Svenska Traforskningsinstitutet

Thomas L Stman

Hakan I Karlsson

Inge J Lundqvist

Valter E Strom

Bengt Y Hardin

Bo-Lennart I Johansson

A method of controlling the properties of a paper web across the feed direction, i.e., cross profile, in a paper machine. The cross profile is adjusted in a plurality of setting positions across the web. Proceeding from a measured cross profile and desired cross profile, an optimum correction in the setting positions is calculated, so that the cross profile is brought into agreement with the desired one. At this calculation the circumstance is utilized, such that a disturbance in the stock in a certain setting position results in a corresponding change in the cross profile of the paper web.

Method of controlling cross profile of properties of paper web

Web tension measurement in that the web (5) is caused to oscillate transversely with the resonance frequency for the portion of the web (5) defined by a support (2,2a). The oscillations are measured by detectors (6,7) for determining the web tension. The measuring is carried out free of contact in that a thin air layer is maintained between the support (2,2a) and web (5).

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Sp.ang.nga, Sweden

Thomas L Stman