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US 12,371,374 B2Granted
Gypsum composition comprising uncooked starch having mid-range viscosity, and methods and products related thereto
AssigneeUnited States Gypsum Company
InventorsYijun Sang, Brian J. Christ
Life of this patent
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Abstract
Disclosed are product (e.g., board), slurry, and methods relating to an uncooked starch that can be used to enhance strength in one or more gypsum layers in the board. The uncooked starch has a hot water viscosity of from about 20 BU to about 300 BU according to the HWVA method, and/or a mid-range peak viscosity of from about 120 Brabender Units to about 1000 Brabender Units.
Claims22
A gypsum board comprising:
- a set gypsum core disposed between two cover sheets, the core formed from a slurry comprising stucco, water, a migratory starch, and at least one uncooked non-migratory, non-substituted starch having a hot water viscosity of from 20 Brabender Units to 300 Brabender Units when the viscosity is measured by the HWVA method;
- wherein the gypsum board has a density of 35 pcf or less;
- wherein the board has a nail pull resistance of at least about 72 lb-f according to ASTM 473-10, method B;
- and
- wherein the at least one uncooked, non-migratory, non-substituted starch is included in the slurry in a weight percentage of total starch content in the slurry that is greater than 30%.
2 more elements
A method of forming a gypsum board comprising:
- chemically modifying an uncooked non-substituted starch having a hot water viscosity outside of a range of 20 Brabender Units to 300 Brabender Units when the viscosity is measured by the HWVA method to provide a chemically modified uncooked non-substituted starch having a hot water viscosity of from 20 Brabender Units to 300 Brabender Units;
- preparing a slurry comprising stucco, water, and the chemically modified uncooked non-substituted starch;
- and
- forming the prepared slurry over a first cover sheet;
- and
- disposing a second cover sheet over the formed prepared slurry,
- wherein the formed prepared slurry sets to form a set gypsum core between the first and second cover sheets;
- wherein the gypsum board has a density of 35 pcf or less;
- wherein the gypsum board has a nail pull resistance of at least about 72 lb-f according to ASTM 473-10, method B;
- and
- wherein the chemically modified uncooked non-substituted starch is included in the slurry in a weight percentage of total starch content in the slurry that is greater than 30%.
8 more elements
Dependencies are inferred from the claim text.