GB2190409A

GB2190409A - Barrier of particle board and vermiculite containing layer

Info

Publication number: GB2190409A
Application number: GB08711176A
Authority: GB
Inventors: Michael James Clark
Original assignee: A E FARR Ltd
Current assignee: A E FARR Ltd
Priority date: 1986-05-12
Filing date: 1987-05-12
Publication date: 1987-11-18
Anticipated expiration: 2007-05-12
Also published as: GB2190409B; GB8611535D0; GB8711176D0

Abstract

An acoustic barrier is described which comprises cement-bonded particle board 2 sprayed or otherwise coated on at least one side with a layer 3 of acoustic material comprising cement or plaster containing vermiculite. The preferred barrier has a layer of said acoustic material on one side and a layer 4 of foamed or fibrous insulating material on the other side. The latter material may be sound and/or heating insulating. The acoustic barrier may be in the form of a lining to a wall, ceiling or the like, in the form of an acoustic door or in the form of a free-standing acoustic barrier. <IMAGE>

Description

SPECIFICATION Improvement in or relating to acoustic systems This invention relates to an acoustic system which is particularly suitable for use as a lining to a structure but can also be constructed as a free standing acoustic barrier.

According to one aspect of the present invention there is provided an acoustic barrier comprising cement-bonded particle board sprayed or otherwise coated on at least one side with a layer of an acoustic material comprising cement or plaster containing vermicu iite.

Preferably the cement-bonded particle board is sprayed or otherwise coated on one side with the acoustic material comprising cement or plaster containing vermiculite and has on the other side a layer of fibrous or foamed insulating material. The insulating material may have sound-insulating or sound-absorbing properties and/or may have heat-insulating properties. Preferred insulating materials include fibrous rock wool which has good sound-absorbing, and therefore sound-insulating, properties and expanded foamed plastics material such as foamed polyurethane which has good heat-insulating properties.

In one embodiment of the present invention, the acoustic barrier is in the form of a lining to a wall, ceiling or the like, comprising a plurality of cement-bonded particle boards coated with said acoustic material and arranged in edge-to-edge relationship with sealing means provided between the edges of adjacent boards and between the edges of the lining and an adjacent ceiling or floor or an adjacent wall respectively.

The sealing means may include preformed sections of rubber or plastics.

In this embodiment, the cement-bonded particle boards are coated on one side with said acoustic material and are covered on the sides nearer the wall, ceiling or the like with said insulating material.

In another embodiment of the present invention the acoustic barrier is in the form of an acoustic door comprising a frame, made for example of cement-bonded particle board or hollow steel sections, and one or more door panels of said cement-bonded particle board coated with said acoustic material. Preferably the, or each door panel is coated on one side with said acoustic material and is covered on the other with with said insulating material held in place by one or more panels of cement-bonded particle board which are thinner than the main panels.

If desired, the surface of the acoustic material comprising cement or plaster containing vermiculite may be covered with a protective and/or decorative overlay or may be subjected to a stabilising treatment to prevent dust and small flakes or particles breaking away from the surface.

The present acoustic barrier has good sound reducing properties and these are due to the presence of the layer of acoustic material which reduces sound reflection.

In order to enable the invention to be more readily understood, reference will now be made to the accompanying drawings, which illustrate diagrammatically and by way of example some embodiments thereof, and in which: Figure 1 is an elevation of an acoustic lining, Figure 2 is a part-section to an enlarged scale showing the mounting of the lining to a coping or ceiling, Figure 3 is a part-section to an enlarged scale showing a joint between panels constituting the lining, Figure 4 is a part-section to an enlarged scale showing the mounting of the lining on a floor, Figure 5 is an enlarged section showing how the acoustic lining is secured to a wall or the like, Figure 6 is a section through an acoustic door, Figure 7 is a section through another acoustic door, and, Figure 8 shows part-sections of various panels of an acoustic lining.

Referring now to Figures 1 to 5, there is shown an acoustic lining to a wall, the lining comprising panels 1 which effectively consist of panels of cement-bonded particle board 2, covered with a layer of vermiculite-containing cement or plaster 3 and backed with a layer of insulating material in the form of rock wool 4 or the like, and which are mounted on a wall 5 by means of Z-shaped corbels 6 (Figure 5).

Each panel 2 of cement-bonded particle board is chamfered at its edges 7 except for the upper ends of the upper panels which are adjacent a ceiling or overhanging coping 8 (Figure 2). As shown in Figure 2, the upper end of the panel 1 is capped by a preformed galvanised mild steel flashing 9 which may be coated with a plastisol or a ceramic paint, and which is held in place by a self-tapping cladding bolt 10. An extruded preformed rubber seal 11 is compressed between the flashing 9 at the upper end of the panel and the overhanging coping 8 and is secured in place by a sealing strip 12 formed of polymer and cement.

Where adjacent panels 2 join one another, an extruded rubber section 14 is located between the chamfered edges of two adjacent panels 2 as shown in Figure 3 and is covered by a sealing strip 15 formed of polymer and cement. Likewise, where the panels 2 adjoin the floor, the chamfered edges of the panels rest on another extruded rubber section 16 which is covered by a sealing strip 17 as shown in Figure 4.

As shown in Figure 5, the panels 2 are mounted on the wall 5 by Z-shaped corbels 6 which are secured at one end to the panels 2 by self-tapping drill screws 18. At the other end, the corbels rest on a galvanised or stainless steel channel 19 which is secured to the wall 5 by means of self-tapping screws 20 with the interposition of a rubber strip gasket 21. The other ends of the corbels are drilled to receive the shanks of bolts 22, the heads of which are disposed within the channel 19 and the corbels are secured in place by nuts 23. This arrangement makes it possible to dismount the panels if necessary.

There are various possibilities for constructing the acoustic lining just described and these will depend upon whether provision is to be made for movement of the panels due to temperature changes, or for their removal or replacement. If desired the panels 1 may comprise panels 2 of particle board backed with rock wool 4 and faced with vermiculitecontaining cement or plaster, or the vermiculite-containing cement or plaster may be sprayed on after the panels of particle board have been assembled.

The layer of rock wool or like insulating material is optional but preferred. In particular, the layer of vermiculite-containing cement or plaster improves the acoustic barrier properties of the system by virtue of the roughness of its surface and of the air voids which exist in the material and which are sufficiently open to accept and dissipate sound energy in the form of heat within the matrix of the material.

Instead of forming the panels 2 with chamfered edges 7 and providing seals between adjacent panels, the panels can be unchamfered and butted against one another and the seals can be dispensed with if desired.

In addition, where the system is to be constructed as a free standing acoustic barrier, two series of panels 2 may be joined in paral lel relation by an arrangement similar to that shown in Figure 5 with the cavity between the panels either empty or filled with rock wool.

Figure 6 shows an acoustic door which has a frame 25 made of cement-bonded particle board and door panels 26 also of cementbonded particle board. The panels 26 are faced with vermiculite-containing plaster or cement 27 and backed with rock wool 28 held in place by a thin panel 29 of cement-bonded particle board supported by stringers 30 of the same material.

Figure 7 shows a similar acoustic door in which an expanded metal mesh 31 is secured to the panels 26 before they are covered with the plaster or cement 27 and in which rubber isolating gaskets are provided between the panels and hollow steel sections 32 forming part of the door frame and between the panels and hollow section stringers 33. The panel 29 may be of cement-bonded particle board or of steel.

The doors of Figures 6 and 7 are shown as being mounted on hinges 34 but it will be appreciated that they could be constructed as sliding doors.

The present acoustic system effects reduction of sound transmission and reflection by combination of a dense preformed board barrier of cement-bonded particle board with a surfacing material of comparable durability and compatability which efficiently absorbs noise energy within its internal air spaces.

The system is not susceptible to deterioration by means of dampness or water, fire, corrosive agents, aviation or petroleum spirits, rot, fungal, insect or vermin attack and is therefore significantly more durable and maintenance free than other preformed panelling type systems available.

The system can include flexible jointing materials of comparable performance to the principal board and surfacing components which overcomes the problem of noise penetration through joints or noise bridging through sympathetic vibration, particularly where temperature changes are likely to cause joint movements. The use of rubber insulated fixings serves to reduce transmission of vibration from one component to another.

The system can be decorated to any colour for aesthetic or camouflage purposes and needs no maintenance but can be washed.

This overcomes the problem of repainting which renders acoustic treatments ineffective.

The system is robust and can withstand local damage without loss of effectiveness or durability. It is vandal resistant but can be readily repaired either in situ with materials applied by semi-skilled labour or by complete replacement of a panel using unskilled labour.

The panels can be individually removeable utilising concealed fixings.

The surfacing material is free draining whereas the board material and joints are impermeable, therefore the system can provide a weather tight cladding and control of water run off in external or wet process situations.

The acoustic material in the form of a layer of vermiculite-containing cement or plaster has, as indicated above, a rough surface.

However, in some instances or uses of the present system, the normal surface of the acoustic material may be too rough for aesthetic reasons or for reasons of safety. Furthermore, rough projections may be knocked off thus creating detritus which could be unacceptable in some situations where the system is used.

It is therefore desirable in many cases to protect or stabilise the surface of the acoustic material, which protection or stabilisation can be combined with decoration of the surface, without at the same time destroying or unduly reducing the acoustic barrier properties of the system.

One way of protecting, stabilising and/or decorating the surface of the acoustic material is to cover the surface with a decorative and/or protective overlay. Such an overlay may be a resin-bonded, woven mesh of nylon or other material and which may be made in a range of different thicknesses, densities and colours, and which may be made fire-retardant. Another overlay material may be a reticulated foam which may also be made in a range of different thicknesses, densities and colours and which may also be made fireretardant, or a plastics material which is available in a form known as "egg crate" sheet which may be made in a range of different thicknesses, patterns and decorative finishes.

These various overlay materials may be made in the form of sheets, strips or slabs which may be fixed to the surface of the acoustic material by means of screws, nails or clips, by adhesives or adhesive systems or any other suitable means including fastenings such as those known under the Registered Trade Mark "Velcro".

Instead of covering the surface of the acoustic material it is possible mechanically to treat the surface to smooth it. Thus the surface or the acoustic material may be scarified or otherwise treated with a rotary tool or wire brush, either automatically or by hand together with, if required, vacuum removal of the loose arisings on the surface. Alternatively, the surface may be subjected to light grit-blasting, again, if required, together with vacuum removal of the loose arisings. The resulting treated surface of the acoustic material can then be subjected to a stabilising treatment by coating with a lacquer or a liquid containing polymers or plastics in order to stabilize the surface against dusting.These treatments remove the flakiness of the surface of the acoustic material while retaining sufficient irregularity to minimise the reflection of sound, and to retain the porous surface of the material.

In general, the acoustic material does not have sufficient wear-resistance to enable the present acoustic barrier to be used as a floor with the acoustic material uppermost, but this disadvantage can be overcome by incorporating a steel grill in the acoustic material. Thus a floor could consist of a steel grill floor backed by the cement-bonded particle board and the interstices of the steel grill floor filled with sprayed-on acoustic material.

Figure 8 shows sections of panels of which the surface has been given a decorative or protective overlay or has been stabilised. The Figure 8 shows a panel of cement-bonded particle board 2 covered with a layer of vermiculite-containing plaster or cement and backed with a layer of expanded foamed polyurethane 36 instead of with a layer of rock wool. The plastics layer 36 has heat-insulating properties as well as some sound-insulating properties.

The upper part of Figure.8 shows the rough surface of the plaster or cement covered with a decorative layer 37 of woven nylon mesh or other material which is nailed in place by means of nails 38.

The centre part of Figure 8 shows a slab 39 of plastics material adhered to the rough surface of the acoustic material 3 and the lower part of Figure 8 shows that the surface 40 of the acoustic material j has been made smooth and has been lacquered to stabilise the surface against dusting. It is to be appreciated that the treatments described with reference to Figure 8 can be applied to the other embodiments of acoustic barrier described.

The present acoustic barrier system is of easily manageable weight and can be readily erected by semi-skilled labour making it more economic than the perforated metai type acoustic treatments, and allowing it to be used in applications where perforated metal systems cannot be applied.

Claims

1. An acoustic barrier comprising cementbonded particle board sprayed or otherwise coated on at least one side with a layer of an acoustic material comprising cement or plaster containing vermiculite.

2. An acoustic barrier comprising cementbonded particle board sprayed or otherwise covered on one side with a layer of an acoustic material comprising cement or plaster containing vermiculite and having on the other side a layer of fibrous or foamed insulating material.

3. An acoustic barrier as claimed in Claim 2, wherein the insulating material is a fibrous layer of sound-absorbing rock wool.

4. An acoustic barrier as claimed in Claim 2, wherein the insulating material is a layer of foamed and expanded plastics material having sound absorbing and/or heat insulating properties.

5. An acoustic barrier as claimed in any one of Claims 1 to 4, wherein the surface of said acoustic material is covered with an overlay of protective and/or decorative material.

6. An acoustic barrier as claimed in any one of Claims 1 to 4, wherein the surface of said acoustic material has been subjected to a stabilising treatment.

7. An acoustic barrier as claimed in any one of Claims 1 to 6, in the form of a lining to a wail, ceiling or the like, comprising a plurality of cement-bonded particle boards coated with said acoustic material and arranged in edge-toedge relationship with sealing means provided between the edges of adjacent boards and between the edges of the lining and an adjacent ceiling or floor or an adjacent wall respectively.

8. An acoustic barrier as claimed in Claim 7, wherein the cement-bonded particle boards are coated on one side with said acoustic ma terial and are covered on their sides nearer the wall, ceiling or the like with said insulating material.

9. An acoustic barrier as claimed in Claim 7 or 8, wherein said sealing means include preformed sections of rubber or plastics.

10. An acoustic barrier as claimed in any one of Claims 1 to 6, in the form of an acoustic door comprising a frame and one or more door pane(s) of said cement-bonded particle board coated with said acoustic material.

11. An acoustic barrier as claimed in Claim 10, wherein the frame is formed of cementbonded particle board.

12. An acoustic barrier as claimed in Claim 10, wherein the frame is formed of hollow steel sections.

13. An acoustic barrier as claimed in any one of Claims 10 to 12, wherein the or each door panel is coated on one side with said acoustic material and is covered on the other side with said insulating material held in place by one or more panels of cement-bonded particle board.

14. An acoustic barrier as claimed in any one of Claims 1 to 6 in the form of a freestanding-acoustic barrier comprising one or more panels of cement-bonded particle board coated on at least one side with said acoustic material, and means supporting said panels.

15. An acoustic barrier as claimed in Claim 14 in the form of a motorway fence.

16. The use as an acoustic barrier of cement-bonded particle board sprayed or otherwise covered on at least one side with a layer of an acoustic material comprising cement or plaster containing vermiculite.

17. The use as an acoustic barrier or cement-bonded particle board sprayed or otherwise covered on one side with a layer of an acoustic material comprising cement or plaster containing vermiculite and having a layer of fibrous or foamed insulating material on the one side.

18. The use claimed in Claim 16 or 17, wherein the acoustic barrier is a lining to a wall, ceiling or the like.

19. The use claimed in Claim 16 or 17, wherein the acoustic barrier is a sound-absorbing door.

20. The use claimed in Claim 16 or 17, wherein the acoustic barrier is a free-standing acoustic barrier.

21. The use claimed in Claim 20, wherein the acoustic barrier is a motorway fence.

22. The use claimed in Claim 17 or any one of Claims 18 to 21, when appended to Claim 17, wherein the insulating material is a fibrous layer of sound-absorbing rock wool.

23. The use claimed in Claim 17 or any one of Claims 18 to 21 when appended to Claim 17, wherein the insulating material is a layer of foamed plastics.

24. An acoustic barrier substantially as hereinbefore described with reference to Figures 1 to 5 alone or as modified by Figure 8, or with reference to Figure 6 or 7 of the accompanying drawings.