ANALYSIS FOR PRESSURE PROFILE BEHAVIOR OF MIXTURES OF PS WITH R22 BLOWING AGENT IN A SINGLE SCREW EXTRUDER

摘要

Both experiments and numerical studies were conducted to investigate the PS foam screw characteristics with R22 blowing agent in a single screw extruder. Five thermocouples and pressure transducers are equipped in this extruder. R22 is the blowing agent for this study, which is injected into the extruder at 18.4D with temperature around 200°C. Without the blowing agent, it is found that the pressure monotonously increases along the screw axis after the distance of 24D. However, the pressure profile changes after the blowing agent is injected. A hybrid FEM/FDM was applied to predict the Q-P characteristic curves for PS and PS foam extrusion.