Influence of rubber parameters on the calculation of nip pressure profile in paper coating

摘要

Rubber covered nip rolls have a number of applications in the paper industry. One of them is the coating process, where color or size is applied on one or both sides of the paper web. Finite element modeling can be an accurate and inexpensive tool in the optimization of the coating process, as long as it reflects the real phenomena. Therefore, the choice of optimal material parameters for the model is one of the most important tasks. In this study, a universal material testing machine and a compressive Split Hopkinson Pressure Bar (SHPB) equipment were used to produce material data for OptiSizer test set-up conditions (strain rate 1 s~(-1), room temperature, ambient moisture) as well as for OptiSizer production conditions (temperature 60℃, strain rate 1600 s~(-1), saturated moisture in artificial paper mill water at test temperature). The OptiSizer machine was modeled using the Abaqus software. The nip pressure was calculated for linear elastic and hyper-elastic models of the covers and compared with measured data. The model shows good agreement with the measurements in the test set-up conditions and can therefore be used to simulate the mechanical contact in coating processes in actual production conditions and to optimize the shape and materials of the contacting rolls.