| 摘要 |
<p>Press section of a paper machine, in particular for printing paper qualities whose grammage is in the range of 40 ... 80 g/m<2>. The press section comprises a pick-up roll (13), on whose suction zone (13a) the web (W) is detached at the pick-up point (P) from the forming wire (10) and is passed on the pick-up felt (15) into the first press nip (N1) in the press section, in which nip the pick-up felt acts as a press fabric. The press section includes an extended nip (Np), which is placed after the first roll nip. Into this extended nip (Np), the web (W) is passed as a closed draw on support of a fabric face or roll face. The first nip (N1) in the press section is a roll nip with relatively low load, which acts as a front nip, in whose area almost or approximately one half of the total amount of the water contained in the web (W) entering into the front nip is removed from the web (W). The extended nip (Np), which is the second press nip in the press section, is formed against a smooth-faced (40';41') back-up roll (40;41). Only one press fabric (15; 30) which receives water passes through the press zone (NP) of the extended nip (Np), said fabric (15;30) being arranged preferably at the side of the face of the web (W) opposite in relation to the web face placed at the side of the forming wire (10), from which forming wire (10) the web was detached at the pick-up point (P). <IMAGE></p> |
