Flow Field Stability And Head Structure Optimization Of Single Roller Extrusion

The single-roller head has the advantages of low extrusion pressure,long service life,and high extrusion efficiency,but in actual production applications,there are still problems such as uneven extruded products and glue spillage on the sealing surface of the head.In this paper,numerical simulations of non-constant fluids and unidirectional steady-state fluid-structure coupling calculations are carried out for a single roller head with the help of the ANSYS Workbench platform.The first aim is to investigate the rheological behavior of the polymer melt in the flow field of a single-roller head and to analyze the influence of extrusion uniformity on extrusion efficiency.The second is to simulate the deformation of the head sealing surface of a single roller and to determine the variation pattern between the influencing parameters of the head sealing performance.In addition,the mathematical model of the flow field and sealing surface of the single-roller head is established in combination with the response surface method,and the design of the single-roller head is optimized to optimize its process parameters and structural parameters,providing a theoretical basis for single-roller extrusion production,which has practical engineering significance for enterprises to adapt to the demanding,low-error and modern tire industry.After summarizing the current state of research on extruder heads at home and abroad,the main work carried out in this paper on your subject is as follows:(1)A fluid-solid coupling model for a single-roller head with non-constant fluid calculation and a single-roller head seal is established,and the fluid domain and solid domain models of the single-roller head are built with the aid of three-dimensional modeling software.(2)Numerical simulation of the flow state of a polymer melt within a single roller head flow field using FLUENT using the single factor analysis method,investigating the rheological behavior of polymer melts in a single-roller head flow field and analyzing the influence of extrusion uniformity on extrusion efficiency,to provide theoretical guidance for the subsequent determination of the factors influencing extrusion efficiency and extrusion uniformity in single-roller heads.(3)One-way steady-state fluid-solid coupling calculation for a single-roller head,combined with single-factor analysis to study the influence of process parameters and head structure parameters on the sealing performance of single-roller head,to provide theoretical guidance for determining the influencing factors of single-roller head sealing performance.(4)Using multi-objective optimization for the first time in a single-roller extrusion flow field.Based on the optimization objective of satisfying both the extrusion quality and the maximum extrusion efficiency,the mean and standard deviation of the velocity in the extrusion direction of the middle layer of the exit section are used as performance parameters for extrusion efficiency and extrusion quality as well as the objective function,and a mathematical model of the flow field in the head of the single roller is established.The results show that the optimal parameters obtained based on the multi-objective optimization method are of great engineering importance in terms of production efficiency and product quality.(5)A method is proposed to optimize the design of the sealing surface influence parameters of a single roller head based on fluid-solid coupling analysis and the response surface method.Determining a mathematical model of the sealing surface of a single roller head with the structural strength as the constraint and the minimum deformation of the sealing surface as the objective function,and quantitatively characterizing the relationship between the parameters affecting the sealing of the flow channel,and then,the optimization combinations are obtained based on the main objective method and the penalty function method respectively,and the optimization effect of each combination is verified.The results show that the way to obtain the optimization combinations based on the above two methods is feasible,and the model is also verified to be highly accurate from the side.