Theoretical investigation of a fluid model in calendering process involving slip at the upper roll surface

In this article, calendering analysis is presented using Johnson-Segalman fluid model along with nonlinear slip condition introduced at the upper roll surface. The flow equations for the problem are developed and converted into dimensionless form with the help of dimensionless variables and then finally simplified by a well-known lubrication approximation theory (LAT). To eliminate the pressure gradient from the governed equations, stream function is introduced. The final equations are solved numerically using Matlab built-in procedure bvp4c to get the stream function and pressure gradient. The pressure and engineering quantities such as power input function and roll-separating force are calculated by Runge-Kutta fourth order method. The impact of the Johnson-Segalman parameter and slip parameter on pressure, velocity and engineering quantities are presented with the help of various graphs. The Newtonian model predicts higher pressure in the nip zone than the Johnson-Segalman fluid model, according to our findings. In the presence of the slip parameter, the force and power functions exhibit 37% and 61.71% decreases from Newtonian values, respectively. As the slip parameter is increased, the pressure distribution diminishes.

Automated summary

In this article, calendering analysis is conducted using the Johnson-Segalman fluid model and a nonlinear slip condition on the upper roll surface. The flow equations are transformed into dimensionless form and simplified using a lubrication approximation theory. The stream function and pressure gradient are obtained numerically using Matlab, and the pressure, velocity, and engineering quantities are analyzed using various graphs. The Newtonian model predicts higher pressure in the nip zone compared to the Johnson-Segalman fluid model, and the force and power functions decrease with the slip parameter. As the slip parameter increases, the pressure distribution diminishes.