Torque Measurement And Characterization During The Process Of Plasticizing And Conveying In A Vane Extruder

The plasticizing and conveying process of polymer in traditional extruder based on shearflow have obvious disadvantages, such as long thermo-mechanical processing, high energyconsumption, occupying large space, highly depending on the properties of materials and soon. To cover these shortages, Prof. Jin-ping Qu developed a novel vane extruder based onextensional flow. Polymeric materials are plasticized and conveyed by the periodically changeof the volume of vane plasticizing and conveying unit (VPCU) and mainly suffer normalstress in vane extruder.This dissertation mainly focused on the torque properties of rotator in a vane extruder.Based on the structure and working principle of VPCU. The torque properties of rotator insolid conveying process and melt conveying process were analyzed respectively. In solidconveying process, the pressure of VPCU was related to structural parameters of VPCU,processing parameters and material properties, and finally, an expression of torque wasdeduced. In melt conveying process, both flow model and mathematic model were built,subsequently, a theoretical expression of torque related to structural parameters of VPCU,processing parameters and material properties was deduced.Finally, a series of experiments were carried out in a single VPCU testing machine, tocheck the theoretical expressions. The results showed that the theoretical data of torqueagreed with the experimental data. In solid conveying process, the value of torque decreasedwith the increase of temperature, increased with the increase of eccentricity distance andincreased with the decrease of discharge angle. The rotating speed did not affect the vale oftorque, but only affected the change period of torque. Additionally, the properties of materialshad a significant affect on the value of torque. In melt conveying process, the value ofextensional rate increased with the increase of eccentricity distance and rotating speed, andincreased with the decrease of the inner radius of plate. The curve of shear rate via rotatingangle was similar with cosine curve, and the amplitude of the curve increased with theincrease of eccentricity distance and rotating speed. The value of torque decreased with theincrease of temperature, increased with the increase of rotating speed, and the properties ofmaterials had a significant affect on the value of torque.