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1. (WO2019032393) RENOVATION CEILING MAT
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RENOVATION CEILING MAT

FIELD

The present invention relates generally to non-woven mats, particularly fibreglass mats, and their use in the renovation of acoustic ceiling tile frameworks.

BACKGROUND

A conventional acoustic panel, such as a ceiling tile, can comprise a non-woven composite structure, including a core or board composed of base fibres, fillers, and binders. In the case of mineral wool boards, the core is generally combined with a veil to provide aesthetic properties and form the panel structure. Veils are generally made up of a mat of fibres, such as glass fibres, mixed with binders, fillers, surfactants, and other additives. Depending on the desired characteristics of the veil, the fillers may be a variety of materials including alumina, clay, calcium carbonate, and the like. The binders are typically resins, starch, polyvinyl alcohol, latex, and the like. Upon curing, the binder forms bonds with the base fibres and fillers to form a fibrous network providing acoustic properties.

Drop or suspended ceiling panels are one form of acoustic panel and are used in a variety of structures to provide versatile ceiling coverage. Over time, individual panels can become stained (e.g., from water leaks above the panel), damaged, or otherwise in need of replacement to improve the aesthetics of the ceiling. When this happens, owners generally replace the existing, stained panel with an identical replacement panel. However, replacing fewer than all of the panels can lead to aesthetic issues as well, since newer panels are likely to have a different appearance than older panels. Furthermore, replacing all of the panels can be costly when only a few of the panels are compromised. Thus, there is an unmet need for a system for renovating an acoustic ceiling tile framework that avoids these drawbacks.

SUMMARY OF THE INVENTION

The present inventors have developed a novel system for renovating an acoustic ceiling tile framework, which successfully balances the need for effective stain covering with the maintenance of the acoustic properties of the existing ceiling tiles.

Accordingly, in one aspect the invention provides a renovation mat for an acoustic ceiling tile framework. The mat comprises a non-woven web of fibres, a first binder, a filler, and a second binder. The filler preferably comprises at least one of aluminium trihydrate, calcium carbonate, magnesium oxide, magnesium hydroxide, titanium dioxide, talc, barium sulphate, kaolin, or mixtures thereof, and is present in an amount of 100 g/m2 to 500 g/m2.

A renovation mat of the present invention meets the following criteria (as further defined below):

(i) an air porosity of at least 100 l/m2/sec at 100 Pa;

(ii) a ΔΕ <2.

The present inventors have identified that mats meeting these criteria are suitable for use in the renovation of damaged/stained ceiling tiles, in particular for use underlying an existing ceiling tile framework. Methods of use of the inventive mats are also provided and described herein. The renovation systems and methods of the invention provide effective stain coverage while maintaining the desired acoustic properties of the ceiling.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a scatterplot of stain covering (ΔΕ) versus acoustic openness (porosity) of mats with different fillers.

Figure 2 is a scatterplot of stain covering (ΔΕ) versus add-on with different fillers.

Figure 3 is a schematic representation of combining stain covering and porosity (acoustics).

Figure 4 is a scatterplot showing the measured performance of tested set-ups.

GENERAL DESCRIPTION AND DEFINITIONS

As described above, the renovation mats and systems of the present invention comprise a non-woven web of fibres, a first binder, a filler, and a second binder.

The non-woven web of fibres, bound together with a (first) binder, may be referred to as a "veil", as is known in the art. The terms "non-woven", "veil" and "scrim" are used interchangeably herein and refer to a bound web of fibres.

The terms "mat" and "renovation mat," are used interchangeably herein to refer to a veil, sheet, or the like comprised of a web of fibres (i.e. a bound web of fibres as described above) which has been impregnated with one or more fillers. Impregnation is preferably such that it meets one or more performance standards described herein for renovating i.e., improving the aesthetic performance of an installed ceiling tile.

The fibres making up the non-woven web of fibres may be composed of various materials. Preferably the fibres are glass fibres i.e. the web of fibres is a non-woven web of glass fibres. Additionally, however, it should be appreciated that other fibres like synthetic polymer (for example, polypropylene, polyethylene, polyester, polyethylene terephthalate, polybutylene terephthalate, aramid, nylon, rayon, viscose, polyimide, polyetherimide, polyamide, carbon fibre), natural fibres (for example, cotton, hemp, kenaf, jute, cellulose), organic and inorganic fibres, both natural and manmade, may be utilized. For example, in certain exemplary embodiments, the web of fibres is comprised of basalt fibres.

Preferred glass fibres may include Advantex glass fibres. Particularly preferred are so-called wet use chopped strands (WUCS). These glass fibre filaments are specifically engineered for use in wet-process, non-woven applications. Wet chopped strands disperse quickly and uniformly in process water.

The thickness of the fibres may vary from about 6 microns to about 21 microns (average diameter). The length of the fibres may vary from about 4 mm to about 38 mm. The diameter of the fibres can be measured using an electron microscope. The average diameter is determined over a minimum of 100 measurements. In some embodiments, mixtures of different fibres (i.e. different thicknesses and/or different lengths and/or different types of fibre) may be used.

The terms "filler" and "impregnant" are used interchangeably herein to refer to materials that are added to a web of fibres to modify one or more performance related attributes. Suitable fillers are described in detail herein. In general terms, a suitable filler is an inorganic, particulate solid (powder) which is white in colour.

In the renovation mats of the invention, the filler comprises one or more of the following: aluminium trihydrate, calcium carbonate, magnesium oxide, magnesium hydroxide, titanium dioxide, talc, barium sulphate, kaolin, and mixtures thereof.

In some embodiments the filler comprises aluminium trihydrate (ATH), which may be beneficial for fire retardance. In some embodiments, the filler preferably comprises aluminium trihydrate in an amount of at least 30% by weight of the solids in the filler, more preferably at least 50% by weight. In these embodiments the filler further comprises at least one of calcium carbonate, magnesium oxide, magnesium hydroxide, titanium dioxide, talc, barium sulphate, kaolin, or mixtures thereof.

In some preferred embodiments, the filler comprises at least one of calcium carbonate, magnesium oxide, magnesium hydroxide, titanium dioxide, talc, barium sulphate, and kaolin. In more preferred embodiments, the filler comprises at least one of: magnesium oxide, magnesium hydroxide, titanium dioxide and kaolin. In further preferred embodiments, the filler comprises titanium dioxide or kaolin.

The filler is preferably present in the mat in an amount of 100 g/m2to 500 g/m2, more preferably from 150 g/m2 to 310 g/m2.

The term "binder," as used herein, refers to a material that holds one or more components of the renovation mat together. Suitable binders are described in detail herein. In the renovation mats of the invention the first binder serves to hold together the non-woven web of fibres (i.e. before impregnation). A second binder is used with the filler to impregnate the non- woven web of fibres and provide the desired physical properties.

In some embodiments, the first binder is selected from thermoplastic and thermoset resins such as polyvinyl alcohol, latexes, acrylics, acrylic acids, epoxy, polyurethanes, melamine, urea formaldehyde, polyester resins, vinyl esters; binders can also be selected from starches, cellulose, saccharides, and combinations thereof. In preferred embodiments, the first binder is polyvinyl alcohol.

In some embodiments, the second binder is selected from thermoplastic and thermoset resins such as polyvinyl alcohol, latexes, acrylics, acrylic acids, epoxy, polyurethanes, melamine, urea formaldehyde, polyester resins, vinyl esters; binders can also be selected from starches, cellulose, saccharides, and combinations thereof. In preferred embodiments, the second binder is polyvinyl alcohol, latex, or a blend thereof.

The binders may be present in the renovation mat in an amount of 5% to 35% by weight (i.e. from 5% to 35% of the total weight of the renovation mat is made up of the two binders).

The term "add-on," as used herein, refers to the amount of filler or impregnant or coating or combinations thereof that is included in a renovation mat.

The renovation mats of the present invention advantageously have the property of being acoustically open. The term "acoustic openness", as used herein, refers generally to the quality of a renovation mat to allow sound to pass through. This is important in ensuring that the acoustic performance of the existing ceiling panels is maintained after renovation using the systems and methods of the invention.

Acoustic absorption is measured by ASTM C423 (NRC - noise reduction coefficient) and EN 13964. Acoustic performance of the mat may be determined by a variety of methods. In the present invention, exemplary methods to measure the acoustic openness or performance of a renovation mat include airflow resistance (mks rayls) and porosity (l/m2/sec). Air porosity may be measured according to IS09237. Airflow resistance may be measured according to ASTM C522-03 (2016).

The mats of the present invention preferably have an air porosity of > 100 l/m2/sec at 100 Pa. The present inventors have found that this provides acceptable acoustic performance of the renovation mat i.e. the mat can be considered 'acoustically open'. Alternatively or additionally, the mats of the present invention may have an airflow resistance of <600 MKS Rayls.

The renovation mats of the present invention also advantageously provide an acceptable aesthetic performance, when used in the renovation systems and methods described herein. The term "aesthetic performance," as used herein, refers to the capacity of a renovation mat to hide, for example, a stain on an existing ceiling tile. Stain covering (one form of aesthetic performance) can be determined by measuring the colour difference of the renovation mat with a white background versus a coloured background (stained surface). More difficult stains are represented by a black or blue coloured background. A grey or yellow stain (or corresponding background during testing) is more easily covered.

The colour difference (stain covering) can be quantified as DELTA-E (ΔΕ, ΔΕ7β). This is a single number used in colour science and is calculated as a distance in the three dimensional colour space (L*, a*, b*) to quantify colour differences. As it is described in the article "Colour difference ΔΕ - A Survey", by Mokrzycki W.S., Oct 2012, University of Warmia and Mazury, details are given on ΔΕ, ΔΕ76 and its thresholds. As used herein, the terms

DELTA-E, delta-E, ΔΕ, and ΔΕ76 are interchangeable and all refer to Eie i.e. ΔΕ as calculated according to the CIE 1976 equation (see below).

In cases where 1< AEie <2, the difference is only noticed by an experienced observer. When ΔΕ76 >2, the difference is noticeable by inexperienced observers.

In the present invention, it is determined by measuring the colour of the renovation mat over a white and a black background (specifically, over a white and black measuring card, such as a 2 A opacity card from the Leneta Company). The black background represents the 'worst case' i.e. the most difficult stain covering challenge. The colour measurements can be conveniently carried out using a spectrophotometer or colourimeter, as is known in the art. Values for L*, a* and b* for the mat over each background colour are determined directly from the measuring device and/or are readily converted from x, y, z (R, G, B) tri-stimulus values. The difference in colour is expressed as ΔΕ (delta-E, ΔΕ76) and is calculated using the formula:

Δ£ = V(0<*i - L*2 2 - (oj - a2*Y - {b{ - b2*)2

The smaller the difference, the lower the ΔΕ number. In certain exemplary embodiments, the renovation mat of the present invention has a ΔΕ76 <3 (or <3); including a ΔΕ76 <2 (or <2), and including a ΔΕ76 <1 (or <1). Preferably, the renovation mat has a ΔΕ of 2 or below.

The mat of the present invention may also be finished with an optional coating layer. This coating layer can be applied using various coating techniques such as roll coating, knife coating, screen printing, impregnation, curtain coating, brush coating or spray-painting techniques. The final coated product should have the target stain covering and acoustic performance.

Ranges as used herein are intended to include every number and subset of numbers within that range, whether specifically disclosed or not. Further, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 2 to 8, from 3 to 7, from 5 to 6, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.

All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made.

All combinations of method or process steps as used herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.

In certain exemplary embodiments, the renovation mat comprises an outward side and an inward side, the outward side being opposite to the inward side. In certain exemplary embodiments, the outward side may be a front side which is facing towards a building space or room environment and the inward side may be a rear side which is facing the ceiling tile or tiles being covered and, thus, is concealed from view when the mat is mounted.

DETAILED DESCRIPTION AND DISCUSSION

The general inventive concepts described herein relate to and contemplate a non-woven fibreglass mat for use in an existing ceiling tile framework.

When developing a mat for use in renovating the aesthetics of an existing ceiling tile framework, there are a number of properties that must be balanced against one another. For instance, in certain embodiments, the mat should be opaque enough to cover stains while also being acoustically open enough not to influence the acoustics of the existing ceiling tile. The mat should be both stiff and light enough not to have visual sag when installed, but at the same time, flexible and resilient enough to be installed under a suspended ceiling tile in an existing framework without being damaged. The mat should not influence the fire

performance of the existing ceiling tile framework. Thus, the inventive mat combines all the above features in a unitary structure while balancing the above properties.

While the general inventive concepts are susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an

exemplification of the principles of the general inventive concepts. Accordingly, the general inventive concepts are not intended to be limited to the specific embodiments illustrated herein.

The materials, systems, and methods described herein are intended to be used to renovate the aesthetics of an existing network of acoustic ceiling tiles. More specifically, the non-woven fibreglass mats disclosed or suggested herein can be used in an existing drop ceiling framework and cover an existing ceiling tile to renovate the aesthetics of the existing ceiling tile (e.g., to cover stains) while relying on the acoustical and other performance (e.g., fire retardance) attributes of the ceiling tile.

Numerous benefits result from employing the materials, systems, and methods according to general inventive concepts. The methods described herein, or otherwise encompassed by the general inventive concepts, provide a simple and convenient approach for renovating suspended ceiling framework and, more particularly, improving the aesthetics of ceiling tiles. Since the old ceiling tiles are maintained in the space above the mat, there is little or no mess created during renovation and the time and effort otherwise required to remove the old ceiling tiles and discard them is eliminated. Accordingly, installation costs are greatly reduced. Further, use of the mat allows one to aesthetically upgrade any existing suspended ceiling independent of the ceiling type and design. Since the existing ceiling tiles remain in place on the ceiling tile framework (grid), hidden by the mat, the original technical properties of the ceiling relating, for example, to fire rating and acoustical characteristics are at least maintained if not improved by the use of the mat. Further, since the ceiling tiles may be replaced without creating any substantial mess and without necessitating their removal, renovation and replacement can be done in a normal work environment with minimal disruption to the work area.

In an exemplary embodiment, a non-woven fibreglass mat for use in an existing ceiling tile framework is provided. The mat ('renovation panel') comprises a non-woven web of fibres; a first binder; a filler; and a second binder. The non- woven web of fibres and the first binder have an area weight of 40 g/m2 to 200 g/m2 prior to inclusion of the filler. In some embodiments, the filler comprises aluminium trihydrate in an amount of at least 30% by weight of the solids in the filler and at least one of aluminium trihydrate, calcium carbonate, titanium dioxide, talc, barium sulphate, and kaolin.

In an exemplary embodiment, a non-woven fibreglass mat comprising a web of fibres, a first binder, a filler, and a second binder, is provided. The mat meets at least one of the following: an air porosity of > 100 l/m2/sec at 100 Pa and ΔΕ < 1. Air porosity may be measured according to IS09237, as described herein.

In an exemplary embodiment, a non-woven fibreglass mat is provided. The mat has a thickness of 0.5 to 2.5 mm, and meets at least one of the following: an air porosity of at least 50 l/m2/sec at 100 Pa, preferably at least 100 l/m2/sec at 100 Pa; and ΔΕ < 3, preferably ΔΕ <2, more preferably ΔΕ <1.

In an exemplary embodiment, a non-woven fibreglass mat comprising a web of fibres, a first binder, a filler, and a second binder, is provided, wherein the web of bound fibres has an area weight of 40 g/m2 to 200 g/m2 prior to inclusion of the filler, and wherein the filler is present in the mat in an amount of 100 g/m2 to 350 g/m2, preferably 150 g/m2 to 310 g/m2.

In an exemplary embodiment, a method for improving the aesthetics of an acoustic panel is provided. The method comprises positioning a non-woven fibreglass mat under a ceiling tile in an existing ceiling tile framework. The mat comprises a non-woven web of fibres; a first binder; a filler; and a second binder. The non-woven web of fibres and the first binder have an area weight of 40 g/m2 to 200 g/m2 prior to inclusion of the filler. In some embodiments, the filler comprises alumimum trihydrate in an amount of at least 50% by weight of the solids in the filler and at least one of aluminium trihydrate, calcium carbonate, titanium dioxide, talc, barium sulphate, and kaolin.

In some embodiments, the mat is placed under a single corresponding ceiling tile. More specifically the non-woven fibreglass mat is placed between the ceiling tiles and frame that supports the tile. In some embodiments, the mat is placed under a plurality of the ceiling tiles in the existing ceiling tile framework. In some embodiments, the mat is placed under all of the tiles in the ceiling tile framework.

In an exemplary embodiment, a method of improving the aesthetics of an installed ceiling tile is provided. The method comprises positioning a non-woven fibreglass mat under a ceiling tile in an existing ceiling tile framework, wherein the mat has a thickness of 0.5 to 2.5 mm, and meets at least one of the following: an air porosity of 100 l/m2/sec and ΔΕ < 3, preferably ΔΕ < 2, more preferably ΔΕ < 1.

A market has emerged for "renovation" ceilings that renew or renovate the aesthetics of an existing ceiling tile framework, without the need to replace it entirely. The renovation ceiling consists of a relatively thin sheet of material (i.e., a mat, veil, scrim, facer, or the like) which is placed under an existing ceiling panel (i.e., the renovation mat is placed in a manner such that it is situated between the occupied area of a structure and the existing ceiling tile). The renovation mat is designed to cover the surface of one or more ceiling panels that were formerly exposed to the occupied space in a room/structure so as to provide an

improved/renewed appearance, while relying on the acoustic performance of the existing ceiling tile situated behind the mat.

When developing a mat for use in renovating the aesthetics of an existing ceiling tile framework, there are a number of properties that must be balanced against one another. For example, in general, the renovation mat should be opaque enough to cover stains and acoustically open enough not to influence the acoustics of the existing ceiling tiles. As another example, the renovation mat should be stiff and light enough not to have visual sag.

After installation but at the same time flexible and resilient enough to be installed under a suspended ceiling tile in an existing ceiling tile framework without being damaged.

Furthermore, the renovation mat should not influence the fire performance of the existing ceiling tiles. The general inventive concepts are able to combine these features in one unitary structure while balancing these competing properties, thereby achieving a renovation mat that can provide the above mentioned properties.

The renovation mat effectively balances stain covering/opacity and the ability to be acoustically open (i.e., not degrade the acoustic absorption of the overall ceiling tile assembly). The mat also avoids problems that might otherwise arise due to the fact that, by increasing its weight (e.g., by including additional stain covering fillers), the potential for unwanted sagging and deflection of the mat once installed in the ceiling (which is known to increase with increasing weight) may also increase.

In an exemplary embodiment, the general inventive concepts relate to a material for use in renovating an existing ceiling panel (tile) assembly. In contrast to an acoustic ceiling tile which will generally have a thickness falling between 10 and 50 mm, the material is in the form of a renovation mat, as described herein, will generally have a thickness that falls between of 0.5 to 2.5 mm In general, the renovation mat is comprised of a web of fibres (e.g., glass) bound together with a first binder in an area weight of from 40 g/m2 to 200 g/m2. In certain embodiments, the renovation mat is comprised of a web of fibres and a first binder in an area weight of from 70 g/m2 to 130 g/m2.

In certain exemplary embodiments, the web of fibres is comprised of glass fibres. The thickness of the fibres may vary from about 6 microns to about 21 microns. The length of the glass fibres may vary from about 4 mm to about 38 mm. Additionally, it should be appreciated that other fibres like synthetic polymer (for example, polypropylene,

polyethylene, polyester, polyethylene terephthalate, polybutylene terephthalate, aramid, nylon, rayon, viscose, polyimide, polyetherimide, polyamide, carbon fibre), natural fibres (for example, cotton, hemp, kenaf, jute, cellulose), organic and inorganic fibres, both natural and manmade, may be utilized. For example, in certain exemplary embodiments, the web of fibres is comprised of basalt fibres. In certain embodiments, the web of fibres is a non- woven web of glass fibres.

In certain exemplary embodiments, the first binder is selected from thermoplastic and thermoset resins such as polyvinyl alcohol, latexes, acrylics, acrylic acids, epoxy,

polyurethanes, melamine, urea formaldehyde, polyester resins, vinyl esters; binders can also be selected from starches, cellulose, saccharides, and combinations thereof. In certain exemplary embodiments, the first binder is polyvinyl alcohol. In certain exemplary embodiments, a binder is present in the renovation mat in an amount of 5% to 35% by weight.

In certain exemplary embodiments, a filler composition is applied to a non-woven fibre material to produce a renovation mat. The filler composition may comprise components that improve one or more physical characteristics of the renovation mat, thereby making the mat more suitable for renovating ceiling tiles (e.g., light reflectance, acoustic openness, whiteness, fire resistance). In an exemplary embodiment, a filler composition is applied to a non-woven glass fibre mat, thereby fillers are impregnated into the web of glass fibres along with a binder to generate a renovation mat.

In certain exemplary embodiments, the fibre web is impregnated with a mixture of fillers and a secondary binder (collectively referred to as an impregnation). In certain exemplary embodiments, aluminium trihydrate is a primary component of the filler and makes up 30% to 100% by weight of the filler. In certain exemplary embodiments, a secondary component is present in the filler in an amount of 0% to 70% by weight of the filler. In certain exemplary embodiments, aluminium trihydrate is a primary component of the filler and is present in an amount of at least 50% (i.e., 50 to 100%) by weight of the solids in the filler. In certain exemplary embodiments, a secondary component is present in the filler in an amount of 0% to 50% by weight of the filler. In certain exemplary embodiments, the second filler (i.e. the secondary component of the filler) is selected from aluminium trihydrate; calcium carbonate; metal oxides such as aluminium oxide, titanium dioxide, magnesium oxide; magnesium hydroxide; talc; barium sulphate; calcium sulphate; magnesium sulphate; kaolin; china clay; nanoclay; graphene; zeolites; silica; silicates; glass; and mica. In certain exemplary embodiments, the filler has a particle size from coarse to medium to fine. In certain exemplary embodiments, the particle size of the filler is in the range of 0.5 micron to 100 microns. In certain exemplary embodiments, the filler should deliver both acceptable stain covering performance (ΔΕ < 1) and acceptable acoustic performance (porosity > 100 l/m2/sec), which may alternatively be expressed as low airflow resistance (< 600 MKS RAYLS).

In certain exemplary embodiments, the second binder is selected from a latex binder, an acrylic binder, a polyvinyl alcohol, a vinyl ester binder, epoxy binder and combinations thereof. In certain embodiments, the second binder is polyvinyl alcohol.

In certain exemplary embodiments, the filler(s) and second binder are included in the renovation panel in an amount of 100 g/m2to 500 g/m2, including 150 g/m2to 320 g/m2, including 180 g/m2 to 310 g/m2, and including 150 g/m2 to 310 g/m2.

In certain exemplary embodiments, the impregnation composition can be applied in the form of atomized droplets to the outward surface of the bound web of fibres. In certain

embodiments, the impregnation can be applied by liquid, spray, mist, fogs, clouds, or aerosol. In certain exemplary embodiments, the impregnation can be applied by roll coating, knife coating, screen printing, full bath impregnation, curtain coating, brush coating or spray-painting. In certain exemplary embodiments, the renovation mat demonstrates good stain covering performance. In certain exemplary embodiments, the renovation mat has a ΔΕ < 3. In certain exemplary embodiments, the renovation mat has a ΔΕ < 2. In certain exemplary embodiments, the renovation mat has a ΔΕ < 1.

In certain exemplary embodiments, the renovation mat can comprise a finishing coating such as a paint layer applied using spray, mist, fogs, clouds, aerosol, liquid applied by roll coating, knife coating, screen printing, full bath impregnation, curtain coating, brush coating or spray-painting.

In certain exemplary embodiments, the renovation mat demonstrates acceptable acoustic performance. In certain exemplary embodiments, the renovation mat has an air porosity >

100 l/m2/sec (i.e., being acoustically open). In certain exemplary embodiments, the renovation mat has an airflow resistance < 600 MKS RAYLS (i.e., being acoustically open).

It is known in the art to apply a coating (e.g., a paint) to a non-woven veil during construction of an acoustic ceiling tile. The coating is often applied after production of the veil after impregnation of the veil with any fillers. The coating is typically applied to improve or modify the aesthetics of the acoustic ceiling tile including colours. In contrast, in certain exemplary embodiments, the general inventive concepts provide a renovation mat that does not include a coating. Further, in general, the renovation mat is not attached to a substrate to form an acoustic panel.

As mentioned previously, the general inventive concepts relate to methods of improving the aesthetics of installed ceiling tiles, without degrading acoustic properties of the tiles. In certain exemplary embodiments, the method comprises positioning a renovation mat under one or more ceiling tiles in an existing ceiling tile framework. The renovation mat comprises a non-woven web of fibres; a first binder; a filler; and a second binder. In certain exemplary embodiments, the fibres are glass. The non-woven web of fibres and the first binder have an area weight of 40 g/m2to 200 g/m2 prior to inclusion of the filler. In some embodiments, the filler comprises aluminium trihydrate in an amount of at least 50% by weight of the solids in the filler and at least one of aluminium trihydrate, calcium carbonate, titanium dioxide, talc, barium sulphate, medium grade china clay, and fine grade china clay.

In certain exemplary embodiments, the general inventive concepts provide a method of improving the aesthetics of a ceiling comprising positioning a renovation mat under one or more ceiling tiles installed in an existing ceiling tile framework. The renovation mat comprises a web of fibres, a first binder, a filler, and a second binder. In certain exemplary embodiments, the fibres are glass. In certain exemplary embodiments, the renovation mat has a thickness of 0.5 to 2.5 mm. In certain exemplary embodiments, the renovation mat demonstrates acceptable acoustic performance. In certain embodiments, the renovation panel has an air porosity > 100 l/m2/sec at 100 Pa. In certain embodiments, the renovation panel has an airflow resistance < 600 MKS RAYLS.

In certain exemplary embodiments, the general inventive concepts provide a method of improving the aesthetics of a ceiling, without degrading acoustic properties of the tiles. The method comprises positioning a renovation mat under one or more ceiling tiles in an existing ceiling tile framework, wherein the renovation mat has a thickness of 0.5 to 2.5 mm, and meets at least one of the following: an air porosity >100 l/m2/sec at lOOPa and ΔΕ< 2, including ΔΕ <1.

In certain exemplary embodiments, the method further includes the step of shaping the renovation mat prior to placing the renovation mat in the grid of the ceiling tile framework. The shaping step includes cutting the renovation mat to a proper size to fit the grid. In certain exemplary embodiments, the shaping also includes the step of cutting an opening in the renovation panel in order to accommodate an obstruction such as a light fixture, speaker, smoke detector, pipe, sprinkler head, or the like. Further, the method includes the optional step of applying adhesive tape or adhesive spray or coating to the renovation mat prior to placing the renovation mat in the grid. In certain exemplary embodiments, the renovation mat is substantially parallel to the ceiling when installed. In certain exemplary embodiments, more than one renovation mat is positioned under the tiles of the ceiling tile framework.

While particular embodiments are described herein, one of ordinary skill in the art will recognize that various other combinations of elements are possible and will fall within the general inventive concepts. Likewise, one of ordinary skill in the art will understand that the various embodiments of renovation mats described herein are suitable for use in the methods described herein.

Examples

As previously mentioned, when developing a renovation mat, it is important to balance the stain covering/opacity of the renovation mat and the ability of the renovation mat to be acoustically open and not to degrade the acoustic absorption of the existing ceiling tile framework (or the individual ceiling tiles with which it is associated). To this end, a series of renovation mats were constructed and tested at various add-on amounts. These products were made by application of an impregnation (filler composition) on a bound web of non-woven glass fibres.

In this example, a 50 grams per square meter (g/m2) veil was used, composed of glass fibres 85wt% and polyvinyl alcohol binder 15wt%. The glass fibres used in this example are so called wet used chopped strands made from Advantex E glass. The glass fibres in this example are a blend of 1 Ι πι / 6 mm and 6.5 μηι / 6 mm fibres at a 70wt% - 30wt% ratio. A veil is formed by using these dispersed fibres in a wet laid process using an inclined wire former. The veil is fed to a belt dryer and dried and cured to form a pre-bonded sheet. The sheet is subsequently in line impregnated using a size press Foulard applicator using a series of impregnation recipes. Add on is controlled using a foulard pressure and a vacuum system. The impregnated sheet is fed to a dryer and the product is obtained.

The composition of the impregnation consists, in general, of at least one inorganic filler and a binder (often organic). In this example, the composition of the impregnation consists of at least one inorganic filler and an organic binder and is applied as a 55 wt% dispersion in water. After drying, the filler to binder ratio is 95:5. The binder in the impregnation recipe used is a 1 :5 blend of a polyvinyl alcohol binder and a latex binder. An example recipe is seen in Table 1.


Table 1 : example recipe

In the examples shown in Figure 4 and in Tables 2 and 3 below, 50wt% of the inorganic filler is aluminium trihydrate (for fire retardance). The other 50wt% of the filler material is selected from aluminium trihydrate, calcium carbonate, medium grade china clay (kaolin), fine grade china clay, and titanium dioxide.

The add-on level (amount of filler and binder) is between 100 g/m2 and 500 g/m2. By varying the add-on level, the stain covering performance and the porosity / acoustic openness can be assessed. This can lead to a combined stain covering and acoustic open product.

As can be seen from Figure 3, there is an area of the graph that shows good performance in both stain covering and acoustic performance. Other areas are either not stain covering or too closed for porosity, or both.

In Figure 4 the performance of different fillers is shown. The different mineral fillers demonstrate unique performance profiles. Specifically, the samples made with a titanium dioxide filler or a fine china clay demonstrate a desirable balance of the required properties, while the calcium carbonate or the aluminium trihydrate did not perform as well. Further, by reducing the add-on weight, the renovation mats according to the general inventive concepts are also able to minimize sagging.

The stain covering capability of the renovation mat (expressed by the colour difference ΔΕ) may also be correlated to the amount of add-on. Generally, more add-on (i.e., more filler) gives more hiding power. However, there is a tradeoff: more add-on has a negative influence on the processability/line speed (as well as corresponding increases in raw material

consumption) and also means more weight per area. Increasing weight per area, in turn, has an effect on the sagging and deflection of the renovation mat once installed in the ceiling. Thus, in some embodiments, a target filler material has high stain covering properties at a low add-on level.

The data shown in Figure 4 is used to determine the add-on level needed to reach a specific ΔΕ level. The same is done for porosities, at specific ΔΕ levels. This is shown in Tables 2 and 3 respectively.


Table 2: Add-on (g/m2) for different fillers to reach stain covering levels (ΔΕ) of 2.0/1.5/1.0/0.5


Table 3 : Porosity (l/m2/sec) corresponding to add-on reported in Table 2

As can be seen e.g. from Tables 2 and 3, different fillers have different performance. For some fillers a lower add on (e.g. 155 g/m2) is needed to reach a ΔΕ of 2 and for some a higher add-on (e.g. 250 g/m2) is needed to get to this level. To reach a ΔΕ of 1, the lower amount of add-on is 190 g/m2 (see table 2, titanium dioxide); The higher amount of add-on is 320 g/m2 (Table 2, calcium carbonate) to reach this level of stain covering ΔΕ.

The corresponding values of porosity, related to Table 2, are reported in Table 3. The set threshold for acoustic openness is an air porosity of at least 100 l/m2/sec at 100 Pa.

In this example the aluminium trihydrate and calcium carbonate become acoustically too closed at stain covering of ΔΕ equal to 1 or lower, where the titanium dioxide and kaolins are still acoustically open at these levels. The titanium dioxide is the only filler identified to reach an even better stain covering level of ΔΕ of 0.5 and still remain acoustically open.

Table 4 also shows the average particle size of the individual filler ingredients. While not wishing to be bound by theory, particle size of the filler materials may also play a role in the balance between stain covering and opacity. In general terms, a smaller particle size should result in better stain coverage at a given add-on level.


Table 4 - Add-on amounts and particle size to reach ΔΕ of 1

As disclosed and suggested herein, the general inventive concepts relate to and contemplate an improved renovation mat for use in an existing ceiling tile framework. Furthermore, the scope of the general inventive concepts are not intended to be limited to the particular

exemplary embodiments shown and described herein. From the disclosure given, those skilled in the art will not only understand the general inventive concepts and their attendant advantages, but will also find apparent various changes and modifications to the methods and systems disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the general inventive concepts, as described and suggested herein, and any equivalents thereof.