Lightweight gypsum board
- Assignee
- United States Gypsum Co
- Inventors
- Mirza A. Baig
- Jurisdiction
- United States (USPTO)
- Filed
- 1996-09-16
- Published
- 1999-07-13
- Priority
- 1996-09-16
A lightweight gypsum board is provided, including, by dry weight, gypsum as the largest single ingredient, perlite as the second largest single ingredient, and starch as a minor ingredient, in the board. The starch may be pre-cooked prior to mixing, and is dispersed in the core of the board to act as a binder for binding the gypsum to the perlite. Gypsum board made according to the invention is lighter in weight, yet has a comparable nail pull value to conventional wallboard.
A lightweight gypsum wallboard comprising: a core including: a. gypsum, said gypsum being the largest single ingredient, by dry weight in the core, said gypsum comprising at least 50% of the dry weight of the core; b. perlite having a bulk density of approximately 3–3.5 pounds per cubic foot, said perlite being the second largest single ingredient, by dry weight, in the core, said perlite comprising less than 50% of the dry weight of the core and being distributed throughout said core; c. fibers comprising in the range of 0.5% to 5.6% of the dry weight of the core; d. starch comprising in the range of 0.25% to 6% of the dry weight of the core: and e. first and second sheets of face paper, said core being surfaced by said first and second sheets; wherein the wallboard has a density of between 21.5 and 37.1 pounds per cubic foot.
Further claims, drawings, prosecution history and legal status: see the official record.
- [1]US 5,922,447 A — Lightweight gypsum board — Google Patents · 1999-07-13