(57) The invention concerns a press section of a paper or board machine, comprising a
number of rolls (1,11,22,32,44,70) which form press nips (N₁,N₂,N₃,N₄) that dewater
the web (in) with each other, the web being arranged to run through said nips. Of
the rolls at least one roll (1;70) is a smooth-faced so-called centre roll, which
forms a press nip (N₂,N₃;N₄) with at least one other press roll (11,32;44), over which
a press felt (10,30;40), which has been formed as an endless loop, is passed to absorb
water out of the web (in) into said press felt (10,30;40). The centre roll (1;70)
in accordance with the invention is a variable-crown roll, which comprises a metallic
roll mantle (2;71) arranged revolving on a stationary roll axle (3;72). The roll includes
at least one set of crown-variation means (4,5;73), which are arranged to load the
roll mantle (2;71) in the direction of the nip plane (K₂,K₃;K₄) of the centre roll
(1;70) and the roll (11,32;44) that forms a press nip (N₂,N₃;N₄) with said centre
roll so as to regulate the profile of linear load in said nip (N₂,N₃;N₄).
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