Abstract: A plaster mixture for forming a machinable composition, includes calcium sulfate hemihydrate; an internal lubricating dispersable binder, and an adhesive binder for adhering the plaster mixture to a substrate. In the preferred embodiment, the composition includes calcium sulfate hemihydrate, a poly(ethylene glycol) internal binder, and an ethylene/vinyl acetate copolymer adhesive binder.

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: This invention is directed to a stand-alone adjustable trim strip system that can be used for the attachment of lighting and signs. The trim strip system is designed to conceal hardware used for attaching lighting and signs and also provides for a system that can be adapted to accommodate architectural design. The system has the capability of being suspended from the structure of a building by wires or rods or can be affixed to walls or ceilings by using fasteners. The system is comprised of one or more trim strips and brackets that can be shaped into different polymeric shapes or can be arranged in a grid format. The system has the ability to attach electric lighting and signs while providing for an aesthetically pleasing structure.

Abstract: A slurry spray machine for spraying a settable slurry includes a main passageway configured for receiving a supply of pressurized slurry and having a supply end and an outlet end opposite the supply end. A first compressed gas inlet is disposed intermediate the supply and outlet ends and in fluid communication with the passageway for introducing a first supply of pressurized gas into the slurry, and a second pressurized gas inlet is disposed closer to the outlet end than the first inlet and in fluid communication with the passageway for introducing a second supply of pressurized gas into the slurry. A pressurized supply of adjuvant is provided in fluid communication with the second pressurized gas inlet for providing a blended gas to the second gas inlet. At least one valve is provided for controlling the flow of slurry through the passageway and the flow of the first and second gases into the passageway.

Abstract: A high strength, low density fiber board panel for use in the furniture industry is provided, including mineral wool, a lightweight aggregate material, cellulosic fiber, a binding agent and gypsum. The mineral wool makes up approximately 0% to 33%, the lightweight aggregate material approximately 25% to 41%, the cellulosic fiber approximately 20% to 35%, the binding agent approximately 5% to 9%, and the gypsum approximately 0% to 23%, of the dry solids weight of the panel.

Abstract: An exterior wall assembly water management system that includes flashing, a drainable weather-resistive membrane, exterior cladding, a basecoat and an exterior finish. The basecoat and the exterior stucco finish are applied to the outer surface of the exterior cladding, or in the alternative to an insulation layer. The disclosed water managed exterior system efficiently directs any penetrating water to weeps, or the like, by providing a water drainage medium between the weather-resistive membrane and the exterior cladding. The water drainage medium is embossed upon the outer surface of the weather-resistive membrane, creating a drainage space between the membrane and the cladding. The unwanted water drains downwards via the drainage space, is caught at the base of the wall by the flashing, and is further drained outside of the wall cladding.

Abstract: A high temperature resistant glass fiber composition consists essentially of glass fibers having a nominal softening point of about 1000° F. (about 538° C.) which is capable of passing the British Standard 476 Part 4 fire test for building materials. The BS476-4 test begins at 750° C., substantially above the nominal softening point of the glass fibers. The increased temperature resistance is provided by coating the glass fibers with a halogenated resin latex binder and a calcium carbonate material. The method of making the glass fiber composition comprises depositing the resin latex and a calcium carbonate material on the glass fibers using a cationic flocculant. The preferred halogenated resin latex binder is selected from polyvinyl chloride and polyvinylidene chloride.

Abstract: A non-combustible gypsum/fiber board comprises two surface layers and at least one core layer, wherein the surface layers comprise a gypsum composition that is reinforced with organic fibers, and the core layer comprises a gypsum composition containing no more than about 3% by weight of organic materials.

Abstract: The disclosed invention consists of a means for conveying a gypsum or gypsum/cellulose fiber board to a rotary cylinder brush station where pMDI resin is delivered onto the rotary cylinder brush just as the board passes under the brush. A resin distribution system is used to coat the rotary cylinder brush applicator with pMDI. Optionally, a second rotary cylinder brush station is included, if desired, to smooth out and spread the pMDI resin over the surface of the gypsum board substrate to achieve complete coverage.

Abstract: A direct mount ceiling grid system comprising a plurality of base grid members, cross grid members, and channel grid members for mounting ceiling panels close to a mounting surface. The base grid members are elongated T-shaped beams having a base flange and a transversely extending web having a thicker bulb portion at its marginal end. The base flange of each base grid member is directly mounted to a mounting surface. The channel grid members are elongated beams having two parallel transversely extending webs forming a channel therebetween. Upon installation of ceiling panels, the channel of the channel grid members removably engage the bulb portion of the transversely extending web of the base grid members. The channels have hook portions of the parallel webs of the channel grid members and deflect to allow capture of the bulb portion. The base flange of the base grid members and the base flange of the channel grid members capture the ceiling panels placed therebetween.

Abstract: An improved method for texturing gypsum fiber panels and producing surface textured panels, edge tapers, and deeper patterned wainscot-type panels, involving the use of a flexible die with a textured surface. The die is pressed onto the panel in its slurry state just after the onset of an exothermic rehydration reaction. Partial hydration and setting occur during pressing by the die to form a textured mat. The mat is removed from contact with the die at a point along the rehydration temperature curve about at or less than one-half of the rise to the greatest rehydration temperature.

Abstract: This invention provides a method and apparatus for mixing calcined gypsum. The invention comprises a mixer which employs high pressure water to eliminate or substantially reduce the formation of lumps of gypsum inside the mixer which cause paper breaks when the calcined gypsum slurry containing the lumps is used to form the gypsum core in a gypsum wallboard product. High pressure water jets direct a spray of high pressure water at the surfaces within the mixer where the lumps of gypsum are formed. The method of this invention utilizes the high pressure water as part of the metered water that is continuously fed to the mixer, with the balance of the water being fed through low pressure nozzles.

Abstract: An improved water resistant gypsum board is made by adding an aqueous wax emulsion containing a cationic surfactant to an aqueous slurry containing calcium sulfate and host particles at a slurry temperature which maintains calcium sulfate hemihydrate crystals. The wax emulsion is stable at the temperature of slurry which maintains the calcium sulfate hemihydrate. The slurry is then dewatered and rehydrated to form a gypsum board and dried at a temperature to melt the wax.

Abstract: A composition suitable for making acoustical tiles in a water-felting process comprises expanded perlite, cellulosic fiber, and, optionally, a secondary binder and mineral wool. The perlite has been treated to reduce its water retention.

Abstract: A composition suitable for making acoustical tiles in a water-felting process comprises expanded perlite, clay, a binder component selected from the group consisting of starch, latex, cellulosic fiber and mixtures thereof and optionally mineral wool. The use of an expanded perlite having a relatively high density, preferably between about 9 pounds per cubic foot to about 20 pounds per cubic foot, enables the formation of a suitable slurry with a relatively low amount of water and enables a more complete dewatering of the mat prior to drying.

Abstract: A process is described for making a gypsum board having improved water resistance. The resulting gypsum board products are also described. The process comprises adding an aqueous siloxane emulsion to an aqueous slurry of a calcium sulfate material and host particles, where the siloxane emulsion is stable under the condition in which the slurry is maintained. The process further includes passing said siloxane containing slurry onto a flat porous forming surface to form a filter cake; removing a substantial portion of the water from the filter cake through the porous surface; pressing the filter cake to form a board and remove additional water; and drying the board to remove the remaining free water and to cause the core of the board to reach a temperature sufficient to cure the siloxane.

Abstract: A sag resistant, cast acoustical ceiling tile which has a mineral wool core and a starch binder and which has a formaldehyde resin impregnated paper backing. A kraft paper backing which has been impregnated with a melamine formaldehyde resin has been found particularly effective in providing sag resistance in high temperature, high humidity conditions such as encountered in Pacific Rim countries. A method has been developed to manufacture the sag resistant, cast acoustical ceiling tile wherein water is applied to the paper backing prior to machining and painting to provide a tile which has a relatively flat initial plane position.

Abstract: A cementitious composition of the setting type which can be kept in a ready-mixed state and which can be caused to set and harden upon introduction of an accelerator with reproducibility and set time predictability. The cementitious base composition contains calcium sulfate hemihydrate as a principal filler material and certain non-calcium bearing phosphate additives which prevent setting action in the presence of water. An accelerator, such as zinc sulfate, may be added to the ready-mixed, cementitious composition to initiate the setting action, or the ready-mixed cementitious composition can be used as a drying type joint compound without the addition of an accelerator.

Abstract: A method and apparatus is disclosed for the continuous calcining of gypsum material in a high-efficiency, refractoryless kettle preferably heated by a multiple series of separate immersion tube burner coils, each coil operating within a specific calcining zone inside the kettle. The lowest, i.e., initial, burner tube coil is formed with a low profile to permit use of a small initial gypsum charge, and hence, a quick kettle start-up cycle. That low profile initial burner design also helps keep the agitator motor's load at a minimum during cycle start-up. Due to the immersion tube burner coil construction, no refractory structure for the kettle is required. Also, no separate hot pit structure is required, as the kettle is used to merely hold the material being calcined and no residual heat is present. A relatively thin kettle can be constructed, as it need only withstand relatively low operating temperatures.

Abstract: The invention provides an improved method for preparing foamed gypsum products. The invention can utilize a single mixing chamber and significantly improve the efficiency of foaming agent usage. In the method of the invention the point of insertion of aqueous foam into calcined gypsum slurry is positioned such that the foam is agitated less than the calcined gypsum to thereby minimize destruction of the foam while still uniformly dispersing the foam in the calcined gypsum slurry. This is accomplished, for example, by locating an inlet for foam closer to the discharge outlet of a slurry mixing chamber than the location of the inlet for calcined gypsum or by locating the foam inlet in a discharge conduit connected to the discharge outlet of the slurry mixing chamber.