Glass mold material for precision glass molding
US6363747B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 2000 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | May 12, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2215/72
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for making working mold tools for use in a compression molding process for molding optical glass elements from high temperature glasses having Tg's in the range of from about 400° C. to about 850° C. An yttria aluminosilicate glass is fabricated by traditional melting and casting processes to thereby make an amorphous base material having a minimum apparent viscosity of 1015 poise at the temperature at which the optical glass elements are to be molded. A mold preform is made from the base material. A first surface figure for the optical element to be molded with the working mold tool is defined. A second surface figure for a master mold tool and a third surface figure for the working mold tool are computed based upon the first surface figure and the coefficients of thermal expansion of the optical element, the master mold tool, and the working mold tool, the temperature at which the working mold tool is molded, and the temperature at which the optical element is to be molded. A master mold tool is then ground and polished to achieve the second surface figure. The working mold tool is then molded from the mold preform using the master mold tool.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.