Method of and apparatus for coating high speed traveling webs
US5112653A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1991 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Jan 31, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05C3/18
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of and apparatus for applying coating liquid to a web of paper traveling over a web supporting surface at speeds of 3,000, 4,000 and more feet per minute to produce a coated web free of streaking and other imperfections comprises apparatus for and the sequential steps of distributing coating liquid in a turbulent state over the supported web through a limited application zone within a very short dwell time of the turbulent liquid on the web; subjecting the coating liquid on the supported web to an initial doctoring by means of a primary doctor blade biased under pressure against the coated web at the rear edge of the application zone to form on the web downstream from the zone a relatively quiescent layer of coating liquid having a wet film thickness sufficiently in excess of the final wet film thickness to accommodate a subsequent final wet film doctoring of the coating liquid on the web; and, a a location downstream and isolated from the application zone, subjecting the relatively quiescent layer of excess coating liquid on the supported web to a final docttoring by means of a final doctor blade biased under pressure against the coated web to remove the excess coating fr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.