U.S. patent application number 10/617250 was filed with the patent office on 2005-03-31 for panel and related wall structure.
Invention is credited to Tucker, Mark Irvine.
Application Number | 20050066618 10/617250 |
Document ID | / |
Family ID | 31190438 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050066618 |
Kind Code |
A1 |
Tucker, Mark Irvine |
March 31, 2005 |
Panel and related wall structure
Abstract
A unitary wall or ceiling panel comprising of a first solid
layer solidified gypsum and a second layer of a solidified gypsum
having a plurality cavities. The second layer is engaged with the
first layer and disposed from one side thereof. The cavities each
including anhydrate material of a kind having a water content
dependent volumetric displacement. The cavities have been formed by
the volumetric shrinking of the anhydrate material resultant from
the dissipation of water from the unitary panel gypsum wet phase
precursor during its curing to a solidified state.
Inventors: |
Tucker, Mark Irvine;
(Auckland, NZ) |
Correspondence
Address: |
JACOBSON HOLMAN PLLC
400 SEVENTH STREET N.W.
SUITE 600
WASHINGTON
DC
20004
US
|
Family ID: |
31190438 |
Appl. No.: |
10/617250 |
Filed: |
July 11, 2003 |
Current U.S.
Class: |
52/782.1 |
Current CPC
Class: |
E04B 2001/8272 20130101;
E04B 9/045 20130101; E04B 2/7453 20130101; E04B 2001/8476 20130101;
E04C 2/043 20130101; E04B 9/0435 20130101; E04B 2/7409 20130101;
E04B 2001/8461 20130101; E04B 1/86 20130101 |
Class at
Publication: |
052/782.1 |
International
Class: |
E04C 002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2002 |
NZ |
520115 |
May 6, 2003 |
NZ |
525714 |
Claims
1. A unitary wall or ceiling panel comprising a first layer
predominantly of a solidified gypsum based material and of a non
cavity defining structure, said first layer defining a first
exterior major surface of the panel and a second layer of a
solidified gypsum based material having a plurality of preferably
substantially homogenously provided cavities, said second layer
engaged with the first layer and disposed from the side of said
first layer opposite to said first exterior major surface, said
cavities each including anhydrate material of a kind having a water
content dependent volumetric displacement, said cavities having
been formed by the volumetric shrinking of said anhydrate material
resultant from the dissipation of water from said unitary panel
gypsum wet phase precursor during its curing to a solidified
state.
2. A unitary wall or ceiling panel as claimed in claim 1 wherein
said second layer is engaged directly to said first layer.
3. A unitary wall or ceiling panel as claimed in claim 1 wherein a
third layer is provided as part of said panel capturing said second
layer between said first and third layer, said third layer being of
a solidified gypsum based material of a non cavity defining
structure and defining a second exterior major surface of said
panel.
4. A unitary wall or ceiling panel as claimed in claim 3 wherein
said third layer is substantially similar to said first layer.
5. A unitary wall or ceiling panel as claimed in claim 3 wherein
said first, second and third layers are coextensive.
6. A unitary wall or ceiling panel as claimed in claim 3 wherein at
least one of said first and second major surface of said panel is
provided with a patterned non planar surface.
7. A unitary wall or ceiling panel as claimed in claim 1 wherein at
least one of said first and second major surface consists of a
plurality of upstands.
8. A unitary wall or ceiling panel as claimed in claim 7 wherein
each said upstand is prismatic in shape.
9. A unitary wall or ceiling panel as claimed in claim 1 wherein at
least one of said first and second major surface of said panel is a
cobbled surface.
10. A unitary wall or ceiling panel as claimed in claim 3 wherein
said first and third layer is substantially of gypsum.
11. A unitary wall or ceiling panel as claimed in claim 9 wherein
said third and first layers include EVA additive.
12. A unitary wall or ceiling panel as claimed in claim 9 wherein
said first and third layers include a fibre re-enforcing
material.
13. A unitary wall or ceiling panel as claimed in claim 1 wherein
said anhydrate material is a polyacrylate.
14. A unitary wall or ceiling panel as claimed in claim 1 wherein
said anhydrate material is a potassium polyacylate.
15. A method of providing a unitary wall or ceiling panel which
comprises the steps of a) providing a layer of wet pre-solidified
phase gypsum based material and anhydrate material homogenous
mixture, onto a layer of wet pre-solidified phase gypsum based
material without said anhydrate, b) allowing curing to a solidified
phase of said gypsum to occur.
16. A method as claimed in claim 15 where the method further
includes the provision of a layer of wet pre-solidified phase
gypsum based material onto to the exposed surface of the layer of
pre-solidified phase based gypsum and anhydrate material homogenous
mixture.
17. A method as claimed in claim 15 wherein the method further
includes the provision of a layer of gypsum based material onto the
exposed surface of wet pre-solidified phase gypsum and anhydrate
material homogenous mixture by the dispersing of a gypsum based
power form material onto the the exposed surface of wet
pre-solidified phase gypsum and anhydrate material homogenous
mixture.
18. A method as claimed in claim 15 wherein said third mentioned
layer is absent of anhydrate material.
19. A method as claimed in claim 15 wherein said anhydrate is a
polyacrylate.
20. A method as claimed in claim 19 wherein said polyacrylate is
potassium acrylate.
21. A method as claimed in claim 16 wherein said third mentioned
layer prior to it setting is screeded to provide a planar surface
finish.
22. A method as claimed in claim 16 wherein a fibrous material is
provided in at least one of the first and third mentioned
layers.
23. A method as claimed in claim 22 wherein said fibrous material
is fibreglass.
24. A method as claimed in claim 15 wherein said second mentioned
layer is applied onto a horizontal moulding surface which during
the curing of said layers provides upward support to said
layers.
25. A method as claimed in claim 24 wherein said moulding surface
has an patterned relief moulding surface to impart a non planar
surface to said second mentioned layer.
26. A wall structure of a building comprising a vertically
extending frame work spanning between a floor and ceiling of said
building a wall panel subassembly comprising a first panel and at
least one other panel said second panel engaged to said first panel
in a substantially parallel manner and separated therefrom to
define a space there between, said first and second panels engaged
to each other in a separated manner by a compressible material
spacer element, wherein said subassembly is mounted from and
affixed to said frame work by mechanical fastening means in a
manner wherein said first panel is positioned facing said frame
work and wherein a compressible material spacer element in provided
intermediate of said first panel and said framework.
27. A wall structure as claimed in claim 26 wherein said first and
second panels are coextensively engaged with each other.
28. A wall structure as claimed in claim 26 wherein said first
panel comprises a first layer predominantly of a solidified gypsum
based material and being of a non cavity structure, said first
layer defining a first exterior major surface of the panel and a
second layer of a solidified gypsum material having a plurality of
substantially homogenously provided cavities, said second layer
engaged with the first layer and disposed from the side of said
first layer opposite to said first exterior major surface, said
cavities each including anhydrate material of a kind having a water
content dependent volumetric displacement, said cavities having
been formed by the volumetric shrinking of said anhydrate material
resultant from the dissipation of water from said unitary panel
gypsum wet phase precursor.
29. A wall structure as claimed in claim 28 wherein said second
panel is of a homogenous gypsum based structure.
30. A wall structure as claimed in claim 27 wherein the surface of
said first panel facing said frame structure side is non
planar.
31. A wall structure as claimed in claim 30 wherein said surface of
said first panel facing 30 said frame structure is of a cobbled or
prismatic texture.
32. A wall structure as claimed in claim 26 wherein said
compressible material spacer is a strip material and extends at
least proximate to the perimeter of and between the first and
second panels.
33. A wall structure as claimed in claim 26 wherein a second wall
panel sub assembly is provided and disposed from the other side of
said frame work, said second wall panel sub assembly comprising a
first panel and at least one other panel said second panel engaged
to said first panel in a substantially parallel manner and
separated therefrom to define a space there between, said first and
second panels engaged to each other in a separated manner by a
compressible material spacer element, wherein said second
subassembly is mounted from and affixed to said frame work by
mechanical fastening means in a manner wherein said first panel is
positioned facing said frame work and wherein a compressible
material spacer element is provided intermediate of said first
panel and said framework.
34. A wall structure as claimed in claim 33 wherein the distance
between the first panel of said first wall panel subassembly and
the first panel of the second wall panel sub assembly is
approximately 170 mm.
35. A wall structure as claimed in claim 33 wherein said frame work
comprises of vertically extending timber studs.
36. A wall structure as claimed in claim 33 wherein said frame work
comprises two parallel and separated rows of studs a first row with
which the first sub assembly is engaged and a second row with which
said second sub assembly is engaged.
37. A wall structure as claimed in claim 33 wherein said first
panel of said first sub assembly and said first panel of said
second sub assembly each included a cobbled or prismatic surface
detail.
38. A wall or ceiling panel assembly comprising a first planar
panel of a rigid sheet material a second planar panel of a rigid
sheet material affixed to said first wall panel in a spaced apart
disposition from said first wall panel, wherein the major surfaces
of said first and second planar panels are parallel and in at least
a significant overlapping relationship with each other at least one
resiliently flexible element disposed between the facing major
surfaces the first and second panels and sealing engaged to the
facing surfaces of each panel, wherein at least one of said first
and second panels (hereinafter the "cavity panel") comprises a
first layer predominantly of a solidified gypsum based material and
of a non cavity defining structure, said first layer defining a
first exterior major surface of the panel and a second layer of a
solidified gypsum based material having a plurality of preferably
substantially homogenously provided cavities, said second layer
engaged with the first layer and disposed from the side of said
first layer opposite to said first exterior major surface, said
cavities each including anhydrate material of a kind having a water
content dependent volumetric displacement, said cavities having
been formed by the volumetric shrinking of said anhydrate material
resultant from the dissipation of water from said unitary panel
gypsum wet phase precursor a third layer predominantly of a
solidified gypsum based material and of a non cavity defining
structure, said third layer defining a second exterior major
surface of the panel.
39. A wall or ceiling panel assembly as claimed in claim 38 wherein
at least one of the first or second exterior major surfaces of said
cavity panel(s) is of a non planar surface consisting of plurality
closely or abuttingly spaced upstands.
40. A wall or ceiling panel assembly as claimed in claim 38 wherein
one of the first or second exterior major surfaces of said cavity
panel(s) is of a non planar surface consisting of plurality closely
or abuttingly spaced upstands.
41. A wall or ceiling panel assembly as claimed in claim 38 wherein
only one of said first and second panels is a cavity panel.
42. A wall or ceiling panel assembly as claimed in claim 38 wherein
the exterior (to said assembly) facing major surface of said cavity
panel is of a non planar surface consisting of plurality closely or
abuttingly spaced upstands.
43. A wall or ceiling panel assembly as claimed in claim 38 wherein
the major surface of said cavity panel facing the other of said
first and second panels is of a non planar surface consisting of
plurality closely or abuttingly spaced upstands.
44. A wall or ceiling panel assembly as claimed in claim 38 wherein
said resiliently flexible element is a strip material and is
provided between the first and second panels at or immediately
inwardly of the overlying perimeter regions of said first and
second panels.
45. A wall or ceiling panel assembly as claimed in claim 38 wherein
said first and second panels are affixed to each other in a
substantially coextensive relationship.
Description
TECHNICAL FIELD
[0001] The present invention relates to a panel and related wall
structure and in particular to a sound absorbing panel and
structure which although not essentially but, preferably is used as
a building panel such as a wall or ceiling panel.
BACKGROUND ART
[0002] Wall and ceiling panels made of a gypsum based material are
well known. Such panels are often also called plaster board panels
and consist of a core of gypsum material overlaid on each side by a
paper sheet. Such panels are used placed against framing timber to
provide a lining for an inferior surface of a room of a house or
building or the like. Similarly suspended ceilings may be provided
wherein the plasterboard is suspended from a framing structure to
thereby reduce the degree of vibrational transmission of sound.
[0003] Such additional steps in providing a further sound proofing
can however be costly and it is advantageous if a single sheet of a
building panel can be provided wherein significant or adequate
sound absorption effects are provided by that panel alone. It will
be appreciated that the provision of intermediary sound absorbing
members add steps to the installation procedure of lining a room of
a building.
[0004] The sound transmission loss of wall-barriers is determined
by physical factors such as mass and stiffness. In double layer
assembly, as in gypsum wallboard on non-continuous wood framing,
the depth of air space, the presence of sound absorbing material
and the degree of mechanical coupling between layers critically
affect sound transmission losses and therefore the sound
transmission class (STC).
[0005] Renewed interest in reducing noise in living chambers has
motivated research in structural-acoustic analysis. Sound is
generated by creating disturbance of the air which sets up a series
of pressure waves fluctuating above and below the air's normal
atmospheric pressure. These pressure waves propagate in all
directions from the source of the sound. There are many sources of
sound in buildings: voices, human activities, external noises such
as traffic, entertainment devices and machinery. They all generate
small rapid variations in pressure about the static atmospheric
pressure. These propagate through the air as sound waves. The
nature of excitation may be unique to each chamber. The sound
transmission loss of wall-barriers is determined by physical
factors such as mass and stiffness. In double layer assembly, as in
gypsum wallboard on non-continuous wood framing, the depth of air
space, the presence of sound absorbing material and the degree of
mechanical coupling between layers critically affect sound
transmission losses and therefore the sound transmission class
(STC). The internal sound field in the enclosed area is
significantly affected by: the acoustic modal characteristics, the
dynamic behaviour of the surrounding structure, and by the nature
of the coupling of these two dynamic systems e.g. that created by
wall and ceiling structures. In addition, depending upon the
relative value of the wall panel and gap resonant frequencies,
sound transmitted from one side of a wall to the other may be
amplified rather than reduced.
[0006] It is common knowledge that for typical partitions, the
transmission loss is much smaller for low frequency sounds than for
high frequency sounds.
SUMMARY OF THE INVENTION
[0007] Accordingly it is an object of the present invention to
provide a panel which overcomes the abovementioned disadvantages or
which at least provides the public with a useful choice.
[0008] It is also an object of the present invention to provide a
wall structure which has improved acoustic transmission properties
over single panelled wall structures, or to at least provide the
public with a useful choice.
[0009] Accordingly the present invention consists in a panel
comprising a unitary wall or ceiling panel comprising
[0010] a first layer predominantly of a solidified gypsum based
material and of a non cavity defining structure, said first layer
defining a first exterior major surface of the panel and
[0011] a second layer of a solidified gypsum based material having
a plurality of preferably substantially homogenously provided
cavities, said second layer engaged with the first layer and
disposed from the side of said first layer opposite to said first
exterior major surface,
[0012] said cavities each including anhydrate material of a kind
having a water content dependent volumetric displacement, said
cavities having been formed by the volumetric shrinking of said
anhydrate material resultant from the dissipation of water from
said unitary panel gypsum wet phase precursor during its curing to
a solidified state.
[0013] Preferably said second layer is engaged directly to said
first layer.
[0014] Preferably a third layer is provided as part of said panel
capturing said second layer between said first and third layer,
said third layer being of a solidified gypsum based material of a
non cavity defining structure and defining a second exterior major
surface of said panel.
[0015] Preferably said third layer is substantially similar to said
first layer.
[0016] Preferably said first, second and third layers are
coextensive.
[0017] Preferably at least one of said first and second major
surface of said panel is provided with a patterned non planar
surface.
[0018] Preferably at least one of said first and second major
surface consists of a plurality of upstands.
[0019] Preferably each said upstand is prismatic in shape.
[0020] Preferably at least one of said first and second major
surface of said panel is a cobbled surface.
[0021] Preferably said first and third layer is substantially of
gypsum.
[0022] Preferably said third and first layers include EVA
additive.
[0023] Preferably said first and third layers include a fibre
re-enforcing material.
[0024] Preferably said anhydrate material is a polyacrylate.
[0025] Preferably said anhydrate material is a potassium
polyacylate.
[0026] In a further aspect the present invention consist in a
method of providing a unitary wall or ceiling panel which comprises
the steps of
[0027] a) providing a layer of wet pre-solidified phase gypsum
based material and anhydrate material homogenous mixture, onto a
layer of wet pre-solidified phase gypsum based material without
said anhydrate,
[0028] b) allowing curing to a solidified phase of said gypsum to
occur.
[0029] Preferably the method further includes the provision of a
layer of wet pre-solidified phase gypsum based material onto to the
exposed surface of the layer of pre-solidified phase based gypsum
and anhydrate material homogenous mixture.
[0030] Preferably the method further includes the provision of a
layer of gypsum based material onto the exposed surface of wet
pre-solidified phase gypsum and anhydrate material homogenous
mixture by the dispersing of a gypsum based power form material
onto the the exposed surface of wet pre-solidified phase gypsum and
anhydrate material homogenous mixture.
[0031] Preferably said third mentioned layer is absent of anhydrate
material.
[0032] Preferably said anhydrate is a polyacrylate.
[0033] Preferably said polyacrylate is potassium acrylate.
[0034] Preferably said third mentioned layer prior to it setting is
screeded to provide a planar surface finish.
[0035] Preferably a fibrous material is provided in at least one of
the first and third mentioned layers.
[0036] Preferably said fibrous material is fibreglass.
[0037] Preferably said second mentioned layer is applied onto a
horizontal moulding surface which during the curing of said layers
provides upward support to said layers.
[0038] Preferably said moulding surface has an patterned relief
moulding surface to impart a non planar surface to said second
mentioned layer.
[0039] In a further aspect the present invention consist in a wall
structure of a building comprising
[0040] a vertically extending frame work spanning between a floor
and ceiling of said building
[0041] a wall panel subassembly comprising a first panel and at
least one other panel
[0042] said second panel engaged to said first panel in a
substantially parallel manner and separated therefrom to define a
space there between, said first and second panels engaged to each
other in a separated manner by a compressible material spacer
element,
[0043] wherein said subassembly is mounted from and affixed to said
frame work by mechanical fastening means in a manner wherein said
first panel is positioned facing said frame work and wherein a
compressible material spacer element in provided intermediate of
said first panel and said framework.
[0044] Preferably said first and second panels are coextensively
engaged with each other.
[0045] Preferably said first panel comprises
[0046] a first layer predominantly of a solidified gypsum based
material and being of a non cavity structure, said first layer
defining a first exterior major surface of the panel and
[0047] a second layer of a solidified gypsum material having a
plurality of substantially homogenously provided cavities, said
second layer engaged with the first layer and disposed from the
side of said first layer opposite to said first exterior major
surface,
[0048] said cavities each including anhydrate material of a kind
having a water content dependent volumetric displacement, said
cavities having been formed by the volumetric shrinking of said
anhydrate material resultant from the dissipation of water from
said unitary panel gypsum wet phase precursor.
[0049] Preferably said second panel is of a homogenous gypsum based
structure.
[0050] Preferably the surface of said first panel facing said frame
structure side is non planar.
[0051] Preferably said surface of said first panel facing said
frame structure is of a cobbled or prismatic texture.
[0052] Preferably said compressible material spacer is a strip
material and extends at least proximate to the perimeter of and
between the first and second panels.
[0053] Preferably a second wall panel sub assembly is provided and
disposed from the other side of said frame work, said second wall
panel sub assembly comprising a first panel and at least one other
panel
[0054] said second panel engaged to said first panel in a
substantially parallel manner and separated therefrom to define a
space there between, said first and second panels engaged to each
other in a separated manner by a compressible material spacer
element,
[0055] wherein said second subassembly is mounted from and affixed
to said frame work by mechanical fastening means in a manner
wherein said first panel is positioned facing said frame work and
wherein a compressible material spacer element is provided
intermediate of said first panel and said framework.
[0056] Preferably the distance between the first panel of said
first wall panel subassembly and the first panel of the second wall
panel sub assembly is approximately 170 mm.
[0057] Preferably said frame work comprises of vertically extending
timber studs.
[0058] Preferably said frame work comprises two parallel and
separated rows of studs a first row with which the first sub
assembly is engaged and a second row with which said second sub
assembly is engaged.
[0059] Preferably said first panel of said first sub assembly and
said first panel of said second sub assembly each included a
cobbled or prismatic surface detail.
[0060] In still a further aspect the present invention consists in
a wall or ceiling panel assembly comprising
[0061] a first planar panel of a rigid sheet material
[0062] a second planar panel of a rigid sheet material affixed to
said first wall panel in a spaced apart disposition from said first
wall panel, wherein the major surfaces of said first and second
planar panels are parallel and in at least a significant
overlapping relationship with each other
[0063] at least one resiliently flexible element disposed between
the facing major surfaces the first and second panels and sealing
engaged to the facing surfaces of each panel,
[0064] wherein at least one of said first and second panels
(hereinafter the "cavity panel") comprises
[0065] a first layer predominantly of a solidified gypsum based
material and of a non cavity defining structure, said first layer
defining a first exterior major surface of the panel and
[0066] a second layer of a solidified gypsum based material having
a plurality of preferably substantially homogenously provided
cavities, said second layer engaged with the first layer and
disposed from the side of said first layer opposite to said first
exterior major surface,
[0067] said cavities each including anhydrate material of a kind
having a water content dependent volumetric displacement, said
cavities having been formed by the volumetric shrinking of said
anhydrate material resultant from the dissipation of water from
said unitary panel gypsum wet phase precursor
[0068] a third layer predominantly of a solidified gypsum based
material and of a non cavity defining structure, said third layer
defining a second exterior major surface of the panel.
[0069] Preferably at least one of the first or second exterior
major surfaces of said cavity panel(s) is of a non planar surface
consisting of plurality closely or abuttingly spaced upstands.
[0070] Preferably one of the first or second exterior major
surfaces of said cavity panel(s) is of a non planar surface
consisting of plurality closely or abuttingly spaced upstands.
[0071] Preferably only one of said first and second panels is a
cavity panel.
[0072] Preferably the exterior (to said assembly) facing major
surface of said cavity panel is of a non planar surface consisting
of plurality closely or abuttingly spaced upstands.
[0073] Preferably the major surface of said cavity panel facing the
other of said first and second panels is of a non planar surface
consisting of plurality closely or abuttingly spaced upstands.
[0074] Preferably said resiliently flexible element is a strip
material and is provided between the first and second panels at or
immediately inwardly of the overlying perimeter regions of said
first and second panels.
[0075] Preferably said first and second panels are affixed to each
other in a substantially coextensive relationship.
BREIF DESCRIPTION OF THE DRAWINGS
[0076] This invention may also be said broadly to consist in the
parts, elements and features referred to or indicated in the
specification of the application, individually or collectively, and
any or all combinations of any two or more of said parts, elements
or features, and where specific integers are mentioned herein which
have known equivalents in the art to which this invention relates,
such known equivalents are deemed to be incorporated herein as if
individually set forth.
[0077] FIG. 1 is a sectional view through a preferred form of the
panel of the present invention,
[0078] FIG. 2 is a side view of a panel of the present
invention,
[0079] FIG. 3 is a sectional view through an installation which
includes the panel of the present invention to define a sound
absorbing wall structure,
[0080] FIG. 4 illustrates a means of joining adjacent panels,
[0081] FIG. 5 illustrates an arrangement for supporting a panel
from a vertical or horizontal surface,
[0082] FIG. 6 illustrates a method of fixing a series of panels to
a wall structure wherein the assembly provides enhanced
soundproofing,
[0083] FIG. 7 illustrates an example of an assembly of a wall
utilising the panel of the present invention in conjunction with
additional panels and framing,
[0084] FIG. 8 illustrates a prismatic surface texture provided on
the panel of the present invention,
[0085] FIG. 9 is a view of the core of the panel of the present
invention,
[0086] FIG. 10 is an illustration of the setup of the acoustic
testing room,
[0087] FIG. 11 is a graph of results of the testing as hereinafter
described,
[0088] FIG. 12 shows a test data sheet of the wall construction
incorporating the cavity panel, and
[0089] FIG. 13 shows a test data sheet of the wall construction
incorporating the cavity panel.
DETAILED DESCRIPTION OF THE INVENTION
[0090] The Wall or Ceiling Panel
[0091] The proposed panel of a first aspect of the inventions
described provides a convenient way of absorbing noise transmission
and is maintained within a standard panel thickness (e.g. 12.5 nm)
commonly used in building trades. With reference to FIG. 1, the
face gauge (exterior layers 4 and 1) consists of a gypsum based
material and provides a high density thin layer. The exterior
layers 1 and 4 are of a non-cavity structure and may hence be
considered of a solid non porous structure. The face gauges 1 and 4
consists of a gypsum based material and provides a substantially
solid thin section to the panel of the present invention. One face
gauge provides its exposed surface 2 to be provided in a condition
in use to be exposed into the room but which can later be subjected
to further treatment such as priming and painting or for the
application by adhesion of a paper layer or similar cellulosic
material.
[0092] Each face gauge 1 is preferably of a high density
consistency. Each face gauge is preferably in a form to provide a
high density thin section to the panel and may be for example be
provided by a reasonably low water content wet mix of solidified
gypsum pre-cursor.
[0093] The body gauge (the interior layer 3) consists of a gypsum
material mixed with anhydrite gelling material.
[0094] The gelling material is a product, which upon contact with
water, results in rapid swelling as a result of electrical forces
pushing the inward structure of the particle away from the centre.
When water is drawn away from the polymer the particle shrinks in
volume.
[0095] Post curing, cavities are formed within the body gauge.
These cavities provide sound wave dissipation. Noise that flanks
past the body gauge is in part reverberated back to the cavities
from the backward high-density exterior surface face of the panel.
As a result of the cavities within the body gauge, many entering
sound waves are internally reflected and dissipated.
[0096] A first face gauge 1 is provided in a mould or onto a mould
in its wet form gypsum based pre-cursor and is spread to a
thickness of for example 2 mm. Provided on top of the face gauge
(i.e. against the surface of the face gauge away from the to be
exposed surface 2 of the face gauge is the body gauge 3. The body
gauge consists of a gypsum material which has been mixed with a
hydrated gelling material such as an anhydrate as potassium
polyacrylate. An example of a potassium polyacrylate is that known
by the trade mark TERAWET.TM. which is a crosslinked potassium
polyacrylate/polyacrylamide copolymer which comes in the form of
white granules and has a bulk density of 540.+-.40 grams per cubic
meter. Its Ph value is somewhere between 6-6.8. Terawet.TM. is a
product which upon contact with water results in rapid swelling as
a result of electrical forces pushing the inward structure of the
particle away from the centre. Small spaces are created inside the
particle which attract water. When water is drawn away from the
polymer the particle shrinks in volume. With the provision of
hydrated potassium polyacrylate with the gypsum to define the body
gauge, a substantially solid, in its wet form, layer of material is
applied to the (preferably still procured form) inwardly facing
surface 10 of the face gauge 1.
[0097] The body gauge may be allowed to cure along with curing of
the face gauge. However preferably a third layer, a backing face
gauge 4 is provided to the then upwardly facing exposed surface of
the body gauge 3. The backing face gauge 4 is preferably made of a
substantially similar material to the face gauge 1. The body gauge
3 may be provided in the form of 8.5 mm layer intermediate of the
backing face gauge 4 and face gauge. Further intermediate layers
may be provided of a different kind however the most preferred form
of the panel is as shown, in cross section in FIG. 1.
[0098] Preferably said third layer 4 has a normal to the plane of
its exterior surface projecting in the opposite direction away from
said panel to the normal of the plane of the exterior surface of
said first layer 1 so the panel is of a uniform thickness . . .
.
[0099] Upon the curing of the gypsum material moisture is drawn out
from the wet phase of the face, backing and body gauges. As the
potassium polyacrylate also contains water, upon the curing of the
panel, that water is removed from the potassium polyacrylate. The
potassium polyacrylate becomes dehydrated and reduces in volume. As
it reduces in volume, cavities are formed within the body gauge
such cavities being substantially of a size of the wet or hydrated
phase of the potassium polyacrylate.
[0100] Once dehydrated, the swelled anhydrites at the core of the
sheet shrinks to form small beads. The result is aerated cavities
30-40 times larger than the remaining bead of anhydrate. The dried
anhydrites can re-swell to its original cavity mass when
atmospheric moisture conditions are present. This phenomenon can
occur repeatedly in a consistent manner.
[0101] The anhydrites within the panel will absorb and contain
water ingress and release it when appropriate warm and dryer
atmospheric conditions are present.
[0102] At the casting stage an anti-mould and fugal agent is added
to at least the body gauge to combat the problems associated with
water ingress such as product breakdown, rot, mildew and mould
growth.
[0103] The application of the backing gauge to form part of the
panel of the present invention, is achieved during the curing of
the face and body gauge. As the curing of the face and body gauge
takes place, moisture is floated to the surface of the body gauge.
This moisture can be removed by the application of gypsum powder to
the upper surface of the body gauge as the moisture is transferred
therefrom. The application of gypsum powder to the upper surface of
the body gauge provides the backing face gauge to the panel of the
present invention. In order to achieve a smooth surface to the
backing gauge the powdered gypsum that is applied to the surface of
the body gauge is smoothed by for example a screed. The thickness
of the backing gauge can be built up appropriately to cover the
upper surface of the body gauge and to thereby define a panel which
is of a desired thickness. By way of example, the thickness of the
panel may be provided to approximately 12.5 mm.
[0104] Cavities in the body gauge, provide a disruption of
reverberation of sound through the panel. The panel allows for mild
reverberation of the face gauge allowing for a reasonably high
percentage of noise to pass through to the body gauge. The
reverberation of sound in the body gauge can be captured in the
cavities in providing a dissipating effect of the noise. Noise that
flanks past the body gauge is in part reverberated back to the
cavities from the exterior layers. As a result of the cavities
within the body gauge of the panel of the present invention, much
sound that enters therein is internally reflected and eventually
some if not most is absorbed.
[0105] To provide strength to the panel, fibre rovings may be
provided throughout the panel or provided within at least one of
the gauges and preferably within the body gauge 3.
[0106] The panel of the present invention with the inclusions of a
dehydrated anhydrate will also provide some degree of humidity or
moisture absorption.
[0107] Further additives may be provided to the gypsum material for
the purposes of hardening and such materials may include EPA and EP
hardener and indeed anti-mould or antifungal agents may be added
particularly considering the possibility of moisture absorption
being provided by the anhydrates.
[0108] In designing the wallboard several factors were taken into
account. These include the right weight for swelled anhydrites, the
right amount of a typical hardener (EP hardener) which is added to
both the face and body gauges, the fibre-glass strands. Table 1
shows one example of material detail. Table 2 shows an alternative.
Table 2 gives weight values of components for the improved mix at a
mass quantity gauge ratio of 100:60.
[0109] The panel of the present invention may further be provided
with a surface modification to at least one of the outwardly facing
surfaces of the face gauge or backing face gauge 1,4. Such a
surface modification is by way of a pattern of upstands or
substantially the entire of the surface and provides a disruption
to the otherwise flat exterior surface of the panel.
[0110] The panel of the present invention provides a convenient way
of absorbing some noise transmission through the panel while still
allowing it to be maintained within a standard thickness wall panel
which are commonly used in the building trade.
[0111] With the provision of surface modifications to at least one
and alternatively to both of the outwardly facing surfaces of the
panel of the present invention, further sound reducing
characteristics may be catered for. Surface upstands which may be
provided as a pattern to the surface of the panel can provide
further sound deflection. With reference to FIG. 3, the panel is
provided as part of a sound absorbing structure and the surface
modifications 12 may be provided exposed into a cavity which is
defined between the panel of the invention and an other like or
other type of panel 13.
[0112] Wall Structure
[0113] The overall function of a wall, in conjunction with floors,
and roofs, is to provide a barrier between two environments, so
that one environment can be adjusted and maintained within
acceptable limits.
[0114] A wall is a selective separator between two spaces where
between an actual or potential flow of energy is involved. The
greater the difference between the two spaces the greater is the
stress of duty imposed on the wall. Thus, the elements of the wall
must be selected so that in the first instance they impart the
necessary resistance to keep noise levels within acceptable limits.
The way they are arranged, however, is also important. This will
determine the variation in conditions throughout the wall.
Interaction between various factors involved may produce conditions
within the wall structure that require special attention.
[0115] The panel 13 may be a standard plaster board sheet which is
provided in association with the panel 14 of the present invention.
The surface modifications 12 may be provided preferably within the
cavities provided between two panels 14, 13. Alternatively the
panel 14 may present the surface modifications outwardly for
positioning facing a frame structure. The surface modifications
will provide a disruption to the sound waves endeavouring to travel
into the panel 14 from any sound transmitted from the inwardly
facing surface of the panel 13. To prevent direct vibrational
transmissions between the two panels a spacer 15 of a low hardness
material such as a foam or rubber is provided to create a space
lamination such may be provided at appropriate locations between
the panels 13 and 14. This spacer will reduce the incidence of
material vibrational transmission of sound.
[0116] The panel 14 is preferably mounted to a frame work structure
16 of a building such as timber framing directly, or with rubber or
foam spaces in between or by way of mounts 17. Such mounts may be
rails of an extruded or roll formed kind to which the panel
structure of the panels 13, 14 are mounted. Rubber grommets 21 or
strip material may be further provided intermediate of the
structure 16 and the mounts 17 and/or between the mounts 17 and the
panel 14. With reference to FIG. 5, there is shown a detailed view
of the arrangement wherein the panel is provided to a timber
framing structure as for example shown in FIG. 16.
[0117] A putty like material may be provided to overlay the
positions where the fastening means 22 may be provided to secure
the panel 14 to the rails 17. The application of such a putty 23
provides a sound seal to the migration of sound via the fastening
means 22 to or from the other side of the panel 14 to which it is
provided.
[0118] With reference to FIG. 6, a wall utilising the panel
construction of the present invention may be provided wherein a
plurality of panels are provided adjacent to each other. Such a
plurality of panels 20 are preferably engaged to adjacent like
panels as for example shown in FIG. 4. A sound sealing material 25
may be provided intermediate of the panels to thereby reduce
transmission of vibration between adjacent abutting panels.
[0119] The spacer seal 15 may extend around or approximate to the
formed perimeter of the plurality of panels. Intermediate of the
spacer there may be provided a sound absorbing putty 26. Such a
sound absorbing may also be provided external of the seal 15.
[0120] The exterior panel 13 may preferably be adhered to the panel
14 by adhesive regions 27 such as adhesive daubs. The adhesive is
that which holds the facing panel 13 to the inner panel 14.
[0121] With reference to FIG. 7 there is shown a double sided wall
structure which includes a frame structure of a first row of studs
102 and a second row of studs 106. The studs preferably extend from
floor to ceiling of a building structure and nogs or dwangs may
extend between adjacent studs in each row. However most preferably
each row remains separated from the other row and accordingly a gap
107 is provided between the rows of studs. The gaps will reduce the
possibility of solid mass sound transmission, between studs and
hence each side of the wall.
[0122] On each side of the studs are provided a wall panel sub
assembly. Each wall panel sub assembly preferably consists of a
first panel 101 and a second panel 100. In a most preferred form
the panel 101 is of a kind as hereinbefore described which utilises
the cavity structure defined by the anhydrate material therein. The
first and second panels are engaged to each other but are separated
by a space therebetween which is preferably defined by a spacer
element 104 which is of a flexible material such as a foam or
rubber strip or strips. The foam may for example be a high density
foam seal. As mentioned above, additional adhesive daubs may be
provided intermediate of the two panels of each sub assembly to fix
these together. As a sub assembly, the two panels are then fixed to
the appropriate side of the frame structure to a respective row of
studs.
[0123] Preferably a high density foam seal is provided intermediate
of the stud and the facing side of the first panel 102 to act as a
vibration absorption spacer between the studs and the
subassemblies. Fixing screws can then extend through the
subassemblies (through both panels 101 and 100 to further fix the
sub assemblies to the frame work). Screws of a sufficient length
and of a kind often used in a plaster board panels can be used.
[0124] Intermediate of the two sub-assemblies of panels a thermal
insulation material such as a fibre insulation mat can be
positioned to further enhance sound absorption and to provide
thermal insulation.
[0125] In the most preferred form the sub assemblies are positioned
such that the non planar (e.g. the surface with the cobbled or
prismatic upstands) panel of the sub assemblies are positioned
engaged to the frame structure, facing the studs or facing the
cavity between the studs. The non planar surface 108 positioned in
this manner will encourage the sound dissipation within the cavity
between the two facing sub assemblies, provided on each side of the
frame structure.
[0126] It is perceived by the inventor that these wall structure as
shown in FIG. 7 may utilise one only subassembly on one side only
and the other side may be of a different kind. A single stud
arrangement against which a single sub assembly is provided may
also be utilised. However it has been recognised in testing that a
double wall structure as shown in FIG. 7 and wherein the spacing
between the interior facing surfaces of the wall sub assemblies
provided at approximately 170 mm apart, provides a very attractive
absorption characteristic of which reference will hereinafter be
made.
[0127] Tests
[0128] In order to achieve high STC valves it has been recognised
by the inventor that, important factors, in addition to masses of
the component layers, are the depth of air space, the use of sound
absorbing materials within the air space and the rigidity of the
mechanical coupling between the layers. This may be achieved by a
wall assembly with no significant rigid mechanical connection
between the two wall panel subassemblies on each side of the frame
structure. The mechanical connection between the subassemblies of
two panels is reduced by the use of separate rows of studs to
support the subassemblies independently of each other.
[0129] With reference to FIGS. 11, 12 and 13 test results indicate
that the cavity panel incorporating sub-assembly of this invention
reached an STC of 63 dB. This value is higher than those reached
with locally and internationally (Canada and USA) produced acoustic
panels of solid (non cavity) configuration. The STC of Standard
Commercial Wall Boards is 54 dB.
[0130] For the wall assembly of FIG. 7 the results also showed a
significant improvement to the lower ranges of frequency (between
50-160 Hz). This effect can be avoided by increasing the air space
between the non-continuous wooden frames to displace the facing
surfaces of the two subassemblies. Tests were conducted to find the
optimum airspace between the facing surfaces of the panel
subassemblies on each side of the frame structure to suppress
resonance. This was found to be optimum at 170 mm.
[0131] It was shown by analysis that the core shear parameter has a
significant effect on the noise transmission characteristics of the
proposed panel, which has better sound transmission characteristics
than a homogenous panel, for two reasons: first, the coincidence
frequencies are shifted to higher frequency ranges, and second, the
coincidence transmission loss is considerably increased due to the
presence of the cavities on the layer surface.
[0132] Tests were conducted on the new panel at the University of
Auckland Acoustic Laboratories. Sound transmission loss was
measured by testing in two separate rooms highly reverberant not in
solid contact with either of them. A loud speaker and amplifier are
used to generate random sound in one of the rooms and sound energy
passes through the partition into the second receiving room (FIG.
10):
[0133] The level in the receiving room is partly determined by the
area of the partition and the total absorption of the receiving
room. The larger the sound transmission class (STC) value, the
better the partition (less sound energy passes through it).
[0134] The reverberation time in the echoic chambers was optimised.
The reverberation time is directly related to the room volume and
inversely related to total absorption in the room. The
reverberation time is calculated using Sabine reverberation time
equation:
RT=0.161 V/(.alpha.S+4 mV)
[0135] where:
[0136] V is the room volume in cubic meters,
[0137] .alpha. is the mean absorption coefficient,
[0138] S is the total surface area of the room, in square
meters,
[0139] m is the energy attenuation constant per meter due to air
absorption.
[0140] An important improvement is achieved on the low frequency
range (between 50-160 Hz). On curve of FIG. 11, the variation of
the transmission loss is shown with frequency:
[0141] For low values of frequency (between 50-160 Hz) the
transmission loss curve follow the mass law. It shows significant
improvement.
[0142] At mid-ranged frequencies (between 200-630 Hz) a deviation
from the mass law takes place. This is attributed to the fact that
at this range the wave resonance acts to increase the frequency
values. The larger the air space between the double layers or the
heavier the materials, the lower the frequency at which resonance
occurs.
[0143] For higher frequency ranges, the transmission loss curve
follows the mass law again.
[0144] The curve shows that the TL is significantly higher at
intermediate frequency range (1000-2000 Hz). This is mainly due to
the fact that the coincidence frequencies are much higher than for
the larger values of frequency. A sharp drop in LT is noticed
between (2000-2500 Hz) to then increase rapidly with increase in
frequency (2500-4000 Hz).
[0145] To maximize the improvement due to airspace, frames should
be designed so that the mass-air-mass resonance is at the lowest
frequency as possible. Many common frame designs do not meet this
criterion. The air trapped in the space between the layers acts as
a spring transferring vibration energy from one frame to the
other.
[0146] The concept of sound transmission of prismatic surface
cavitated core of a wall barrier is of a significant importance in
the research for more cost effective methods related to development
of acoustic wallboards.
[0147] The sound transmission losses of a single or double layer
walls are determined by the physical properties of the component
materials and the method of assembly.
[0148] We believe that noise management of the whole system will
dictate whether the subsystems will perform satisfactorily.
Furthermore, it is estimated that the major failures can be avoided
by proper design and suitably implemented wall barriers. The rate
of noise failures can be reduced effectively if corrective measures
are taken by the whole industry.
[0149] Summary of the Measurement of Airborne Sound Insulation of
Building Elements Regarding the Results of FIGS. 11-13.
[0150] Installation of Test Sample:
[0151] The wall under test is installed in the opening between two
reverberation chambers chambers C and A for a wall, chambers A and
B for a floor. These chambers are vibration isolated from each
other which results in a structural discontinuity at the middle of
the test opening. This gap is covered over by a collar, which seals
the gap and provides for each of fixing of samples. The wall sample
is constructed by the client following the techniques normally used
in practice for that type of wall or floor/ceiling, and is sealed
into the test opening with perimeter seals of acoustic sealant. For
each of removal, the surfaces of the test opening are covered with
an adhesive, heavy fabric tape prior to the construction of the
building element.
[0152] Method:
[0153] The measured transmission loss values are obtained in
accordance with the recommendations of ISO standard 140-3:1995(E)
"Laboratory Measurement of Airborne Sound Insulation of Building
Elements" using a B&K 2133 analyser. The measurements were
repeated and checked by an independent measuring system, the
B&K 2260 sound level meter.
[0154] Essentially the transmission loss of a building element is
measured by generating sound on one side of the building element
(the source chamber) and measuring how much sound is transmitted
into the receiving chamber. In the source chamber pink noise is
radiated from a loudspeaker. Time and space averaged sound pressure
levels in both the source and receiving chambers are measured by
using a rotating boom microphone, and the average sound pressure
levels are obtained by sampling the sound pressure levels as the
boom rotates through one cycle (taking 32 seconds). This is
repeated for a different loudspeaker position in the source
chamber.
[0155] Measurements of the background noise levels in the receiving
chamber are also made. Then, should it prove necessary, the
transmitted noise levels are corrected for the influence of
background noise as prescribed in the standard.
[0156] The sound absorption of the receiving chamber is also
determined by measuring the reverberation times (ISO-354:1985(E)
"Measurement of Sound Absorption in a Reverberation Room").
[0157] Results:
[0158] The third octave band sound reduction indices R are
presented in both table and graph formats. Sometimes a highly
reflective test sample means that the lower frequency sound
pressure levels cannot be reliably measured; this is indicated by
#N/A in the table of results. Additionally, if the specimen is
highly insulating, sometimes the background noise affects the
measurements, resulting in only an upper threshold being found;
this is indicated by a > sign preceding the tabulated
results.
[0159] Single figure ratings are also presented. The weighted sound
reduction index R.sub.w, determined according to ISO 717-1, is
presented along with spectrum adaptation terms C.sub.tr and C.
R.sub.w is determined by fitting a reference curve to the third
octave band sound reduction indices R from 100 Hz to 3150 Hz, and
gives a single figure rating of the sound reduction through the
building element (higher is better). The spectrum adaptation terms
are added to R.sub.w and are used to take into account the
characteristics of particular sound spectra. C is used for living
activity noise, children playing, railway traffic at medium and
high speed, highway (>80 km/h) road traffic, and jet aircraft at
short distances. C.sub.tr is used for lower frequency noise such as
urban road traffic, low speed railway traffic, aircraft at large
distances, pop music, and factories which emit low to medium
frequency noise. C and C.sub.tr without further subscripts are
applied to a frequency range of 100 Hz to 3150 Hz. Other spectrum
adaptation terms are provided with enlarged frequency ranges (if
measured), e.g. C.sub.tr,50-5000 is applied to urban traffic noise
with a frequency range of 50 Hz to 5000 Hz. For light timber
constructions C.sub.tr will be negative, indicating the poor sound
insulation abilities of such constructions at low frequencies.
[0160] The sound transmission class (STC) determined according ASTM
E413 is also presented. This is determined by fitting a reference
curve to the third octave band sound reduction indices R from 125
Hz to 4000 Hz, but in a slightly different way to ISO 717-2. The
sound transmission class gives a single figure rating of the sound
reduction through the building element so that higher is
better.
1TABLE 1 Gauge Type Weight Per Thickness Body (8.5 mm) Swelled
anhydrates 1.42 kg/m.sup.2 (i) Face (2 mm) Hardened (EPA) 19
mlt/m.sup.2 (ii) Backing Face (2 mm) 76 mtl/m.sup.2 (iii) Body (8.5
mm) Nil Body gauge surface Fibre-glass strands 220 gms/m.sup.2
[0161]
2TABLE 2 Gauge Type Weight Per Thickness Body (8.5 mm) Swelled
anhydrites 1.54 kg/m.sup.2 (i) Face ((2 mm) Hardener (EPH) 61.7
mlt/m.sup.2 (ii) Body (0.5 mm) 185.2 mlt/m.sup.2 (iii) Backing Face
(2 mm) 61.7 mlt/m.sup.2 (i) Face layer Fiber-glass strands 24
gms/m.sup.2 (ii) Body layer 208 gms/m.sup.2
* * * * *