Carbon fiber-reinforcing gypsum models and forming molds, gypsum powder materials for making such models and molds, and a method for producing them
US4859243A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1987 |
| Grant date | Aug 22, 1989 |
| Priority date | — |
| Expiry date | Nov 12, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B20/0048
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Gypsum models and molds made of a dihydrate gypsum (CaSO.sub.4 .multidot.2H.sub.2 O) having uniformly dispersed therein carbon fibers having a predetermined length in a defined range of amount are described. The molds include various types of molds such as original molds, basic molds, forming molds and the like. A method for manufacturing these molds is also described in which sizing agents deposited on carbon fibers are decomposed and removed by heating or dissolution in solvent, separating the carbon fibers into single fibers in water, adding a major part of hemihydrate gypsum (CaSO.sub.4 .multidot.1/2H.sub.2 O) powder to the carbon fiber dispersed water to obtain a gypsum slurry dispersing uniformly those single fibers, and casting the slurry in a case mold to obtain forming molds. Production efficiency for manufacturing white wares by the gypsum forming molds on which a pottery or porcelain plastic clay is jiggered removing the resulting green product from the mold is also described hemihydrate gypsum. Gypsum powder materials comprising carbon fibers and a method for making the same are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.