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Numerical simulation and experimental study of polymer micro extrusion flow

The uniformity of polymer melt flow in micro extrusion die determines the quality of products directly. It is the base of extrusion die design. According to rheology testing theory and with the help of capillary rheometer, the reasonable extrusion parameters have been achieved. The comparative micro scale viscosity model is built based on Kelvin-Voigt constitutive equation and the wall slip model is built based on Navier slip law. The extrusion of double-lumen is taken for example. By use of both numerical simulation and orthogonal experiment, the effects of main structure parameters on flow uniformity are studied. The conclusions show that shunting angle affects the uniformity most, then length of center stereotyping part, compression angle and compression ratio. Meanwhile, the best lumen structure parameters are determined. After that, double-lumen catheter die is fabricated by precision machining technology. The results of experiment validate the correctness and validity of numerical simulation for polymer micro extrusion flow.