Coupling Effect between Viscosity and Viscous Dissipation in the Microscale Flow of Polymer Melt

doi:10.3901/JME.2022.06.052

Abstract

Abstract: There exists a coupling relationship between viscosity and viscous dissipation during polymer micro molding. In order to explore the coupling effect on the rheological properties of the melt, it is studied by combining numerical simulation and experimental. A coupling model which is based on a common variable temperature is presented, and the rheological characteristic parameters of polymer melt which flows in rectangular cross section micro channels are calculated and analyzed. Then the numerical result is evaluated by the melt experiment temperature along the flow direction. The results indicate that as the equivalent diameter decreases, viscosity decreases, viscous dissipation increases, and the coupling effect on viscosity and viscous dissipation becomes stronger. The temperature of the melt increases along the flow direction. The temperature rise value of the melt is higher when the coupling is not considered than when the coupling is considered, and the deviation increases with the decrease of the equivalent diameter. The maximum deviation where the average temperature rise value is 7.26% and 7.05% respectively for different inlet velocities and different inlet temperatures. The numerical simulation values by considering the coupling are consistent with the experimental results. As the different inlet velocities, the minimum deviation of the average temperature rise value between the numerical simulation results with considering the coupling and the experimental results is 0.49 K. As the different inlet temperatures, the minimum deviation of the average temperature rise value between the numerical simulation results with considering the coupling and the experimental results is 0.59 K. Therefore, it can be more accurately reflect the actual change regularities of melt rheological properties with considering the coupling between viscosity and viscous dissipation, when analyzing the melt flow in the polymer micro molding process.

Key words: polymer, microscale, viscosity, viscous dissipation, melt temperature

CLC Number:

TG156

ZHANG Jiakun, WANG Minjie, LI Hongxia, YU Tongmin. Coupling Effect between Viscosity and Viscous Dissipation in the Microscale Flow of Polymer Melt[J]. Journal of Mechanical Engineering, 2022, 58(6): 52-61.

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