Effect of Duct Cross-Section Design on Temperature Profile Measurement of Flowing Polymer Melts in Injection Moulding

Abstract

This article involved designing and manufacturing an experimental apparatus coupled withtwo thermocouple-network sensors to measure the temperature changes of flowing polymer meltsin an injection machine, using a high speed data logger and a computer, under various ductgeometries. The results in general suggested that the melt temperature increased at the initial stageand then decreased progressively with screw displacement, this concerning shear heating and heatconduction effects and the flow pattern development of polymer melts in the duct. With the effectof die (duct) geometry, it was found that the circular cross-sectional die gave the highest melttemperature rise, this being about 24 ^oC as compared to slit, tapered circular and cross ducts dueto the nature and the complexity of the flows occurring.