US20110284320A1

US20110284320A1 - Acoustic attenuation system

Info

Publication number: US20110284320A1
Application number: US13/061,737
Authority: US
Inventors: Anthony C. Bongiovi; Herman Novak
Original assignee: Baltek Inc
Current assignee: Baltek Inc
Priority date: 2008-09-03
Filing date: 2009-08-21
Publication date: 2011-11-24
Also published as: WO2010027699A1

Abstract

An acoustic attenuation system and a method for attenuating or isolating vibration, including one or more multilayer laminate sheets having at least one rigid layer and at least one soft layer. The rigid layer may contain urethane foam, fibrous material and optionally other fillers, while the soft layer may be made of open or closed cell polymeric foam. The attenuation system includes the laminate sheets in place of or in addition to building partition materials such as flooring, drywall, and the like. In addition, the laminate sheets may be used to isolate vibration from transferring beyond objects, for example amplifiers, speakers, musical instruments and mechanical equipment located on surfaces or floors. Further, the laminate sheets may be used as exercise boards to protect the joints of the exerciser as well as isolate vibration created during physical training on the board.

Description

FIELD OF THE INVENTION

This invention relates to materials and methods for acoustic attenuation. In particular, this invention relates to laminate sheets for attenuating or isolating vibration.

BACKGROUND OF THE INVENTION

Many objects produce vibration in the form of audible and/or mechanical vibration, such as audio speakers, musical instruments, and mechanical equipment. In addition, the movements and speech of humans also produce vibration. The transmission of such vibrations between rooms or through surfaces can cause disruption to occupants of the space.
Current partitions between rooms in a building provide some dampening and isolation of vibration, but may not be sufficient, especially in the case of a home theater, recording studio, multi-family housing, gymnasium, etc. Accordingly, it is desirable to decrease the amount of noise and/or vibrations that could be passed through surfaces or building partitions using laminate materials in place of and/or in addition to standard materials. Features and advantages of the invention or of certain embodiments of the invention will be apparent to those of skill in the art from the following disclosure and description of exemplary embodiments.

SUMMARY OF THE INVENTION

In accordance with a first aspect, an acoustic attenuation system is provided comprising at least one laminate sheet having a urethane foam sheet and a soft foam layer. Certain embodiments of the acoustic attenuation system disclosed herein include a laminate sheet that comprises two urethane foam sheets with a soft foam layer disposed between the urethane sheets. The at least one urethane sheet may have a density between about 9 pounds per cubic foot and 100 pounds per cubic foot.
In accordance with another aspect, a method for attenuating vibration is provided. In an embodiment, the method includes the steps of providing at least one laminate sheet comprising two urethane foam sheets with a soft foam layer disposed between the urethane sheets, then affixing at least one laminate sheet to a building structure such as a wall or wall framing, a floor or floor framing, and/or a ceiling or ceiling framing. In certain embodiments of the invention, the acoustic attenuation system exhibits a sound transmission class (STC) of at least 50.
In accordance with a further aspect, a method for isolating vibration is provided. The method comprises the steps of providing at least one laminate sheet having a urethane foam sheet and a soft foam layer and placing at least one object that produces vibration on the laminate sheet. In certain aspects of the invention, the at least one object may be a musical instrument, an amplifier or an audio speaker.
In accordance with yet a further aspect, an exercise board is provided comprising a laminate sheet having a urethane foam sheet and a soft foam layer. In an embodiment according to the invention, the exercise board may comprise a fabric cover that covers at least one outer surface of the laminate sheet.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

It should be understood that acoustic attenuation systems in accordance with this disclosure may have any of numerous different specific compositions or structures. The composition of an acoustic attenuator may vary to a certain extent, depending upon such factors as the product's desired characteristics, such as density. For example, the amount of urethane included in the urethane foam may be selected based on the desired density, or fillers may be added to any of the laminate layers to provide additional density to the system. In general, an acoustic attenuation system in accordance with this disclosure typically comprises at least urethane foam, a filler material and a soft material such as a foam or adhesive. Additional and alternative suitable components will be recognized by those skilled in the art given the benefit of this disclosure.
It has been discovered that vibrations may be attenuated using a structural composite material, such as a laminate sheet, that comprises a combination of at least one substantially rigid layer and at least one soft layer. In particular, the at least one rigid layer may comprise urethane that has been cured into a foam, for example a polyurethane foam having isocyanate groups. As used herein, the term “rigid” refers to a material that maintains its shape when subjected to a compression force. The soft layer may comprise a resilient polymeric material or adhesive. As used herein, the term “soft” refers to a material that deflects when subjected to a compression force. The soft layer may be disposed on an outer surface of one rigid layer or in between two rigid layers. The combination of the soft and rigid layers provides the dual functions of vibration absorption and isolation.
The urethane foam may also include filler comprising fibrous material, such as glass. For example, the urethane foam may contain one or more of continuous strand non-woven glass, lofted glass, woven glass, or combinations thereof. In an embodiment, the urethane foam comprises one layer of lofted glass disposed between two layers of continuous strand non-woven glass. The fibrous material may include spaces between some of the individual fibers such that the urethane will fill the open areas as it cures into the foam. Further, the location of the fibrous material within the urethane sheet is configured such that urethane foam substantially completely surrounds the layers of fibrous material.
The rigid layer may further comprise filler materials to provide additional weight to the rigid layer. In addition, these fillers may provide discrete particles, grids or sheets off of which acoustic waves may bounce as they travel through the rigid layer. The interference caused by the fillers in the rigid layer may cause individual waves to scatter or travel in different directions. As a result, one wave may cancel out another wave, thereby attenuating some of the waves and minimizing the amount of vibration that may pass through the rigid layer. Filler material may be selected from the group consisting of calcium carbonate, thermoplastic dust, Balsa wood dust, urethane sanding dust, wood chips, tires, ceramics, aluminum, copper, iron, lead, steel, basalt, granite, Woolastonite, Cinnabar, gypsum, limestone, potash, dry sand, gravel, metal sheets, metal screens, fiberglass screens and combinations thereof.
The rigid layer may have a density of between about 9 pounds per cubic foot and about 100 pounds per cubic foot. In certain embodiments, a rigid layer has a density of about 20 pounds per cubic foot, while in an alternate embodiment according to the present invention, a rigid layer has a density of about 48 pounds per cubic foot. A rigid layer may be prepared to have any specific density desired, such as by selecting the amount of liquid urethane to include in the rigid layer. Further, the density of a rigid layer may be increased by incorporating fillers, examples of which are disclosed above. The optimal density of a rigid layer typically depends on the intended use for the laminate sheet. Generally, the greater the amount of vibration to be attenuated, the higher the density required to provide an effective acoustic attenuation system.
The rigid layer may also include various other materials, such as electrical components built into the layer during the molding process. Electrical wiring, such as Belden 8451 wiring, or microphone cables, for instance, may be incorporated into the rigid layer as would be convenient for the particular application.
The soft layer may comprise any suitable material that is capable of absorbing vibration and physically distorting when subjected to a vibration, such as an open cell or closed cell foam. The soft layer may comprise an elastomer, for example. In certain embodiments of the invention, the soft layer comprises a material selected from the group consisting of neoprene, ethylene propylene diene, styrene butadiene rubber, polyvinyl chloride, nitrile, polyethylene, ethylene vinyl alcohol, and combinations thereof. The soft layer may have a density of between about 3.5 and 16 pounds per cubic foot, depending on the material used to form the soft layer.
Alternatively, the soft layer may comprise an adhesive material, such as an adhesive that comprises a filler material selected from the group consisting of calcium carbonate, thermoplastic dust, Balsa wood dust, urethane sanding dust, wood chips, tires, ceramics, aluminum, copper, iron, lead, steel, basalt, granite, Woolastonite, Cinnabar, gypsum, limestone, potash, dry sand, gravel, metal sheets, metal screens, fiberglass screens and combinations thereof. Added fillers increase both the density and the viscosity of the adhesive. In certain embodiments, the adhesive may have a Shore A hardness between about 10 and 80, as determined by ASTM method D2240-00. Shore A hardness is a measurement of the resistance of plastics to indentation, and the Shore A hardness chosen for a soft layer will depend on the characteristics required for the particular application. As discussed above, the filler material may also provide the dual functions of increasing the weight of the layer and attenuating vibration waves.
In certain embodiments, laminate sheets further comprise a polymeric layer, such as including polypropylene, polyethylene, polyethylene terephthalate, and/or acrylonitrile butadiene styrene, and filled with glass and/or other fillers as disclosed above. The particular fillers employed are selected to match the thermal coefficient of linear expansion of the polymeric layer and the rigid layer of the laminate sheet. A polymeric layer included in the laminate sheet may be affixed to other layers using any adhesive capable of holding the layers together and having a final density and hardness appropriate for the acoustic attenuation requirements of the intended use of the laminate sheet.
Laminate sheets may be produced by any suitable method. In an embodiment, laminate sheets may be prepared in a mold, by first placing any fibrous material in the mold. If other fillers are being used, they are mixed with the liquid urethane, which is then cast into the mold. Any size mold may be employed depending on the size sheet desired. For example, a mold may be used that will provide a laminate sheet having final dimensions of about ¾ inch×48 inches×96 inches. A soft layer may then be placed on top of the urethane. The mold is placed into a press, where it is held until the urethane cures, typically eight to ten minutes. The press may be either heated or cooled during curing if desired. Next, the laminate sheet is removed from the mold and any excess urethane, or flash, is trimmed off of the sheet. Optionally, one or more outer surfaces of the laminate sheet may be sanded, for instance to provide a surface suitable for adhering to another material.
In an embodiment, the rigid layer is prepared separately from the soft layer. In such an embodiment the steps are the same except that the soft layer is not placed in the mold. Once the rigid layer has been trimmed and sanded, a soft layer may then be affixed to the rigid layer with an adhesive to complete the laminate sheet. Any suitable adhesive may be used that will adhere the soft and rigid layers together, such as a contact cement of polyurethane adhesive. One suitable polyurethane adhesive is Gorilla Glue, which is commercially available from The Gorilla Glue Company, Cincinnati, Ohio. It is important only that the outer surfaces of the soft and rigid layers of the laminate sheet are disposed directly adjacent to each other to provide substantially complete contact between the surfaces of the two layers.
In certain embodiments, laminate sheets according to the present invention comprise a soft layer disposed between two rigid layers to provide a three layer laminate sheet. In such embodiments, each layer may be formed separately and adhered together, or alternatively the first rigid layer and the soft layer may be formed together as described above. In this case, the second rigid layer is formed separately, trimmed and sanded, then adhered to an outer surface of the soft layer. Any number of rigid and soft layers may be employed in laminate sheets of the present invention depending on the intended use and desired characteristics of the laminate sheets.
In an aspect of the invention, an acoustic attenuation system is provided, comprising at least one laminate sheet as disclosed in detail above. One or more layers of the at least one laminate sheet may be affixed to at least one building structure, such as a structure selected from the group consisting of floor framing, ceiling framing, wall framing, a floor, a ceiling and a wall. Floor framing may comprise trusses or joists, such as wood trusses configured to support a floor surface or subfloor surface. Typically, a floor or subfloor is affixed to the floor framing with connectors such as screws, nails, and the like. Similarly, wall framing or ceiling framing may comprise studs, joists or rafters, such as wood pieces configured to hold a wall surface or ceiling surface, respectively, in place with the use of connectors. Wall and ceiling surfaces are generally secured in place using screws, nails, adhesive tape, etc. In one embodiment, a laminate sheet comprising two rigid layers on either side of a soft rubber layer may be placed on a 2×6 floor joist framing to isolate any vibration to which the floor is subjected.
Accordingly, the at least one laminate sheet may be used in place of plywood, drywall, or other typical floor, wall and/or ceiling materials to prevent vibration from being transferred through the floor, wall and/or ceiling. Further, insulation may be provided between the floor, wall and/or ceiling frame and the at least one laminate sheet. If a laminate sheet needs to be cut to a particular shape or smaller size, a circular saw may be used having a carbide-tipped saw blade.
In another aspect, at least one laminate sheet may be disposed on both sides of a floor, wall, and/or ceiling frame. For example, in a two-story building structure, laminate sheets prepared according to embodiments of the invention may be employed as at least a portion of the ceiling surface of the first story and as at least a portion of the floor surface of the second story, directly above the laminate sheet used in the first story. Likewise, laminate sheets may be affixed to either side of a wall frame, for example onto the studs of adjacent rooms in a building.
In an alternate embodiment, the at least one laminate sheet may be disposed adjacent to or affixed to an existing partition, such as a floor, wall and/or ceiling surface, to provide greater acoustic attenuation than achieved with the use of only a laminate sheet or the existing partition. For example, a soft rubber layer between about ⅜ inches and 2 inches thick may be placed on an existing floor, with a ¾ inch rigid layer having a density of about 20 pounds per cubic foot placed on the rubber layer to isolate vibration from transferring to the room directly below it. In another embodiment, one or more laminate sheets may be affixed to either side of a floor surface, a wall surface and/or a ceiling surface. Accordingly, the at least one laminate sheet may be used in addition to a partition. In another embodiment, the at least one laminate sheet may be used both in place of a standard partition surface and in addition to a partition surface within a structure to attenuate vibration.
In another aspect of the invention, a vibration isolator is provided. A vibration isolator may be used to minimize the transfer of vibration from a source object. For example, an amplifier or audio speaker placed on a table surface may transfer acoustic and mechanical vibration from the amplifier or speaker to the table. A laminate sheet prepared according to various embodiments of the invention may be employed as a vibration isolator in such an example, simply by placing a laminate sheet between the amplifier or audio speaker and the table surface. Of course, one or more laminate sheets may be used to isolate vibration from various other source objects, such as musical instruments or motorized equipment. In an embodiment, at least one laminate sheet may be placed on the floor surface of a room and a drum set may be set up on top of the at least one laminate sheet. In a further embodiment, a musician playing an instrument such as a guitar, may have his amplifier positioned on a laminate sheet of the present invention to decrease the transfer of any vibration that may emanate while playing the musical instrument.
In a further aspect of the invention, an exercise board is provided. An exercise board comprising at least one laminate sheet prepared according to embodiments of the invention may be employed during physical training exercises such as aerobics, pilates, yoga, free weights, jogging or running in place, calisthenics, and the like. The soft layer of the at least one laminate sheet provides cushioning to protect the joints of a person exercising on the board. Further, the combination of the soft and one or more rigid layers of the at least one laminate sheet isolates any noise or other vibration generated during performance of the exercise from the floor surface on which the exercise board has been placed. The rigid layer will disrupt vibration generated by the vertical and horizontal impact energy of the person exercising and attenuate the vibration. The exercise board may have a thickness of between about ¼ inch and about 2 inches and may have a density between about 9 and 100 pounds per cubic foot. The exercise board may further comprise a cover, for example a sturdy fabric cover included over at least one outer surface of a laminate sheet to protect the laminate sheet and to provide a comfortable surface on which to exercise. In an embodiment, the at least one laminate sheet comprises a cover that surrounds the entire sheet. Any suitable material may be used as a cover, and the cover may further be removable and washable.

EXAMPLES

The following examples are specific embodiments of the present invention but are not intended to limit it.

Example 1

A laminate sheet was prepared according to a method of the present invention. An aluminum mold was provided having outer dimensions of 50.5 inches wide, 98.5 inches long and 1 inch deep. The inner dimensions of the mold were 48.5 inches wide, 96.5 inches long and 0.81 inches deep. First, a layer of continuous strand non-woven glass weighing 3 pounds was placed in the bottom of the mold, followed by 1.5 pounds of lofted glass in a 2 inch thick layer. Another 3 pound layer of continuous strand non-woven glass was placed on top of the lofted glass layer. Next, 99.5 pounds of methylene diphenyl diisocyanate (MDI) urethane was poured into the mold. The mold was then placed into a press containing the mold lid and contained for over eight minutes until the MDI urethane cured into solid foam. The material was removed from the mold, the flash was trimmed off, and the sheet was sanded with 36 grit sandpaper in a widebelt sander, then squared. Last, a 97 inch long layer of soft closed-cell foam was affixed to the urethane sheet using polyurethane adhesive.
The laminate sheet comprised a ¾ inch urethane foam sheet having a density of 48 pounds per cubic foot, with a layer of ½ inch closed cell polyvinyl chloride/nitrile/neoprene foam having a density of between about 3.5 and 5.5 pounds per cubic foot adhered to the urethane foam sheet, providing a final thickness of 1.25 inches.

Example 2

A laminate sheet comprising two ¾ inch urethane foam sheets each having a density of 48 pounds per cubic foot, with a layer of ½ inch closed cell polyvinyl chloride/nitrile/neoprene foam disposed between the urethane foam sheets was prepared according to an embodiment of the invention. The first urethane foam sheet was produced in accordance with the method of Example 1 except that a layer of ½ inch soft closed cell foam was placed in the mold on the liquid urethane prior to the step of pressing. Further, a second urethane sheet was prepared according to the method of Example 1 and then affixed to the soft foam layer by placing Gorilla Glue on an outer surface of the second urethane sheet and misting water on the outer surface of the soft foam layer. The glued surface of the second urethane sheet was placed on top of the water-misted surface of the soft foam layer and the laminate sheet was weighted with about fifty pounds and allowed to cure for approximately forty-eight hours. Excess soft foam was then trimmed around the perimeter of the 4 foot×8 foot laminate sheet.

Example 3

A laminate sheet comprising one ¾ inch urethane foam sheet having a density of 20 pounds per cubic foot, with a layer of ½ inch closed cell polyvinyl chloride/nitrile/neoprene foam disposed on an outer surface the urethane foam sheets was prepared according to the method of Example 1 except that instead of using 99.5 pounds of liquid MDI urethane, only 38.3 pounds of MDI urethane was added to the glass layers in the mold. All of the other steps were the same, and the resulting urethane foam sheet had a density of 20 pounds per cubic foot.

Example 4

A laminate sheet was prepared according to an embodiment of the present invention, having a thickness of 2 inches. The laminate sheet comprised two ¾ inch urethane foam sheets each having a density of 48 pounds per cubic foot, with a layer of ½ inch closed cell polyvinyl chloride/nitrile/neoprene foam disposed between the urethane foam sheets. The urethane foam contained two layers of continuous strand non-woven glass with a layer of lofted glass, with urethane foamed into the spaces within and surrounding the glass layers. The entire three-layer laminate sheet had a weight of 6.56 pounds per square foot.
The laminate sheet was tested according to ASTM method E90-04 to determine the sound transmission class (STC) of the laminate sheet. Measurement of STC provides a rating that may be used to compare the acoustic insulating capability of a material, and the higher the STC rating, the greater the ability of a material to insulate acoustic vibration. The test involved mounting the laminate sheet, and perimeter sealing it, as a partition between two reverberation rooms. Sound was introduced in the source room and sound measurements were taken in the receiving room. For ASTM method E90-04, the laminate sheet is placed on a ⅝ inch thick plywood subfloor over the floor and ceiling framing, which includes wood floor trusses and single leaf resilient channels. Insulation was also provided between the plywood and a ⅝ inch gypsum board ceiling.
The results of the test are displayed below in Table 1. The three-layer laminate sheet exhibited a sound transmission class of 55, both when tested without a load and when tested having a one thousand pound load placed on the laminate sheet. In contrast to the laminate sheet, a ⅝ inch layer of plywood exhibited a STC of 49.

TABLE 1

Results of ASTM test E90-04 for a three-layer laminate sheet of
the invention.

			Three layer
		Three layer	Laminate Sheet
		Laminate Sheet	(Having two ¾
		(Having two ¾	Inch Rigid
		Inch Rigid	Layers With
		Layers With	48 Pounds
	⅝-Inch	48 Pounds	Per Cubic Foot
⅓ Octave Band	Thick	Per Cubic Foot	Density) Loaded
Center Frequency	Plywood	Density)	with 1000 lbs

(Hertz)	Sound Transmission Loss (dB)

80	23	29	33
100	27	33	35
125	28	34	34
160	26	43	43
200	39	42	42
250	38	41	42
315	40	43	45
400	44	50	50
500	48	52	52
630	51	58	58
800	55	59	61
1000	57	64	64
1250	56	67	66
1600	57	67	69
2000	51	63	64
2500	50	62	65
3150	54	68	68
4000	56	64	67
5000	58	65	67
Sound	49	55	55
Transmission Class

Example 5

A laminate sheet was prepared according to an embodiment of the present invention, having a thickness of 2 inches. The laminate sheet comprised two ¾ inch urethane foam sheets each having a density of 48 pounds per cubic foot, with a layer of ½ inch closed cell polyvinyl chloride/nitrile/neoprene foam disposed between the urethane foam sheets. The urethane foam contained two layers of continuous strand non-woven glass with a layer of lofted glass, with urethane foamed into the spaces within and surrounding the glass layers. The entire three-layer laminate sheet had a weight of 6.56 pounds per square foot.
The laminate sheet was tested according to ASTM method E492-04 to determine the impact insulation class (IIC) of the laminate sheet. Measurement of IIC provides a rating that may be used to compare the impact insulating capability of a material, and the higher the IIC rating, the greater the ability of a material to insulate impact sounds. The test involved mounting the laminate sheet, and perimeter sealing it, as a partition between two rooms. A standard tapping machine (a Bruel & Kjaer Type 3207) was placed at four positions on the test floor and sound measurements were taken in the room directly below the source room. For ASTM method E492-04, the laminate sheet is placed on a ⅝ inch thick plywood subfloor over the floor and ceiling framing, which includes wood floor trusses and single leaf resilient channels. Insulation was also provided between the plywood and a ⅝ inch gypsum board ceiling.
The results of the test are displayed below in Table 2. The three-layer laminate sheet exhibited an impact insulation class of 52, both when tested without a load and when tested having a one thousand pound load placed on the laminate sheet. In contrast to the laminate sheet, a ⅝ inch layer of plywood exhibited an IIC of 43.

TABLE 2

Results of ASTM test E492-04 for a three-layer laminate
sheet of the invention.

			Three layer
		Three layer	Laminate Sheet
		Laminate Sheet	(Having two ¾
		(Having two ¾	Inch Rigid Layers
		Inch Rigid Layers	With 48 Pounds
		With 48 Pounds	Per Cubic Foot
	⅝-Inch Thick	Per Cubic Foot	Density) Loaded
⅓ Octave Band	Plywood	Density)	with 1000 lbs

Center Frequency	⅓ Octave Band Sound Pressure Level
(Hertz)	(dB re 0.002 Microbar)

100	74	64	63
125	70	62	61
160	72	62	62
200	70	62	62
250	70	62	62
315	71	63	62
400	71	61	62
500	70	59	61
630	68	57	58
800	63	54	54
1000	58	49	48
1250	56	47	46
1600	55	46	45
2000	57	48	47
2500	57	46	45
3150	52	38	37
Impact	43	52	52
Insulation Class

Example 6

Several laminate sheets were prepared according to an embodiment of the present invention, each having a thickness of 2 inches. The laminate sheets each comprised two ¾ inch urethane foam sheets each having a density of 48 pounds per cubic foot, with a layer of ½ inch closed cell polyvinyl chloride/nitrile/neoprene foam disposed between the urethane foam sheets. The urethane foam contained two layers of continuous strand non-woven glass with a layer of lofted glass, with urethane foamed into the spaces within and surrounding the glass layers. Each three-layer laminate sheet had a weight of 6.56 pounds per square foot.
The laminate sheets were tested according to ASTM method E90-2004 to determine the sound transmission class (STC) of the laminate sheets in different wall configurations. The test involved mounting the laminate sheet, and perimeter sealing it, as a partition between two reverberation rooms. Sound was introduced in the source room and sound measurements were taken in the receiving room.
For wall configuration #1, the laminate sheet and one layer of ⅝ inch drywall were placed on either side of a 2×4 inch framing with studs 16 inches on center, with one layer of R-13 insulation between the studs.
For wall configuration #2, two laminated sheets were placed in the middle of a 2×4 inch framing and one layer of ⅝ inch drywall was placed on either side of the framing.
For wall configuration #3, one layer of ⅝ inch drywall and one laminated sheet were placed on one side of a 2×4 inch framing with no studs, and three layers of R-13 insulation with staggered directions and one layer of ⅝ inch drywall were placed on the other side of the framing.
For wall configuration #4, two layers of ⅝ inch drywall were placed on either side of 2×4 framing with studs 16 inches on center, with 1 layer of R-13 insulation between the studs.
For wall configuration #5, one laminated sheet and one layer of ⅝ inch drywall were placed on one side of a 2×4 framing with studs 16 inches on center and two layers of ⅝ inch drywall was placed on the other side, with one layer of R-13 insulation between the studs.
For wall configuration #6, one laminated sheet and one layer of ⅝ inch drywall were placed on each side of a 2×4 framing with studs 24 inches on center, with one layer of R-13 insulation between the studs.
The results of the test are displayed below in Table 3. Wall configuration #6 exhibited the highest sound transmission class, with an STC of 56. In contrast to the use of a laminate sheet and a layer of drywall on either side of a framing, wall configuration # 4, without any laminated sheets, exhibited the lowest STC of 42.

TABLE 3

Results of ASTM test E90-2004 for a three-
layer laminate sheet of the invention.

⅓ Octave
Band
Center	Wall	Wall	Wall	Wall	Wall	Wall
Frequency	#1	#2	#3	#4	#5	#6

	(Hertz)	Sound Transmission Loss (dB)

80	28	26	29	23	25	31
100	33	29	30	24	31	35
125	32	33	37	21	32	37
160	35	34	38	21	37	39
200	38	36	40	31	37	42
250	41	36	42	39	42	47
315	43	36	43	38	42	48
400	46	37	45	41	45	50
500	48	38	47	44	46	52
630	50	37	49	47	48	54
800	51	36	51	48	50	57
1000	51	38	53	51	51	60
1250	53	41	54	54	54	64
1600	54	45	55	56	56	65
2000	54	48	56	51	53	67
2500	56	51	58	47	54	66
3150	60	54	65	52	59	70
4000	62	57	68	56	62	71
5000	64	61	68	60	63	73
STC	50	45	51	42	50	56

While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. Variations and modifications of the foregoing are within the scope of the present invention. It is also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.

Claims

1. An acoustic attenuation system comprising at least one laminate sheet comprising:

a first urethane sheet comprising:

a first layer of a first fibrous material;

a second layer of a first fibrous material;

a layer of second fibrous material disposed between the first and second layers of a first fibrous material; and

urethane foam disposed within and substantially surrounding the first and second fibrous materials; and

a layer of soft foam disposed on an outer surface of the first urethane sheet.

2. The acoustic attenuation system of claim 1, wherein the at least one laminate sheet further comprises a second urethane sheet, wherein the layer of soft foam is disposed between the first and second urethane sheets, the second urethane sheet comprising:

a first layer of a first fibrous material;

a second layer of a first fibrous material;

a layer of a second fibrous material disposed between the first and second layers of a first fibrous material; and

urethane foam disposed within and substantially surrounding the first and second fibrous materials.

3. The acoustic attenuation system of claim 2, wherein the first urethane sheet has a density between about 9 pounds per cubic foot and about 100 pounds per cubic foot.

4. The acoustic attenuation system of claim 3, wherein the first urethane sheet has a density of about 20 pounds per cubic foot.

5. The acoustic attenuation system of claim 3, wherein the first urethane sheet has a density of about 48 pounds per cubic foot.

6. The acoustic attenuation system of claim 5, wherein the at least one laminate sheet has a sound transmission class (STC) of at least 50 when tested according to ASTM method E90-04, E90-2004 or E492-04.

7. The acoustic attenuation system of claim 1, wherein the first fibrous material comprises continuous strand non-woven glass and the second fibrous material comprises lofted glass.

8. The acoustic attenuation system of claim 1, wherein the soft foam comprises a material selected from the group consisting of neoprene, ethylene propylene diene, styrene butadiene rubber, polyvinyl chloride, nitrile, polyethylene, ethylene vinyl alcohol, and combinations thereof.

9. The acoustic attenuation system of claim 1, wherein the soft foam layer is affixed to the outer surface of the first urethane sheet with an adhesive.

10. The acoustic attenuation system of claim 9, wherein the adhesive comprises at least one filler material that attenuates sound, the at least one filler material selected from the group consisting of calcium carbonate, thermoplastic dust, Balsa wood dust, urethane sanding dust, wood chips, tires, ceramics, aluminum, copper, iron, lead, steel, basalt, granite, Woolastonite, Cinnabar, gypsum, limestone, potash, dry sand, gravel, metal sheets, metal screens, fiberglass screens and combinations thereof.

11. The acoustic attenuation system of claim 1, wherein the first urethane sheet further comprises a filler material selected from the group consisting of calcium carbonate, thermoplastic dust, Balsa wood dust, urethane sanding dust, wood chips, tires, ceramics, aluminum, copper, iron, lead, steel, basalt, granite, Woolastonite, Cinnabar, gypsum, limestone, potash, dry sand, gravel, metal sheets, metal, screens, fiberglass screens and combinations thereof.

12. A method for attenuating vibration comprising the step of: affixing at least one laminate sheet comprising:

a first urethane sheet comprising:

a first layer of a first fibrous material;

a second layer of a first fibrous material;

a layer of soft foam disposed on an outer surface of the first urethane sheet to at least one structure selected from the group consisting of a floor framing, a ceiling framing, a wall framing, a floor, a ceiling and a wall.

13. The method of claim 12, wherein the wall framing comprises at least one stud comprising wood or metal.

14. The method of claim 13, wherein the wall framing further comprises an insulator.

15. The method of claim 12, wherein the wall comprises at least one layer of drywall.

16. The method of claim 12, wherein the floor framing comprises at least one wood truss.

17. The method of claim 12, wherein the ceiling framing comprises at least one wood joist.

18. The method of claim 12, wherein the at least one laminate sheet further comprises a second urethane sheet, wherein the layer of soft foam is disposed between the first and second urethane sheets, the second urethane sheet comprising:

a first layer of a first fibrous material;

a second layer of a first fibrous material;

19. The method of claim 12, wherein the first urethane sheet has a density between about 9 pounds per cubic foot and about 100 pounds per cubic foot.

20. An exercise board comprising at least one laminate sheet comprising:

a urethane sheet comprising:

a first layer of a first fibrous material;

a second layer of a first fibrous material;

a layer of soft foam disposed on an outer surface of the first urethane sheet.

21. The exercise board of claim 20, further comprising a fabric cover disposed over at least one outer surface of the at least one laminate sheet.

22. A method for isolating vibration comprising the step of:

placing at least one object on an outer surface of at least one laminate sheet comprising:

a urethane sheet comprising:

a first layer of a first fibrous material;

a second layer of a first fibrous material;

a layer of soft foam disposed on an outer surface of the first urethane sheet;

wherein the at least one object is capable of producing vibration.

23. The method of claim 22, wherein the at least one object is selected from the group consisting of at least one drum, at least one guitar, at least one amplifier, at least one audio speaker and combinations thereof.