(19)
(11) EP 1 378 604 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
19.10.2005 Bulletin 2005/42

(43) Date of publication A2:
07.01.2004 Bulletin 2004/02

(21) Application number: 03445084.1

(22) Date of filing: 30.06.2003
(51) International Patent Classification (IPC)7: D21J 1/04
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
Designated Extension States:
AL LT LV MK

(30) Priority: 04.07.2002 SE 0202099

(71) Applicant: Metso Paper, Inc.
00101 Helsinki (FI)

(72) Inventors:
  • Pichler, Walter
    856 30 Sundsvall (SE)
  • Klinga, Leif
    184 52 Österskär (SE)

(74) Representative: Hopfgarten, Nils 
Groth & Co.KB P.O. Box 6107
102 32 Stockholm
102 32 Stockholm (SE)

   


(54) Method for controlling the pressure in a multi-level press


(57) Device and method for controlling the pressure in pressing cellulose-based boards, where at least one board initially and lastly during said period of time of the pressing is subjected to a high pressure compared to the pressure of an intermediate period called drying period. During the drying period the board is subjected to at least one breathing cycle, during which the pressure first is decreased to a lower pressure compared to the initial high pressure, and subsequently is increased to a higher pressure compared to the lower pressure of the breathing cycle, and subsequent to the breathing cycle, to a lower pressure compared to the higher pressure of the breathing cycle.






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