Abstract: A head-box for depositing slurry upon a moving web including a main metering roll, a companion roll disposed in closely spaced relation to the metering roll and a vibrating gate which forms a nip between the metering roller and the gate. The nip is arranged to retain a supply of the slurry, and the rolls are driven so slurry retained in the nip progresses over an upper outer peripheral surface of the metering roll to be deposited upon the web. Also, preferably included is a doctor blade disposed in operational relationship to the metering roll for directing the slurry downwardly from the outer metering roll surface to a point above the surface of a carrier for a fiberglass layer upon which the slurry layer is deposited. The vibrating gate and doctor blade may be pivotally mounted to either side of the surfaces of the head-box.

Abstract: A process employing a wet mixer having a vertical mixing chamber for forming a wet slurry of a cementitious powder and liquid. The vertical mixing chamber is designed to provide the required amount of mixing to provide thoroughly mixed, uniformly thin slurry within a mixing residence time that allows for adequate supply of slurry to ensure continuous operation of an associated cement panel production line. Gravity feed for supply of cementitious powder and water to the slurry mixing area of the chamber is also disclosed.

Abstract: A wet mixer apparatus and method for its use, the mixer having a vertical mixing chamber for forming a wet slurry of a cementitious slurry and water. The vertical mixing chamber is designed to provide the required amount of mixing to provide thoroughly mixed, uniformly thin slurry within a mixing residence time that allows for adequate supply of slurry to ensure continuous operation of an associated cement panel production line. Gravity feeding for separate supply of cementitious powder and water to the slurry mixing area of the chamber without pre-mixing of the powder and water is also disclosed.

Abstract: A process employing a wet mixer having a vertical mixing chamber for forming a wet slurry of a cementitious powder and liquid. The vertical mixing chamber is designed to provide the required amount of mixing to provide thoroughly mixed, uniformly thin slurry within a mixing residence time that allows for adequate supply of slurry to ensure continuous operation of an associated cement panel production line. Gravity feed means for supply of cementitious powder and water to the slurry mixing area of the chamber is also disclosed.

Abstract: A head-box for depositing slurry upon a moving web including a main metering roll, a companion roll disposed in closely spaced relation to the metering roll and a vibrating gate which forms a nip between the metering roller and the gate. The nip is arranged to retain a supply of the slurry, and the rolls are driven so slurry retained in the nip progresses over an upper outer peripheral surface of the metering roll to be deposited upon the web. Also, preferably included is a doctor blade disposed in operational relationship to the metering roll for directing the slurry downwardly from the outer metering roll surface to a point above the surface of a carrier for a fiberglass layer upon which the slurry layer is deposited. The vibrating gate and doctor blade may be pivotally mounted to either side of the surfaces of the head-box.

Abstract: A wet mixer apparatus and method for its use, the mixer having a vertical mixing chamber for forming a wet slurry of a cementitious slurry and water. The vertical mixing chamber is designed to provide the required amount of mixing to provide thoroughly mixed, uniformly thin slurry within a mixing residence time that allows for adequate supply of slurry to ensure continuous operation of an associated cement panel production line. Gravity feeding for separate supply of cementitious powder and water to the slurry mixing area of the chamber without pre-mixing of the powder and water is also disclosed.

Abstract: A process for making a thin, sealant-coated, fire and indentation resistant gypsum panel. A layer of a mixture of cellulosic fibers moistened with water and an additive to restrict the adhesion of cellulosic fibers to one another, is deposited on at least two separate conveyors to form a fibrous matt on each conveyor. A layer of dry calcined gypsum containing set accelerator is deposited on the fibrous matt on each conveyor which contains, by weight on a dry weight basis, about 70-90% gypsum, about 10%-19% cellulosic fiber and about 1%-9% of combined additive and set accelerator. Each layer on each conveyor is directed to a mixing station to form a homogeneous layer, and the formed homogeneous layers on separate conveyors are placed atop one another on a single conveyor to form a combined homogeneous layer. Water is added to the layer or layers to rehydrate calcined gypsum. The combined homogeneous layer is subjected to pressure to form a pressed, homogeneous fiber-reinforced gypsum panel, and dried.