Effect of dynamic regime of rollers of pocket folding machine to quality of printing products

Abstract

Measurements of dynamics of rollers and their segments in the direction of transverse axis of rotation of eight cassettes of folding machines were carried out in this work. Measurements were carried out in pre-selected positions of rollers and their segments for two different rotating velocities of the rollers. In the first case the roller was rotated at 9 m/min velocity and in the second – at 90 m/min. It was determined that before renewal some rotating rollers for the investigated velocity of rotation of the roller 90 m/min experienced the displacements up to 80 μm. The displacements (beatings) of the rollers and their segments originating during the process of rotation in the direction of transverse axis of rotation have substantial effect to the quality of folding of printing products. Numerical investigation of the rollers was performed by using the axisymmetric model. Supplementary stiffness from the static loading caused by centrifugal forces is taken into account. The eigenmodes are calculated. The standing waves on the surface of the roller are investigated.