CEILING TILE AND METHOD OF MAKING

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. § 119 (e) to U.S. Provisional Patent Application No. 63/729,736, entitled “CEILING TILE AND METHOD OF MAKING,” by Sandhya JAYARAMAN RUKMANI et al., filed Dec. 9, 2024, which is assigned to the current assignee hereof and is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to a ceiling tile and methods of making the same.

BACKGROUND

Fiberglass and mineral wool fibers are typically used as construction materials in ceiling tiles due to their ease of fabrication, high mechanical strength, resistance to spread of fire, and soundproofing properties. The ceiling tiles may be made from a water slurry of the fibers and a binder such as starch. To control the properties of ceiling tiles, additives are often added to the slurry during the tile making process. For example, foaming agents, inorganic compounds, and other additives may be included in the slurry to modulate the density, strength, and/or fire resistance properties of the ceiling tile.

In the manufacture of a desirable type of ceiling tiles, the fibers, binder, and any additives are introduced to the slurry. A mat is then formed by continuously depositing the slurry upon a moving wire screen and removing the water by drainage and suction. The mat thus formed is dried and the binder set, after which the mat is cut into units of desired dimensions. The mat may be provided with other components on at least one surface such as layered materials, fissures, perforations, or otherwise textured in order to improve its appearance and enhance its aesthetic and/or sound-absorption properties of the final ceiling tile.

There is a need in the art to find compositions that allow for improved ceiling tiles, depending on the final properties desired.

SUMMARY

According to one embodiment, a ceiling tile formulation to form a ceiing tile is disclosed. The ceiling tile formulation includes a first set of fibers and a second set of fibers, wherein the second set of fibers is different from the first set of fibers; a filler including a majority portion of the ceiling tile formulation; and at least one cationic starch; wherein the ceiling tile has a modulus of rupture (MOR) that is at least 10% greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037.

According to a further embodiment, a ceiling tile formulation to form a ceiling tile is disclosed. The ceiling tile formulation includes a first set of fibers including paper; a second set of fibers, wherein the second set of fibers is different from the first set of fibers; a filler; and at least one cationic starch; wherein the ceiling tile has a modulus of rupture (MOR) that is greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037.

According to a further embodiment, a method of forming a ceiling tile is disclosed. The method includes: providing a ceiling tile formulation including: a first set of fibers including paper and a second set of fibers, wherein the second set of fibers is different from the first set of fibers; a filler; and at least one cationic starch; wherein the ceiling tile has a modulus of rupture (MOR) that is at least 10% greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and are not limited by the accompanying figure.

FIG. 1 is a bottom schematic perspective view of a ceiling panel according to an embodiment of the disclosure.

FIG. 2 is a graphical depiction of a modulus of rupture for exemplary ceiling tiles with native starch versus cationic starch.

FIG. 3 is a graphical depiction of a modulus of rupture for exemplary ceiling tiles with native starch versus cationic starch.

FIG. 4 is a graphical depiction of a starch retention for exemplary ceiling tiles with native starch versus cationic starch.

FIG. 5 is a graphical depiction of a starch retention for exemplary ceiling tiles with native starch versus cationic starch.

Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures can be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.

DETAILED DESCRIPTION

The following description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings.

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus.

As used herein, and unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and may be found in textbooks and other sources within the construction products arts.

Various embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings.

The present disclosure is concerned with a ceiling tile formulation and methods for making them. In an embodiment, the ceiling tile formulation to form a ceiling tile includes at least a first set of fibers and a second set of fibers, where the first and second set of fibers are different. Further included in the ceiling tile formulation are components such as a filler and at least one cationic starch. In an embodiment, the use of cationic starch provides a ceiling tile with a modulus of rupture (MOR) that is greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037. In an embodiment, the modulus of rupture is at least 10% greater than an equivalent ceiling tile without a cationic starch. “An equivalent ceiling tile without a cationic starch” is defined as a ceiling tile made from a formulation having all the same components but with a non-modified starch, i.e. natural starch without an ionic charge, in place of the cationic starch. In an embodiment, the ceiling tile formulation may have a particular composition that may facilitate improved performance and/or manufacturing of the ceiling tile.

In an embodiment, the ceiling tile formulation may include at least one set of fibers, and in particular, a first set of fibers and a second set of fibers. Any fibers are envisioned. In an embodiment, the first set of fibers and second set of fibers include mineral wool, fiberglass, gypsum, wood fiber, paper, cellulose fiber, or combination thereof. In a particular embodiment, the first set of fibers is paper. In an example, the second set of fibers are mineral wool, fiberglass, or combination thereof.

In an embodiment, any amount of the at least one set of fibers is envisioned. For instance the at least one set of fibers is present at greater than 10 wt. %, such as greater than 12.5 wt. %, such as greater than 15 wt. %, such as greater than 17.5 wt. %, or even greater than 20 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the at least one set of fibers are present at less than 95 wt. %, such as less than 90 wt. %, or less than 85 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that the at least one set of fibers may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the at least one set of fibers may be present at any value between any of the minimum and maximum values noted above. For example, the at least one set of fibers can be present in a range of from 15 wt. % to 60 wt. % or from 25 wt. % to 85 wt. % of the total weight of the ceiling tile formulation. In a particular embodiment, the at least one set of fibers are present from 10 wt. % to 95 wt. % of the total weight of the ceiling tile formulation.

Typically, in a particular embodiment, the paper fibers are present at an advantageous amount in the ceiling tile formulation. For instance, the paper fibers are present at greater than 5 wt. %, such as greater than 7.5 wt. %, such as greater than 10 wt. %, such as greater than 12.5 wt. %, such as greater than 15 wt. %, such as greater than 17.5 wt. %, or even greater than 20 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the paper fibers are present at less than 40 wt. %, such as less than 35 wt. %, or less than 30 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that the paper fibers may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the paper fibers may be present at any value between any of the minimum and maximum values noted above. For example, the paper fibers can be present in a range of from 7.5 wt. % to 40 wt. % or from 10 wt. % to 32 wt. % of the total weight of the ceiling tile formulation. In a particular embodiment, the paper fibers are present from 5.0 wt. % to 15 wt. % or from 10 wt. % to 20 wt. % of the total weight of the ceiling tile formulation.

In an embodiment, the second set of fibers are mineral wool. When present, the mineral wool fibers are present at greater than 1.0 wt. %, such as greater than 5.0 wt. %, such as greater than 10 wt. %, such as greater than 15 wt. %, such as greater than 20 wt. %, such as greater than 25 wt. %, or even greater than 30 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the mineral wool fibers are present at less than 80 wt. %, such as less than 75 wt. %, such as less than 70 wt. %, such as less than 65 wt. %, such as less than 60 wt. %, such as less than 55 wt. %, such as 50 wt. %, such as less than 45 wt. %, such as less than 40 wt. %, such as less than 35 wt. %, such as less than 30 wt. %, or less than 25 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that the mineral wool fibers may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the mineral wool fibers may be present at any value between any of the minimum and maximum values noted above. In a particular embodiment, the mineral wool fibers are present from 30 wt. % to 80 wt. % or from 0 wt. % to 25 wt. % of the total weight of the ceiling tile formulation.

In an embodiment, the ceiling tile formulation may include yet another set of fibers, such fiberglass. When present, the fiberglass is present at greater than 0.5 wt. %, such as greater than 1.0 wt. %, such as greater than 1.5 wt. %, or even greater than 2.0 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the fiberglass is present at less than 20 wt. %, such as less than 17.5 wt. %, such as less than 15 wt. %, such as less than 12.5 wt. %, such as less than 10 wt. %, such as less than 7.5 wt. %, or less than 5.0 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that the fiberglass may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the fiberglass may be present at any value between any of the minimum and maximum values noted above. In a particular embodiment, the fiberglass is present from 0 wt. % to 20 wt. % or from 0 wt. % to 5 wt. % of the total weight of the ceiling tile formulation.

In an embodiment, the at least one set of fibers may have any sizing. In a particular embodiment, the sizing enhances the processability of the material. The sizing may be, for instance, on the first set of fibers, the second set of fibers, or combination thereof. Any sizing is envisioned. For instance, the sizing includes rosin, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), or combination thereof. In a particular embodiment, a sizing is present on the first set of fibers when the first set of fibers are paper. Although not being bound by theory, the AKD may be particularly advantageous as a cationic sizing that may react with cellulose fibers in paper pulp to form a water-repellent film on the surface of the fibers. In another embodiment, and also not being bound by theory, the ASA may improve the water repellency of paper fibers as well as resistance to liquid penetration and liquid absorption.

In a particular embodiment, the at least one set fibers can be any length such as continuous strand, chopped, or combination thereof. In a more particular embodiment, the fibers are chopped into a suitable length to provide a substantially random orientation of fibers. A “chopped fiber” typically describes randomly oriented chopped filaments or fibers, wherein the chopped fibers are randomly oriented individually or in a group. Any reasonable length of fibers is envisioned and may be the same or different, depending on the set of fibers. Generally, the fibers have an average length of about 0.5 mm to about 12.5 mm. Any reasonable diameter of fibers is envisioned and may be the same or different, depending on the set of fibers. Generally, the fibers have an average diameter of about 0.5 microns to about 100 microns. It will be appreciated that the fibers length and diameter may be present within a range between any of the minimum and maximum values noted above.

Further included in the ceiling tile formulation is the cationic starch. In a particular embodiment, the cationic starch has a positive charge and can be from a chemical modification of a natural starch. For instance, any reasonable chemical modification may be envisioned that imparts a positive charge on the starch. In an embodiment, the cationic starch includes an amine group, a phosphate group, an amino group, an imino group, an ammonium group, a sulfonium group, a phosphonium group, or combination thereof. In an embodiment, the cationic starch that is chemically modified is formed from a natural starch, such as, a corn starch, a sorghum starch, a wheat starch, a tapioca starch, a rice starch, a pea starch, a potato starch, a maize starch, barley starch, cassava starch, arrowroot starch, beet starch, or any combination thereof.

In an embodiment, the cationic starch may be present to provide desirable properties to the final ceiling tile. In an embodiment, the cationic starch is present at less than 15 wt. %, such as less than 10 wt. %, such as less than 9 wt. %, or less than 8 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the cationic starch is present at greater than 2 wt. %, such as greater than 3 wt. %, such as greater than 4 wt. %, or greater than 5 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that cationic starch may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the cationic starch may be present at any value between any of the minimum and maximum values noted above. In a particular embodiment, the cationic is present from 5 wt. % to 15 wt. % or from 5 wt. % to 10 wt. % of the total weight of the ceiling tile formulation.

In a particular embodiment, the cationic starch has a desirable particle size. For instance, the cationic starch has a median particle size of at least 25 microns (μm) and not greater than 100 microns. The particle size may be particularly advantageous for particle distribution. For instance, the particle size of the cationic starch provides particle distribution that is homogenous through the ceiling tile formulation. Although not being bound by theory, the cationic starch acts as a binder in the ceiling tile formulation and with the homogenous particle distribution, the uniformity throughout the ceiling tile formulation provides desirable mechanical properties. For instance, the particle size is particularly advantageous for retention within the resulting ceiling tile.

Further included in the ceiling tile formulation is a filler. Any reasonable filler is envisioned. In a particular embodiment, the filler is inorganic. Examples of suitable fillers include dolomite, wollastonite, saw dust, fly ash, recycled plastic, rubber crumb, gypsum, glass, perlite, wood pulp, recycled paper, recycled glass, or combination thereof. In a particular embodiment, the filler consists essentially of perlite. As used herein the phrase “consists essentially” refers to including at least 95 wt. % of a given material, such as perlite is at least 95 wt. % of a total weight % of the filler. In a more particular embodiment, the filler consists of perlite.

In an embodiment, the filler may be present to provide desirable properties to the final ceiling tile. In an embodiment, the filler is present at greater than 5 wt. %, such as greater than 10 wt. %, such as greater than 15 wt. %, such as greater than 20 wt. %, such as greater than 25 wt. %, such as greater than 30 wt. %, such as greater than 35 wt. %, such as greater than 40 wt. %, such as greater than 45 wt. %, such as greater than 50 wt. %, such as greater than 55 wt. %, such as greater than 60 wt. %, or greater than 65 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the filler is present at less than 90 wt. %, such as less than 85 wt. %, such as less than 80 wt. %, such as less than 75 wt. %, such as less than 70 wt. %, such as less than 65 wt. %, such as less than 60 wt. %, such as less than 55 wt. %, such as less than 50 wt. %, such as less than 45 wt. %, such as less than 40 wt. %, such as less than 35 wt. %, or even less than 30 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that filler may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the filler may be present at any value between any of the minimum and maximum values noted above. In a particular embodiment, the filler is present from 5 wt. % to 35 wt. % or from 35 wt. % to 75 wt. % of the total weight of the ceiling tile formulation. In an embodiment, the filler is a majority portion of the ceiling tile formulation. “A majority portion” as used herein refers to a component with the highest weight percent (wt. %) of the total weight of the ceiling tile formulation. In an example, perlite is a majority portion of the ceiling tile formulation.

The formulation of the ceiling tile may also contain a variety of other known additives such as an adhesion promoter to enhance the bonding strength between the at least one set of fibers, a silica colloid to enhance fire resistance, a recycled ceiling board, an antifoamer, a biocide, a pigment, the like, or combinations thereof. In an embodiment, the ceiling tile formulation can include less than about 40% by weight of additives, such as less than about 35 wt. %, such as less than about 30 wt. %, or even less than about 25 wt. %, of the total weight of the ceiling tile formulation. The additives may be present at greater than 0 wt. %, such as greater than 1 wt. %, such as greater than 5 wt. %, such as greater than 10 wt. %, such as greater than 15 wt. %, such as greater than 20 wt. % of the total weight of the ceiling tile formulation. It will be appreciated that additive may be present within a range between any of the minimum and maximum values noted above. It will be further appreciated that the additive may be present at any value between any of the minimum and maximum values noted above. In a particular embodiment, the additive is present from 0 wt. % to 40 wt. % of the total weight of the ceiling tile formulation. In another embodiment, the ceiling tile formulation is substantially free of additives. “Substantially free” as used herein refers to less than about 1% by weight of additives, less than about 0.5% by weight of additives, or even less than about 0.1% by weight of additives of the total weight of the ceiling tile formulation.

In an embodiment, the ceiling tile may have a particular thickness that may facilitate improved performance and/or manufacturing of the ceiling tile. In an embodiment, the thickness may be at least 0.05 inches. In an embodiment, the thickness may be less than 1.5 inches. Alternatively, the thickness may be at least 0.5 inches and not greater than 1.2 inches. It will be appreciated that the thickness may be between any of the minimum and maximum values noted above.

Any method of forming the ceiling tile is envisioned. Typically, an aqueous solution of the ceiling tile formulation is formed including, for instance, the first set of fibers and the second set of fibers, where the second set of fibers is different from the first set of fibers; the filler; and at least one cationic starch to form a slurry. Any order of dispersing the components of the slurry are envisioned to form the aqueous dispersion. The aqueous dispersion is then agitated under any reasonable conditions so that the components are uniformly distributed throughout the slurry. Any rate and duration of agitation are envisioned. For instance, the slurry may be mixed for about 10 to 60 minutes by means of a rotary agitator (impeller) revolving at a rate of about 100 to 150 revolutions per minute.

Once agitated, the slurried ceiling tile formulation may be transferred to a support surface. The aqueous solution is removed to form a wet laid mat. The aqueous solution is removed from the wet laid mat, which is subsequently dried via any method envisioned such as gravity, suction, heat, rollers, air blowers, the like, or combination thereof to form a ceiling tile that has a first surface and a second surface. Typically, the dried mat has a moisture content of less than about 1.0 wt. % based on the final weight of the ceiling tile formulation.

Any further processing of the ceiling tile is envisioned and depends on the final properties desired. For instance, perforations may be formed. In an embodiment, the ceiling tile may be cut into panels. In an embodiment, the dried product can be subjected to any suitable conventional finishing apparatus, depending on the applications for which it is intended. Such apparatuses may include applicators for applying coatings to protect and/or decorate the product surface, such as bevel coaters, finish spray coaters, printers, multi-color decorative coaters, and the like, and further drying equipment.

In an embodiment, the ceiling tile may include any further components such as a veil, an abrasive material, a liner, a polymer layer that may be a coating layer and/or a finish coating, the like, or combination thereof. For instance, a polymer layer includes polyurethanes, polyacrylates, styrene-acrylate copolymers, styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-butadiene copolymers, poly(vinyl acetate) (PVAc), poly(ethylene-vinyl acetate) (EVA), ethylene-vinyl chloride copolymers, polystyrene, poly vinyl alcohol, or combination thereof. When present, the polymer layer is present at an amount of at least 2 wt. % and not greater than 20 wt. % of the total weight of the ceiling tile.

In an embodiment, the veil includes an air permeable material. For example, in some embodiments, the veil is formed of a fiberglass mat. In other embodiments, the veil is formed by an air permeable polymer sheet, such as a sheet including polyester or PET. In some embodiments, the veil is formed of a woven or non-woven fibrous material. In a particular embodiment, the veil is a non-woven fiberglass mat.

In an embodiment, a textured appearance can be created on one of the two major surfaces of the ceiling tile by any suitable texturing means, such as by abrading, scoring, brushing, etc. For instance, suitable abrasive material for eroding the surface includes metal grit, plastic abrasive, and walnut shells. Typically, the surface abrasion removes only about 0.01 inch to 0.04 inch of the ceiling tile surface in producing the desired look. The finish coat is suitably applied to the ceiling tile surface after its treatment by a blasting machine.

In an embodiment, the ceiling tile may have a density of from about 10 to 25 pounds per cubic foot, such as from about 10 to 20 pounds per cubic foot. In a particular embodiment, the ceiling tile has advantageous acoustic properties. For instance, the ceiling tile may have a noise reduction coefficient (NRC) of about 0.50-0.70, or even greater than 0.55, and can be secured without the use of mechanical punching or fissuring, although, if desired, the latter means of perforating the board surface can be employed to further enhance the NRC.

An exemplary ceiling panel is shown in a bottom perspective view in FIG. 1. A finished ceiling panel 110 has a length 112 extending from a first end 114 to a second end 116, a width 118 extending from a first side 120 to a second side 122, and a thickness 124 extending between an upper surface 126 and a lower surface 128. In an embodiment, ceiling panel 110 includes a ceiling tile 130 formed of the ceiling tile formulation. Ceiling panel 110 has an upper face 132 and a lower face 134. As shown in FIG. 1, a pattern 136 of perforations 138 may be formed in the lower face 134 of the ceiling tile 130. Pattern 136 of perforations 138 may cover any portion of the overall area of lower face 134.

In an embodiment, the ceiling panel 110 may provide advantageous acoustic properties by including a polymer-coating layer 150 that is disposed on upper face 132 of ceiling tile 130 and a veil 155 that is disposed on lower face 134 of ceiling tile 130. A portion of veil 155 is removed to reveal the pattern 136 of perforations on lower face 134 of ceiling tile 130. Each of the polymer-coating layer 150 and veil 155 are coextensive over the entire upper face 132 and lower face 134 of ceiling tile 130, respectively. Although not illustrated, the ceiling tile 130 may include an additional second polymer layer or second veil on the upper face 132, lower face 134, or combination thereof. In an embodiment, the ceiling panel 110 does not include a veil 155, a polymer-coating layer 150, or combination thereof.

In an embodiment, the ceiling tile formulation forms a ceiling tile having desirable properties, such as physical and mechanical properties. In an embodiment, the ceiling tile may have an advantageous modulus of rupture. In an embodiment, the modulus of rupture may be at least 10% greater, such as at least 15% greater, such as at least 20% greater, or at least 25% greater than the equivalent ceiling tile without the cationic starch. The modulus of rupture is measured according to the procedure outlined in the examples section of this application. In an embodiment, the ceiling tile has a modulus of rupture of at least 45 psi. Although not being bound by theory, the cationic starch provides improved product strength compared to a natural starch with no ionic charge. For instance, the cationic starch may provide an improved modulus of rupture due to an interaction of the cations with any anions that may be present on the at least one set of fibers.

Further, the ceiling tile formulation has an advantageous starch retention. An advantageous starch retention provides an efficient process and less waste of starch. Further, an improved starch retention may help increase the product strength (i.e. modulus of rupture). For instance, the cationic starch has a retention that is at least 5% greater, such as at least 10% greater, or at least 15% greater than the equivalent ceiling tile without the cationic starch. The starch retention is measured according to the procedure outlined in the examples section of this application.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the items as listed below.

Embodiments

Embodiment 1. A ceiling tile formulation to form a ceiling tile includes: a first set of fibers and a second set of fibers, wherein the second set of fibers is different from the first set of fibers; a filler including a majority portion of the ceiling tile formulation; and at least one cationic starch; wherein the ceiling tile has a modulus of rupture (MOR) that is at least 10% greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037.

Embodiment 2. A ceiling tile formulation to form a ceiling tile includes: a first set of fibers; a second set of fibers, wherein the second set of fibers is different from the first set of fibers; a filler; and at least one cationic starch; wherein the ceiling tile has a modulus of rupture (MOR) that is greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037.

Embodiment 3. A method of forming a ceiling tile, wherein the method includes: providing a ceiling tile formulation including: a first set of fibers and a second set of fibers, wherein the second set of fibers is different from the first set of fibers; a filler; and at least one cationic starch; wherein the ceiling tile has a modulus of rupture (MOR) that is at least 10% greater than an equivalent ceiling tile without a cationic starch, wherein the MOR is measured by modified ASTM D 1037 or the cationic starch has a median particle size of at least 25 microns (μm) and not greater than 100 microns, or both.

Embodiment 4. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the cationic starch is present at less than 15 wt. %, such as less than 10 wt. %, such as less than 9 wt. %, or less than 8 wt. % of the total weight of the ceiling tile formulation.

Embodiment 5. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the cationic starch is present at greater than 2 wt. %, such as greater than 3 wt. %, such as greater than 4 wt. %, or greater than 5 wt. % of the total weight of the ceiling tile formulation.

Embodiment 6. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the cationic starch includes an amine group, a phosphate group, an amino group, an imino group, an ammonium group, a sulfonium group, a phosphonium group, or combination thereof.

Embodiment 7. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the cationic starch has a median particle size of at least 25 microns (μm) and not greater than 100 microns.

Embodiment 8. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the first set of fibers and second set of fibers include mineral wool, fiberglass, gypsum, wood fiber, paper, cellulose fiber, or combination thereof.

Embodiment 9. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 8, wherein the first set of fibers includes paper.

Embodiment 10. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 9, wherein the paper fibers are present at greater than 5 wt. %, such as greater than 7.5 wt. %, such as greater than 10 wt. %, such as greater than 12.5 wt. %, such as greater than 15 wt. %, such as greater than 17.5 wt. %, or even greater than 20 wt. % of the total weight of the ceiling tile formulation.

Embodiment 11. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the paper fibers are present at less than 40 wt. %, such as less than 35 wt. %, or less than 30 wt. % of the total weight of the ceiling tile formulation.

Embodiment 12. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 8, wherein the second set of fibers includes mineral wool, fiberglass, or combination thereof.

Embodiment 13. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the first set of fibers and second set of fibers have an average length within the range of about 0.05 mm to about 12.5 mm.

Embodiment 14. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, further including an anionic sizing on the first set of fibers, the second set of fibers, or combination thereof.

Embodiment 15. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the filler includes dolomite, wollastonite, saw dust, fly ash, recycled plastic, rubber crumb, gypsum, glass, perlite, wood pulp, recycled paper, recycled glass, or combination thereof.

Embodiment 16. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 15, wherein the filler consists essentially of perlite.

Embodiment 17. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiments 1 or 3-16, wherein the filler is present at greater than 30 wt. %, such as greater than 45 wt. %, such as greater than 50 wt. %, such as greater than 55 wt. %, such as greater than 60 wt. %, or greater than 65 wt. % of the total weight of the ceiling tile formulation.

Embodiment 18. The ceiling tile formulation of method of making the ceiling tile in accordance with embodiments 2-16, wherein the filler is present at less than 90 wt. %, such as less than 85 wt. %, such as less than 80 wt. %, such as less than 75 wt. %, such as less than 70 wt. %, such as less than 65 wt. %, or even less than 60 wt. % of the total weight of the ceiling tile formulation.

Embodiment 19. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the ceiling tile further includes a polymer layer.

Embodiment 20. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 19, wherein the polymer layer includes polyurethanes, polyacrylates, styrene-acrylate copolymers, styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-butadiene copolymers, poly(vinyl acetate) (PVAc), poly(ethylene-vinyl acetate) (EVA), ethylene-vinyl chloride copolymers, polystyrene, poly vinyl alcohol, or combination thereof.

Embodiment 21. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 19, wherein the polymer layer is present at an amount of at least 2 wt. % based on the total weight of the ceiling tile.

Embodiment 22. The ceiling tile formulation or method of making the ceiling tile in accordance with embodiment 19, wherein the polymer layer is present at an amount of not greater than 20 wt. % based on the total weight of the ceiling tile.

Embodiment 23. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the ceiling tile has a thickness of about 0.05 inches to 1.5 inches.

Embodiment 24. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the modulus of rupture is at least 15% greater, such as at least 20% greater, or at least 25% greater than the equivalent ceiling tile without the cationic starch.

Embodiment 25. The ceiling tile formulation or method of making the ceiling tile in accordance with any of the preceding embodiments, wherein the cationic starch has a retention that is at least 5% greater, such as at least 10% greater, or at least 15% greater than the equivalent ceiling tile without the cationic starch.

Embodiment 26. The method of making the ceiling tile in accordance with embodiments 3-25, wherein providing the ceiling tile formulation includes dispersing the first set of fibers and second set of fibers, filler, and at least one cationic starch in an aqueous solution to form an aqueous dispersion; agitating the dispersion; removing the aqueous solution to form a wet laid mat; and drying the wet laid mat to form the ceiling tile.

Embodiment 27. The method of making the ceiling tile in accordance with embodiments 3-26, further including applying a polymer layer on at least one surface of the ceiling tile.

Embodiment 28. The method of making the ceiling tile in accordance with embodiments 3-26, further including applying a fiberglass veil on at least one surface of the ceiling tile.

Embodiment 29. A ceiling tile formulation to form a ceiling tile includes: a first set of fibers including paper; a second set of fibers comprising mineral wool, fiberglass, or combination thereof; a filler including a majority portion of the ceiling tile formulation; and at least one cationic starch.

Embodiment 30. The ceiling tile formulation in accordance with embodiment 29, wherein the cationic starch is present at less than 15 wt. %, such as less than 10 wt. %, such as less than 9 wt. %, or less than 8 wt. % of the total weight of the ceiling tile formulation.

Embodiment 31. The ceiling tile formulation in accordance with embodiments 29-30, wherein the cationic starch is present at greater than 2 wt. %, such as greater than 3 wt. %, such as greater than 4 wt. %, or greater than 5 wt. % of the total weight of the ceiling tile formulation.

Embodiment 32. The ceiling tile formulation in accordance with embodiments 29-31, wherein the cationic starch includes an amine group, a phosphate group, an amino group, an imino group, an ammonium group, a sulfonium group, a phosphonium group, or combination thereof.

Embodiment 33. The ceiling tile formulation in accordance with embodiments 29-32, wherein the cationic starch has a median particle size of at least 25 microns (μm) and not greater than 100 microns.

Embodiment 34. The ceiling tile formulation in accordance with embodiments 29-33, wherein the first set of paper fibers are present at greater than 5 wt. %, such as greater than 7.5 wt. %, such as greater than 10 wt. %, such as greater than 12.5 wt. %, such as greater than 15 wt. %, such as greater than 17.5 wt. %, or even greater than 20 wt. % of the total weight of the ceiling tile formulation.

Embodiment 35. The ceiling tile formulation in accordance with embodiments 29-34, wherein the first set of paper fibers present at less than 40 wt. %, such as less than 35 wt. %, or less than 30 wt. % of the total weight of the ceiling tile formulation.

Embodiment 36. The ceiling tile formulation in accordance with embodiments 29-35, wherein the first set of paper fibers, the second set of fibers, or combination thereof have an average length within the range of about 0.05 mm to about 12.5 mm.

Embodiment 37. The ceiling tile formulation in accordance with embodiments 29-36, further including an anionic sizing on the first set of paper fibers, the second set of fibers, or combination thereof.

Embodiment 38. The ceiling tile formulation in accordance with embodiments 29-37, wherein the filler includes dolomite, wollastonite, saw dust, fly ash, recycled plastic, rubber crumb, gypsum, glass, perlite, wood pulp, recycled paper, recycled glass, or combination thereof.

Embodiment 39. The ceiling tile formulation in accordance with embodiment 38, wherein the filler consists essentially of perlite.

Embodiment 40. The ceiling tile formulation in accordance with embodiments 29-39, wherein the filler is present at greater than 30 wt., %, such as greater than 35 wt. %, such as greater than 40 wt. %, such as at greater than 50 wt. %, such as greater than 55 wt. %, such as greater than 60 wt. %, or greater than 65 wt. % of the total weight of the ceiling tile formulation.

Embodiment 41. The ceiling tile formulation in accordance with embodiments 29-40, wherein the ceiling tile has a thickness of about 0.05 inches to 1.5 inches.

Embodiment 42. The ceiling tile formulation in accordance with embodiments 29-41, wherein the ceiling tile has a modulus of rupture at least 10% greater, such as at least 15% greater, such as at least 20% greater, or at least 25% greater than an equivalent ceiling tile without the cationic starch.

Embodiment 43. The ceiling tile formulation in accordance with embodiments 29-42, wherein the cationic starch has a retention that is at least 5% greater, such as at least 10% greater, or at least 15% greater than an equivalent ceiling tile without the cationic starch.

The concepts described herein will be further described in the following examples, which do not limit the scope of the disclosure described in the claims. The following examples are provided to better disclose and teach processes and compositions of the present invention. They are for illustrative purposes only, and it must be acknowledged that minor variations and changes can be made without materially affecting the spirit and scope of the invention as recited in the claims that follow.

Examples

Ceiling tiles with Formula A (mineral wool with native starch) and Formula B (mineral wool with cationic starch) were fabricated through wet-felt process referenced under embodiments. Formula A and Formula B both had mineral wool, paper, expanded perlite filler, either a native starch or cationic starch within the ranges disclosed above. Formula A and Formula B each had the same amount (wt. %) of mineral wool, paper fiber, expanded perlite, and starch with Formula A having native starch and Formula B having cationic starch, with the same amount (wt. %) of starch being used in each formulation.

Ceiling tiles with Formula C (fiberglass and native starch) and Formula D (fiberglass with cationic starch) were fabricated through wet-felt process referenced under embodiments. Formula C and Formula D both had fiberglass, paper (e.g. DLK pulp), expanded perlite filler, either a native starch or cationic starch within the ranges disclosed above. Formula C and Formula D each had the same amount (wt. %) of fiberglass, paper fiber (e.g. DLK pulp), expanded perlite, and starch with Formula C having native starch and Formula D having cationic starch, with the same amount (wt. %) of starch being used in each formulation.

The particle size distribution of all the starches was measured in water (at room temperature) with the Mastersizer 3000 from Malvern equipment (laser diffraction). Ultrasounds were added in order to avoid any agglomeration. Commonly, the few data are extracted from the PSD curves: D10, D50 and D90.

The mean particle sizes of the native starch versus the cationic starch can be seen in Table 1.

	TABLE 1
	Starch type	D10 (μm)	D50 (μm)	D90 (μm)

	Native	9.8	14.8	23.5
	Cationic	16.1	53.1	97.9

D10, D50 and D90 represent the particle size or particle diameter at which 10%, 50% (median) and 90% of the particles are smaller, respectively. For instance, D10 is the particle diameter at which 10% of the sample's particles are smaller than this size. D50 is also known as the median diameter or median particle size and is the particle diameter at which 50% of the sample/s particles are smaller than this size, and 50% are larger. D90 is the particle diameter at which 90% of the sample's particles are smaller than this size, meaning only 10% are larger. Clearly, the cationic starch had a larger mean particle size than the native starch. Although not being bound by theory, the larger median particle size of the cationic starch may have contributed to the increased modulus of rupture and starch retention compared to the native starch in the ceiling tile formulations.

Samples were tested as follows:

MOR test method: The max load was measured by 3-point bend test per modified ASTM D 1037. The only variance from ASTM method was the sample size (used 6 “×12” vs. method references 3″×6″). The MOR (psi) was calculated using the following equation:

MOR = 3 × Load × Span 2 × Sample ⁢ Width × ( Thickness ) 2

• • Load=the value from the Instron (lb.)
  • Span=10 inches
  • Sample Width=6 inches
  • Thickness=average value previously calculated (inches)

Starch retention test:

For starch retention, a calibration curve based on the specific starch was completed first. The calibration curve relates the absorbance reading to a specific mass of starch. To do this, various starch solutions were made ranging from 0 to 100 PPM and the iodine assay was performed. This generated the slope used in the equations later.

For sample prep, a white water drain sample was taken during the TAPPI making process. This represented the soluble starch. The headbox (initial) starch content was calculated based on solid content and consistency (see below). Using vacuum filtration, all the solid material was removed and obtained by our filtrate. The filtrate was diluted and used for an Iodine assay. The dilution factor was determined based on what dilution would give an absorbance reading from 0.2 to 1. If the absorbance was outside this range, the dilution factor was changed. The diluted filtrate was then placed in a spectrometer first without iodine to zero the equipment. Iodine was then added and measured again in the spectrometer. This gave the absorbance value which was used to determine retention.

Soluble ⁢ starch ⁢ ( white ⁢ water ) ⁢ ( ppm ) = D × A uncooked × S ;

• • where D-dilution factor, A_uncooked−absorbance for an uncooked sample at 600 nm, S−slope from the calibration curve.

Total ⁢ starch ⁢ ( Headbox ) ⁢ ( ppm ) = Consistency * 10000 * ( starch ⁢ solids / total ⁢ solids ) Retention = ( ( Total ⁢ starch - soluble ⁢ starch ) / Total ⁢ starch ) ) × 100

The graphs in FIGS. 3, 4, 5, and 6 show the improvement in MOR (modulus of rupture), a measure of product strength, as well as starch retention of exemplary ceiling tiles made with cationic starch vs. native starch-based formulations.

In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the invention.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.