Abstract: The product is produced from a settable aqueous calcium sulphate dispersion which has a water to solids ratio of less than 0.4 to 1, and has distributed therethrough lightweight hollow bodies having water-impervious surfaces (such as expanded polystyrene beads). The dispersion contains a hydratable cement (such as calcium sulpho aluminate) which is capable of hydration in the presence of the calcium sulphate dispersion. The hydratable cement is such that it reacts with excess water in the dispersion thereby enhancing the water resistance of the resulting product.

Abstract: The product is produced from a settable aqueous calcium sulphate dispersion which has a water to solids ratio of less than 0.4 to 1, and has distributed therethrough lightweight hollow bodies having water-impervious surfaces (such as expanded polystyrene beads). The dispersion contains a hydratable cement (such as calcium sulpho aluminate) which is capable of hydration in the presence of the calcium sulphate dispersion. The hydratable cement is such that it reacts with excess water in the dispersion thereby enhancing the water resistance of the resulting product.

Abstract: The formulation for making plasterboard with paper cover sheets comprises finely divided gypsum, a minor amount by weight of starch and, as crosslinking agent for the starch, a tri-functional reactive s-triazine having substituents at positions 2, 4 and 6 of the triazine ring which are reactive with the starch. A preferred crosslinking agent is 2,4,6-trichloro-s-triazine, which is preferably partially reacted with the starch before further reaction with the paper cover sheets for the plaster board.

Abstract: The present invention relates to a plaster-based material which includes an agent capable of trapping formaldehyde, in particular a plasterboard intended for the interior fittings of residential buildings. The agent capable of trapping formaldehyde is chosen from ethylene urea and its derivatives, compounds comprising active methylene(s), sulphites, tannins and their mixtures. Another subject-matter of the invention is the use of the said material for reducing the amount of formaldehyde present in the atmosphere inside residential buildings.

Abstract: A water-resistant calcium sulphate based body comprises a matrix of crystalline calcium sulphate anhydrite, crystals of the matrix being connected to one another by water-resistant phosphate bonding zones, optionally also containing aluminum. The body can be produced by impregnating a porous calcium sulphate with a source of phosphate ions (optionally containing aluminum), and then calcining. Alternatively, a paste comprising calcium sulphate and a source of phosphate ions (optionally containing aluminum) is heated or compressed to form a ‘green body’ and then calcined to produce the body.

Abstract: Gypsum plasterboard is produced by combining calcium sulphate hemihydrate (stucco) with water to form an aqueous slurry. Uncalcined gypsum having a specific surface area below 0.3 m2/g is added to the slurry and the slurry is discharged onto a support so as to form a sheet of gypsum plasterboard.

Abstract: The formulation for making plasterboard with paper cover sheets comprises finely divided gypsum, a minor amount by weight of starch and, as crosslinking agent for the starch, a tri-functional reactive s-triazine having substituents at positions 2, 4 and 6 of the triazine ring which are reactive with the starch. A preferred crosslinking agent is 2,4,6-trichloro-s-triazine, which is preferably partially reacted with the starch before further reaction with the paper cover sheets for the plaster board.

Abstract: This interior wall includes at least one cladding panel (4) covered with a luminous fabric (6), lying in a substantially vertical plane and having a front face receiving the luminous fabric, a rear face opposite the front face, a bottom edge, and a top edge. The luminous fabric includes optical fibers (7) extending substantially vertically over the front face of the first cladding panel and first ends of which are bent around the bottom edge of the first cladding panel toward its rear face. A casing (8) accommodates light sources and includes connecting elements (10) for the ends of the optical fibers (7) of the luminous fabric bent around the bottom edge of the first cladding panel. The first casing (8) is fastened to the first cladding panel and is supported by feet (20) extending beyond the bottom edge of the first cladding panel.

Abstract: Disclosed is a cutting tool that is capable of performing cutting operations on a variety of materials such as, for example, plasterboard, glass, wood, laminated wood, cardboard, plastics, such as PERSPEX®, tiles, or the like. The cutting tool comprises an upper and lower part with the upper and lower parts being separated by spacing means that are preferably retractable. The upper and lower parts include at least one cutting device. The upper and lower parts are held together by magnetic attraction.

Abstract: A laminated acoustic building panel comprises a pair of plasterboard substrates which are bonded together by an adhesive layer, the panel having a dynamic Young's modulus of 0.1 to 5 GPa and a damping loss factor of 5-30% (?=0.05-0.3), and the ratio of the adhesive to the applied surface area of the substrates being 80-250 g/m2. The laminated panel is relatively soft in construction and hence sound waves caused by knocking or impact noise is surprisingly damped using considerably less adhesive than known panels. The use of soft substrates and less adhesive significantly reduces the weight of the panel. Furthermore, the use of less adhesive significantly reduces costs and makes production easier.

Abstract: A method of producing gypsum building board, in which there is added, to an aqueous gypsum slurry containing a water swellable clay, a basic water-soluble polymer having preferential affinity for clay. The slurry is allowed to set so as to form a board. The basic water-soluble polymer may be, for example, a polyvinyl alcohol or a polymer consisting essentially of carbon, nitrogen and hydrogen and having amine groups (which may be primary, secondary, tertiary or quaternary) in the polymer backbone and/or in side chains thereof.

Abstract: This board is a complex including a rigid support covered with a luminous fabric. The rigid support has a front face, a rear face, a first edge, and a second edge opposite the first edge. The luminous fabric at least partly covers the front face of the rigid support, extending from the first edge toward the second edge, and includes optical fibers extending over the front face of the rigid support substantially perpendicular to the first edge and the second edge. First ends of the optical fibers are bent around the first edge toward the rear face of the rigid support, and a gripping element are provided on the first edge and form a clamp for gripping the bent parts of the optical fibers and the first edge of the rigid support.

Abstract: A process for reducing the set time a plaster slurry. The process comprises the steps of, providing a pre-determined amount of water, providing a pre-determined amount of the plaster, mixing the water and the plaster together at a first time to form a slurry, and, re-directing a portion of the slurry formed at the first time to combine with slurry formed at a second time.

Abstract: The present invention relates to a plaster-based material which includes an agent capable of trapping formaldehyde, in particular a plasterboard intended for the interior fittings of residential buildings. The agent capable of trapping formaldehyde is chosen from ethylene urea and its derivatives, compounds comprising active methylene(s), sulphites, tannins and their mixtures. Another subject-matter of the invention is the use of the said material for reducing the amount of formaldehyde present in the atmosphere inside residential buildings.

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: The product is produced from a settable aqueous calcium sulphate dispersion which has a water to solids ratio of less than 0.4 to 1, and has distributed therethrough lightweight hollow bodies having water-impervious surfaces (such as expanded polystyrene beads). The dispersion contains a hydratable cement (such as calcium sulpho aluminate) which is capable of hydration in the presence of the calcium sulphate dispersion. The hydratable cement is such that it reacts with excess water in the dispersion thereby enhancing the water resistance of the resulting product.

Abstract: A laminated acoustic building panel comprises a pair of plasterboard substrates (10,13) which are bonded together by an adhesive layer (16), the panel having a dynamic Young's modulus of 0.1 to 5 GPa and a damping loss factor of 5-30% (?=0.05-0.3), and the ratio of the adhesive (16) to the applied surface area of the substrates (10,13) being 80-250 g/m2. The laminated panel is relatively soft in construction and hence sound waves caused by knocking or impact noise is surprisingly damped using considerably less adhesive (16) than known panels. The use of soft substrates (10,13) and less adhesive (16) significantly reduces the weight of the panel. Furthermore, the use of less adhesive (16) significantly reduces costs and makes production easier.

Abstract: The formulation for making plasterboard with paper cover sheets comprises finely divided gypsum, a minor amount by weight of starch and, as crosslinking agent for the starch, a tri-functional reactive s-triazine having substituents at positions 2, 4 and 6 of the triazine ring which are reactive with the starch. A preferred crosslinking agent is 2,4,6-trichloro-s-triazine, which is preferably partially reacted with the starch before further reaction with the paper cover sheets for the plaster board.

Abstract: This board is a complex including a rigid support covered with a luminous fabric. The rigid support has a front face, a rear face, a first edge, and a second edge opposite the first edge. The luminous fabric at least partly covers the front face of the rigid support, extending from the first edge toward the second edge, and includes optical fibers extending over the front face of the rigid support substantially perpendicular to the first edge and the second edge. First ends of the optical fibers are bent around the first edge toward the rear face of the rigid support, and a gripping element are provided on the first edge and form a clamp for gripping the bent parts of the optical fibers and the first edge of the rigid support.

Abstract: This interior wall includes at least one cladding panel (4) covered with a luminous fabric (6), lying in a substantially vertical plane and having a front face receiving the luminous fabric, a rear face opposite the front face, a bottom edge, and a top edge. The luminous fabric includes optical fibers (7) extending substantially vertically over the front face of the first cladding panel and first ends of which are bent around the bottom edge of the first cladding panel toward its rear face. A casing (8) accommodates light sources and includes connecting elements (10) for the ends of the optical fibers (7) of the luminous fabric bent around the bottom edge of the first cladding panel. The first casing (8) is fastened to the first cladding panel and is supported by feet (20) extending beyond the bottom edge of the first cladding panel.