The Study Of Plastic Energy Dissipation On Solid Conveying Section Of Extruder

Single-screw extruder is one of the important polymer processing equipment. In the development of extrusion industry, high capacity, high efficiency, high speed and low energy consumption has become the basic trend of the single-screw extruder. As the first stage of an extruder production, solid conveying section plays a role of conveying and raising temperature of material. Its required energy consumption accounts for a large part of total energy consumption of a single-screw extruder. Therefore, in order to reduce energy consumption and increase productivity, it is crucial to clear the energy exchange of solid conveying section.However, most of the existing theories and references are mainly aimed at the research of melt plastic section, while the heat conversion theory of solid conveying section is relatively few. It has been considered that in the internal of solid conveying section, the heat of the material is come from the heat conduction of the barrel and the friction heat. However, the thermal conductivity of polymer is relatively low, it is basically impossible to spread the surface temperature of barrel across the grooves in a short residence time. Research has shown that in the solid conveying section, solid particles undergo significant deformation, which will produce the plastic energy dissipation, consequently causing the change of the temperature of solid particle. The study will open up a new path for the temperature rise of material.To solve above problems, firstly, the material conveying and melting in single-screw extruder was simulated with the software FLOW2000, in order to obtain the initial data. Meanwhile, the reasonable assumptions are made to simplify a complex transport condition of solid conveying section, and then a calculation model is constructed, the particle stress is analyzed and calculated thoroughly.ANSYS software is used to simulate the plastic deformation of the material, the simulation results is analyzed, equation of the plastic energy dissipation is deduct, which could calculate the plastic energy dissipation, finally the influence factors about the plastic energy dissipation are studied. The Research reveals that all particles in Solid conveying section are plastically deformed under the cylinder pressure, the deformation could produce the plastic energy dissipation, so that the temperature of material could rise, and the desired heat for temperature rise of more than 70% particle in the screw slot nearly come from the plastic energy dissipation, which could be affected by the material properties of the particle and external conditions.At the same time, the paper compares and analyzes the heat transfer effect of the heat conduction of the barrel and the friction heat in the solid conveying section.Comparison result shows that both methods present the low heat efficiency and large energy consumption.In contrast, the plastic energy dissipation presents a higher heat transfer efficiency and a lower energy consumption. Articles provides a new method for the further study about energy conversion of the solid conveying section, In addition, it lays the theoretical foundation about the plastic energy dissipation of the solid conveying section.