GB2375358A

GB2375358A - Sound attenuating board

Info

Publication number: GB2375358A
Application number: GB0109961A
Authority: GB
Inventors: Julian Donnelly
Original assignee: SOUND REDUCTION SYSTEMS Ltd
Current assignee: SOUND REDUCTION SYSTEMS Ltd
Priority date: 2001-04-24
Filing date: 2001-04-24
Publication date: 2002-11-13
Anticipated expiration: 2021-04-24
Also published as: GB0109961D0; GB2375358B

Abstract

A sound attenuating board comprises a sheet of polymeric material 1, preferably a mineral loaded PVC, sandwiched between first and second panels of plaster or cement based materials 2 and 3. The plaster or cement based panels 2 and 3 differ in thickness and/or composition so that all three layers of the board have different sound attenuating properties.

Description

SOUND ATTENUATING BOARD The present invention relates to a sound attenuating board and in particular to a sound attenuating building board. More particularly, but not exclusively, the invention provides a building board for incorporation in a wall structure (for instance as a wall liner) and to a wall structure comprising such boards.

There are a variety of different types of building board currently available, including plasterboard and cement boards. Plasterboard for instance simply comprises a panel of gypsum plaster covered on both sides by a thin sheet of paper. Plasterboard is commonly used to construct non-load bearing walls (such as office partitions) and for lining existing wall structures both to provide a good finish and to provide some sound insulation.

It is known to improve the sound insulating properties of a wall comprising plasterboard by fixing a sheet of relatively dense polymeric material, such as mineral loaded PVC, to the plasterboard wall structure. It is also known to provide prefabricated composite sound attenuating building boards comprising a layer of felt, mineral fibre or polystyrene bonded to plasterboard.

It is an object of the present invention to provide a sound attenuating board, and in particular a prefabricated composite building board, which has improved sound attenuating properties compared to the conventional boards mentioned above.

According to a first aspect of the present invention there is provided a sound attenuating board comprising a sheet of polymeric material layered with first and second panels of plaster or cement based material, said first and second panels differing in thickness and/or composition.

The present invention provides a multi-layer composite board comprising three layers each having different sound attenuating properties which combine to provide total sound attenuation far superior to that of the conventional boards mentioned above. Specifically, the polymeric material is relatively dense and thus has completely different sound attenuating properties to the cement/plaster panels. In addition, by ensuring that the two panels have either a different composition and/or a different thickness each panel will have a different resonant frequency. The resonant frequency of each panel can be regarded as the frequency around which most sound is

transmitted, i. e. a frequency at which sound attenuation is least effective. By ensuring that the two panels have different resonant frequencies the combined effect together with the polymeric sheet is to provide good sound attenuation across a wide range of frequencies.

The sound attenuation is improved by ensuring that the resonant frequencies of each panel are well separated. Accordingly, in preferred embodiments the panels have different compositions and different thicknesses. For instance, one panel preferably comprises a plaster based material and the other a cement based material.

In this embodiment the plaster based panel is preferably thicker than the cement panel.

The polymeric sheet is preferably sandwiched between the first and second panels. This both provides a board which has a good surface finish on both sides (beneficial in walling applications) and takes full advantage of the good intrinsic damping of the polymeric material. That is, the polymeric material will dampen resonant vibrations in each of the panels providing additional sound attenuation.

The polymeric material is preferably a dense mineral loaded polymeric material, such as mineral loaded PVC having a density in the region of 7.5kg per

square meter and a thickness of the order of 3mm. The thickness may, however, vary from less than Imm up to about 12mm and the density may similarly vary. It is envisaged that conventional polymeric sound attenuating sheet material may be incorporated in the invention, such sheet material being readily available and in common use in sound proofing floor systems.

The plaster/cement panels are preferably gypsum plaster/portland cement based materials. It is also preferred that the plaster/cement panels are fibre reinforced. For instance, in a preferred embodiment the first panel is gypsum fibre board. This is commercially available in a thickness range of about 6mm to 20mm which is appropriate for incorporation in the present invention. Similarly, fibre reinforced cement board is commercially available in a thickness range typically of the order of 2 to 10mm which is also appropriate for incorporation in the present invention.

Thus, the sound attenuating boards according to the present invention can be readily fabricated by bonding together layers of commercially available material. For instance the panels may be glued together using a suitable adhesive.

According to a second aspect of the present invention there is provided a method of manufacturing a pre-fabricated sound attenuating board, the method comprising bonding a sheet of polymeric material to first and second panels of plaster or cement based material.

Sound attenuating boards in accordance with the present invention can be used as building boards, particularly in the construction of wall structures. For instance, the boards may be used to line an existing wall structure to provide sound insulation.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a sound attenuating board according to an embodiment of the present invention; and Figure 2 is a schematic illustration of the use of sound attenuating boards according to Figure 1 to line a wall structure to provide sound insulation.

Referring to Figure 1, the illustrated embodiment of the invention is a building board comprising a 3mm thick sheet of relatively dense mineral loaded PVC 1 bonded between a 10mm thick panel of gypsum fibre board 2 and a 3.2mm thick panel of fibre reinforced cement board 3. The gypsum fibre board panel 2 has a density per unit area of 11. 5kg/m2, the polymeric sheet 1 has a density per unit area of 7. 5kg/m2 and the cement board 3 has a density per unit area of 4. 6kg/m2. The panels are glued together using a polyurethane adhesive.

The resonant frequency, and thus the sound attenuating properties, of each layer of the board is quite different providing overall sound attenuation which is far superior to that that could be achieved using a single or even double layer board.

Thus, greatly improved sound attenuation is achieved without significantly adding to the size and cost of the board. In particular, the board can be fabricated from conventionally available materials already widely used in the building industry.

It will be appreciated that the precise composition of the board may vary. For instance, the panels 1 and 2 may both be constructed from the same material, differing acoustic properties being obtained by using different thicknesses of panel.

Alternatively, the panels 1 and 2 could have the same thickness but have a different composition to provide the differing acoustic properties.

The relative thicknesses of the three layers may vary considerably. However, as mentioned above the board can be fabricated from conventionally available materials. As such, gypsum fibre board is commonly available in thickness from about 6 to about 20mm and fibre reinforced cement board is commonly available in thicknesses from about 2mm to 10mm.

A variety of different compositions of polymeric material suitable for use in the invention are known. Mineral loaded polymeric materials are commonly used in sound attenuating flooring systems. Such conventional materials, typically available in thicknesses from less than lmm to around 10 to 12mm, can be used in the present invention.

Although the preferred arrangement, as mentioned above, is to have the polymeric sheet sandwiched between the two plaster/cement panels, in alternative embodiments the polymeric sheet could be provided at an outer surface.

It will also be appreciated that additional layers of material could be provided to the board to suit particular applications. For instance, additional sound attenuating layers of cement/plaster panels or polymeric material may be added, as may additional layers of other conventional materials desirable either to improve the sound attenuating properties or external finish of the board. However, the preferred embodiment is a relatively simple three layer structure which manages to combine effective sound attenuation in a low cost product.

Building boards in accordance with the present invention can be used in the construction of simple non-load bearing partition walls, or as sound insulating linings for existing wall structures. Figure 2 is a simple schematic illustration of use of building boards according to the present invention in the latter application.

Referring to Figure 2, a supporting framework of vertical timber batons 4 (e. g.

25 x 50mm batons) are fixed to a wall at a spacing appropriate to the size of building board to be used. Resilient bars 5 are then screw fixed horizontally to the timber batons 4, again at a spacing appropriate to the building boards to be used (for instance 600mm centres for 1200mm high boards or 500mm centres for 1500mm high boards).

Glass fibre quilting 6 (e. g. 25mm thick) is laid in between the timber batons. Building boards 7 according to the invention are then screw fixed to the resilient bars. If necessary the boards 7 can be plaster skimmed to finish.

It will be appreciated that the above is only one of a wide range of possible applications for building boards in accordance with the present invention. Such building boards can for instance be used to replace conventional plaster or cement boards in any applications to which such boards are commonly put.

Claims

1. A sound attenuating board comprising a sheet of polymeric material layered with first and second panels of plaster or cement based material, said first and second panels differing in thickness and/or composition.

2. A sound attenuating board according to claim 1, wherein said sheet of polymeric material is sandwiched between said first and second panels.

3. A sound attenuating panel according to claim 1 or claim 2, wherein said polymeric material is a relatively dense mineral loaded material.

4. A sound attenuating panel according to claim 3, wherein said polymeric material is mineral loaded PVC.

5. A sound attenuating panel according to any preceding claim, wherein said polymeric material has a thickness in the range between 0.5 and 15mm and a density between 1. 5kg/m2 and 10kg/m2.

6. A sound attenuating panel according to any preceding claim, wherein the first and/or second panel comprises gypsum plaster.

7. A sound attenuating panel according to any one of claims 1 to 4, wherein said first and/or second panel comprises portland cement.

8. A sound attenuating board according to any preceding claim, wherein said first panel comprises gypsum plaster and said second panel comprises portland cement.

9. A sound attenuating board according to any preceding claim, wherein the thickness of said first and second panels is in the range of 1 mm to 20mm.

10. A sound attenuating board according to claim 9, wherein the thickness of the first panel is in the range of 5mm to 20mm and the thickness of the second panel is in the range of 2mm to 10mm.

11. A sound attenuating board according to any preceding claim, wherein the first panel is thicker than the second panel.

12. A sound attenuating board according to claim 11, wherein the first panel is about 10mm thick and the second panel is about 3mm thick.

13. A sound attenuating panel according to claim 12, wherein said polymeric sheet is about 3mm thick.

14. A sound attenuating board according to any preceding claim, wherein said first and/or second panel is fibre reinforced.

15. A method of manufacturing a pre-fabricated sound attenuating board, the method comprising bonding a sheet of polymeric material to first and second panels of plaster or cement based material, the first and second panels having a different composition and/or thickness.

16. A wall structure comprising one or more sound attenuating boards according to any one of claims 1 to 14.

17. A method of providing a wall structure with sound insulation, the method comprising lining the wall structure with one or more sound attenuating boards according to any one of claims 1 to 14.

18. A sound attenuating board, substantially as hereinbefore described, with reference to the accompanying drawings.

19. A method of pre-fabricating a sound attenuating board, substantially as hereinbefore described, with reference to the accompanying drawing.

20. A wall structure incorporating sound attenuating boards, substantially as hereinbefore described, with reference to the accompanying drawings.

21. A method of providing sound attenuation, substantially as hereinbefore described, with reference to the accompanying drawings.