0212 Temperature distribution measurement of melted polar polymer using temperature dependence of the permittivity

Temperature control is one of the issues of polymer processing. Electrical Capacitance Tomography (ECT) is a non-intrusive technique which obtains two-dimensional relative permittivity distribution. The relative permittivity distribution means the temperature distribution, because relative permittivity has temperature dependence. In this study, the relative permittivity of polyethylene (PE) and poly methyl methacrylate (PMMA) was measured under a condition which is high temperature polymers melt. A two-electrode sell was used for the measurement and 5000mm^3 polymer was filled between the electrodes. The condition is not ideal for relative permittivity measurement but close to actual polymer processing. Smooth temperature dependence of relative permittivity was observed. It is necessary to select a measuring frequency because the proper frequency depends on temperature range and polymer.