EP 1040222 B1 20080206 - BLEACHING OF CHEMICAL PULP WITH PERACID
Title (en)
BLEACHING OF CHEMICAL PULP WITH PERACID
Title (de)
BLEICHEN VON ZELLSTOFF MITTELS PERSÄURE
Title (fr)
BLANCHIMENT DE PATE CHIMIQUE AVEC DU PERACIDE
Publication
Application
Priority
- FI 9800993 W 19981218
- FI 974575 A 19971219
Abstract (en)
[origin: WO9932710A1] The invention relates to a process for the bleaching of chemical pulp and the use of a bleaching solution. According to the invention the pulp is treated in a plurality of different steps by using at least in one step a bleaching solution which contains a peracid, and the essential idea of the invention is that the peracid is used in a post-bleaching which is the last step of the bleaching process, the post-bleaching being carried out in the presence of one or more earth-alkali metal compounds. By using a peracid the pulp is brought to its final brightness, and the purpose of the earth-alkali metal added is to combat the lowering of the viscosity of the pulp. According to the invention the post-bleaching can be carried out after the bleach plant steps in a pulp flow pipe, a storage tower or in the paper machine at a paper mill.
IPC 8 full level
D21C 9/16 (2006.01); D21C 9/10 (2006.01); D21H 21/32 (2006.01)
CPC (source: EP)
D21C 9/166 (2013.01); D21H 21/32 (2013.01)
Citation (examination)
- US 5632859 A 19970527 - HEITTO PERTTI [FI], et al
- SINGH R.P.: "The Bleaching of Pulp", 1979, TAPPI PRESS, ATLANTA
- REEVE D.W.: "Pulp Bleaching, pages 12,13", 1996, TAPPI PRESS, ATLANTA
Designated contracting state (EPC)
AT BE CH CY DE DK ES FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
WO 9932710 A1 19990701; AT E385526 T1 20080215; AU 1674399 A 19990712; BR 9813747 A 20001017; BR 9813747 B1 20090113; CA 2315063 A1 19990701; CA 2315063 C 20081118; DE 69839097 D1 20080320; DE 69839097 T2 20090129; EP 1040222 A1 20001004; EP 1040222 B1 20080206; ES 2302362 T3 20080701; FI 112958 B 20040213; FI 974575 A0 19971219; FI 974575 A 19990620; JP 2001527168 A 20011225; JP 4499280 B2 20100707; PT 1040222 E 20080505
DOCDB simple family (application)
FI 9800993 W 19981218; AT 98961279 T 19981218; AU 1674399 A 19981218; BR 9813747 A 19981218; CA 2315063 A 19981218; DE 69839097 T 19981218; EP 98961279 A 19981218; ES 98961279 T 19981218; FI 974575 A 19971219; JP 2000525621 A 19981218; PT 98961279 T 19981218