发明名称 |
METHOD AND DEVICE FOR DEWATERING OF A PAPER WEB BY PRESSING |
摘要 |
Method and device in the manufacture of paper or board for dewatering of a paper web that is being manufactured. The paper web is transferred from a forming wire onto a wire in the drying section while constantly on support of a fabric that receives water, a transfer fabric, or of any other, corresponding transfer surface as a closed draw, at a particularly high speed, which is higher than about 25-30 m/s. Dewatering of the paper web is carried out by means of at least two subsequent press nips, of which nips at least one press nip is a so-called extended-nip zone, whose length in a machine direction is larger than about 100 mm. The extended-nip zone is formed in connection with a mobile flexible press-band loop. The distribution of the compression pressure employed within said extended-nip press zone is regulated and/or selected both in the transverse direction of the web and in the machine direction so as to set or to control the different profiles of properties of the web.
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申请公布号 |
CA2055927(C) |
申请公布日期 |
1999.02.02 |
申请号 |
CA19912055927 |
申请日期 |
1991.11.20 |
申请人 |
VALMET CORPORATION |
发明人 |
LAAPOTTI, JORMA;KARVINEN, MIKKO;TASKINEN, PEKKA;PAJULA, JUHANI;HIRSIMAKI, MARTTI;KIVIMAA, JUHA |
分类号 |
D21F3/02;D21F3/04;(IPC1-7):D21F3/00;D21F1/66 |
主分类号 |
D21F3/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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