Multivariable grammage and fibre orientation CD control with dilution water headboxes, advantages and limitations

摘要

Head boxes with dilution water and slice lip opening allow the simulataneously control of grammage and fibre orientation. A change inslice lip opening leads to a simultaneous change in fibre orientation profile and grammage cross profile. On the other hand, a change in dilution water flow leads to a change in grammage cross profile, but not to a change in fibre orientation corss profile, due to the head box construction, which guarantees a constant total flow, Thus, the new actuator concept my be described by a 2x2 multivatiable plant.