Abstract: Gypsum boards formed from synthetic gypsum and other gypsum sources having high chloride salt concentrations. The gypsum boards may include a set gypsum board core layer between a front and back paper cover sheets. The back paper cover sheet has a plurality of perforations extending therethrough. Methods of making the gypsum boards, and a wall system for employing the gypsum boards, are also provided. The concentration of the chloride anion in aqueous gypsum slurry used to make the set gypsum board core layer and to perform the methods of the invention may range from about 500 ppm to about 3000 ppm, typically from about 500 ppm to about 2000 ppm per 1,000,000 parts by weight calcium sulfate hemihydrate, more typically from about 500 ppm to about 1500 ppm per 1,000,000 parts by weight calcium sulfate hemihydrate.

Abstract: A device is provided for closing, sealing and conveying corrugated cartons having a top flap and a next adjacent flap, and includes a frame, a moving conveyor belt associated with the frame and defining a track with an inlet end and an outlet end, and a fixed bracket secured to the frame and having a first plurality of linearly aligned rollers defining a first side of the track. A movable bracket is associated with the frame, having a second plurality of linearly aligned rollers defining a second side of the track and being transversely movable relative to the track under operator control.

Abstract: Aqueous cementitious slurries including predominantly Type I Portland cement containing an aluminate additive. The aluminate additive is an aluminate salt other than calcium aluminate or calcium sulfoaluminate, preferably sodium aluminate. Cementitious reactive powders of the slurry include the Type I Portland cement and 0.1-10 wt. % of the aluminate additive as an accelerator. The slurries may have a set time of about 10 minutes or less. Due to the short set time, the cementitious reactive powders may facilitate cement board fabrication by continuous manufacturing processes. Methods for making cement boards may include disposing the aqueous cementitious slurry including the cementitious reactive powders in a continuous layer, preferably upon a porous support, and setting the aqueous cementitious slurry with a set time of about 10 minutes or less.

Abstract: A method in which a stream of dry cementitious powder passes through a first conduit and aqueous medium stream passes through a second conduit to feed a slurry mixer to make cementitious slurry. The cementitious slurry passes through a third conduit and a reinforcement fiber stream passes through a fourth conduit to feed a fiber-slurry mixer which mixes the slurry and discrete fibers to make a stream of fiber-slurry mixture. An apparatus for performing the method is also disclosed.

Abstract: Disclosed are product (e.g., panels), slurry, and methods relating to a pregelatinized starch having a mid-range viscosity (i.e., from about 20 centipoise to about 700 centipoise), and an extruded pregelatinized starch.

Abstract: Disclosed are product (e.g., panels), slurry, and methods relating to a pregelatinized starch having a mid-range viscosity (i.e., from about 20 centipoise to about 700 centipoise).

Abstract: A gypsum tile backer panel with a pre-impregnated or pre-coated nonwoven fiber face mat. Methods for manufacturing these gypsum tile backer panel which include applying a gypsum slurry to a pre-impregnated or pre-coated nonwoven fiber face mat are also provided. A gypsum tile backer panel system employing the gypsum tile backer panel is also provided.

Abstract: A system for controlling a line speed of a conveyor belt of a conveyor system during product changeovers in a wallboard production line includes a computer processor, a calculation module for calculating a predetermined mass rate of a supply of ingredients transported on the conveyor belt and deposited into a mixer during a product changeover period, and a speed adjustment module for adjusting the line speed of the conveyor belt, using the processor, based on at least one of the predetermined mass rate and the line speed of the conveyor belt for reducing an overshoot during said product changeover period.

Abstract: Composite roofing structures can include mineral fiber roof cover boards with high concentration of mineral wool or mineral wool and perlite. The roofing structure may include: a roof cover board including a dried base mat including: 8-25% mineral wool, 40-65% perlite, 9-15% binder, 9-15% cellulosic fiber, and 0.25-2% sizing agent, all % by weight; an insulation layer; and a roofing membrane. The roof cover board is over the insulation layer, the roofing membrane is over the roof cover board. The roof cover board is attached to the insulation layer. The roofing membrane is attached to the roof cover board. Alternatively dried base mat may include: 30-70% mineral wool, 10-50% perlite, 5-15% binder, 2-20% cellulosic fiber, and 0.25-2% sizing agent. Alternatively the dried base mat may include: 60-90% mineral wool, 0-10% fiber, 0-10% perlite, 4-10% binder, 0-5% gypsum, and 0.25-2% sizing agent.

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: 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 joint tape to be applied to wallboard is provided and includes a base substrate having opposing sides. In certain embodiments, a first adhesive layer is applied to one of the sides of the base substrate and a second adhesive layer is applied to the first adhesive layer, where the first adhesive layer is different than the second adhesive layer. In certain other embodiments, two different adhesives are used in a single adhesive layer. In use, the joint tape is positioned over and removably secured to a joint or corner between adjacent wallboard panels using the first adhesive layer. After the joint tape is in position, joint compound is applied to the joint tape, and the water in the joint tape activates it to form a secure bond with the wallboard panels.

Abstract: A heating system for a floor is provided and includes a plurality of heating devices, where each of the heating devices includes a membrane, and a plurality of heating elements and at least one electrical coupling member attached to the membrane. At least one heating device coupling member is attached to the at least one electrical coupling member on adjacent heating devices of the plurality of heating devices, where the at least one heating device coupling member conveys electricity between the adjacent heating devices.

Abstract: A decorative interior trim piece is provided for use in a low voltage power transmission system, and includes an outer, decorative surface, an opposite inner surface facing a substrate, a first end surface and an opposite second end surface. At least one conductive element extends from the first end surface to said second end surface on the inner surface. Each conductive element has a connector surface at each of the first end and second ends. At least one magnetic fastener is secured to the inner surface for releasably attaching the trim piece to the substrate. A complementary low voltage power transmission system is also disclosed.

Abstract: Disclosed are a composite gypsum board and a method of preparing gypsum board. The board contains at least one set gypsum layer sandwiched between face and back 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). The board and methods improve the bond between the gypsum layer(s) and at least one of the cover sheets (e.g., the back cover sheet). Also provided are methods and systems relating to drying gypsum board.

Abstract: Disclosed is a composite gypsum board comprising a board core comprising set gypsum sandwiched between face and back cover sheets. The composite gypsum board also comprises an intermediate sheet between the board core and the face cover sheet, with a thin, dense gypsum layer disposed between the intermediate sheet and the face cover sheet. Optionally, a second dense gypsum layer can be disposed between a first major side of the board core and the back cover sheet. Also disclosed is a method of preparing a composite gypsum board in which an intermediate sheet is applied over a dense gypsum layer disposed on a face cover sheet. A back cover sheet is applied to the other major side of the board core, with a second dense gypsum layer optionally disposed therebetween.

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: Disclosed is a composite gypsum board comprising a board core and a concentrated layer of substantial thickness (e.g., at least about 0.02 inches). The concentrated layer includes a higher weight percentage of an enhancing additive than the board core. The board core has a thickness greater than the thickness of the concentrated layer and forms the bulk of the board volume. The concentrated layer has a higher density (e.g., at least about 1.1 times greater) than the density of the board core. Also disclosed is a method of preparing a composite gypsum board.

Abstract: A drying-type joint compound, a setting-type joint compound, and/or a ready-mixed, setting-type joint compound can include a phospholipid dedusting agent. For example, a drying-type joint compound can include: (a) a primary filler at 50 weight percent (wt %) to 98 wt % on a dry basis, wherein the primary filler includes one of calcium carbonate, calcium sulfate dihydrate, and talc, and a mixture thereof (b) a secondary filler at up to 25 wt % on a dry basis; (c) a binder at 1 wt % to 15 wt % on a dry basis; (d) a polymer thickener at 0.05 wt % to 3 wt % on a dry basis; (e) a phospholipid dedusting agent at 0.01 wt % to 3 wt % on a dry basis; (f) an additive up to 10 wt % o on a dry basis; and (g) water at a weight ratio of water to dry components of 1:6 to 2:1.

Abstract: A procedure is provided for evaluating the score, snap and edge appearance of wallboard panels, and includes scoring a wallboard panel with a knife at a constant and known force using a benchtop board scoring device; snapping the scored panel in a Universal Board Testing Machine to measure the breaking force, forming a snapped panel edge; measuring a cleanliness of the snapped panel edge by placing a straight edge against the snapped panel edge and measuring gaps between the snapped panel edge and the straight edge in a plurality of locations on a face of the panel, and a plurality of locations on a back of the panel; and averaging all of the measured gaps to create an Index Score.