Temperature-Dependent Viscosity Analysis of Powell-Eyring Fluid Model during a Roll-over Web Coating Process.

Area of Science:

• Fluid dynamics
• Rheology
• Coating technology

Background:

• Roll coating is vital in industries like paint, textiles, and plastics.
• Understanding non-Newtonian fluid behavior under non-isothermal conditions is crucial for process optimization.

Purpose of the Study:

• To theoretically and computationally analyze Powell-Eyring fluids with variable viscosity during non-isothermal roll coating.
• To investigate key engineering parameters including coating thickness, Nusselt number, and shear stress.

Main Methods:

• Formulation based on lubrication approximation theory (LAT).
• Simplification of partial differential equations (PDEs) to ordinary differential equations (ODEs).
• Application of the regular perturbation method and response surface methodology (RSM).

Main Results:

• Velocity profiles were found to be a decreasing function of non-Newtonian and Reynolds viscosity parameters.
• Engineering characteristics such as coating thickness, Nusselt number, shear stress, separating force, and power transmission were quantified.
• RSM was used to analyze the sensitivity of shear stress and Nusselt number.

Conclusions:

• The study provides a comprehensive analysis of non-isothermal roll coating for Powell-Eyring fluids.
• Findings offer insights into fluid behavior and process parameters for industrial applications.
• The research contributes to optimizing coating processes through theoretical and computational modeling.