二軸押出機のロングベント部の脱揮能力に関する実験的考察
An Experimental Study on Devolatilizing Performance of a Long Vent Section in a Twin-screw Extruder
王 寧和・橋本憲明・酒井忠基
Wang, Ning He / Hashimoto, Noriaki / Sakai, Tadamoto
The devolatilizing performance of a long vent section in an intermeshing co-rotation twin-screw extruder manufactured by The Japan Steel Works was measured by using an ethylbezene/polystyrene mixture. The experimental data were fitted by using the previous devolatilization models and a new model proposed by the authors. As a result, a plot of ln {(wout-w*)/(win-w*)} against N1/2/Q based on the previous models shows the flow rate dependence. In contrast, a plot of ln {(wout-w*)/(win-w*)}/(LabN1/2/Q) against N based on the new model can be approximated by a linear relationship. This suggests that the effect of the changes in degree of filling, length of filled zone in a vent section as well as the change in viscosity of fluid induced by shear heating on the devolatilizing performance should be taken into account. Hence, the new model is more applicable for analyzing the devolatilizing performance of a twin-screw extruder.
Key words: Devolatilization / Twin-screw extruder / Long vent / Polystyrene / Ethylbenzene