Coating by means of a coating hopper with coating slots where the coating composition has a low slot Reynolds number
US5143758A · kind A · utility
15Cited by
8References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1991 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Mar 28, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S118/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In the hopper coating of liquid compositions on moving webs, as in the coating of photographic layers on film supports, the trapping of solid particles or bubbles in the hopper slots causes line defects or streaks in the coated layers. These defects are avoided or reduced by determining the conditions under which the composition can be flowed through one or through a plurality of adjacent slots of the coating hopper at slot Reynolds numbers less than about 10 and flowing the composition through such slot or slots under said conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.