二軸押出機内の樹脂挙動解明 溶融・吐出ステップにおける二次元樹脂流動モデルと解析

Abstract

The present paper is concerned with the study of the resin behavior during the melting and pumping step of intermeshing counter-rotating twin screw extruder. In order to propose a fundamental understanding and a practical methodology to make an optimal design of twin screw, a 2-dimensional predictive model is newly developed and a simulation methodology for intermeshing twin screw extruders is presented. The model is based on a modification of the original by Janssen into an analytical formulation by using hydrodynamic lubrication theory, to allow for the application to rigid polyvinylchloride (PVC) resin, which can be treated as a power law fluid. From the proposed model the inherent pressure profile along a screw channel is predicted and confirmed experimentally by pressure measurement. Comparisons of calculated results with experimental data show that the resin flow behavior can be analyzed with reasonable applicability and engineering significance, such that wear-resistant screws can be successfully designed by using the developed simulation methodology.