Gypsum wallboard core, and method and apparatus for making the same
US6699426B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 10, 2000 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | May 10, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2111/0062
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A gypsum wallboard core, and methods and apparatus for making the same are disclosed. Methods of making a gypsum wallboard core include extruding a gypsum slurry containing water, gypsum, slip agents, water-reducing agents, surfactants and, optional additives, through a die and onto a substantially flat, smooth, moving surface. The die has provisions at its outer sides for the introduction of slip agents into the slurry, and provisions at its lateral outer edges for the introduction of a strength-enhancing agent. Once extruded onto the conveyor belt, the slurry is chemically-activated to set and form a hardened board core which then may be easily removed from the conveyor belt and dried.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.