Experimental Study on Viscous Dissipaition of Polymer Melt in Micro-Channels

Abstract

The polymer melts viscous dissipation effects of micro scale dimensions are different from that of macro-scale dimensions. In this paper, the temperature rises due to viscous dissipation were investigated when amorphous polymer material, PMMA, flows through several micro-channels with the diameters of 350μm, 500μm and different aspect ratios. The results indicate that, temperature rises reduce with the increase of inlet temperature of melt and increase with increasing channel’s diameter and aspect ratio at the same shear rate. The outlet temperature rises due to viscous dissipation in all micro channels increase with the increase of shear rate. In addition, the outlet temperature rise grows faster with the decrease of micro-channel’s diameter. Therefore, viscous dissipation effect is significant and should not be neglected in micro channel.

Computational Modeling of the Effects of Viscous Dissipation on Polymer Melt Flow Behavior During Injection Molding Process in Plane Channels

“…Therefore, studying of viscous dissipation effects on the polymer melt flow in the analytical [2-5] and numerical [6][7][8][9][10] investigations has received a great attention in recent years for the optimization of existing manufacturing processes in addition to alternative research studies [11,12] for analyzing effects of nanoparticles and processing conditions on the development of local microstructures under thermal and deformation fields experienced in injection molding processes. The recent experimental studies [13,14] also emphasize the importance of the viscous dissipation effects in high viscous flows or in presence of high gradients in velocity distributions for polymer process applications of micro channels. Yankov et al [2] obtain generalized solutions of polymetric liquids under nonisothermal conditions where the polymetric liquid viscosity varies with temperature exponentially or hyperbolically under the assumption that the temperature is constant over a channel cross section.…”