Manufacturing method for a glass substrate for magnetic disk
US8806895B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2011 |
| Grant date | Aug 19, 2014 |
| Priority date | — |
| Expiry date | Dec 7, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2215/70
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention provides a manufacturing method of a sheet glass material excellent in flatness. A manufacturing method of glass substrate for magnetic disk including a pair of principal surfaces, the method comprising the steps of: dropping process for dropping a lump of molten glass; pressing process for forming a sheet glass material by performing press forming to the lump while sandwiching the lump from both sides of the dropping path of the lump with facing surfaces of a pair of dies, the pair of dies being set to substantially the same temperature; and processing process for processing the sheet glass material, while the lump drops down while revolving around its dropping axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.