GB2550373A

GB2550373A - Sound absorbing impact resistant laminate

Info

Publication number: GB2550373A
Application number: GB1608677.9A
Authority: GB
Inventors: Clifford Neil; Absolon Paul
Original assignee: SIG PLC
Current assignee: SIG PLC
Priority date: 2016-05-17
Filing date: 2016-05-17
Publication date: 2017-11-22
Anticipated expiration: 2036-05-17
Also published as: GB201608677D0; GB2550373B

Abstract

Sound absorbing impact resistant laminate comprising a sound absorption layer 101, a gas permeable layer 103 and an intermediate spacer layer 102 having an open structure defining pockets. The gas permeable layer secured in position under tension of 0.5 5 N. The gas permeable layer may be fabric comprising a natural fibre such as wool, or cotton, a synthetic fibre such as polypropylene, polyester, nylon, viscose or viscose rayon. The fabric may be woven or non-woven. The sound absorption layer may be foam based, which may be open celled, or fibrous, which may be mineral or textile fibres. The spacer layer may comprise a mesh, grid, lattice, net or web structure which may be formed of a textile fibre, cotton, steel wires or a synthetic fibre. The defined pockets may be air filled. The spacer layer may be rigid or semi-rigid to resist deformation. The laminate may comprise an edging 113 which may be a rigid or semi rigid plastic, aluminium, timber, steel or an alloy thereof. The laminate may be formed as a panel. Also included are claims for a building, wall, floor or roof structure comprising the laminate.

Description

Sound Absorbing Impact Resistant Laminate

Field of invention

The present invention relates to a sound absorbing impact resistant laminate and in particular although not exclusively to a laminate panel or cladding to form at least a part of a floor, wall, roof or ceiling.

Background art

Sound absorbing panels are used in construction to line floors, ceilings and walls to absorb acoustic energy so as to inhibit or prevent undesirable sound transmission between a first side to a second side of the floor, wall or ceiling. Such panels find particular application for structures commonly associated with appreciable noise levels such as support centres, gymnasiums, theatres, auditoriums, emergency service stations, hospitals, industrial processing and manufacturing centres and the like.

Example sound insulting materials are described in EP 0 271 681; US 5,258,585; US 2011/0284689; WO 2013/159240; US 2014/0224407; US 2015/0008281; US 2015 0050469 and US 2015/0122399.

However, existing sound absorbing materials are susceptible to damage due to static or dynamic loading forces for example resultant from impact with a high hardness object such as a football, cricket or hockey ball travelling at for example 2 to 20 meters per second. As most sound absorbing materials are formed as laminate structures, the generally planar layers deform on impact with the object and are generally incapable of returning to their pre-impact state. Such damaged panels exhibit appreciably lower sound absorbing capability and require replacement which is both labour and time intensive, particularly where the material is located at a roof or ceiling. Accordingly, what is required is sound absorbing material that addresses these problems.

Summary of the Invention

It is an objective of the present invention to provide a sound absorbing material that is resistant to both static and dynamic (impact) loading forces so as to maintain sound absorbing characteristics following such impacts.

It is a further specific objective to provide a sound absorbing impact resistant material configured to withstand impact from an object, projectile, equipment and in particular sports ball travelling at over 1 meter per second. It is a further specific objective to provide a sound absorbing impact resistant material that is compact, lightweight and durable so as to provide convenient and discreet installation at floor, wall, ceiling or roof structure so as to occupy a minimum volume at or within such structures.

The objectives are achieved by providing a sound absorbing impact resistant laminate having a sound absorption layer that is maintained spatially separated from a gas permeable layer via a spacer layer that is resistant to deformation via static or dynamic loading forces applied to the material. The subject invention is particularly advantageous to be resistant to loading forces applied perpendicular or transverse to an exposed face of the material.

According to a first aspect of the present invention there is provided a sound absorbing impact resistant laminate comprising: a sound absorption layer; a gas permeable layer; and a spacer layer having an open structure positioned intermediate and defining pockets between the sound absorption layer and the gas permeable layer; the gas permeable layer secured in position so as to be placed under tension in a plane of the layer in a range 0.5 N to 50 N.

The tension created and maintained within the gas permeable layer is advantageous in a number of respects. Firstly, the tension enhances the capability of the laminate to reflect sound waves and reduce transmission through the laminate body. Secondly, the tension is advantageous to resist impact forces applied transverse or perpendicular to a plane of the panel so as to inhibit damage and in particular to minimise or eliminate non-elastic deformation of the panel material. Thirdly, the tension in the gas permeable layer acts to maintain the cavities or pockets between the sound absorbing layer and the gas permeable layer which reduces the transmission of sound waves through the material by increasing the acoustic absorption via acoustic attenuation. The inventors have identified a tension in the range 0.5 N to 50 N is particularly advantageous to achieve these advantages with regard to sound absorption and impact resistance.

Reference within this specification to a gas permeable layer placed under tension encompasses a tension applied to strands, filaments, cords, wefts and/or warps forming part of the material of the layer. Such tension also encompasses axial tension in such cords, filaments or elements and in particular a tension at a central region in a plane of the layer. Reference to a gas permeable layer encompasses an air permeable material having a generally porous structure configured to allow transmission of a gas phase medium through the body of the material from a front face to a rear face. Advantageously, the gas permeable layer of the subject invention allows transmission of gas and in particular air into the pockets between the two external facing sound absorption and gas permeable layers.

Optionally, the tension within the gas permeable layer and in particular the strands, filaments, elements, warps or wefts that form the gas permeable layer may be in the range of 5 N to 30 N, 5 N to 40 N, 5 N to 20 N, 0.5 N to 10 N, 15 N to 40 N, 30 N to 50 N. Such tension is beneficial to resist loading impact forces and to reflect sound waves incident at the laminate.

Optionally, the gas permeable layer comprises a fabric. Preferably, the fabric is woven being formed from warps and wefts in which the warps and/or wefts comprise the tension in the range 0.5 N to 50 N. In particular, the tension within the gas permeable layer may be provided at warps and/or wefts extending through a generally central region of the layer with respect to a perimeter region of the layer.

Preferably, the gas permeable layer may derive its permeability from its porosity.

Reference within this specification to the gas permeable layer being porous includes the layer having internal cavities, voids or empty spaces in which the volume of such empty spaces relative to a total volume of the material of the layer may be expressed as a porosity percentage. Preferably, the gas permeable layer comprises a porosity in a range 0.5 to 50%, 0.5 to 40%, 0.5 to 35%, 0.5 to 30%, 0.5 to 25%, 0.5 to 20%, 0.5 to 15% and 0.5 to 10%. Preferably, the gas permeable layer comprises a porosity between 3% and 30%. Optionally, the gas permeable layer comprises a weight in a range 20 to 550 g/m2, 150 to 350 g/m2, 50 to 170 g/m2. Such a configuration is advantageous to allow gas (and in particular air) transfer through the permeable layer into and from the air pockets defined by the spacer layer and between the permeable layer and the sound absorption layer. Such a porosity and weight also provides resistance to impact loading forces as the permeable layer is stretched across the spacer layer and is resistant to indentation and deflection into the body of the laminate.

Optionally, the gas permeable layer comprises any one or a combination of the following set of: a natural fibre; a synthetic fibre; a textile; a woven fabric; a non-woven fabric; wool; cotton; a plastic; polypropylene; polyester; viscose; nylon; viscose rayon.

Optionally, the sound absorption layer comprises a fibrous or a foam based material. Optionally, the sound absorption layer comprises a density in a range 5 kg/m3 to 200 kg/m3, 10 kg/m3 to 180 kg/m3, 20 kg/m3 to 100 kg/m3 or optionally 60 kg/m3 to 70 kg/m3.

Optionally, the sound absorption layer comprises a thickness in a range 2 to 180 mm, or 5 to 150 mm.

Optionally, the sound absorption layer comprises any one or a combination of the following set of: a fibrous material; an acoustically absorbing fibrous material; a foam based material; an open cell foam; a mineral fibre based material; a textile fibre based material; a cotton fibre based material; a plastic fibre based material; a polyester fibre based material.

Optionally, the spacer layer comprises a mesh, grid, lattice, net or web type structure. Preferably, the spacer layer is formed as a mesh structure wherein the mesh comprises a mesh pocket size in a range 0.2 mm to 30 mm, 0.5 mm to 20 mm or optionally 3 mm to 5 mm. Optionally, the pockets comprise a rectangular, square or circular shape in a plane parallel to the plane of the layer.

Optionally, the mesh is formed from filaments extending transverse or perpendicular to one another in generally the same plane of the spacer layer wherein the filaments comprise a thickness transverse or perpendicular to the plane of 0.1 mm to 10 mm, 0.2 mm to 5 mm or 0.25 mm to 5 mm.

Preferably, the pockets are air filled. However, the pockets may be filled with a gas such as an inert gas. Preferably, the pockets are defined exclusively by the three layers and in particular the spacer layer and a rear face of the permeable layer and a front or mount face of the sound absorption layer.

Preferably, the spacer layer is formed from a rigid or semi-rigid material that is configured to be resistant to deformation that would otherwise close or compress the pockets. Optionally, the spacer layer comprises a material comprising any one or a combination of the following set of: a textile fibre; cotton; steel wires or filaments; a polymer; nylon, polyester, polyethylene or polypropylene; a polymer blend.

Preferably, the laminate is a three layer structure. Optionally, the laminate may comprise one or more additional layers including for example a reflective layer, a further sound absorption layer, a lower emissivity layer such as a thermally insulating layer, a coating such as decorative layer. Such additional layers may be positioned intermediate to any one of the three primary layers. Optionally, the additional layers or layer may be provided at an external facing face of the sound absorption layer or gas permeable layer. Optionally, the additional layer, film or sheet may be adhered to the laminate or may be secured by attachment elements such as pins, screws, rivets or the like. In particular, the laminate may comprise a honeycomb board or layer positioned at a rear face of the sound absorption layer. Optionally, the honeycomb board may comprise a thickness in a range 2 to 250 mm. Optionally, the honeycomb board comprises honeycomb cavities or voids, with each cavity comprising a spacing in a range 4 to 100 mm.

Optionally, the laminate may further comprise edging positioned at a perimeter of the laminate to surround at least a part of the laminate. Optionally, the edging may comprise any one or a combination of the set of: a plastic; a rigid or semi-rigid plastic; polyvinylchloride (PVC); acrylonitrile butadiene styrene (ABS); steel; aluminium; a steel alloy; timber. Optionally, the edging may comprise a thickness in at least one plane of any of the layers in a range 0.2 mm to 60 mm.

Preferably, the laminate if formed as a panel. Optionally, the laminate may be formed as a sheet, roll or blanket.

According to a second aspect of the present invention there is provided a building comprising a laminate as described and claimed herein.

According to a third aspect of the present invention there is provided a wall, floor or roof structure comprising a laminate as described and claimed herein.

Preferably, the laminate and in particular the sound absorption layer and/or the gas permeable layer comprises a material that satisfies British Standard Fire Test BS476 Parts 6 & 7 to be classified as a class 1 or 0 material. Additionally, the laminate is further configured to satisfy Euroclass fire performance standards such as 13501-1 including in particular ΕΝ 11925, EN 13823, EN 1716 and EN 1182.

Brief description of drawings A specific implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:

Figure 1 is an exploded perspective view of a sound absorbing impact resistant laminate having a sound absorption layer, a gas permeable layer and an intermediate spacer layer according to a specific implementation of the present invention;

Figure 2 is a cross sectional view through A - A of laminate of figure 1 with all three layers assembled in touching contact with one another;

Figure 3 is a magnified cross sectional view of the three layer laminate of figure 2;

Figure 4 is a perspective view of the spacer layer positioned intermediate the sound absorbing layer and gas permeable layer of figures 1 to 3 according to a specific implementation of the present invention.

Detailed description of preferred embodiment of the invention

Referring to figure 1, a sound absorbing impact resistant laminate comprises a three layer structure according to a specific implementation comprising a sound absorption layer 101, a gas permeable layer 103 and an intermediate spacer layer 102. Each layer 101, 102, 103 may be regarded as generally planar extending in an x - y plane and having a respective thickness in a z direction.

Sound absorption layer 101 is preferably formed from an acoustically absorbing fibrous material optionally including a mineral or textile based fibre. However, as will be appreciated, the material may comprise a natural or synthetic plastic based fibrous material or a foam based material. A density of the fibrous material of layer 101 may be in a range 10 kg/m3 to 180 kg/m3 and may preferably be in the region of 60 to 70 kg/m3. Such a configuration is advantageous to provide a material that is resistant to indentation following impact with a football or hockey ball travelling at between 2 to 20 meters per second. In particular, the sound absorbing layer comprising a spun or textile grass fibre at these densities is configured to not deform permanently by more than 5 mm in a z direction following impact with a ball travelling at such a velocity.

The intermediate spacer layer 102 is formed as a grid, mesh or webbing so as to comprise an ‘open’’ structure. Reference within the specification to an open structure includes a layer having internal cavities or pockets defined between the sound absorption layer 101 and the gas permeable layer 103. The structure of spacer layer 102 is described in more detail with reference to figures 2 to 4. Gas permeable layer 103 according to the specific implementation is a fabric layer being formed from natural or synthetic fibres including in particular textile fibres such as wool or cotton. However, the fabric may be formed from natural or synthetic polymers including polypropylene, polyester, viscose, nylon and the like. According to the specific implementation, fabric layer 103 comprises a permeability represented as a porosity of between 3 to 30% and having a weight of between 170 g/m2 to 300 g/m2. Gas permeable layer 103 when arranged in mounted position (in contact with and adjacent to layers 101, 102) is placed and maintained under tension. In particular, permeable layer 103 is formed as a woven fabric having warps and wefts each comprising an axial tension of between 0.5 N to 50 N where such a tension is measured at a central region of layer 103 with respect to a surrounding perimeter. Such a tension is advantageous in a number of respects including increased reflection of sound waves (to reduce sound wave transmission through the laminate 100) and to enhance the impact resistant characteristics of the laminate 100.

Sound absorption layer 101 comprises a rear face 105 and an opposed mount face 106 with faces 105, 106 separated by perimeter defining end faces 107. Spacer layer 102 similarly comprises a rear face 108 and a front face 109 with rear face 108 configured for positioning and overlaying the sound absorption mount face 106. Gas permeable layer 103 comprises a corresponding rear face 110 and an opposed front face 111 with rear face 110 configured for positioning against and overlaying spacer layer front face 109 so as to form the three layer laminate structure. The three layers 101, 102, 103 are fixed together via an adhesive applied to either or both sound absorption layer mount face 106 and/or discreet regions of gas permeable layer rear face 110 so as to sandwich spacer layer 102 between the external facing layers 101, 103. Importantly, a volume of adhesive applied to face 106 and/or 110 is not sufficient to fill the pockets defined by spacer layer 102. When assembled, each layer 101,102,103 is aligned generally parallel to the x - y plane and comprises a thickness in the z direction. According to the specific implementation, a thickness in the z direction of sound absorption layer 101 is at least 2 to 10 times greater than a corresponding thickness of the gas permeable layer 103 and/or the spacer layer 102.

The generally planar three layer laminate 100 is preferably formed as a panel. According to the specific implementation, edging in the form of struts or batons 104 is applied to the end faces 107 or edges of the assembled layers 101,102,103. The batons 104 extend completely around the perimeter of laminate 100 and are preferably formed from a rigid or semi-rigid material such as a plastic, steel or timber. According to the specific implementation, edging batons 104 comprise a thickness in the x - y plane of between 0.5 mm to 50 mm. Batons 104 enhance the impact resistance of the laminate 100 both by restraining lateral deflection of the layers 101, 102, 103 and protecting the side faces from lateral impacts.

Referring to figures 2 to 4, the intermediate spacer layer 102 is formed as a rigid or semirigid mesh or grid comprising filaments or elements 203 extending in the x - y plane as warps 203a and wefts 203b. The elements 203 may be formed as strands that may overlap in the z direction so as to pass over and under one another. Alternatively, the filaments or elements 203 may be formed integrally as a single one-piece structure via a moulding process as will be appreciated. According to the specific implementation, the elements 203 comprise a rectangular or square cross sectional profile in the x - z and u - z planes. However, and as will be appreciated, the elements 203 may comprise any cross sectional shape profile including circular, elliptical, oval or other irregular shapes. The elements 203 are generally rigid or semi-rigid so as to provide minimum flex or bending in the x - z and y - z planes. Accordingly, spacer layer 102 is configured to resist projectile impacts onto gas permeable layer front face 111 at an external region 200 and in turn spacer layer front face 109. Elements 203 are also configured to be resistant to deformation in the x - y plane that would otherwise close the open pockets 202 as defined between the transverse extending warps 203a and wefts 203b.

According to the specific implementation, elements 203 comprise a thickness in the z direction of between 0.25 mm to 5 mm. The mesh layer 102 also comprises a size of pocket 202 in the x - y plane of 0.5 mm to 20 mm with regard to pocket length, width or diameter in the x - y plane. Accordingly, the pockets are defined by the relative thickness of the elements 203 in the z direction and the pocket length, width or diameter in the x - y plane. The pockets 202 are further defined by the rear face 110 of gas permeable layer 103 and the mount face 106 of sound absorption layer 101.

The present laminate 100 via the tension maintained within the gas permeable layer 103 is advantageous to reflect sound waves incident at front face 111 of gas permeable layer 103 exposed within the external region in addition to enhancing resistant to deformation of the layers 101, 102, 103 in the z direction due to static or dynamic (impact) loading forces incident at front face 111 of gas permeable layer 103. Furthermore, the tension within layer 103 helps maintain the air filled pockets 202 which is beneficial to inhibit transmission of sound waves from a first external region 200 to a second adjacent external (or internal) region 201 of the laminate 100.

Claims

1. A sound absorbing impact resistant laminate comprising: a sound absorption layer; a gas permeable layer; and a spacer layer having an open structure positioned intermediate and defining pockets between the sound absorption layer and the gas permeable layer; the gas permeable layer secured in position so as to be placed under tension in a plane of the layer in a range 0.5 N to 50 N.

2. The laminate as claimed in claim 1 wherein the tension is in a range of 5 N to 30 N.

3. The laminate as claimed in claim 1 wherein the tension is in a range of 5 N to 40 N.

4. The laminate as claimed in claim 1 wherein the tension is in a range of 5 N to 20 N.

5. The laminate as claimed in claim 1 wherein the tension is in a range of 0.5 N to 10 N.

6. The laminate as claimed in claim 1 wherein the tension is in a range of 15 N to 40 N.

7. The laminate as claimed in claim 1 wherein the tension is in a range of 30 N to 50 N.

8. The laminate as claimed in any preceding claim wherein the gas permeable layer comprises a fabric.

9. The laminate as claimed in claim 8 wherein the fabric is woven being formed from warps and wefts in which the warps and/or wefts comprise the tension in the range 0.5 N to 50 N.

10. The laminate as claimed in claim 9 wherein the tension is provided at warps and/or wefts extending through a generally central region of the layer with respect to a perimeter region of the layer.

11. The laminate as claimed in any preceding claim wherein the gas permeable layer comprises a porosity in a range 0.5 to 50%.

12. The laminate as claimed in any preceding claim wherein the gas permeable layer comprises a weight in a range 20 to 550 g/m2.

13. The laminate as claimed in claim 12 wherein the weight is in a range 150 to 350 g/m2.

14. The laminate as claimed in claim 12 wherein the weight is in a range 50 to 170 g/m2.

15. The laminate as claimed in any preceding claim wherein the gas permeable layer comprises any one or a combination of the following set of: • a natural fibre; • a synthetic fibre; • a textile; • a woven fabric; • a non-woven fabric; • wool; • cotton; • a plastic; • polypropylene; • polyester; • viscose; • nylon; • viscose rayon.

16. The laminate as claimed in any preceding claim wherein the sound absorption layer comprises a fibrous or a foam based material.

17. The laminate as claimed in any preceding claim wherein the sound absorption layer comprises a density in a range 5 kg/m3 to 200 kg/m3.

18. The laminate as claimed in claim 17 wherein the density is in a range 20 kg/m3 to 100 kg/m3.

19. The laminate as claimed in any preceding claim wherein the sound absorption layer comprises a thickness in a range 2 to 180 mm.

20. The laminate as claimed in any preceding claim wherein the sound absorption layer comprises any one or a combination of the following set of: • a fibrous material; • an acoustically absorbing fibrous material; • a foam based material; • an open cell foam; • a mineral fibre based material; • a textile fibre based material; • a cotton fibre based material; • a plastic fibre based material; • a polyester fibre based material.

21. The laminate as claimed in any preceding claim wherein the spacer layer comprises a mesh, grid, lattice, net or web type structure.

22. The laminate as claimed in claim 21 comprising a mesh structure wherein the mesh comprises a mesh pocket size in a range 0.2 mm to 30 mm.

23. The laminate as claimed in claim 22 wherein the mesh is formed from filaments extending transverse or perpendicular to one another in generally the same plane of the spacer layer wherein the filaments comprise a thickness transverse or perpendicular to the plane of 0.1 mm to 10 mm.

24. The laminate as claimed in claim 23 wherein the thickness is in a range 0.2 mm to 5 mm.

25. The laminate as claimed in any preceding claim wherein the pockets are air filled pockets.

26. The laminate as claimed in any preceding claim wherein the spacer layer is formed from a rigid or semi-rigid material that is configured to be resistant to deformation that would otherwise close or compress the pockets.

27. The laminate as claimed in any preceding claim wherein the spacer layer comprises a material comprising any one or a combination of the following set of: • a textile fibre; • cotton; • steel wires or filaments; • a polymer; • nylon, polyester, polyethylene or polypropylene; • a polymer blend.

28. The laminate as claimed in any preceding claim wherein the laminate is a three layer structure.

29. The laminate as claimed in any preceding claim further comprising edging positioned at a perimeter of the laminate to surround at least a part of the laminate.

30. The laminate as claimed in claim 29 wherein the edging comprises a material comprising any one or a combination of the set of: • a plastic; • a rigid or semi-rigid plastic; • polyvinylchloride (PVC); • acrylonitrile butadiene styrene (ABS); • steel; • aluminium; • a steel alloy; • timber.

31. The laminate as claimed in claims 29 or 30 wherein the edging comprises a thickness in at least one plane of any of the layers in a range 0.2 mm to 60 mm.

32. The laminate as claimed in any preceding claim wherein the laminate is formed as a panel.

33. A building comprising a laminate as claimed in any preceding claim.

34. A wall, floor or roof structure comprising the laminate as claimed in any preceding claim.