Abstract: The present invention relates to a system and associated method for the production of gypsum in manufacturing plant. More specifically, the invention relates to the production of alpha-type gypsum in a gypsum board manufacturing plant. The system yields increased efficiencies by capturing heat given off during processing steps and using that heat to reduce the energy needed for calcination. The invention finds particular application in the production alpha-type gypsum. The present invention is described in greater detail hereinafter in conjunction with the following specific embodiments.

Abstract: A gypsum board forming device (10) constitutes an apparatus of producing gypsum boards. A layered formation of a lower sheet (1), an upper sheet (2) and a gypsum slurry (6) passes through a forming gate (40). The forming device forms the formation into a plate-like configuration with use of upper and lower plates (20, 30). The upper plate (20) is constituted from a fixed substrate plate (21) and a movable plate (22), and the movable plate is in surface-to-surface contact with the upper sheet of the layered formation. A plurality of actuators (50) is supported by the substrate plate. Each of the actuators applies an upward or downward load (P) to the movable plate locally for a local deformation of the movable plate owing to a deflection thereof. A gate size (T) is locally changed by displacement of the movable plate relative to the substrate plate.

Abstract: A gypsum stucco composition comprising the following components finely divided; calcium sulphate hemihydrate in calcined solid beta crystalline form; and in intimate mixture with said finely divided calcium sulphate hemihydrate and mixed therewith no later than calcination to form the hemihydrate, a sulphate salt comprising at least one of ammonium sulphate and aluminium sulphate, in an amount such that when the stucco composition is mixed with water and allowed to set, the resulting set plaster has increased compressive strength, flexural strength and/or E-modulus compared to a set plaster produced from said finely divided calcium sulphate hemihydrate containing no said sulphate salt.

Abstract: Wallboards, as well as other building materials, are produced by methods which use significantly reduced embodied energy, generating far less greenhouse gases when compared with the energy used to fabricate gypsum wallboard. A novel cementitious core, consisting in one embodiment of post-industrial waste such as slag and combined with pH modifiers, provides a controlled exothermic reaction to create a gypsum-wallboard-like core which can be wrapped in a selected material such as recycled paper and manufactured on a conveyor system to appear, weigh and handle similar to gypsum wallboard, but without the large amounts of energy required to make gypsum wallboard. The manufacturing process results in lower greenhouse gas emissions than the processes used to make gypsum wallboard.

Abstract: The present invention relates to a method for producing three-dimensional plaster objects via thin layer deposition. The inventive method comprises steps of depositing a layer of a calcium sulfate hemihydrate slurry onto the surface of a support in a predetermined pattern and activating the slurry with an activating agent so as to accelerate the setting reaction of calcium sulfate hemihydrate and water to form set calcium sulfate dihydrate. The depositing and activating steps can be repeated as necessary until the desired three-dimensional plaster object is formed.

Abstract: A building material product comprising a cementitious binder, an aggregate and cellulose reinforcing fibers wherein the cellulose reinforcing fibers have been treated with cationic or nonionic oil. The resulting fiber when included in a fiber cement composite results in improved deflection of the composite at peak loading as well as improved impact strength while maintaining overall board strength.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: Cementitious compositions and methods for making same, in which the cementitious compositions include 35-60 wt. % cementitious reactive powder (also termed Portland cement-based binder), 2-10 wt. % expanded and chemically coated perlite filler, 20-40 wt. % water, entrained air, and optional additives such as water reducing agents, chemical set-accelerators, and chemical set-retarders. In addition, the lightweight cementitious compositions may contain 0-25 wt. % on a wet basis secondary fillers such as expanded clay, shale aggregate, and pumice.

Abstract: Provided herein is an aqueous wax emulsion, comprising water; a paraffinic hydrocarbon; polyvinyl alcohol and a wax component comprising synthetic olefin wax component. The synthetic olefin wax component may be selected from the group consisting of (i) a synthetic normal ?-olefin wax; (ii) a synthetic olefin wax of a carbon chain length of about 20 or more carbon atoms, that is modified by oxidizing and/or by refining through distillation or stripping; and (iii) combinations thereof. Such emulsions are also useful for settable gypsum compositions and water-resistant wallboard formed therefrom. Also included herein is a montan wax substitute for use in an aqueous montan-based wax emulsion.

Abstract: A slurry for manufacturing gypsum board comprises calcined gypsum, water, a foaming agent, and a coalescing agent. The foaming agent imparts a plurality of bubbles in the slurry. Typically, a foam is pre-generated with the foaming agent and the foam is used to form the slurry such that the foam imparts the plurality of bubbles in the slurry. The coalescing agent coalesces the plurality of bubbles imparted by the foam. Typically, the coalescing agent coalesces a plurality of small and partially joined bubbles imparted by the foam to create larger and more discrete bubbles. A gypsum board and method of forming the slurry and the gypsum board are also disclosed. The gypsum board comprises a gypsum layer formed from the slurry. The gypsum layer defines a plurality of bubbles dispersed therein, which are imparted by the foam and coalescing agent of the slurry.

Abstract: The invention provides in one embodiment a gypsum-containing slurry including stucco and an aqueous pre-dispersion of a pregelatinized starch. Also provided is a method of making gypsum wallboard by providing a pre-dispersion of the pregelatinized starch in water, and adding the pregelatinized starch pre-dispersion to the gypsum-containing slurry. The pregelatinized starch can have a particle size distribution within the following range: d (0.1)=about 20?-35?, d (0.5)=about 60?-110?, d (0.9)=about 100?-220?.

Abstract: Aspects of this disclosure relate to a method of manufacturing wallboard which includes providing a first layer of facing material, creasing the first layer facing material intermittently to create a series of creased portions, providing a gypsum slurry on the first layer of facing material and providing a second layer of facing material over the gypsum slurry. Further, creasing the first layer of facing material intermittently can include intermittently creasing the first layer of facing material in a substantially linear fashion extending in a first direction of the first layer of facing material so that the first layer of facing material exhibits a linear series of creased portions extending in the first direction of the first layer of facing material and a series of portions that are not creased extending in the first direction of the first layer of facing material.

Abstract: The subject of the invention is a novel plasterboard and its manufacturing processes. The novel board comprises, on one side, two first parallel feathered edges and, on the other side, two other, second, parallel feathered edges that are perpendicular to the first ones; or, on one side, two first parallel feathered edges and, either on the same side or on the other side, two second parallel feathered edges that are perpendicular to the first ones, the said other parallel feathered edges having a width of between 100 and 200 mm; or, on one side, two first parallel feathered edges and, either on the same side or on the other side, two second parallel feathered edges that are perpendicular to the first ones, the said second parallel feathered edges having a width such that the ratio of the width of the said second parallel feathered edges to the width of the said first parallel feathered edges is between 1.5 and 5.

Abstract: Disclosed herein are multilayered core cementitious boards with increased nail-pull resistance. The boards can comprise two or more layers of cementitious compositions, where each layer can be a different density. Methods of making the multilayered core boards are also disclosed. The methods include having a layer of cementitious composition partially set prior to applying the next layer.

Abstract: A building material product comprising a cementitious binder, an aggregate and cellulose reinforcing fibers wherein the cellulose reinforcing fibers have been treated with oil which is bound to the fiber by a retention aid. The resulting fiber when included in a fiber cement composite results in improved deflection of the composite at peak loading as well as improved impact strength while maintaining overall board strength.

Abstract: A method of producing gypsum building board, comprises allowing a layer of an aqueous gypsum slurry to set so as to form a board, in which the improvement comprises mixing the gypsum slurry with an aqueous foam produced by foaming water containing at least one non-ionic alkylpolysaccharide foaming agent of the general formula (I) R—O-(G)x??(I) where: R represents a linear or branched alkyl group having from 6 to 20 carbon atoms; G represents a reducing saccharide moiety connected to R via an ethereal O-glycosidical bond; and x is 1 to 10.

Abstract: The invention generally provides gypsum-containing slurries including stucco, naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1%-3.0% by weight based on the weight of dry stucco. The pregelatinized starch is present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts, accelerators, binders, paper fiber, glass fiber, and other known ingredients. The invention also comprises the gypsum-containing products made with such slurries, for example, gypsum wallboard, and a method of making gypsum wallboard.

Abstract: Disclosed is a gypsum board forming device which provides improved slurry spread. The device includes a forming table with an arcuate or angled profile that promotes a uniform slurry spread. An arcuate or angled hinge plate can also be included to further promote the uniform distribution of slurry prior to an extrusion plate. As a result of the improved slurry spread, gypsum board with increased strength and durability can be created.

Abstract: Formed building materials comprising a sequestered CO2 are provided. The building materials of the invention include a composition comprising a carbonate/bicarbonate component. Additional aspects of the invention include methods of making and using the formed building materials.

Abstract: A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. A gypsum building panel is made from the gypsum slurry.

Abstract: A process for making a fiber reinforced cementitious product such as a panel which hardens to an ultra-high compressive strength composite for use in making panels with ballistic and blast resistant properties. The panel has a continuous phase resulting from curing an aqueous mixture, in the absence of silica flour, of inorganic cement binder, inorganic mineral filler having a particle size of about 150-450 microns, pozzolanic mineral filler, and polycarboxylate based superplasticizer self-leveling agent, and water. The mixture may also include alkanolamine and acid or acid salt. The continuous phase may be reinforced with fiber distributed in the continuous phase before curing to form a panel. The panel may be reinforced with a fiber reinforced skin attached to at least one surface of the core, e.g., by lamination with an adhesive, e.g., epoxy, to form a ballistic and blast resistant cementitious armor panel.

Abstract: A gypsum board comprises a set gypsum layer having a first face and a second face. A fibrous mat is affixed to at least one of the faces. The mat comprises a non-woven web bonded together with a resinous binder. The web is composed of chopped continuous glass fibers having an average fiber diameter ranging from about 9.5 to 12.5 ?m. The board is exceedingly durable. It has a smooth surface that is readily finished in an aesthetically pleasing way, using paint or other wall covering systems.

Abstract: A fibrous mat-faced cementitious article comprising (a) a cementitious core, and (b) a first fibrous mat comprising polymer or mineral fibers and a hydrophobic finish on at least one surface thereof, wherein the hydrophobic finish is in contact with the cementitious core, and a method of preparing a fibrous mat-faced cementitious article, as well as a method of preparing a water-resistant cementitious article comprising (a) preparing an aqueous siloxane dispersion, wherein the dispersion comprises about 4 wt. % to about 8 wt. % siloxane, (b) combining the siloxane dispersion with a cementitious mixture to provide a cementitious slurry, (c) depositing the cementitious slurry onto a substrate, and (d) allowing the cementitious slurry to harden, thereby providing a cementitious article.

Abstract: The acoustical product of the present invention comprises an acoustical product including a matrix of calcium sulfate dihydrate crystals and expanded perlite distributed throughout the matrix. The expanded perlite has a particle size distribution with at least 10% of the perlite having a particle diameter of 700 microns or more, and the amount of expanded perlite to calcium sulfate dihydrate is about 35% to about 75% by weight, based upon the dry weight of the calcium sulfate dihydrate. A dispersing agent and glass fibers having a particle length of about ¼ inch to about 1 inch are dispersed throughout the gypsum matrix.

Abstract: Repulped fiber that has been treated with an aqueous solution of a caustic selected from sodium hydroxide, potassium hydroxide and sodium carbonate, is used to make wallboard paper that is used to make a gypsum wallboard having improved nail pulling strength compared to gypsum wallboard made with fiber wallboard paper that has not been treated with caustic.

Abstract: Provided are methods and systems for introducing a wet gypsum accelerator or other high viscosity production additive to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: A coalescing additive is used in the manufacturing process for gypsum wallboard. Such an additive increases the surface area and density of the slurry at the paper to core interface by coalescing the foam cells away from the paper core interface. This permits a stronger paper to core bond to form and increases the compressive strength of the gypsum wallboard as compared to standard wallboards made from slurries with reduced water levels.

Abstract: A method of determining face paper properties of all types of wallboard including providing a core strength value of the wallboard, determining a required nail pull value based the wallboard specifications and calculating a face paper stiffness value based on the provided core strength value and the determined nail pull value. The method includes displaying the calculated face paper stiffness value on a display device.

Abstract: A method for manufacturing of building boards is described. The method comprises the steps to arrange a first reinforcement layer on an underlayer such that the first reinforcement layer is essentially flat, the first reinforcement layer comprising a first side edge and a second side edge, to arrange a first edge strip having a length axis along the first side edge with the length axis being parallel to the first side edge, to arrange a hardenable substance on the first reinforcement layer in contact with the first edge strip, to arrange a second reinforcement layer on the hardenable substance such that the second reinforcement layer is essentially parallel to the first reinforcement layer, and to harden the hardenable substance.

Abstract: Laminated structures for use in building construction are fabricated by a manufacturing process such that the laminating steps to not require elevated drying temperatures or an extended dwell time at any point. The process employs stock materials that simultaneously reduce cost and improve performance. This is accomplished using a specially formulated viscoelastic glue and ambient temperature drying apparatus. As a result, the production capacity of the manufacturing facility, cost of goods, and delivered performance are greatly improved over existing methods.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The present invention relates to a system and associated method for the production of gypsum in manufacturing plant. More specifically, the invention relates to the production of alpha-type gypsum in a gypsum board manufacturing plant. The system yields increased efficiencies by capturing heat given off during processing steps and using that heat to reduce the energy needed for calcination. The invention finds particular application in the production alpha-type gypsum. The present invention is described in greater detail hereinafter in conjunction with the following specific embodiments.

Abstract: The present invention describes a fire resistant building material composition, useful for example as a fire door core and to a method of making this composition where the building material of the present invention is prepared from an aqueous slurry of calcined gypsum, paper fibers, a water insoluble organic binder, fiber reinforcement and a set retarder.

Abstract: An energy efficient method for making a gypsum cellulose fiberboard comprising adding a first portion of cellulose fiber to gypsum before the gypsum and cellulose fiber are co-calcined in a reactor, adding a second portion of cellulose fiber to the slurry after it leaves the reactor to form a second slurry, depositing the slurry to form a mat, dewatering the mat, rehydrating the mat and then finishing the mat to form a final gypsum cellulose fiberboard. A reduction of up to about 40% to 50% of steam energy used can be achieved when the second portion of added cellulose fiber is 50% or more of the total cellulose fiber used in the final board compared to gypsum cellulose board made with the same ingredients but when all of the fiber is added to the gypsum prior to the reactor.

Abstract: A composite fabric for use in reinforcement of cementitious boards and similar prefabricated building wall panels. The fabric includes an open mesh first component of continuously coated, high modulus of elasticity strands and a nonwoven second component fabricated from alkali resistant thermoplastic material. The high modulus strands of the first component are preferably bundled glass fibers encapsulated by alkali and water resistant thermoplastic material. The composite fabric also has suitable physical characteristics for embedment within the cement matrix of the panels or boards closely adjacent the opposed faces thereof. The reinforcement provides long-lasting, high strength tensile reinforcement and impact resistance for the panels or boards. The reinforcement also enables the boards to have smooth outer faces suitable for painting, papering, tiling or other finishing treatment.

Abstract: A gypsum board comprises a set gypsum layer having a first face and a second face. A fibrous mat is affixed to at least one of the faces. The mat comprises a non-woven web bonded together with a resinous binder. The web comprises a blend of a major portion composed of chopped continuous glass fibers having an average fiber diameter ranging from about 8 to 17 ?m and a minor portion composed of fine staple fibers having an average fiber diameter of less than about 5.5 ?m, the minor portion comprising about 1-30 percent of the dry weight of the web. The board is exceedingly durable. It has a smooth surface that is readily finished in an aesthetically pleasing way, using paint or other wall covering systems.

Abstract: A gypsum stucco composition comprising the following components finely divided; calcium sulphate hemihydrate in calcined solid beta crystalline form; and in intimate mixture with said finely divided calcium sulphate hemihydrate and mixed therewith no later than calcination to form the hemihydrate, a sulphate salt comprising at least one of ammonium sulphate and aluminium sulphate, in an amount such that when the stucco composition is mixed with water and allowed to set, the resulting set plaster has increased compressive strength, flexural strength and/or E-modulus compared to a set plaster produced from said finely divided calcium sulphate hemihydrate containing no said sulphate salt.

Abstract: A gypsum slurry includes calcium sulfate hemihydrate, water and calcium sulfate dihydrate, where the calcium sulfate dihydrate is added downstream of the mixer. In an optional embodiment, the a gypsum slurry includes calcium sulfate hemihydrate, a polycarboxylate dispersant, water and coated calcium sulfate dihydrate. In this case, the hydrophilic, dispersible coating is selected to serve as a modifier to enhance the ability of the dispersant to fluidize the gypsum slurry.

Abstract: A method of continuously forming a multilayer panel includes making a gypsum slurry, then dividing the gypsum slurry into at least a primary gypsum slurry and a secondary gypsum slurry. An additive slurry having water and an intumescent material is created, then added to the secondary gypsum slurry to make an expandable layer slurry that is spread over at least a portion of a facing material. The primary gypsum slurry is distributed over the secondary gypsum slurry over the facing material and the expanding layer slurry to form a core. Optionally, another layer, an edge coating, is applied to the expanding layer for additional fire protection. The edge coating includes a second intumescent material. During a fire, the expanding layer expands to increase the thickness of the fire exposed gypsum panel and the edge coating expands to seal the gap between adjoining gypsum panels.

Abstract: Provided herein are mixtures, emulsions and other additives for use in manufacturing gypsum wallboard. The mixtures and emulsions may be wax-based emulsions or wax-free mixtures or emulsions, with wax-based emulsions including water; at least one wax, a dispersant which may include sulfur or a sulfur-containing group, and a particular wetting agent or surfactant. Mixtures may also be prepared including water, a dispersant, and a particular wetting agent or surfactant. Gypsum slurries may be prepared using such emulsions and mixtures.

Abstract: The subject invention relates to a facer which is comprised of a breathable film and a glass-mat, wherein the breathable film and the glass mat are bonded together with an adhesive, wherein the breathable film is comprised of a breathable polymeric material selected from the group consisting of polyolefins, nylons, polyesters, and thermoplastic elastomers, and wherein the facer is water resistant. The facers of this invention can be employed in manufacturing construction board, such as polyisocyanurate boards, polystyrene boards, or gypsum boards.

Abstract: The invention provides a light weight composite gypsum board including a foamed low density set gypsum core, a top non-foamed (or reduced-foamed) bonding high density layer and a bottom non-foamed (or reduced-foamed) bonding high density layer, a top cover sheet bonded to the foamed low density set gypsum core by the top non-foamed (or reduced-foamed) bonding high density layer, and a bottom cover sheet bonded to the foamed low density set gypsum core by the bottom non-foamed (or reduced-foamed) bonding high density layer. The foamed low density set gypsum core is prepared having a density of less than about 30 pcf using soap foam in the gypsum-containing slurry. The combination of components provide a composite gypsum board having light weight and high strength.

Abstract: The invention generally provides gypsum-containing slurries including stucco, naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1%-3.0% by weight based on the weight of dry stucco. The pregelatinized starch is present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts, accelerators, binders, paper fiber, glass fiber, and other known ingredients. The invention also comprises the gypsum-containing products made with such slurries, for example, gypsum wallboard, and a method of making gypsum wallboard.

Abstract: A gypsum board forming device (10) constitutes an apparatus of producing gypsum boards. A layered formation of a lower sheet (1), an upper sheet (2) and a gypsum slurry (6) passes through a forming gate (40). The forming device forms the formation into a plate-like configuration with use of upper and lower plates (20, 30). The upper plate (20) is constituted from a fixed substrate plate (21) and a movable plate (22), and the movable plate is in surface-to-surface contact with the upper sheet of the layered formation. A plurality of actuators (50) is supported by the substrate plate. Each of the actuators applies an upward or downward load (P) to the movable plate locally for a local deformation of the movable plate owing to a deflection thereof. A gate size (T) is locally changed by displacement of the movable plate relative to the substrate plate.

Abstract: Methods and systems are provided for preparing a heat resistance accelerator (HRA) slurry. Also provided are methods and systems for introducing a HRA slurry to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: A method of producing a water resistant fiber-cement product. The water repelling agent can be added or applied to the fiber-cement or indeed the material forming the fiber cement at a number of different stages in the process. The resultant material has increased water impermeability over conventional fiber-cement products.

Abstract: Provided herein are an aqueous wax emulsion, comprising water; a paraffinic hydrocarbon; polyvinyl alcohol and a wax component comprising synthetic olefin wax component. The synthetic olefin wax component may be selected from the group consisting of (i) a synthetic normal ?-olefin wax; (ii) a synthetic olefin wax of a carbon chain length of about 20 or more carbon atoms, that is modified by oxidizing and/or by refining through distillation or stripping; and (iii) combinations thereof. Such emulsions are also useful for and disclosed herein are settable gypsum compositions and water-resistant wallboard formed therefrom.

Abstract: A composition, utility material, and method of making a utility material is disclosed. A composition having an improved setting time may include a plurality of microparticles mixed with a sodium silicate binder and an isocyanate setting agent, where the microparticle composition has a setting time of less than or equal to one hour. A utility material may be a wallboard that includes the composition.

Abstract: A method of forming a gypsum-based panel product including the steps of: mixing calcined gypsum, water, a foaming agent and a core strengthening agent to form a foamed slurry; depositing the slurry; shaping the slurry to form a board having a core and core surfaces, optionally sandwiched between sheets of liner; and allowing the core to set, and drying the board, wherein the strengthening agent is dextrin, used in an amount not less than 0.1% by weight, based on the amount of calcined gypsum, so that, after drying, there is provided a strengthening dispersion of dextrin throughout the core. Less than 5% dextrin in preferred.

Abstract: A gypsum/fiber board having improved impact resistance is produced by mixing predetermined amounts of fibers, calcined gypsum and water to form a mixture of wetted, loose fibers; laying out a reinforcing mesh over the upper surface of a forming belt; depositing said mixture on said mesh to form a layer of said mixture, said; and compressing said mesh together with said layer of mixture to embed said mesh in the lower surface of said layer to form a board composed of bonded fibers and gypsum with said mesh embedded in the surface thereof.