摘要:
The invention provides gypsum wallboard, made from gypsum-containing slurries having outstanding hydration rate characteristics comprising alpha-hemihydrate ground to a particular particle size distribution range and having a Blaine surface area in the range from about 3100 cm2/g to about 9000 cm2/g, alone or in combination with beta-hemihydrate.
摘要:
The invention generally provides gypsum-containing slurries including stucco, naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1%-3.0% by weight based on the weight of dry stucco. The pregelatinized starch is present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts, accelerators, binders, paper fiber, glass fiber, and other known ingredients.
摘要:
The invention provides in one embodiment a gypsum-containing slurry including stucco and an aqueous pre-dispersion of a pregelatinized starch. Also provided is a method of making gypsum wallboard by providing a pre-dispersion of the pregelatinized starch in water, and adding the pregelatinized starch pre-dispersion to the gypsum-containing slurry. The pregelatinized starch can have a particle size distribution within the following range: d (0.1)=about 20μ-35μ, d (0.5)=about 60μ-110μ, d (0.9)=about 100μ-220μ.
摘要:
The invention provides a light weight composite gypsum board including a foamed low density set gypsum core, a top non-foamed (or reduced-foamed) bonding high density layer and a bottom non-foamed (or reduced-foamed) bonding high density layer, a top cover sheet bonded to the foamed low density set gypsum core by the top non-foamed (or reduced-foamed) bonding high density layer, and a bottom cover sheet bonded to the foamed low density set gypsum core by the bottom non-foamed (or reduced-foamed) bonding high density layer. The foamed low density set gypsum core is prepared having a density of less than about 30 pcf using soap foam in the gypsum-containing slurry. The combination of components provide a composite gypsum board having light weight and high strength.
摘要:
A method and apparatus for providing an evenly mixed additive enhanced gypsum slurry to a web. Calcined gypsum and water are inserted into a mixer through at least one inlet of the mixer. The contents are agitated to form a slurry. The slurry is passed from an outlet of the mixer into a conduit. An additive is introduced into the slurry along a length of the conduit to achieve a flow stream of a slurry/additive mixture. A cross section of the flow stream is expanded in the conduit while not changing direction of the flow stream and a direction of the flow stream is changed while not expanding the cross section of the flow stream and conduit, all prior to the flow steam exiting from an outlet of the conduit.
摘要:
A slurry distributor for use in a continuous manufacturing process includes an inlet opening and a shaped duct adapted to receive a flow of slurry provided at the inlet opening. The shaped duct has a parabolic guide surface adapted to redirect the flow of slurry. An outlet opening in fluid communication with the shaped duct is adapted to discharge the flow of slurry from the slurry distributor.
摘要:
A method and apparatus for providing an evenly mixed additive enhanced gypsum slurry to a web. Calcined gypsum and water are inserted into a mixer through at least one inlet of the mixer. The contents are agitated to form a slurry. The slurry is passed from an outlet of the mixer into a conduit. An additive is introduced into the slurry along a length of the conduit to achieve a flow stream of a slurry/additive mixture. A cross section of the flow stream is expanded in the conduit while not changing direction of the flow stream and a direction of the flow stream is changed while not expanding the cross section of the flow stream and conduit, all prior to the flow steam exiting from an outlet of the conduit.
摘要:
This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.
摘要:
A slurry distribution system can include a feed conduit and a distribution conduit in fluid communication therewith. The feed conduit can include a first feed inlet and a second feed inlet disposed in spaced relationship thereto. The distribution conduit can extend generally along a longitudinal axis and include an entry portion and a distribution outlet in fluid communication therewith. The entry portion is in fluid communication with the first and second feed inlets of the feed conduit. The distribution outlet extends a predetermined distance along a transverse axis, which is substantially perpendicular to the longitudinal axis. The slurry distribution system can be placed in fluid communication with a gypsum slurry mixer adapted to agitate water and calcined gypsum to form an aqueous calcined gypsum slurry.