Differential-speed gravure coating of magnetizable layers in the manufacture of magnetic recording media
US5620514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1995 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Sep 1, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/842
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetizable layer can be applied to a flexible backing web by gravure coating at high speeds by independently driving the backing web at a speed that is substantially different from the surface speed of the gravure roll. Especially high coating speeds have been achieved when the gravure roll rotates oppositely to the direction in which the backing web is advancing. In one embodiment, a nip roll presses the backing web against the backup roll, there is a gap between the gravure roll and a backup roll, and an idler roll is positioned downstream of the gap to force the backing web into contact with the gravure roll over a short arc. When that backup roll has a hard surface such as metal, its surface can be machined with precision, and that precision can be maintained in spite of exposure to solvent vapors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.