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US 7,803,296 B2Granted
Methods and systems for preparing gypsum slurry containing a cellulose ether
AssigneeUnited States Gypsum Company
InventorsDavid Paul Miller, Qingxia Liu, Qiang Yu
Life of this patent
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Abstract
A method for forming a gypsum slurry comprises the steps of combining gypsum and water to form a slurry, combining cellulose ether with at least a second material configured to delay solubilization of the cellulose ether, and adding the combined cellulose ether and at least a second material to the slurry.
Claims22
A method for preparing a gypsum slurry useful for making a gypsum board product comprising the steps of:
- obtaining calcined gypsum and water in the form of a slurry;
- preparing an emulsion of cellulose ether as a dispersed phase with at least a second material as a continuous phase, said emulsion being configured to delay solubilization of said cellulose ether;
- and
- adding said emulsion to said slurry, wherein said cellulose ether is solid and wherein said at least a second material comprises water at an elevated temperature selected to maintain said cellulose ether in solid form.
1 more element
A method for preparing a a fiberboard product, comprising:
- mixing gypsum dihydrate with water to form a slurry;
- adding a cellulosic fiber to said slurry;
- heating said slurry under pressure to convert said gypsum dihydrate to a hemihydrate;
- preparing an emulsion of cellulose ether as a dispersed phase with at least a second material as a continuous phase, said emulsion being configured to delay solubilization of said cellulose ether;
- transferring said slurry to a headbox;
- and transferring said slurry from said headbox to one or more presses;
- and,
- adding said emulsion to said slurry at said headbox;
- and wherein said emulsion releases said dispersed phase cellulose ether into said slurry after said slurry has been transferred to said one or more presses.
6 more elements
A method for preparing a gypsum slurry, comprising:
- obtaining calcined gypsum and water in the form of a slurry;
- preparing an emulsion of cellulose ether as a dispersed phase with at least a second material as a continuous phase, said emulsion being configured to delay solubilization of said cellulose ether;
- adding said emulsion to said slurry;
- and
- adding a cross linker to said slurry, wherein said cross linker comprises said at least a second material, wherein said methyl cellulose and said cross linker are solids, and wherein the step of combining said cellulose ether with said at least a second material comprises causing said particles of solid cellulose ether to adhere to particles of said cross linker.
2 more elements
Dependencies are inferred from the claim text.