Patent ID: 6491792
Filing Date: 2002-12-10
Classification: D21F,D21G,Y10S

Abstract:
An apparatus for controlling a cross-direction profile of at least one property of a paper web manufactured by a paper machine, comprisinga first headbox for receiving at least two different feed streams and discharging a pulp suspension formed from said at least two feed streams to thereby form a web, said first headbox having separated cross-machine sections defining separate feed zones, first supply means for supplying said at least two feed streams to said first headbox such that each of said at least two feed streams is directed into a plurality of said feed zones of said first headbox and each of said feed zones is supplied with a combination of at least two of said at least two feed streams, each of said at least two feed streams containing feedstuffs for the paper to be manufactured suspended in aqueous solution, control means for regulating said first headbox, first measurement means coupled to said control means for measuring the profile of the at least one property, generating a first measurement signal based thereon, and directing said first measurement signal to said control means, said first measurement means being arranged at a location downstream of said first headbox, sampling means for obtaining samples of said at least two feed streams from a location upstream of said first headbox continuously or at intervals, second measurement means for measuring at least one property of said samples of said at least two feed streams, generating a second measurement signal based thereon, and directing said second measurement signal to said control means, and regulation means for regulating the supply of said at least two feed streams into each of a plurality of said feed zones of said first headbox, said regulation means being controlled by said control means, said control means being structured and arranged to control said regulation means based on said first and second measurement signals to thereby regulate the supply of said at least two feed streams being fed into each of said plurality of said feed zones of said first headbox.