Method and system for regulation and on-line measurement of the fibre orientation in a web produced by a paper machine

• Main Authors: MIINALAINEN; TAPANI, PAKARINEN; PEKKA, KOSKIMIES; JOUNI, LAITINEN; ERKKI, NEITTAANMAEKI; PEKKA
• Format: Patent
• Language: English
• Published: 27.10.1998
• Edition: 6
• Subjects: ACCESSORIES FOR PAPER-MAKING MACHINES; CALENDERS; METHODS OF PRODUCING PAPER THEREON; PAPER-MAKING; PAPER-MAKING MACHINES; PRODUCTION OF CELLULOSE; TEXTILES

A method for regulation of the transverse distribution of the fiber orientation of a web produced by means of a paper machine or equivalent, by regulating the transverse profile of the discharge opening (16) of the headbox (10) of the paper machine. The transverse grammage profile of the paper web (W0 . . . W1) produced by means of the paper machine is measured, and the measurement signal obtained in this way is used as a feedback signal in the control system. With the machine configuration and parameters present in the paper machine to be controlled, data are collected concerning the relationship between the directional angle of the transverse distribution of fiber orientation and the transverse distribution of grammage of the web (W0 . . . W1) that is being produced by, carrying out response runs of the paper machine in its various states of operation (i). The relation data are stored in the memory of the computer (52). By making use of the relation data, the distribution of fiber orientation in the web (W0 . . . W1) to be produced is corrected by regulating the transverse profile of the discharge opening (16) of the headbox (10). Moreover, a corresponding method for on-line measurement of the fiber orientation is described.