Pressure control forming section
US5011577A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1989 |
| Grant date | Apr 30, 1991 |
| Priority date | — |
| Expiry date | Jun 8, 2009 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21F9/02
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus are disclosed whereby the rate of drainage of the stock on a Fourdrinier paper making machine can be controlled for the full length of an open surface forming section. A continuous sealed drainage box is used from adjacent the head box slice to the end of the forming section, within which the air pressure can be controlled. In the area adjacent the head box slice drainage is hindered by the use of a positive (above ambient atmospheric) pressure, while further along the forming section the pressure is decreased to a negative value (below ambient atmospheric). Improved paper formation and first pass retention are obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.