EP 0672207 A1 19950920 - VISCOSE PRODUCTION PROCESS.
Title (en)
VISCOSE PRODUCTION PROCESS.
Title (de)
VERFAHREN ZUR HERSTELLUNG VON VISKOSEZELLSTOFFEN.
Title (fr)
PROCEDE DE PRODUCTION DE VISCOSE.
Publication
Application
Priority
- AT 9300183 W 19931202
- AT 238292 A 19921202
Abstract (en)
[origin: US5676795A] PCT No. PCT/AT93/00183 Sec. 371 Date Jul. 13, 1995 Sec. 102(e) Date Jul. 13, 1995 PCT Filed Dec. 2, 1993 PCT Pub. No. WO94/12719 PCT Pub. Date Jun. 9, 1994The present invention relates to a process for producing viscose pulp from lignocelluloses, such as hardwood, softwood or annual plants, in which process the lignocellulose is treated in a digester at first with saturated steam to prehydrolyze hemicelluloses and subsequently, without flashing, with hot black liquor (HSL) of a preceding sulfate pulp digestion as well as, if desired, under addition of fresh white liquor (WL) to neutralize the acidic reaction products formed, neutralization liquor (NL) thus being formed in the digester. Upon addition of the amount of alkali required for delignification in the form of fresh white liquor (WL), if desired, in combination with a displacement of neutralization liquor (NL) and temperature adjustment, digestion then will take place with or without temperature gradient. When reaching the desired degree of digestion, digestion is terminated by displacement of the hot black liquor (HSL) with cold alkaline washing filtrate (WF), at the same time the pulp is freed from still adhering lignin degradation products, and the thus obtained pulp is discharged from the digester at a temperature of below 100 DEG C.
IPC 1-7
IPC 8 full level
CPC (source: EP US)
D21C 1/02 (2013.01 - EP US); D21C 3/022 (2013.01 - EP US)
Citation (search report)
See references of WO 9412719A1
Citation (examination)
DATABASE WPI Section Ch, Week 8814, Derwent Publications Ltd., London, GB; Class F09, AN 88-097086 & SU,A,1 331 924 (CELLULOSE PAPER IND RES) 23. August 1987 s
Designated contracting state (EPC)
DE ES FR GB PT SE
DOCDB simple family (publication)
US 5676795 A 19971014; AT 398588 B 19941227; AT A238292 A 19940515; BR 9307589 A 19990831; CA 2150381 A1 19940609; CA 2150381 C 20041102; CN 1041645 C 19990113; CN 1094108 A 19941026; DE 59304443 D1 19961212; EP 0672207 A1 19950920; EP 0672207 B1 19961106; ES 2097021 T3 19970316; FI 952509 A0 19950523; FI 952509 A 19950523; JP H08503744 A 19960423; RU 2122055 C1 19981120; RU 95113599 A 19970527; WO 9412719 A1 19940609
DOCDB simple family (application)
US 44681995 A 19950713; AT 238292 A 19921202; AT 9300183 W 19931202; BR 9307589 A 19931202; CA 2150381 A 19931202; CN 93121600 A 19931202; DE 59304443 T 19931202; EP 94900624 A 19931202; ES 94900624 T 19931202; FI 952509 A 19950523; JP 51256794 A 19931202; RU 95113599 A 19931202