Patent ID: 8414741

Claim:
A tissue papermaking machine for manufacturing a tissue paper web ( 1 ″), comprising: a wet section ( 2 ) for forming a fibre web ( 1 ′), a press section ( 3 ) for pressing the fibre web ( 1 ′), said press section ( 3 ) comprising: a single press ( 11 ), comprising: a first press element ( 12 ), a second press element ( 13 ), said press elements ( 12 , 13 ) forming a press nip (N 1 ) therebetween with a predetermined pressure, a press felt ( 17 ) running in an endless loop around a plurality of guide rolls ( 18 ) and through said press nip (N 1 ) together and in contact with the formed fibre web ( 1 ′), the second press element ( 13 ) being arranged inside the loop of the press felt ( 17 ), a smooth belt ( 14 ) running in an endless loop around a plurality of guide rolls ( 15 ) and through said press nip (N 1 ) together and in contact with the formed fibre web ( 1 ′), the first press element ( 12 ) being arranged inside the loop of the belt ( 14 ), and a transfer roll ( 16 ) arranged inside the loop of the smooth belt ( 14 ), a dry section ( 4 ) for final drying of the fibre web ( 1 ″) pressed in the press nip (N 1 ), said dry section ( 4 ) comprising a drying surface ( 20 ) for final drying of the pressed fibre web ( 1 ″), said transfer roll ( 16 ) being arranged to form a transfer nip (N 2 ) together with the drying surface ( 20 ) for transfer of the fibre web ( 1 ″) to the drying surface ( 20 ), whereby the smooth belt ( 14 ) is arranged to carry the pressed fibre web ( 1 ″) between the press nip (N 1 ) and the transfer nip (N 2 ), wherein: a pre-dewatering device ( 25 ) is arranged substantially adjacent the press felt ( 17 ) at a location upstream of and spaced apart from the first press element ( 12 ) and the second press element ( 13 ) of the press ( 11 ), and prior to any contact between the fibre web ( 1 ″) and the smooth belt ( 14 ), the pre-dewatering device ( 25 ) being configured to pre-dewater the fibre web ( 1 ′) to a dry content of 15-30% before the fibre web ( 1 ′) runs into the press nip (N 1 ) of the press ( 11 ); and the press felt ( 17 ) and the smooth belt ( 14 ) are arranged to be separated from each other immediately after the exit of the press nip (N 1 ) and define therebetween an angle α, which is at least 5° in order to prevent rewetting of the pressed fibre web ( 1 ″).