Acoustic tile and its use in vehicle sound proofing
OwnerDarren Aster Gunasekera, Marilyn De Alwisinventors
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Abstract
An acoustic tile for damping vibration in a vehicle body panel, comprises a base layer (11) comprising a closed cell synthetic elastomeric foam bonded on one surface to a dense, stiff, non-cellular constraining layer (12). The base layer (11) preferably comprises nitryl rubber foam and the constraining layer preferable comprises an elastomeric/plastomeric polymer-bitumen blend.
Claims18
1 An acoustic tile for damping vibration in a vehicle body panel, comprising a base layer (11) comprising a closed cell synthetic elastomeric foam bonded on one surface to a dense, stiff, non-cellular constraining layer (12).
2 An acoustic tile according to claim 1 wherein foam of the base layer (11) has a density between 10 kg/m3 and 140 kg/m3 and a modulus of elasticity between 4×107 and 8'107 N/m2.
3 An acoustic tile according claim 1 or claim 2, wherein the thickness of the base layer (11) is between 3 mm and 15 mm.
4 An acoustic tile according to claim 3, wherein the thickness of the base layer (11) is about 6 mm.
5 An acoustic tile according to any one of claims 1 to 4, wherein the base layer (11) comprises closed cell polyurethane foam, closed cell polyethylene foam or closed cell nitrile rubber foam.
6 An acoustic tile according to any one of claims 1 to 5, wherein the thickness of the constraining layer (12) is between 1 and 5 mm.
7 An acoustic tile according to claim 6, wherein the thickness of the constraining layer (13) is about 3 mm.
8 An acoustic tile according to any one of claims 1 to 7, wherein the material of the constraining layer (13) has a density between 200 kg/m3 and 400 kg/m3,
9 An acoustic tile according to claim 8, wherein the material of the constraining layer (13) has a density between 300 kg/m3 and 375 kg/m3
10 An acoustic tile according to any one of claims 1 to 9, wherein the constraining layer (12) comprises bitumen.
11 An acoustic tile according to claim 10, wherein the constraining layer (12) comprises a bitumen-polymer blend.
12 An acoustic tile according to any one of claims 1 to 11, wherein the constraining layer (12) includes a protective layer (13).
13 An acoustic tile according to claim 12, wherein the protective layer (13) comprises embossed polyethylene film.
14 An acoustic tile according to any one of claims 1 to 13, wherein constraining layer (12) includes a reinforcing layer (14).
15 An acoustic tile according to claim 14, wherein the reinforcement layer (14) comprises non-woven polyester fibre.
16 An acoustic tile according to any one of claims 12 to 15, wherein the constraining layer (12), the protective layer (13) and/or the reinforcing layer (14) form an integral structure.
17 An acoustic tile according to any one of claims 1 to 16, wherein the tile is formed in two parts (2,3) with interlocking fingers (4,5) so that the area of coverage of the tile can be increased by drawing the two parts apart while retaining contact between at least the ends of the fingers.
18 A method of damping vibration in a body panel of a motor vehicle, which comprises applying to the surface of the panel at least one acoustic tile according to any one of claims 1 to 17.