EP 0279845 A4 19910109 - PULP BLEACHING PROCESS
Title (en)
PULP BLEACHING PROCESS
Publication
Application
Priority
US 90099286 A 19860828
Abstract (en)
[origin: WO8801661A1] A multistage pump bleaching process comprising at least three bleaching stages including oxygen extraction (20) in an alkaline medium (EO) of a chlorine (C) or chlorine/chlorine-dioxide (CD) bleaching step (5) followed by a hot alkaline hypochlorite treatment (H*/E), (28) or followed by a chlorine dioxide (D) treatment with simultaneous treatment with chlorine dioxide (H*/ED) in the sequence EOH*/ED or EO(H*/ED). The novel bleaching sequences result in significant savings in time and operating costs as compared with conventional bleaching sequences capable of producing products of comparable brightness.
IPC 1-7
IPC 8 full level
D21C 9/14 (2006.01)
CPC (source: EP)
D21C 9/144 (2013.01)
Citation (search report)
- [A] US 4238281 A 19801209 - HISTED JOHN A [CA]
- [A] ABSTRACT BULLETIN OF THE INSTITUTE OF PAPER CHEMISTRY, vol. 53, no. 10, April 1983, page 1150, abstract no. 10639, Appleton, Wisconsin, US; J. GUPTA: "Hot hypochlorite sequence reduces bleaching capital [and] chemical costs", & PULP PAPER 56, NO. 10, PAGES 103-105 (OCTOBER 1982)
- See references of WO 8801661A1
Designated contracting state (EPC)
DE FR GB SE
DOCDB simple family (publication)
WO 8801661 A1 19880310; EP 0279845 A1 19880831; EP 0279845 A4 19910109; FI 881930 A0 19880425; FI 881930 A 19880425
DOCDB simple family (application)
US 8702130 W 19870825; EP 87905881 A 19870825; FI 881930 A 19880425