Synthetic Double Screw Extrusion Machine Extrusion Mechanism And Performance Analysis

Twin-screw extrusion technology is a kind of advanced extrusion modeling technology widely applied in feed and food processing field. Screw is the key part of co-rotating twin-screw extruder, so some research on the shear mixing and screw mechanical property are necessarily conducted. These researches have an important significance in the extrusion mechanism study and performance improvements of twin-screw extruder. Firstly, this thesis conducts research on flow channel fluid analysis theory of co-rotating twin-screw extruder and screw mechanical model. Then finite element model of flow channel is established and the flow field is analyzed. In addition, the finite element model of screw is built and the analysis of mechanical performance is conducted. The detailed work is as follows:With respect to the basic research, geometry theory of co-rotating twin-screw is analyzed including the theory of engagement for twin-screw and mathematical model of face curve. Based on geometry theory, flow field analysis theory of channel and screw mechanical model is sequently founded.Velocity field analysis, pressure field analysis and viscosity field analysis is conducted with regard to the flow channel. First of all, the necessary material parameters and boundary conditions are elaborated. Then velocity field analysis is made at different threads, screw speeds and internal diameters. Besides, the pressure field analysis is carried out. Finally, the viscosity field analysis is conducted.Analysis of mechanical performance of screw is carried out. Firstly, based on geometry theory of co-rotating twin-screw and mechanical model of screw, the solid mode and finite element model has been established. Secondly, on basis of this, the effect of parameters such as SAR and lead on the mechanical property of screw is studied. Finally the effect of the same parameters on the mechanical property of screw is considered.Through these research and analysis, it lays a foundation for extrusion mechanism research and the performance enhancements with respect to twin-screw extruder.