Global Patent Index - EP 0970277 A1

EP 0970277 A1 2000-01-12 - METHOD AND APPARATUS FOR CONTROL OF A HEADBOX IN A PAPER MACHINE

Title (en)

METHOD AND APPARATUS FOR CONTROL OF A HEADBOX IN A PAPER MACHINE

Title (de)

VERFAHREN UND VORRICHTUNG ZUR STEUERUNG EINES STOFFAUFLAUF IN EINER PAPIERMASCHINE

Title (fr)

PROCEDE ET APPAREIL DE REGULATION DE LA CAISSE DE TETE D'UNE MACHINE A PAPIER

Publication

EP 0970277 A1 (EN)

Application

EP 98900864 A

Priority

  • FI 9800032 W
  • FI 970294 A

Abstract (en)

[origin: WO9832916A1] Method of controlling cross-direction property profiles of a paper web (5). The method employs a control system (150) for regulating a headbox (3) or headboxes (3a, 3b) of a paper machine. Said property profile or profiles is/are measured by a measurement system (40, 140). The measurement signal thus obtained is supplied to said control system (150). The headbox (3) or headboxes (3a, 3b) is/are supplied with at least two feed streams (11, 12) which contain feedstuffs for the paper suspended in aqueous solution. The feed streams are divided into feed zones in cross-machine sections of the headbox (3) or headboxes (3a, 3b). Said feed zones are each supplied with combinatory streams of said feed streams (11, 12; 11, 12, 13; 11, 12, 13, 14). A property, such as, concentration and/or consistency and/or brightness and/or color and/or equivalent, of one or more feedstuffs of said feed streams (11, 12; 11, 12, 13; 11, 12, 13, 14) is measured. The thus obtained measurement signal is fed to said control system (150). Based on said measurements of the property profile or profiles and based on said measurements of said property and based on setpoint values, control signals are formed. By means of them, an actuator (10) or an actuator combination (10a, 10b) situated at each of said feed zones of the headbox (3) or headboxes (3a, 3b) is regulated, by which actuator or actuator combination combinatory proportions of different feed streams (11, 12) supplied to the feed zone are affected to achieve a desired property profile or profiles of the web (5).

IPC 1-7 (main, further and additional classification)

D21F 1/02; D21F 7/06

IPC 8 full level (invention and additional information)

D21F 1/06 (2006.01); D21F 1/02 (2006.01); D21F 1/08 (2006.01); D21F 7/06 (2006.01); D21G 9/00 (2006.01)

CPC (invention and additional information)

D21G 9/0027 (2013.01); D21F 1/02 (2013.01); D21F 1/08 (2013.01); D21F 7/06 (2013.01)

Citation (search report)

See references of WO 9832916A1

Designated contracting state (EPC)

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

DOCDB simple family

WO 9832916 A1 19980730; AT 252179 T 20031115; AU 5665198 A 19980818; BR 9807110 A 20000425; CA 2278647 A1 19980730; CA 2278647 C 20071120; CN 1093201 C 20021023; CN 1244225 A 20000209; DE 69818982 D1 20031120; DE 69818982 T2 20040812; EP 0970277 A1 20000112; EP 0970277 B1 20031015; FI 100345 B 19971114; FI 970294 A0 19970124; JP 2001508839 A 20010703