Pattern Formation of Roll-Covering Rubber in a Paper-Making Machine and Its Countermeasures

This paper deals with pattern formation of smoother roll covering rubber in a paper-making machine and its countermeasures carried out using a controlled damper roll, taking the lateral deformation of the rolls in the axial direction into account. The authors describe the modelling of the system, regarding this vibration phenomenon as unstable vibration due to time lag and attributable to the viscoelastic characteristics of the rubber. It was made clear that (1) the pattern formation due to the rigid modes and the elastic modes between the top and bottom rolls was easily quenched by the external friction of support-bearing parts, and (2) that due to the combined rigid and elastic mode, called convex mode, between the top and bottom rolls was effectively quenched not by the external friction but by the internal friction and the additional rigidity generated using the controlled damper roll.