Manufacturing method of a glass blank for magnetic disk and manufacturing method of a glass substrate for magnetic disk
US8806893B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2012 |
| Grant date | Aug 19, 2014 |
| Priority date | — |
| Expiry date | Feb 15, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2215/70
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A manufacturing method of a glass blank for magnetic disk including a pair of principal surfaces, the method including: dropping process for dropping a lump of molten glass; pressing process for forming a sheet glass material by sandwiching simultaneously the lump from both sides of the dropping path of the lump with surfaces of the pair of dies facing together, and performing press forming to the lump; and temperature adjusting process for adjusting temperature of the lump before the pressing process such that viscosity variation of the lump is reduced with respect to positions over the entirety of the lump in the pressing process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.