Flow characteristics in a headbox and fiber orientation of paper

(Part 2) Verification by the experimental paper machine

Abstract

It is suggested that fiber orientation have relation to a shear force and shear direction in the stock at the forming section after jet trapping on the wire. This mechanism would be mainly influenced by a flow velocity and direction of a stock jet from headbox.
This paper shows about the jet flow characteristics relation with edge sides flow rate increase, side bleeds flow rate change, slice lip profile, using a 500 mm pond width experimental headbox. And further, paper making trial was made and the fiber orientation mechanisms are studied.
At the result of the flow characteristics test and the paper making trial study, the fiber orientation could be controlled with the edge side flow rate, bleed flow rate.
To improve the fiber orientation, it is most important to reduce a cross flow, especially the edge sides flow, of the jet.