Abstract: Disclosed is a ready-to-use self-gauging coating compound containing about 65%-75% solids that provides a flat finely textured finish with improved abuse (abrasion) resistance properties. The coating composition comprises a resin binder in which there is dispersed an aggregate consisting of particles in a selected size range in a quantity sufficient to form a layer of particles one particle deep on the substrate when the coating is applied to the substrate.

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.

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: A landplaster production method includes the steps of providing a supply of particulate gypsum material, drying the gypsum material by passing a stream of heated air thereby as the material is rotated, classifying and separating the dried particles into fines and coarse particles, collecting the suspended fines in a collector, passing the coarse particles to a grinder such as a roller mill for reducing the particles, and mixing the reduced particles with the collected fines for processing into landplaster. The elimination of fines from the feed to the grinder results in significantly greater production by increasing the efficiency of the grinder. Further, the dryer is modified to agitate the dried gypsum material so that it may be more easily introduced into the classifier/separator situated adjacent the drier discharge outlet.

Abstract: This invention is a polymer modified, high density gypsum composition that is useful as a machinable plaster. For example, the machinable plaster can be used with computer aided carving machines for modeling in the automobile industry. The polymer is a redispersable polymer such as ethylene/vinyl acetate/vinyl chloride polymer.