High amylose starch wallboard and method of making same
AssigneeNational Gypsum Properties, LLC
InventorsMatthew M. Hilken, David G. Peterson, Jr.
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Abstract
The subject invention relates to compositions and methods for the preparation of stucco slurry compositions. The compositions and methods involve replacing typically used starches with modified high amylose starches that can be used in the normal wallboard manufacturing process. The compositions and methods provide wallboards having increased core strength and increased paper-to-core bond integrity compared to standard wallboards made from slurries with reduced water levels.
Claims10
A wallboard slurry composition comprising:
- (a) calcium sulfate hemihydrate;
- (b) water, wherein the water to calcium sulfate hemihydrate ratio is less than about .80;
- and
- (c) a high amylose starch having an amylose fraction greater than about 25% and that gels at a temperature of about 160° F. to about 212° F., wherein the said high amylose starch comprises about 0.26 mass % to about 0.71 mass % of the wallboard slurry composition.
A wallboard slurry composition comprising:
- (a) calcium sulfate hemihydrate;
- (b) water, wherein the water to calcium sulfate hemihydrate ratio is less than about .80;
- and
- (c) a high amylose starch having an amylose fraction greater than about 25% and that gels at a temperature of about or below 212° F., wherein the said high amylose starch comprises about 0.26 mass % to about 0.71 mass % of the slurry.
A method of preparing wallboard, the method comprising the steps of:
- forming a slurry comprising water and calcium sulfate hemihydrate, wherein the water to calcium sulfate hemihydrate ratio is less than about .80 and wherein the slurry further comprises a high amylose starch having an amylose fraction greater than about 25% and that gels at a temperature of about 160° F. to about 212° F., wherein the said high amylose starch comprises about 0.26 mass % to about 0.71 mass % of the slurry;
- depositing the slurry on a first sheet of paper;
- applying a second sheet of paper on the slurry to form a wet wallboard;
- allowing the slurry to set and form a core between the first and second sheets of paper;
- and
- causing the high amylose starch to gel and form a bond between each of the first and second sheets of paper and the core.
Dependencies are inferred from the claim text.