Comparison of Conical Twin Screw Extrusion Performance


In order to provide theoretical basis and technical sup […]

In order to provide theoretical basis and technical support for the design and actual machining of the same-direction conical twin-screw, numerical simulation of the same direction and anisotropy using the POLYFLOW software under the condition of screw speed of 25r/min and zero inlet and outlet pressure difference. The three-dimensional isothermal flow field of the melt in the flow path of three kinds of twin-screw metering section was calculated by rotating conical twin-screw and parallel co-rotating twin-screw. The three kinds of twin-screw mixing were statistically analyzed by particle tracer method. Extrusion performance, the mixed extrusion performance of the same-direction conical twin-screw is compared with the mixed extrusion performance of the isotropic conical twin-screw and parallel twin-screw. The statistical analysis results show that the co-directional conical twin-screw dispersive mixing ability is the largest. The distribution mixing ability is larger than the anisotropic cone and smaller than the parallel twin screw.

The same-direction conical twin-screw not only preserves the advantage of the isotropic conical twin-screw to facilitate the compression of the material, but also overcomes the shortcoming of the shearing ability of the anisotropic conical twin-screw. The melt in the flow channel of the conical twin-screw metering section The pressure fluctuation is the smallest, which is beneficial to the stability of the extruded product. The residence time of HT30 parallel twin-screw extrusion RPVC was studied by experimental and numerical calculations, and the reliability of the numerical calculation method was verified.