EP 0717800 A4 19981028 - MEDIUM CONSISTENCY OZONE BRIGHTENING OF HIGH CONSISTENCY OZONE BLEACHED PULP

Title (en)

MEDIUM CONSISTENCY OZONE BRIGHTENING OF HIGH CONSISTENCY OZONE BLEACHED PULP

Title (de)

MITTLERES KONSISTENZ-OZONBLEICHEN VON HOCHKONSISTENZ-OZONGEBLEICHTEM ZELLSTOFF

Title (fr)

BLANCHIMENT D'UNE P TE A PAPIER A CONCENTRATION MOYENNE AVEC DE L'OZONE, APRES DECOLORATION DE CETTE P TE A HAUTE CONCENTRATION AVEC DE L'OZONE

Publication

EP 0717800 A4 19981028 (EN)

Application

EP 94928024 A 19940901

Priority

US 9410050 W 19940901
US 11677693 A 19930903

Abstract (en)

[origin: WO9506773A1] A process for delignifying and bleaching a lignocellulosic material (2) without the use of elemental chlorine or chlorine-containing compounds by forming (4) a pulp, oxygen delignifying (40) the pulp and thereafter further delignifying the oxygen delignified pulp by lifting, displacing and tossing the pulp in a radial direction while advancing it in an axial direction in a plug fow-like manner with an effective amount of ozone (88) for a sufficient time to obtain a substantially delignified pulp having a GE brightness of at least about 35 %. The substantially delignified pulp may then be brightened to a final product by treating the pulp with a brightening stage peroxide compound, followed by subsequently treating the pulp at low to medium consistency with ozone.

IPC 1-7

D21C 9/153; D21C 9/16

IPC 8 full level

D21C 9/10 (2006.01); D21C 9/147 (2006.01); D21C 9/153 (2006.01); D21C 9/16 (2006.01)

CPC (source: EP SE)

D21C 9/1057 (2013.01 - EP); D21C 9/147 (2013.01 - EP); D21C 9/153 (2013.01 - EP SE); D21C 9/163 (2013.01 - EP); D21C 9/163 (2013.01 - SE)

Citation (search report)

[Y] EP 0426652 A1 19910508 - CHEMIEFASER LENZING AG [AT]
[Y] WO 9118145 A1 19911128 - UNION CAMP CORP [US]
[Y] EP 0557112 A1 19930825 - KAMYR INC [US]
See also references of WO 9506773A1

Designated contracting state (EPC)

AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT

DOCDB simple family (publication)

WO 9506773 A1 19950309; AU 7721694 A 19950322; BR 9407457 A 19961112; CA 2170733 A1 19950309; EP 0717800 A1 19960626; EP 0717800 A4 19981028; FI 960973 A0 19960301; FI 960973 A 19960430; SE 9600773 D0 19960228; SE 9600773 L 19960418; ZA 946807 B 19950628

DOCDB simple family (application)

US 9410050 W 19940901; AU 7721694 A 19940901; BR 9407457 A 19940901; CA 2170733 A 19940901; EP 94928024 A 19940901; FI 960973 A 19960301; SE 9600773 A 19960228; ZA 946807 A 19940905