOLD
As noted, the utility material can be in the form of wallboard panels. The
panels
can optionally be formed by using the porous vinylester resin mold. First, a
wallboard
backing paper is cut using a backing paper template. Although a particular
backing paper
shape is illustrated, it should be understood that the backing paper can be of
any shape or
size sufficient to form a segment of wallboard. Facing paper is cut to a
rectangle sized
just smaller than the greater dimensions of the backing paper. In the present
embodiment,
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the facing paper is cut to an 11.625 inch by 15.25 inch rectangle. The backing
paper is
folded and placed in the porous mold. A wallboard mixture may be formed using:
700 to 900 g microspheres
1100 to 1300 g sodium silicate solution, such as that sold by "0"
300 to 500 g latex binder
20 to 30 cc foaming agent
Specifically, the foaming agent is added first to the sodium silicate solution
and
mixed using a squirrel mixer at 540 RPM for 2 minutes. The latex binder is
added to the
mixture and mixed for an additional 30 seconds on the same settings. The
microspheres
are added slowly while mixing, over 1 to 2 minutes, until the mixture is
uniform.
The wallboard mixture is poured into the lined mold and leveled out using a
spatula or paint stick. It should be noted that any tool or method could be
used at this
point to level the mixture. The mixture is further leveled by vigorous
shaking. The sheet
of facing paper is placed on top of the mixture and covered with the top panel
of the
vinylester resin mold. The mold is placed in a microwave and the panel is
radiated for the
desired amount of time. Preferably, the mold is turned often to produce a more
even
drying of the panel. The panel should not be subjected to continuous radiation
for any
extended amount of time to reduce or prevent large voids in the wallboard
core. The
power level of the microwave radiation can be set to control the amount of
time the
microwave is on. The time on and off of the microwave can be according to
Table 1:
Table 1
Power Level Time On (Seconds) Time Off (Seconds)
1 3 19
2 5 17
3 7 15
4 9 13
5 11 11
6 13 9
7 15
8 17 5
9 19 3
10 22 0
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Once properly heated, the resulting panel of wallboard can be carefully
removed from the
mold.
EXAMPLE 4 - FLEXURAL STRENGTH TESTING
An important feature of wallboard is the flexural strength of the board. Each
sample board was prepared by forming a core matrix material including the
components
outlined in Table 2 and spreading the mixture into a mold cavity and leveling
it off. The
resulting sample is 0.50 inches thick and 2 inches wide. Each sample is dried
in an oven
at 100 C until dry as determined by Aquant moisture meter. The sample is
suspended
between two supports that are 6 inches apart so that 1-1.5 inches rests on
either side of the
support. A quart size paint can is placed in the center of the suspended
sample and slowly
filled with water until the sample breaks at which point the weight of the can
is measured
and recorded. Flexural strength is important for normal handling,
installation, and use.
Strength at least equal to gypsum wallboard was desired, for uses wherein the
wallboard
could replace conventional gypsum wallboard. Each wallboard includes a
different
composition as outlined in Table 2.
Table 2
Run Cenospheres Water (g) Binder Foaming Dry Weight to
(g) (type, g) Agent (g) weight (g) break (kg)
1 50 6.0 O, 52.4 1.0 70.2 5.0
2 50 0 O, 87.2 2.0 83.7 20.6
3 50 14.1 RU, 42.9 1.0 70.2
4 50 14.4 RU, 71.4 2.0 83.6 18.0
Foam 50 20 RU, 71.4 16.4 83.6 9.2
5 50 8.0 BW-50, 1.0 70.2 5.1
47.6
6 50 7.0 BW-50, 2.0 83.7 7.4
79.2
The ingredients in each row were combined then mechanically whipped to produce
a
foamed product. The foamed product was then cast in a mold. All binders used
are
sodium silicate based. Type 0 binder is a viscous sodium silicate solution
from PQ
Corporation. Type RU binder is also from PQ Corporation and is a sodium
silicate
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solution that is similar to 0 type but not as viscous. RU type is more watery
and has a
lower solids content. And, type BW-50 binder, also from PQ Corporation. BW-50
is
also a sodium silicate solution, and has a lower ratio of silica to disodium
oxide. As
illustrated, the amount and type of binder can be optimized to create a wide
range of
flexural strengths.
EXAMPLE 5 - FLEXURAL STRENGTH TESTING II
Flexural strength testing was conducted on seven sample boards according to
the
procedure outlined in Example 4. The components of each sample board and the
flexural
strength testing weight are recorded in Table 3.
Table 3
Run Ceno- Water Binder Foaming Dry Weight Weight Weight
spheres (g) (g) Agent weight to to to
(g) (g) (g) break break break
(kg) - (kg) - (kg) -
no Manilla card-
paper folder board
1 50 17.9 14.3 1.0 56.7
2 50 15.5 28.6 1.0 63.5 2.06
3 50 12.1 42.9 1.0 70.2 1196 21.55
4 50 14.3 57.1 2.0 76.9 14.37
5 50 14.4 71.4 2.0 83.6 15.35 26.89 36.65
6 50 11.6 85.7 2.0 90.4 21.8
7 50 9.4 100.0 2.0 97.1 20.85 29.40 34.99
Ceiling 5.57
Tile %"
thick
Dry 26.91
wall %2"
thick
As illustrated, increasing the density and increasing the binder content in
the sample
generally results in stronger samples. Increasing the amount of water in the
sample
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mixture generally decreases the density of the mixture and results in
decreased strength of
the sample. In the samples including testing with a Manilla folder and/or
cardboard, the
noted material was placed on both sides of the sample. Such arrangement, with
the core
material flanked by a paper product, is comparable to conventional gypsum
wallboard.
As illustrated, the inclusion of paperboard on both sides, either in the
illustrated form of
Manilla folder or cardboard, significantly increased the sample's strength.
EXAMPLE 6 - FLEXURAL STRENGTH TESTING III
A number of sample panels were formed according to the procedure outlined in
Example 4, with the exceptions that strips of paper of the noted thickness to
2 inches wide
by 11 inches long. One strip is placed in the mold cavity before pouring in
the core
matrix material. After pouring and leveling the mixture, another sheet of the
same
thickness is placed on top of the mixture. The mixture is covered with wire
mesh and
weighed down to keep it in place during drying. For the results listed below,
the paper
did not properly adhere to the core matrix, so the test results reflect
samples having only
one sheet of paper attached. The flexural strength tests were performed paper
side down.
Presumptively, the results would be higher for a sample including both facing
sheets.
The core matrix material for each sample included 250 g Extendospheres, 40 g
water, 220 g binder, 10 g foaming agent. The dry weight for each sample is
334.9. For
paper having a thickness of 0.009", the weight to break was 6.6 kg. For paper
having a
thickness of 0.015", the weight to break was 7.5 kg. For paper having a
thickness of
0.020", the weight to break was 5.2 kg.
EXAMPLE 7 - ADDITIONAL TESTING ON SAMPLE BOARDS
A number of sample panels were formed in accordance with the methods and
compositions outlined in the previous Examples. Typically, a mixture such as
that given
above is cast in a mold comprising paper disposed above and below the core and
a frame
around the perimeter of the sample to contain the wet core material while it
dries and
cures. After drying and heating the wallboard sample can be tested for
mechanical
properties. The composition of each sample and the associated results are
illustrated in
Table 4.
Flexural Strength testing - "Flex "
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A 0.5 inch thick sample that is 2 inches wide by 6 to 8 inches long is placed
on the
test fixture and is thus suspended between two legs. The legs are
approximately 4.25
inches apart. The test apparatus is equipped with the flexural test
attachment, with the bar
on the attachment situated parallel to the test specimen. The flexural test
attachment is
centered midway between the legs of the test fixtures. A bucket is hooked to
the end of
the test apparatus and weight is slowly added to the bucket until the test
specimen fails.
The weight of the bucket is measured to obtain the Flex results.
Nail Pull Resistance testing
A 0.5 inch thick sample that is 6 inches wide by 6 inches long is drilled to
have a
5/32 inch pilot hole in the center of the sample. The sample is placed on a
nail pull
fixture, with the pilot hole centered on the 2.5 inch diameter hole in the
nail pull fixture.
A nail is inserted into the pilot hole. The shank of the nail should be
approximately 0.146
inches in diameter, and the head of the nail should be approximately 0.330
inches in
diameter. A screw is inserted into the indicated hole on the test apparatus so
that it sticks
out a distance of approximately 2 inches. The head of the screw should be
smaller than
the head of the nail used in the test. The sample and fixture are positioned
underneath the
apparatus so that the centerlines of the nail and screw line up. A bucket is
hooked to the
end of the test apparatus. Weight is slowly added to the bucket until the test
specimen
fails. The weight of the bucket is measured.
Cure, End, and Edge Hardness testing
A 0.5 inch thick sample that is 2 inches wide by 6 to 8 inches long is clamped
in
the vice of the testing equipment. A screw is inserted into the indicated hole
on the test
apparatus so that it sticks out a distance of approximately 1.5 inches. The
head of the
screw should be 0.235 inches in diameter. The vice and sample are positioned
underneath
the test apparatus, so that the head of the screw is centered on the 0.5 inch
edge of the
sample. A bucket is hooked to the end of the test apparatus. Weight is slowly
added to
the bucket until the screw penetrates at least 0.5 inches into the sample. If
the screw slips
off of the side and tears through the paper, the sample is discarded and the
test is
repeated.
Table 4
Run Ceno- Organic Foaming Water Dry Flex Hard- Nail Density
spheres Binder Agent J(g) Weight ness Pull
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(g) (g) (g) (g)
1 50 75 0 20 78.73 30.3 10.5
2 50 75 0 20 78.73 41.6 7.9
3 50 75 0 20 78.73 24.7 7.7
4 50 75 1 0 78.73
50 75 2 0 78.73 17.6
6 50 100 0 0 88.30 17.6 10.3
7 50 100 1 0 88.30 31.3 13.6 22.6
8 50 100 1 0 88.30 16.3 6.8
9 50 100 1 0 88.30 19.4 6.3
50 100 2 0 88.30 16.6
11 50 125 0 0 97.88 22.5 8.2
12 50 125 0 0 97.88 35.0 8.5
13 50 125 0 0 97.88 31.6 7.9
14 50 125 1 0 97.88 23.7 7.3
50 125 2 0 97.88 22.4 6.5
16 50 150 0 0 107.45 35.8 41.8 31.0 9.8
17 50 150 0 0 107.45 27.5 8.3
18 50 150 0 0 107.45 21.8 7.5
19 50 150 1 0 107.45 18.0 9.0
50 150 2 0 107.45 16.6 6.6
Dry-wall average of 5 tests 30.9 38.0 53.6 10.4
EXAMPLE 8 - TEST RESULTS II
A sample of wallboard including 50 g Extendospheres, and 2 cc surfactant. The
5 first type of wallboard tested included 100 g of sodium silicate binder
mixture. The
second type of wallboard tested included 75 g sodium silicate binder mixture
and 25 g
latex binder. The test boards had a thickness range from 0.386 inches to 0.671
inches.
Testing was completed according to ASTM 473-3, 423, E119, and D3273-00
standards.
Flexural strength was tested and determined to be an average of 170 lbf (white
10 side up) for the wallboard of the first type, based on three samples. The
wallboard of the
second type was found to average 101 lbf (white side down), based on three
samples.
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The highest measurement of the six test samples was 197 lbf. A comparative
conventional gypsum wall board was measured to be 107 lbf.
Edge hardness was determined to be an average of 15 lbf. The gypsum wall board
had an average minimum edge hardness of 11 lbf. The sample showed a 36%
improvement over the gypsum sample.
Nail pull resistance was measured to be 99 lbf, based on a 3 sample average.
The
gypsum wall board, on the other hand, measured a 77 lbf.
The thermal resistance of the sample wall board was tested. One side of the
wall
board was raised to 100 C for two hours with no measurable temperature
increase on the
cool side of the sample.
The weight of the sample was compared to the conventional gypsum and found to
be approximately 30% less than the gypsum board.
EXAMPLE 9 - WALLBOARD FORMATION
As another example of wallboard formation, a sodium silicate wallboard is
formed
by the following procedure. Sodium silicate is first foamed by adding 2 cc
Steol FS 406
to 100 g sodium silicate solution (PQ Corporation 0 binder). The mixture is
placed in a 6
inch diameter paint container. The mixture is mixed using a 3 inch diameter
"Squirrel"
mixer attached to a drill press running at 540 rpm. The operator rotates the
paint
container in the opposite direction than that of the mixer. The mixture is
foamed for
approximately one minute and fifteen seconds. The volume of the sodium
silicate should
at least double during the foaming process. 50 g of ExtendospheresTM (having a
size of
300 to 600 microns) are added to the mixture and mixed for one more minute
with the
"Squirrel" mixer. The vanished mix is then poured into the mold and smoothed
with a
paint stick.
Once the foamed mixture is smoothed in the mold, the mold is placed in an oven
set at 85 C. The mixture is allowed to dry for approximately 12 hours at this
temperature.
The backing paper is added to the core after the core has dried sufficiently.
A
light coat of sodium silicate is painted onto the back of the paper, and the
paper is placed
on the core matrix. The core and paper are covered on all sides by a polyester
breather
material and then placed in a vacuum bag. The vacuum bag is placed in an oven
set at
85 C and a vacuum is applied to the part. The part is allowed to dry for 45
minutes to
one hour in the oven. The finished part is then removed from the oven and
trimmed to
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desired size. Various materials can optionally be added to the core
composition to
accelerate drying.
EXAMPLE 10 - WALLBOARD FORMATION II
Another wallboard is produced according to the method in Example 9. The
composition of the wallboard is altered in that 75 g of sodium silicate binder
solution is
used along with 25 g organic binder. The organic binder is added to the sodium
silicate
binder solution along with the Steol, prior to foaming.
EXAMPLE 11 --- WALLBOARD FORMATION III
Another wallboard is produced by first masking a mold. A base board is lined
with FEP. The FEP is wrapped tightly to reduce wrinkling on the surface.
Boarder
pieces of the mold are wrapped with Blue Flash Tape. Killer Red Tape is used
to
attached to border pieces to the base piece to form a border with an inside
dimension of
14 inches by 18 inches.
500 g of microspheres (300-600 microns in size), 750 g "0" binder, 250 g
organic
binder, and 20 cc foaming agent are measured and set aside. The 0 binder and
foaming
agent are mixed using a Squirrel mixer at 540 RPM for about 2 minutes. The
organic
binder is added to the mixture and mixed for an additional 30 seconds. The
microspheres
are slowly added while mixing. When all microspheres are added, the mixture is
mixed
for an additional 30 seconds or until the mixture is uniform. The mixture is
poured into
the mold and leveled with a spatula. The mold is additionally subjected to
vigorous
shaking for additional leveling. The mold is placed into an oven at 100 C and
dried for
12 to 18 hours until completely dry. Paper is applied to the sample by first
cutting a piece
of backing paper and a piece of facing paper slightly larger than the panel.
An even coat
of sodium silicate solution is applied to one side of the paper. The paper is
placed on top
and bottom surfaces of the panel and pressure is applied evenly across the
surface. The
pressure can optionally be applied by vacuum bagging the panel. The panel can
be placed
back in the oven at 100 C for about 15 minutes until the paper is fully
adhered to the
surface of the panel.
EXAMPLE 12 - SOUND TRAP ACOUSTIC TEST
A control sound trap is constructed in a configuration as described herein,
where
each of the first and second building materials have a core matrix of
microparticles in a
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binder with facing material on both sides of each of the first and second
building
materials. A test sound trap is constructed in a similar configuration, but
where the first
building material lacks the facing material on the side facing the second
building material.
The two sound traps are further tested as follows:
Each sound trap is placed in an anechoic chamber with a sound presentation
speaker on one side of the sound trap and sound pressure level meter
positioned on the
other side of the sound trap. A series of tones ranging from 110 Hz to 8000 Hz
are
sequentially delivered at approximately 100 dB from the sound presentation
speaker
toward the sound trap, and the sound pressure level is recorded on the other
side of the
sound trap. The average sound pressure level for the tones from 110 Hz to 8000
Hz for
the control sound trap is about 58.5 dB. The average sound pressure level for
the tones
from 110 Hz to 8000 Hz for the test control trap is about 51.5 dB. Thus the
removal of
the facing paper from one of the building material members results in a sound
reduction
of about 7.0 dB across the sound trap.
The foregoing detailed description describes the invention with reference to
specific exemplary embodiments. However, it will be appreciated that various
modifications and changes can be made without departing from the scope of the
present
invention as set forth in the appended claims. The detailed description and
accompanying
drawings are to be regarded as merely illustrative, rather than as
restrictive, and all such
modifications or changes, if any, are intended to fall within the scope of the
present
invention as described and set forth herein.
More specifically, while illustrative exemplary embodiments of the invention
have
been described herein, the present invention is not limited to these
embodiments, but
includes any and all embodiments having modifications, omissions, combinations
(e.g., of
aspects across various embodiments), adaptations and/or alterations as would
be
appreciated by those in the art based on the foregoing detailed description.
The
limitations in the claims are to be interpreted broadly based on the language
employed in
the claims and not limited to examples described in the foregoing detailed
description or
during the prosecution of the application, which examples are to be construed
as non-
exclusive. For example, in the present disclosure, the term "preferably" is
non-exclusive
where it is intended to mean "preferably, but not limited to." Any steps
recited in any
method or process claims may be executed in any order and are not limited to
the order
presented in the claims. Means-plus-function or step-plus-function limitations
will only
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be employed where for a specific claim limitation all of the following
conditions are
present in that limitation: a) "means for" or "step for" is expressly recited;
and b) a
corresponding function is expressly recited. The structure, material or acts
that support
the means-plus function are expressly recited in the description herein.
Accordingly, the
scope of the invention should be determined solely by the appended claims and
their legal
equivalents, rather than by the descriptions and examples given above.
What is claimed and desired to be secured by Letters Patent is:
38
