AU764898B2

AU764898B2 - Acoustic barrier

Info

Publication number: AU764898B2
Application number: AU11400/00A
Authority: AU
Inventors: Nereo Castelli
Original assignee: BARRIERBOARD Pty Ltd
Current assignee: BARRIERBOARD Pty Ltd
Priority date: 1998-10-28
Filing date: 1999-10-21
Publication date: 2003-09-04
Anticipated expiration: 2019-10-21
Also published as: AU1140000A

Description

PCT/AU99/00903 Received 9 June 2000 -1- TITLE: ACOUSTIC BARRIER FIELD OF THE INVENTION The present invention relates to the provision of acoustic barriers, and in particular to the provision of sound barriers in conjunction with walls, ceilings and the like in buildings.

.BACKGROUND OF THE INVENTION 0 Sound sources in homes and apartments need to be isolated so as not to cause annoyance AMENDED SHEET

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PCT/AU99/00903 Received 9 June 2000 -2to people in the house or apartment, or particularly to people in adjacent apartments.

Sound striking a solid surface causes the surface to vibrate,just as sounds striking the ear drum cause it to vibrate.

Impact noise, like footsteps or vibrations from appliances or plumbing can also induce vibrations in a structure.

Sound usually travels better through the structure of a building than through air, so it is necessary to pay attention to the sound insulation qualities of a building to minimise noise transmission.

Sound transmission is affected by the ability of surfaces to reflect sound and by the ability of the structure to absorb it.

Different sounds require different solutions. Impact noise will be directly transmitted through the structure unless it is dissipated or damped.

Airborne noise will be reflected by surfaces but needs to be dissipated by the structure as much as possible, over the range of problem frequencies.

Noise management designs need to take a composite system approach by reducing the sound transmission at all possible leakage points.

Direct leaks through gaps under doors or via flanking paths through ceiling perimeters or wall junctions can have a serious detrimental effect on sound insulation performance of a wall or ceiling.

However, it is also necessary to reduce transmission of airborne noise through walls.

One current method of reducing noise transmission through walls is to provide two wall leaves which are separated by an air gap. That is, two separate but adjacent sets of wall studs and noggings are built, with wall board cladding on the exterior faces of each set.

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S PCT/AU99/00903 Received 9 June 2000 -3- This method has the disadvantages that it is relatively expensive and cannot be retrofitted to abate an existing wall noise without some demolition of existing structures.

An alternative current method of reducing noise transmission through walls is to use furring channels in conjunction with resilient mounts. A furring channel is a metal or timber mounting batten which can be used as a simple spacing frame. Furring channels are generally useful where wall board is used as a facing to a main wall of masonry or brick. Furring channel is fixed (usually screwed) to the reverse side of wallboard, cooperating mountings are mounted on the brick or masonry, and the wallboard is installed in place by clipping the furring channel into the mountings. Noise transmission through the assembly can be reduced by using resilient mountings on the masonry or brick.

However, this method of noise reduction has the relative disadvantages that it cannot be retro-fitted where there is an existing noise problem, it is more difficult and expensive to fit, and the resilient mountings must be properly chosen to be sound attenuating at the weight loading which is imposed by the wall board.

It is accordingly an aim of the present invention to provide a sound barrier which is suitable for use in walls, ceilings and the like.

It is also an aim of the present invention to provide a sound barrier which can be retrofitted to walls in existing buildings or which can be part of the original construction of a building.

SUMMARY OF THE INVENTION The present invention accordingly provides an acoustic barrier which includes: a first wall which has a face which is orientated to the exterior of the barrier and a face which is orientated to the interior of the barrier; a second wall which has a face which is orientated to the exterior of the barrier and a face which is orientated to the interior of the barrier; AMENDED

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•PCT/AU99/00903 Received 9 June 2000 -4a layer of flexible material between the interiorly orientated faces of the first and second walls; and at least one support pad which extends between the first wall and the second wall.

PREFERRED FEATURES OF THE INVENTION It is preferred that the layer of flexible material is a layer of foam material.

It is preferred that the layer of flexible material is adhered to the interiorly orientated faces of the first and second walls. It is particularly preferred that the adhesive used for this be a water based contact adhesive, which is catalyst activated.

Alternative preferred forms of the flexible material include polyurethane foam, acrylic foam, polyester foam, polyester compressed fibre and natural fibre.

It is preferred that each support pad extend from the exterior face of the first wall to the interior face of the first wall, through the layer of flexible material and through the interior face of the second wall.

It is further preferred that each support pad be fabricated from a flexible material.

Alternative preferred materials for the support pads include polyurethane, polyvinyl chloride, synthetic rubber, natural rubber, polypropylene and silicone.

When the acoustic barrier is to be used for soundproofing walls or ceilings, it is preferred that each support pad have a diameter in the range of 8mm to 20mm. When the acoustic barrier is to be used for soundproofing floors, it is preferred that each support pad have a diameter in the range of 15mm to Alternative preferred forms of the first wall and of the second wall include plaster board, particle board, metal, timber and laminated timber.

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PCT/AU99/00903 Received 9 June 2000 Where the first wall and the second wall are of plaster board, it is preferred that the first wall have a thickness in the range of 8mm to 13mm and that the second wall have a thickness in the range 10mm to It is preferred that the layer of flexible material have a thickness in the range 5mm to 12mm.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an acoustic barrier according to one embodiment of the present invention.

Figure 2 is a cross-sectional view on the line 1-1 of Figure 1.

Figure 3 is a cross-sectional view of an acoustic barrier according to another embodiment of the present invention.

In order that the invention may be more readily understood, embodiments of it will now be described with reference to the accompanying drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS An acoustic barrier according to one embodiment of the present invention is indicated generally at 1.

The acoustic barrier 1 includes a first wall 6, a second wall 7 and a layer of flexible material 8. The first wall 6 has a face 11 which faces to the exterior of the barrier 1 and a face 12 which faces to the interior of the barrier 1. Similarly, the second wall 7 has a face 13 which faces to the exterior of the barrier 1 and a face 14 which faces to the interior of the barrier 1.

The first and second walls 6 and 7 are separated by a layer of flexible material 8. The layer of flexible material 8 is adhered to the interior face 12 of the first wall 6 and to the interior face 14 of the second wall 7.

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PCT!AU99/00903 Received 9 June 2000 -6- First wall 6 and the second wall 7 are also preferably connected by at least one support pad 16. According to the embodiment of the invention which is illustrated in the drawings, each support pad 16 extends from the exterior face 11 of the first wall 6, through the layer 8 to the interior face 14 of the second wall 7.

According to alternative embodiments of the invention which are illustrated in Figure 3, each support pad 16 extends from the exterior face 11 of the first wall 6, through the layer 8, through the interior face 14 of the second wall 7 and into the material of the second wall 7, but not through the exterior face 13 of the second wall 7.

The materials of the first and second walls 6 and 7 are chosen to be both dense and stiff relative to the material of the layer of flexible material 8. Suitable materials for the walls 6 and 7 include plaster board, particle board, metal and timber. Suitable materials for the flexible layer 8 include polyurethane foam, acrylic foam, polyester foam, polyester compressed fibre, fibre-glass batting and natural fibre. Suitable materials for the support pads 16 include polyurethane, polyvinyl chloride, synthetic rubber, natural rubber, polypropylene and silicone.

Each of the first wall 6 and the second wall 7 according to the present embodiment is a plaster board in the form of a gypsum cement clad on each side with a layer of paper.

The first wall 6 is 10 Omm thick, and the second wall 7 is 16mm thick. The layer of flexible material 8 according to the present embodiment is a layer of polyurethane foam which is 6mm thick. The support pads 16 according to the present embodiment are of polyurethane and are circular in cross section with a diameter of 15mm. They are placed in staggered rows on 30cm centres, with 15cm spacing between the rows. The support pads 16 according to this embodiment protrude a distance of 7mm into the second wall 7. When an acoustic barrier according to this embodiment of the invention is used as a wall cladding, it provides an average sound attenuation of between 8dB to 20dB over a frequency range from 125Hz to 4,000Hz.

The acoustic barrier 1 is fabricated by providing the second wall 7, and then adhering a layer of flexible material 8 to it. The first wall 6 is then adhered to the flexible material AMENDED SHEET

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PCT/AU99/00903 Received 9 June 2000 -7- 8. Bores are then made through the first wall 6 and the layer of flexible material 8 to the second wall 7. The support pads 16 are then moulded in the bores thus provided.

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EDITORIAL NOTE APPLICATION NUMBER 11400/00 This specification does not contain a page(s)

Claims

2. An acoustic barrier as claimed in Claim 1, wherein each support pad has a 'diameter in the range of 8mm to
3. An acoustic barrier as claimed in any one of the preceding claims wherein the layer of flexible material is a layer of foam material.
4. An acoustic barrier as claimed in any one of the preceding claims wherein the layer of flexible material is adhered to the interiorly orientated faces of the first and second walls. An acoustic barrier as claimed in Claim 4 wherein the adhesion between the layer of flexible material and the interiorly orientated faces of the first and second walls is produced by a water based contact adhesive which is catalyst activated.
6. An acoustic barrier as claimed in any one of the preceding claims wherein the flexible material is a material chosen from the group consisting of polyurethane foam, acrylic foam, polyester foam, polyester compressed fibre and natural fibre. SUBSTITUTE SHEET (RULE 26) WO 00/24979 PCT/AU99/00903
7. An acoustic barrier as claimed in any one of the preceding claims wherein the layer of flexible material has a thickness in the range 5mm to 12mm.
8. An acoustic barrier as claimed in any one of Claims 1 to 7 wherein each support pad extends from the exterior face of the first wall to the interior face of the first wall, through the layer of flexible material and through the interior face of the second wall.
9. An acoustic barrier as claimed in any one of Claims 1 to 8 wherein each support pad consists of a flexible material. An acoustic barrier as claimed in Claim 9 wherein the flexible material is a material chosen from the group consisting.of polyurethane, polyvinyl chloride, synthetic rubber, natural rubber, polypropylene and silicone.
11. An acoustic barrier as claimed in any one of the preceding claims wherein the first wall is composed of a material which is a material chosen from the group consisting of plaster board, particle board, metal and timber.
12. An acoustic barrier as claimed in any one of the preceding claims wherein the second wall is composed of a material which is a material chosen from the group consisting of plaster board, particle board, metal and timber.
13. An acoustic barrier as claimed in any one of the preceding claims, substantially as described with reference to the drawings.
14. An acoustic barrier, substantially as described with reference to the drawings. SUBSTITUTE SHEET (RULE 26)