Reduction Of Twist On Board Machines

摘要

This paper presents some of the benefits of measuring a proxy for twist on multilayer board machines. In particular, it presents the improvement possible in twist for machines making liquid packaging and folding boxboard using FotoFiber sensors. The proxy for twist is defined as the difference in fiber orientation angles between the top layer and the bottom layer. Measurements of the surface fiber orientation are required on both surfaces, which provide an angle and an anisotropy as profiles. Although most paper makers know that the amplitude of a twist profile can be controlled (to some extent) by changing the jet to wire ratio setpoint, some do not know that twist profiles can be controlled quite precisely by the top and bottom slice lips.