| 摘要 |
A pressing section of a papermaking machine is configured to increase press ed dryness significantly while maintaining substantial "one-sidedness", where both sides of the paper sheet have essentially identical surface characteristics. To strik e a commercially useful balance between the application of high temperatures and pressures which increase paper dryness but can result in the production of two-sided paper and lowering nip pressure, which enhances one-sidedness but lowers effectiveness in removing water from the paper web, a press section according to the present invention has two conventional presses followed by two or three presses including one heat ed Extended Nip press. Preferably, smooth high temperature press felts are used to assis t in the reduction of two-sidedness of the formed web. The dryer section may, alternatively, add a fifth press utilizing the first dry roll as the backing roll, two Extended N ip presses, a heated Extended Nip press followed by a heated conventional press, or a heated Extended Nip press in the third pressing section, followed by a conventional unheated pre ss utilizing the first dryer as the backing roll.
|
