Abstract: A method of making a setting type compound by injecting an activator compound into a plaster compound wherein the activator compound tube is coaxial and within the plaster compound tube, each at the same flowrate, the same pressure and the same viscosity. The cross sectional transverse areas of an annulus containing the plaster compound and the hole in the annulus containing the activator compound are the same.

Abstract: Disclosed are a composite gypsum board and a method of preparing composite gypsum board. The board contains at least one set gypsum layer sandwiched between two cover sheets. The set gypsum layer is formed from at least stucco and water. The stucco material generally includes a high salt impurity content, for example, when the stucco is calcined from certain sources of low-quality synthetic gypsum. For example, in some embodiments, the salts are chloride salts, e.g., sodium chloride (NaCl), potassium chloride (KCl), magnesium chloride (MgCl2), and/or calcium chloride (CaCl2)). At least one of the cover sheets is composed of high absorption paper, which enhances the bond between the set gypsum layer and the cover sheet.

Abstract: This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.

Abstract: Disclosed are a composite gypsum board and a method of preparing composite gypsum board. The board contains a set gypsum core sandwiched between two cover sheets. The core is formed from a slurry containing stucco, water, and optional ingredients such as foaming agent, accelerator, retarder, polyphosphate, starch, and dispersant, and core intumescent material. The board also contains at least one skim coat and/or hard edges. A face skim coat layer can be included on one side of the core, facing a face cover sheet. A back skim coat layer can be included on the other side of the core, facing a back cover sheet. Hard edges are known in the art and can be formed, e.g., continuously from a stucco slurry for forming the face and/or back skim coats. Preferably, the back skim coat layer and/or the hard edges are formed from a slurry containing stucco, water, skim coat or edge intumescent material (which have the same desired characteristics), and other optional additives as desired.

Abstract: An accelerator for accelerating the rate of hydration of calcined gypsum is disclosed. The accelerator comprises calcium sulfate dihydrate particles and a starch. The starch has a cold water solubility of at least about 25% (e.g., at least about 35%) and a viscosity of about 25 Brabender Units (BU) or less when the starch is in a 30% aqueous slurry at 92° C. Also disclosed are a method of preparing an accelerator, method of hydrating stucco to form set gypsum, slurry, and method of making gypsum board.

Abstract: Gypsum boards formed from synthetic gypsum and other gypsum sources having high chloride salt concentrations. Gypsum boards may include a board core including set gypsum between a front cover sheet and a back cover sheet. A total concentration of the chloride anion in the board core ranges from about 150 to 4000 parts by weight (pbw) chloride, typically about 300 to about 3000 pbw, more typically from about 400 to about 2000 pbw, further typically from about 1000 to about 2000 pbw, and further typically from about 600 to about 1000 pbw, per 1,000,000 pbw calcium sulfate dihydrate. A polymer layer contacts an inner surface of the back cover sheet. A densified gypsum layer contacts an inner surface of the front cover sheet. Methods of making the gypsum board, and a wall system for employing the gypsum boards, are also provided.

Abstract: A pallet centering device includes a frame upon which is mounted a plurality of conveyor rollers, the conveyor rollers mounted transverse to a direction of pallet travel. A first pallet pusher unit and a second pallet pusher unit are associated with respective sides of the support frame, both for reciprocal movement transverse to the direction of pallet travel. The first and second pallet pusher units each have pallet pusher members configured for engaging respective sides of a pallet. At least one transverse U-channel rail is mounted to the support frame beneath the conveyor rollers and defining a channel track. Each first and second pallet pusher unit has at least one depending bearing mount aligned with the channel track and provided with a bearing rotatably engaging the channel track. A drive assembly moves the first and second pallet pusher units reciprocally for centering the pallet located on the conveyor rollers.

Abstract: Disclosed is an acid-modified flour and a method of making the acid-modified flour. The acid-modified flour is desirably prepared using a dry milling process. A starting flour is combined with a strong acid to form a mixture. The mixture is heated. A neutralizer is added to increase the pH of the mixture. If desired, the mixture can be dried and any agglomerates can be removed. The acid-modified flour can be used as a binder in a slurry for preparing one or more gypsum layers in a gypsum board.

Abstract: A method of recovering desalinated activated alumina (AA) beads from a composition including salt laden (high salt absorbed) activated alumna (AA) beads and free anions and free cations, comprising the step of electrodialysis of the composition to reduce salt content of the activated alumina (AA) beads to produce a stream comprising the desalinated activated alumina (AA) beads.

Abstract: An impact resistant exterior sheathing gypsum building panel with an integrated impact resistant woven mesh which protects against impact from projectiles such as those conveyed by hurricane force winds is provided. Methods for manufacturing these exterior sheathing gypsum building panels with an integrated impact resistant woven mesh are also provided. An exterior sheathing system employing the exterior sheathing cementitious building panel is provided.

Abstract: A reduced weight, reduced density gypsum panel that includes high expansion vermiculite with fire resistance capabilities that are at least comparable to (if not better than) commercial fire rated gypsum panels with a much greater gypsum content, weight and density.

Abstract: Disclosed are product (e.g., board), slurry, and methods relating to an uncooked starch that can be used to enhance strength in one or more gypsum layers in the board. The uncooked starch has a hot water viscosity of from about 20 BU to about 300 BU according to the HWVA method, and/or a mid-range peak viscosity of from about 120 Brabender Units to about 1000 Brabender Units.

Abstract: A snap-setting joint compound with reduced calcium sulfate hemihydrate and improved sandability, as well as methods for building wall assemblies and repairing walls with the joint compound.

Abstract: A cementitious panel system reinforced on its opposed surfaces by a fabric of basalt fiber woven or non-woven mesh. Preferably the mesh is a woven basalt scrim with thicker yarn and larger mesh openings to provide a cementitious panel with improved handling properties while retaining tensile strength and long term durability. The fabric is constructed as a mesh of high modulus strands of bundled basalt fibers. The fabric also has suitable physical characteristics for embedment within the cement matrix of the panels or panels closely adjacent the opposed faces thereof. The fabric provides a panel system with long-lasting, high strength tensile reinforcement and improved handling properties regardless of their spatial orientation during handling. Included as part of the invention are methods for making the reinforced cementitious panel.

Abstract: Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

Abstract: An impact resistant exterior sheathing gypsum building panel with an integrated impact resistant woven mesh which protects against impact from projectiles such as those conveyed by hurricane force winds is provided. Methods for manufacturing these exterior sheathing gypsum building panels with an integrated impact resistant woven mesh are also provided. An exterior sheathing system employing the exterior sheathing cementitious building panel is provided.

Abstract: A production line and process including a moving carrier web for transporting the panel, and a device for controlling thickness of a formed, but not yet set, fiber reinforced cementitious panel slurry on the web. The thickness control device may include an angled rigid plate for contacting a downstream end of the angled plate with the slurry on the moving carrier web and a mounting stand for mounting the angled rigid. The thickness control device may include a flat horizontal plate at a fixed height over the moving carrier for contacting the entire lower surface of the horizontal plate with a facer on the slurry on the moving carrier web. Or, the thickness control device may include the angled plate and include the horizontal plate that contacts the facer.

Abstract: A gypsum wallboard having a core with a central core layer and one or more densified layers is disclosed. At least one densified layer contains salt absorbent particles of zeolite and/or hydrotalcite to improve adhesion of the gypsum core to a cover sheet. Also, methods of making the gypsum wallboard and a wall system for employing the gypsum wallboard are disclosed.

Abstract: Embodiments of a system and a method for manufacturing calcined gypsum can include an in-line calcination control device having an x-ray analyzer. The x-ray analyzer is adapted to analyze at least one of the calcined gypsum being discharged from the calciner and the calcined gypsum being fed into a mixer of a gypsum boardline. The x-ray analyzer is configured to determine the proportion of different calcium sulphate phases found therein which can be used to control at last one of the calciner and the boardline.

Abstract: Disclosed is a composite gypsum board comprising a board core and a concentrated layer, as well as related methods of preparing board and slurries. The board core and the concentrated layer both are formed from water and stucco. The concentrated layer is designed to have higher density and/or nail pull than the core. The concentrated layer is further formed from a polysaccharide that forms a complex with calcium ions, e.g., an alginate compound such as sodium alginate. In some embodiments, the concentrated layer is formed from an enhancing additive to enhance strength therein, while the core is formed without using enhancing additive or less enhancing additive than used in forming the board core.