Apparatus and method for treating a fibrous material web in a long nip press unit
OwnerWilhelm Mausser, Andreas Anzelinventors
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Abstract
The invention relates to an apparatus and a method for treating a fibrous material web (9) in a paper or cardboard machine in a long nip press unit (29) comprising a press roll (24), which has a rotating press jacket (25) and a mating roll (23), wherein the fibrous material web (9) is dewatered in an extended press nip (26) between the mating roll (23) and the press jacket (25) of the press roll (24). According to the invention, the fibrous material web (9) is guided after the extended press nip (26) on a special rotating press jacket (25) of the press roll (24) to a transfer region (30), in which the fibrous material web (9) is transferred from the press jacket (25) to a transfer element (31, 27).
Claims20
A press arrangement of a paper or board machine for treating a pulp web (9), in which
- the pulp web (9) is guided through an extended press nip (26) of a long-nip pressing unit (29),
- the long-nip pressing unit (29) has a press roll (24) in the form of a shoe press with a revolving press belt (25) and an opposing roll (23),
- the pulp web (9) is carried on the press belt (25) of the press roll (24) after the extended press nip (26) to a transfer element (31, 27) to which the pulp web (9) is transferred, wherein the improvement comprises that
- the pulp web (9) is carried on a felt (33) to and through the extended press nip (26),
- the revolving press belt (25) includes a supporting material and an elastic, compressible polymer layer,
- the polymer layer has a surface that faces the pulp web and has a hardness between 50 and 97 Shore A, and
- said surface of the polymer layer contacts the pulp web and has reversible, pressure-dependent roughness of Rz=2-80 microns, measured in accordance with ISO 4287, when pressure-relieved and Rz=0-20 microns when pressure-loaded with a line load of 20-600 kN/m.
(canceled)
A process for treating a pulp web (9) in a paper or board machine in a long-nip pressing unit (29) with one press roll (24) that is formed as a shoe press roll and which has a rotating press belt (25) and one opposing roll (23), wherein
- the pulp web (9) is dewatered in an extended press nip (26) between the opposing roll (23) and the press belt (25) of the press roll (24),
- the pulp web (9) is carried on the rotating press belt (25) of the press roll (24), after the extended press nip (26) to a transfer zone (30) in which the pulp web (9) is transferred from the press belt (25) to a transfer element (31, 27),
- the pulp web (9) is carried on a felt (33) to and through the extended press nip (26), in contact with the rotating press belt (25) which press belt (25) includes a supporting material and an elastic, compressible polymer layer,
- the polymer layer has a surface that faces the pulp web and has a hardness between 50 and 97 Shore A, and
- said surface of the polymer layer contacts the pulp web and has reversible, pressure-dependent roughness of Rz=2-80 microns, measured in accordance with ISO 4287, when pressure-relieved and Rz=0-20 microns when pressure-loaded with a line load of 20-600 kN/m.
Dependencies are inferred from the claim text.