EP 1604061 A1 20051214 - BLEACHING OF CELLULOSE PULP IN A FIRST CHLORINE DIOXIDE BLEACHING STEP
Title (en)
BLEACHING OF CELLULOSE PULP IN A FIRST CHLORINE DIOXIDE BLEACHING STEP
Title (de)
BLEICHEN VON ZELLSTOFF IN EINER ERSTEN CHLORDIOXIDBLEICHSTUFE
Title (fr)
BLANCHIMENT DE PATE CELLULOSIQUE AU COURS D'UNE PREMIERE ETAPE DE BLANCHIMENT AU BIOXYDE DE CHLORE
Publication
Application
Priority
- SE 2004000303 W 20040304
- SE 0300608 A 20030307
Abstract (en)
[origin: WO2004079087A1] The invention concerns a method for bleaching cellulose pulp having an MC consistency in a first step with chlorine dioxide in a bleaching sequence with several bleaching steps. The pulp is bleached in this first chlorine dioxide step in a first phase at a lower temperature of 60 +/- 10 °C during a retention time of from 30 seconds to 30 minutes, after which the pulp is heated by at least 10 °C to a reaction temperature of 90 1/- 10 °C for a second phase, which has a retention time of 60-200 minutes. With this process modification of a first chlorine dioxide step, an efficient destruction of undesired organic acids is obtained, while at the same time improved viscosity/strength of the pulp can be obtained of the finally bleached pulp with a whiteness of approximatels 90 % ISO.
IPC 1-7
IPC 8 full level
D21C 9/14 (2006.01)
CPC (source: EP US)
D21C 9/142 (2013.01 - EP US)
Citation (search report)
See references of WO 2004079087A1
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR
DOCDB simple family (publication)
WO 2004079087 A1 20040916; BR PI0408171 A 20060321; EP 1604061 A1 20051214; JP 2006519939 A 20060831; SE 0300608 D0 20030307; SE 0300608 L 20040908; SE 524896 C2 20041019; US 2006118260 A1 20060608
DOCDB simple family (application)
SE 2004000303 W 20040304; BR PI0408171 A 20040304; EP 04717335 A 20040304; JP 2006507938 A 20040304; SE 0300608 A 20030307; US 54703803 A 20030307