Basis Weight Variability

The paper and accompanying presentation, titled The Struggle for Paper Uniformity, outline the machine direction basis weight variability at a specific paper mill. It shows the problems that resulted from the MD basis weight variation and the steps taken to solve the problems. The clearly identified problems were register variations and cockling. Other problems that would be associated with variations but not clearly identified were paper runnability on the machine, on the winder and in the pressroom. The problem solving process included spectral analysis, operating deflection shape analysis, modal analysis and finite element analysis. The presentation shows an animation of the headbox vibration, the key problem area.