| 摘要 |
An endless belt for a press section forces a controlled amount of air into a sheet to relieve a vacuum in the sheet during dewatering of the sheet. The first surface of the belt is impermeable to water and permeable to air and the second surface of the belt is impermeable to water and air. Between the first and second surfaces is a body that is resiliently compressible and that has a plurality of air pockets that communicate vertically with the first surface. The air pockets are arranged to essentially stop passage of air through the belt in machine and cross machine directions. Air is compressed in the air pockets as the belt enters the nip, and the compressed air leaves the air pockets to relieve the vacuum in the sheet as the belt passes beyond mid-nip, preventing water from reentering the sheet.
|
