AU2005254578B2

AU2005254578B2 - Acoustic laminate

Info

Publication number: AU2005254578B2
Application number: AU2005254578A
Authority: AU
Inventors: Philippe Pierre Marie Joseph Doneux; Bela Takacs
Original assignee: PHILIPPE DONEUX
Current assignee: Acoustic Space Pty Ltd
Priority date: 2004-06-17
Filing date: 2005-04-11
Publication date: 2007-02-01
Anticipated expiration: 2025-04-11
Also published as: AU2005254578B8; AU2005254578A1

Description

PCT/AU2005/00052 1 P.P OCSs'.Vli pc(MSl~e L PCT ipsw iOdO'&4ff

-V-

ACOUSTIC LAMINATE Field of the Invention The present invention relates generally to materials which attenuate incident acoustic energy or attenuate acoustic energy passing through the material, Some embodiments of the present invention have application as, or within laminate structures which increase the Transmission Loss (TL) of enclosures, walls, ceilings, floors and other dividing structures by reducing both the airborne and structural components of the TL.

Other embodiments have application in incident noise attenuation to reduce acoustic wave reflection within an enclosure.

Background to the Invention Sound absorbing and decoupling material such as batts constructed from mineral fibre (rock wool), glass fibre, and polyester are often placed in a space between two dividing panels to absorb incident sound energy and reduce noise transmission from one side of the panel to another. Often the dividing structure is a single panel, and may be a ceiling panel, disposed generally horizontally. It is often the case that a layer of limp, dense material is adhered to one side, often the underside, of the batt, so that the limp layer "floats" on the batt with respect to the panel, providing a barrier to, and much reducing the energy of incident sound waves.

Over time, especially where the panel is a ceiling panel, and also in vertical wall installations, the mass of the limp layer or barrier tears the fibres of the batt away from their hold on each other. The barrier falls away, and any sound energy is subsequently less impeded from passing through the dividing structure. Heavy vibrations generally associated with high sound levels generally accelerate this process.

PCT/AU2005/000521 Received 13 April 2006 -2- Also, transmission through dividing structures via structural vibration and reflection of energy from surfaces within a enclosure or space all combi-ne to increase the L, within the space, causing distractions to users of the space.

The present invention seeks to ameliorate one or more of tihe. abovementioned disadvantages.

Summary of the Invention According to one aspect of the present invention there is provided an acoustic lamirinate including: a first layer ofviscoelastic acoustic barrier material a flexible sound absorbing sound decoupling bat affixed to the first layer viscoelastic acoustic barrier material, the flexible bat' a rest defining a batt lane; the batt including a plurality of batt, the flexible batt fluther including retaninfg fiaments wherein the bat filaments andex retaining filaments are disposed perpendicular to the bant plane and having end portions thereof disposed at a bal surface, the end portions a fixed to the viscoelastic barrier material so that either the firu-st laver of viscoelastic acoustic barrier material or the flexible sound absoxbing/decoupiing batt itself may be retained in spaced relation from a mounting surface when the laminate is so mounted, the retention being achieved in any orientation by bearing a mass load of the bat or first >ayr of viscoelastic material along the axis of the affixed batt fament s and/or reraininy filaments.

Preferably, the end portions of the batt filaments and/or retaining filaments are embedded in the first layer of viscoelastic barrier material so as to improve retention of the first layer.

Preferably, the first layer of viscoelastic acoustic barrier material is in the form of strips spaced apart fri-om one another along an axis of the batt plane so as to provide some effective damrping when mounted against a mounting surface, and to reduce mass, Amended Sheet

IPEA/AU

PCT/AU2005/000521 Received 13 April 2006 -3- Preferably, the first layer of viscoelastic acoustic barrier material is in the form of pads spaced apart from one another across a matix ox gid in the batt plane so as to provide some effective damping when mnounted against a mounting surface, and to reduce mass.

Preferably, the batt filaments are in the form of one or more folds or loops arranged along fold or loop axes of the batt plane into leaves, the or each fold or loop conunencing at a first surface, extending towards the other surface and returning t the first surface, so that sound absorption and load bearing is carried out by the batt filaments Preferably, a plurality of leaves are arranged along a surface or between two surfaces, along an axis perpendicular to die fold or loop axis to form the o each batt.

Preferably, the batt filaments and retention filaments are constructed from mineral wool, glass filaments or polyester, or indeed any suitable absorptive material.

Preferably, the batt filaments are aligned parallel with the batt plane, and the retention filaments are formed from the bart filaments by needle-pibching the batt filaments into the first layer of viscoelastic acoustic barrier material to become retention filaments.

Preferably, the first layer of viscoelastic acoustic barrier material is of a density of between approximately 1000kg/mn 2 to 3000kg/mrn. However, it is preferred that the first layer ofviscoelastic acoustic barrier material has a density of approximately 1470Okg/m Preferably, the first layer of viscoelastic acoustic barrier material has a surface density of approximately 2.5kg/rn 2 Preferably, the first layer of viscoelastic acoustic barrier material has a thicness of below 6nr. However, it is preferred that the first layer of viscoelastic acoustic barrier material has a thickness of approximately 1.7mm.

Amended Sheet

IPEA/AU

PCT/AU2005/000521 P:1WCOCSs.NcSpeci;LL 8-O T sp)c.-0 M'OS -4- Preferably, the first layer of viscoelastic acoustic barrier is constructed from a polymeric elastomer impregnated with any kind of particulate material. Preferably, the particulate material is calcium carbonate.

Preferably, the first layer of viscoelastic acoustic barrier material is a composition including water, gelatine, glycerine and a filler material.

Preferably, the composition includes: 40 wt% water 5 30 wt% gelatine 40 wt% glycerine; and 60 wt% filler material.

Preferably, the composition also includes I to 15 wt% of a group II metal chloride such as for example calcium chloride or magnesium chloride.

Preferably, the composition includes 2 to 10 wt% magnesium chloride.

Preferably, the composition includes 0.5 to 7 wt% starch or gluten.

Preferably, the starch is provided from the addition of cornflour to the composition.

Preferably, the filler material is a non-reactive material with a high density.

Preferably, the density of the filler material is greater than 1 g/cm 3 Preferably, the density of the filler material is approximately 2.0 to 3.0 g/cm Preferably, the filler material may be chosen from any non-reactive material with a high density such as for example barium sulphate or KAOLIN.

Preferably, the composition includes: PCT/AU2005/000 52 1 Received 10 May 2006 -25 wt% water Wt% gelatine 5 wt% glycerine; 60 filler material; 1 10 wt% magnesium chloride; and 3 wt% starch.

Preferably, the composition includes constituents such as for example ethylene and/or propylene glycols; polyvinyl alcohols; deodoriscrs; anti-oxidants and/or fungicides.

Preferably, the Young's Modulus of the first layer of viscoelastic material is less than 344kPa.

Preferably, the first layer of viscoelastic acoustic barrier material is face d on one side with a nonwoven polyester of thickness approximately 0,05mm.

Preferably, on one side of the first layer of viscoelastic material there is provided an aluminium film reinforced with polyester as a water barrier and to provide some resistance for the laminate from fire damage, Preferably, a second layer of viscoelastic acousic barrier material is mounted on the other side of the laminate from the first layer of viscoelastic acoustic barrier material, the second layer to provide some structural damping to a mounting surface or structure.

Preferably, a spacer is provided on which a floor covering may "float" in order to reduce peak impact forces from footfalls, reducing structural vibration through, and reflection from the surfaces within an enclosure, Amended Sheet

IPEA/AU

PCT/AU2005/0005 2 1 Received 10 May 2006 According to one aspect of the present invention there is provided a method for producing an acoustic laminate, the method including the steps of: affixing a layer of viscoelastic acoustic barrier material onto a flexible batt which has batt filaments and/or retaining filaments arranged perpendicular to a batt plane in which the flexible batt is disposed at rest, so that ends of the batt filaments and/or retaining filaments at a surface of the batt plane are affixed to the layer of the viscoelastic acoustic barrier material for retention of the batt or first layer in spaced relation to a mounting surface when the laminate is so mounted, Preferably, the step of affixing the first layer involves adhering the first layer to the batt.

Preferably, the step of affixing the first layer involves pouring the first layer onto the batt so that the ends of the batt filaments and/or retaining. filaments are embedded in the first layer when it cures, providing improved retention of the first layer to the flexible batt.

Preferably, the first layer is poured in spaced-apart strips along an axis of the batt plane or in a matrix of pads spaced across a batt surface plane.

Description of the Preferred Embodiments In order to enable a clearer understanding of the invention, it will hereinafter be described with reference to drawings and description of preferred embodiments. In the drawings: Fig. 1 is a side view of a laminate structure according to a preferred embodiment of the present invention; Fig. 2 is a side view of a laminate structure according to a second preferred embodiment of the present invention; Fig. 3 is a side view of a laminate structure according to a third preferred embodiment of the present invention; Amended Sheet

IPEA/AU

PCT/AU200S/00052 I Received April 2006 Fig. 4 is an, isomeitric view of a four-thj pjeferrede emi-bodimkent of the present invention; Amended Sheet

FWAA

PCT/AU2005/00052 I Received 13 April 2006 tWE~S~2,'2\~RYCS ~t&o~..t47 Figs 5 and 6 are isometric views of a laminate structure sho.wing' a tertiary ayei the tertiary layer being in the formn of spaced apart geometric portins of daraping matenal; Fig,7 is an isometric View of a preferred embodiment of the, present itnventiotl, being a lminatestructur having tx 'o complete secondany iayers saudwiching, a bat.

ReferTing to Fig, I there is shown a first embodiment of acutcatnaiglatrinate generally indicawld at 10 the laminate 10 including a tlextuble batt 12 icluding a top urface 14 and a bottom surface 16. lIn its relaxed state the bant 12 adopts a flat planef 13, howe-ver, it flexible.

enougsh to conform to convoluted surfaces (not shiowi-n) if pressed gently. The flexible bat 12 icludes a plurality of filaments 18 which are arranged so thiat major portion.-s thereof £Lie perpendicular to tie flat plane 1 3 when thie batt is in a relaxod slate.

The Laments IS in he hr 2aeaaiedit itdyofloso od 0 Each fold or loop 20 commences at or near the top surface 14. Each fotld or loop 20, i side ele'vation, is curved slightly, to form a fold or loop 20 in time shape of a crescetnt 22, T111s cr.escent 22 assists tehttoperform, a sound-absorpton lmncticuo, wishrmt reducing to a great degree the axiallod bearing capsability of thec flaments 18.

Each fold or loop is alignedi along an axis 23 (inito the page of figs I ande 2) to: form leaves 24. To form the ball, a plurality of leaves 24 are afged along an axis 26 in. the plane of one of the top or bottom surfaces wich is also perpendicular to the fold or loop 20 axis. The filamnlts 18 axe constructed from polye ster.

A first layer of v-isco-istio acoustic bardier material 30 Is provi ded in the emubodinent show.n, fixed byx adhesive to the tpstuflce 14 of the baa 12, TheI first taxer, of vsoisi acoustic, ba.r rtaterial 30 is in t form of a limp mnaterial, bein g i this form a polymeric elastotneq, 32 impregnated with a material (not shown) in the foan of calciuma carbonK~ate (not shown). The Lamina 30 is approximaiely 1,7nam thick, of density !4'70kgm t) naothler embodiment the first layer of iselatcacoutstic barrer mnater"ia.

Amnended Sheet

TPEA/AU

PCT/AU2005/000521 P;\W'i p CS'i-N4.pct\:i;?l&~ 7 PC? coc O 3 -8is a composition including a mixture of water, gelatine, glycerine and a filler material, an example of which is described below in a non-limiting example.

A facing 34 is provided in the form of aluminium foil 36 to provide a degree of fire protection for the polymeric elastomer 32 and batt 12. The facing 34 is adhered to an upper surface of the first layer of viscoelastic acoustic barrier material In Figure 2, a similar arrangement to that shown in Figure I is shown, however, the embodiment is a double-layer so that the first layer ofviscoelastic acoustic barrier material 130 floats between two batts 112. Advantageously, the structure of preferred embodiments of the present invention allows these stackings because load-bearing is much improved over known batts. Like numerals between the Figures denote like features.

A second embodiment does not differ greatly in side view from that shown in Figs 1 and 2 and will be hereinafter described. A first layer 30 is applied to the batt 12 by being poured onto the top surface 14 of the batt 12. This allows the ends of the loops 20 at the top surface to be incorporated or embedded by the first layer 30 and are retained therein upon curing of the viscoelastic acoustic barrier 30. This improved retention of the layer along the axes of the fibres.

In operation, when the laminate is installed on an overhead ceiling panel or even a vertical wall (not shown), the layer 30 is spaced from the panel by the batt, and the tendency for the mass of the first layer of viscoelastic acoustic barrier material 30 to tear the fibres 1 8 away from each other and the wall is reduced. Thiis sbecause the fibres 18 support the mass of the first layer of viscoelastic acoustic barrier material 30 along their axis an efficient mode of support, at a lower cost than other materials.

The first layer 30 is in one form in the form of strips of pads and is affixed to the batt and mounted to the mounting surface, so that the mounting surface is damped.

Referring to Figures 3 and 4 there is shown laminate structures according to preferred embodiments of the present invention. Firstly turning to Figure 3, a laminate PCT/AU2005/000521 Received 13 April 2006 RWYD~CSCRU.Pbikbhmpped DnELOB:1_3CLitpeewede:r-10~9 -9structure 210 is shown, the structure 210 including a batt 212 having a top suface 214 and a bottom surface 216. In its relaxed stae the batt 212 adopts a flat plane 213, however, It is flexible enough to conform to slightly convoluted sutces (not shown) if pressed gently The batz 212 includes a plurality of filaments which are arranged to lie parallel to the flat plane 213 when the flexible bait 212 is in a relaxed state The filaments 218 are constructed from polyester.

Retaining means 250 are provided to grasp a plurality of filament sections together. The retaining means 250 includes n anchor portion 252, one or more leg portions 254 and a retaining portion, 256. The retaining means 250 is in the form of a tWaantet 251 and the anchor portion 252 is in the form of a filamentenm edded in the fam layer of viscoelasi acoustic barrier material 230, The retaining portion 256 is in the form of a loop 260. he filament 251 is fonrmed from the same matenal as the batt, by the process of needle punching in which a needle drives a batt filament perpendicular to the bat plane and into the curing or cured first vIscoelasic layer 230 An additional layer of viscoelasic stic aust barrier material is provided in some etbodimnents such as Figs 2, 4, and 5 7. That is, the additional layer of viscoelastic acoustic banier material 230 is affixed to the top surface 214 of the baitt 212; in one embodiment by adihesive and in another embodiment by enveloping or embedding the ends of the bat fianents or retaining fhlaments ito the curing viscoelastic material The additional layer of' viscoelastic acoustic banier material 230 is in the form of a litp material, being a polymeric elastomer 232 impgnated with a material (not shown) in the form of calcium carbonate (not showna), or, in another embodiment, a composition inchiding a mixture of wates, gelatine, glycerine and a iler aateriaL. A nonlinmiting example appears below. The additional layer 230 is like the other layer, approximately 17mm thick, of density 1470kg/n).

In another prefemed embodiment, the layer 230 is poured onto the needlc-pnched filaments of the batt so that the needle-puached laments are enveloped, or embedded in the curing or cured layer 230 for imprved retention of the layer 230 b y the needle-punched filamerta Amended Sheet

IPEA/AU

PCTAU2005/00052 1 Received 13 April 2006 A facing 234 is provided in the form of aluminiun foil 236 to provide a degree of fire protection and constrained-layer damping effect for the polymeric elastomer 232 and batt 212. The facing 234 is adhered to an upper surface of the first layer of viscoeblastic acoustic bayrier material 230.

The needle-punch retention filament 251 holds and compresses the filaments 218 together to forn a stiffer, denser batt 212 than would otherwise have been constructed.

The advantage is that in operation, the mass of the first layer of viscoelastic acoustic barrier material is less likely to tear the filamrents 218 away from their hold on each other. The filaments 251 tend to provide additional support alng the filament 251 axis for the polyester filaments 218 and laruina 230 so that the lamina 230 does not tear the batt 212 andlor stricture 210 apart. The result is that an intact bairier to incident noise is provided by the structare 210 for a lonsger period of time, at a lower cost than other materials Another second preferred embodiment of the second aspect of the present invention is shown in Figure 4. It is a double-thickness of that embodiment shown in Figure 3, where like numerals denote like parts.

A laminate structure 94 is provided according to yet another preferred emboimrent of the present invention which has an additional layer 95, the additional layer 95 being in the form of barrier/damping portions 96 and shown in Figures 5 and 6. In use, the additional layer 95 is pressed against the surface upon which it is mounted. The damping portions 96 are in the formr of the viscoelastic acoustic material 230 in any of its preferred forns the filled gelatine composition or the filled polymeric composition. The portions 95 and 96 are poured onto, or adhered or otherwise affixed to the batt to attach to or embed the batt filaments or retaining fBlament for improved retention along the axis of the relevant filanim-ent. The portions 96 may be affixed in strips or a matrix of pads in order to reduce mass of laminate, without appreciably reducing the retention, absorption, decoupling or damping.

Tunming to Figure 7, a similar embodime-r to those shown in Figs 3 and 4 is shown, except that there are two first layers of viscoelastic ban-rir material saadwichxug a batt.

Amended Sheet

IPEA/AU

PCT/AU2005/000521 P \WPDOC'LtNM'Sp\c 2l i i 6? PCTr ipec o-C '0;iT, This panel is used in squares of approximately 300mm x 300mm which form floor tiles.

These tiles are placed underneath floor coverings to reduce peak impact forces and reduce structural vibration, reflection and thus overall Leq.

In some applications, the specially formulated non slip viscoelastic strips or pad matrix situated on the batt are, when installed, generally in contact with a substrate in the form of rigid support (panel, pipe, bulkhead etc.), effectively increasing the decay rate of any vibration. Decay rate is the speed in dB/second at which the vibration reduces after panel excitation has ceased the higher the decay rate, the better the acoustic performance.

One feature of a preferred embodiment of the present invention, being the composition of the first viscoelastic barrier material, will become better understood from the following example of a preferred but non-limiting embodiment thereof.

Example 100 g of water together with 100 g of glycerine and 10 g of starch was mixed and then heated to a temperature of 85 80 g of gelatine and 20 g of magnesium chloride was then dissolved into the mixture and a gel was formed. 310 g of barium sulphate was then added to the gel providing a composition with good flexibility, elasticity, tensile strength, and density with good film forming properties. The composition had the following composition by weight: 16% water; 16% glycerine; starch; 13% gelatine; magnesium chloride; and 50% barium sulphate.

PCT/AU2005/000521 f\WVOKX S pi.M\il25\];l71 ?CT 12- The composition was then extruded into a flat sheet and bonded onto an aluminium film and then brought down to room temperature whereby the composition cured to form a sheet of composite material of 4mm in thickness that showed excellent sound dampening properties.

In one embodiment, the layer or layers of viscoelastic barrier material are poured onto the end of the fibres of the batt with pouring heads (not shown), the heads being computer controlled in order to pour a broad, covering panel, or strips, or a matrix of pads.

SO Finally, it is to be understood that various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention,

Claims

1. An acoustic laminate including: a first layer of viscoelastic acoustic barrier material a flexible Ssound absorbingsound decoupling batt affixed to the first layer of viscoelastic acoustic barrier S 5 material, the flexible batt at rest defining a batt plane; the flexible batt including a plurality of batt filaments, the flexible batt further including retaining filaments wherein the batt filaments and/or retaining filaments are disposed perpendicular to the batt plane and having end Sportions thereof disposed at a batt surface, the end portions affixed t tthe viscoelastic barrier material so that either the first layer of viscoelastic acoustic barrier material or the flexible sound absorbing/decoupling batt itself may be retained in spaced relation from a mounting surface w thn the laminate is so mounted, the retention being achieved in any orientation by bearing a mass load of the batt or first layer of viscoelastic material along the axis of the affixed batt filaments and/or retaining filaments.

2. An acoustic laminate according to claim I wherein the end portions of the batt filaments and/or retaining filaments are embedded in the first layer of viscoelastic barrier material so as to improve retention of the first layer or batt. 3, An acoustic laminate according to claim I or 2 wherein the first layer of viscoelastic acoustic barrier material is in the form of strips spaced apart from one another along an axis of the batt plane or pads spaced apart from one another across a matrix or grid in the batt plane so as to maintain a similar degree of damping as a full sheet when the layer is mounted on a mounting surface but also to reduce mass and cost of the laminate.

4. An acoustic laminate according to any previous claim wherein the batt filaments are in the form of one or more folds or loops arranged along fold or loop axes of the batt plane into leaves, the or each fold or loop commencing at a first surface, extending towards the other surface and returning to the first surface, so that sound absorption and load bearing is carried out by the batt filaments. PCT/AU2005/000 52 1 Received 13 April 2006 -14- An acoustic laminate according to any previous claim wherein a plurality of ieaves are au-anged along a srwface or between two surfaces, along an axis perpendicular to the fold or loop axis to form the or each flexible batt.

6. An acoustic laminate according to any previous claim whereint the hart filaments and retention filaments axe constructed from mineral wool, glass filaments or polyester.

7. An acoustic laminate according to any previous claim wherein the batt filaients are aligned parallel with the batt plane, and the retention filaments are fanned to be perpendiclarly-orientaied from the batt filaments by needle-puuching the batt filaments into the first layer ofviscoelastic acoustic barrier mtraterial. 3. An acoustic laminate according to claim 7 wherein the ends of the needle-punched filamants are embedded in the first layer of viscoelastic material during curing of the first layer.

9. An acoustic laminate according to any previous claim wherein a second layer of viscoelasti material is provided on an opposite side of the batt from the first layer, the assembly being held together by the perpendicular orientation of the retention filaments of the acoustic decoupling bati I 0.An acoustic laminate according to any previous claim wherein a second bat- and further layers viscoelastic material are provided, suitably retained by the perpendicular orientation of the retention filaments of the decoupling halt. I I.An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier material is of a density of between approximately 1000kg/ 3 m.

12.An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier material has a density of approximately 1470kg/r. Amended Sheet IPEA/AU PCT/AU2005/000521 P WPIX)CS lS.W.;IIc 26fS PCT sx x loc.00i'O5

13. An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier material has a surface density of approximately 2.5kg/m 2

14. An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier material has a thickness of below 6rm, An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier material has a thickness of approximately 1.7mm.

16. An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier is constructed from a polymeric elastomer impregnated with a particulate material

17. An acoustic laminate according to any previous claim wherein the particulate material is calcium carbonate.

18. An acoustic laminate according to any previous claim wherein the first layer of viscoelastic acoustic barrier material is a composition including water, gelatine, glycerine and a filler material.

19. An acoustic laminate according to claim 18 wherein the composition includes: 40 wt% water 30 wt% gelatine 40 wt% glycerine; and 20 60 wt% filler material. An acoustic laminate according to claim 18 or 19 wherein the composition also includes 1 to I5 wt% of a group II metal chloride such as for example calcium chloride or magnesium chloride.

21. An acoustic laminate according to any one of claims 18 20 wherein the composition includes 2 to 10 wt% magnesium chloride. PCT/AU2005/000521 p 1WDOCSihWpS l 2: 7 CT sps 4W: ct- '047,i 16-

22. An acoustic laminate according to any one of claims 18 21 wherein the composition includes 0.5 to 7 wt% starch or gluten, 23, An acoustic laminate according to any one of claims 18 22 wherein the starch is provided from the addition of cornflour to the composition.

24. An acoustic laminate according to any one of claims 18 23 wherein the filler material is a non-reactive material with a high density. An acoustic laminate according to claim 24 wherein the density is greater than 1 g/cm 3

26. An acoustic laminate according to claim 25 wherein the density of the filler material is approximately 2.0 to 3.0 g/cm

27. An acoustic laminate according to any one of claims 24 26 wherein the filler material may be chosen from any non-reactive material with a high density such as for example barium sulphate or KAOLIN.

28. An acoustic laminate according to any one of claims 18 27 wherein the composition includes: -25 wt% water 20 wt% gelatine 25 wt% glycerine; 40 60 wt% filler material; 1 10 wt% magnesium chloride; and 3 wt% starch.

29. An acoustic laminate according to any one of claims 18 28 wherein the composition includes constituents such as for example ethylene and/or propylene glycols; polyvinyl alcohols; deodorisers; anti-oxidants and/or fungicides. PCT/AU20051 0 00 52 1 Received 13 April 2006 r:\sriosrjXUl.Nla'Swp witcEL~~IdyMn~l LfSINt~l~D thMeIO%%! -17- acoustic laminate according to any previous claim wherein the Young's Modules of the first layer of viscoelastic material is less than 344kPa.

31.An acoustic laminate according to any previous claimu wherein the first layer of viscoelastic acoustic banier material is faced on one side with a nonwoven polyester of thickness approximately 0$0nm.

32.An acoustic lantinate according to any previous claim wherein on one side of the first layer of viscoelastic material there is provided an aluminilunm film reinforced with polyester as a water barrier and to provide some resistance for the laminate from fire damage.

33.Axz acoustic laminate according to any previous claiinm wherein a floor covering is mounted thereon which "floats" on the acoustic laminate in order to reduce peak impact forces from footfall, reducing stuctural vibration through, and reflection from the surfaces within an enclosure.

34.A. miethod for producing an acoustic lauinate, the method including the steps of: affixing a layer of iscoelastic acoustic barr-ier material onto a flexible batt which has batt filaments andlor retaining filaments arranged perpendicular to a batt plane in which the flexible batt is disposed at rest, so that ends of the batt filaients and/or retaining filaments at a surface of the batt plane are. affixed to the layer of the viscoelastic acoustic barrier material for retention of the batt or first layer in spaced relation to a mounting surfie when the laminate is so mounted. method according to claim 34 wherein affixing the firs; layer involves adhernag the first layer to the batt

36.A method according to claim 34 wherein affixing the first layer involves pouring the first layer onto the flexible batt so that the ends of the batt filaments andior retaining filaments are embedded in the first layer when it cures, providing improved retention of the first Amended Sheer IPEA/AU PCI'T/AU2005/000521 Received 13 April 2006 floct*u d~op~~~e -s18- layer to the flexible batt. 37A method according to claim 34 or 36 wherein the firsi layer is poured in spaced-apart strips along a axis of the batt plane or in a matrix of pads spaced across a batt surface plane.

38.A method according to claim 36 or 37 wherein a second flexible batt is affixed to the first layer while the first layer is cuing so as to embed the ends of the retaining filaments for imprioved retention of the flexible batt or assembly.

39.A method according to claims 34 38 wherein further layers of viscoelastic acoustic material and flexible batis are provided, wich may be effectively retained by the perpendicular orientation of the retaining filaments. acoustic laminate substantially as hereinbefore described with reference to the attached drawings.

41.A floor title substantially as hereinbefore with reference to the attached drawings. Amended Sheet IPEAJAU