Analysis Of Draw Flow Field And Deformation Control During Extrusion Of Polymer Catheter

Abstract:Sizing device is used in the extrusion process of plastic catheter to ensure the accuracy of the catheter molding usually. It’s difficult to ensure accuracy of catheter due to the small size, high processing precision and bad operational stability of sizing device. Catheter of cross-sectional can’t be processed because of the shackles of the sizing device. The extrusion deformation of catheters is relatively uniform and can be changed by drawing stretching action in order to achieve extrusion of cross-sectional catheter. It’s of great theoretical and practical significance to catheter extrusion of varying cross-section by researching the extrusion flow field and deformation law and deformation control method of catheter extrusion.The extrusion process of catheter under tension is studied based on theory of fluid dynamics and polymer rheology, the extrusion flow and deformation of catheter extrusion under tension is analyzed without sizing device.Single-factor control method and orthogonal experimental method have been used to take the catheter extrusion experiments, the data of deformation is got and provided for the numerical simulation of the extrusion molding process and the model to control the deformation.Then the extrusion flow field and deformation in different extrusion parameters is simulated by POLYFLOW which is polymer finite element simulation software. The simulation results is analyzed combined with the experimental data, which provides theoretical basis for analysis of catheter extrusion without sizing device.Finally, the relationship between the extrusion parameters and catheter deformation is established by neural networks, extrusion parameters are optimized by genetic algorithm, and the model is verified with experiment. Found that the model of the neural network and genetic algorithm can accurately predict and control catheter extrusion deformation without sizing device, which provide method to control the deformation of catheter of small size and cross-section.