Numerical study on the influence of Rapid Temperature Cycling (RTC) on polymer flow at maximum injection pressure

Injection molding is the widely used processing technology of polymeric materials. In the classic variant of the injection molding low, constant mold temperature is used for the efficient heat removal to obtain shorter cycle times. However, low temperature of the mold cavity is not feasible for thin-walled and micro-featured parts. For these situations the RTC (Rapid Temperature Cycling) technology was developed, where the temperature of the mold is increased to above transition temperature of the polymer before the filling phase. In this article the relation between processing parameters, part thickness and the maximum flow length at specific time achieved by polymer melt with RTC technology was investigated with numerical simulations for thin-walled geometry. According to obtained results strongly nonlinear relations between maximum flow length and part thickness and volumetric flow rate were present, whereas relation between injection pressure and cavity surface temperature were linear. Obtained results showed that the most significant influence on the maximum flow length had the cavity surface temperature, whereas the least significant influence had a maximum injection pressure.