FaxénLabratoriet

Applied research area
III. Paper Technology III:1 The dynamics of plane free jets III:2 Twin-wire forming III:3 Initial roll forming III:4 Fibre suspensions in contractions III:5 Flow in stratified headboxes
III:2 Initial roll forming
In initial roll forming, the free jet from the head box impinges on the wires just at, or before, the roll. The flow in the f irst part of this process occurs with a free surface, and is of great importance for the forming of the paper sheet. The process will be studied in an specially designed experimental apparatus. A pressure probe in the forming roll will measure the pressure distribution. The velocity field will be mapped with the LDA-(Laser Doppler Anemometry) and PIV-(Particle Image Velocimetry) techniques. The flow will also be modelled numerically using computational fluid dynamics. The project is complemented, through funding by Dept. of Paper technology at KTH, with a study of how shear forces can be used to break down flocs. In model experiments an artificial floc will be introduced in the head box and followed through the forming section.
Researchers: Richard Holm, Roger Bergström Supervisors: Bo Norman, Henrik Alfredsson


FaxénLaboratoriet (FLA) Last modified:2001-06-25