Heat Transfer And Numerical Study Of Polymer Melt Cooling Equipment

During the process of foaming extrusion,it is necessary to cool the polymer melt to improve the melt strength of the polymer system,so as to obtain good quality foamed products because the viscosity of the polymer system would drop sharply after being mixed with foaming agent.Cooling single screw extruder is still an important equipment that determines the production output in the whole production process,and its performance basically controls the stability of the whole foaming extrusion production line.For many years,most of the specific details about the cooling single screw design in the foam industry are still trade secrets,and there is no specific research report.Therefore,this paper obtains a model to predict the cooling process of cooling single screw by theoretical analysis,and optimizes the screw structure parameters and process parameters.The heat transfer performance of the second-order cooling single screw in the series foaming extrusion production line was studied.The cooling single screw model was simplified,and the average temperature was used to characterize the melt temperature,and the theoretical analysis model of polymer melt heat transfer was established.The viscous heat generation was simplified as an external heat source,which is substituted into the energy equation.By solving the energy equation,the prediction model and cooling curve of the average cross-sectional temperature of polymer melt along the extrusion direction were obtained.According to the theoretical analysis model of polymer melt heat transfer,the influence of structural parameters and process parameters on the cooling process of polymer melt was analyzed,and DOE test was designed.The results showed that the influence on the cooling process of polymer melt from large to small was channel depth,screw speed,output and helix angle.The accuracy of the theoretical analysis model of polymer melt heat transfer was verified by CFD numerical simulation.Finally,the prediction program of polymer melt cooling process was designed by Visual Basic programming,which provides some guidance for the design of cooling single screw and the selection of structural parameters and process parameters.