The effect of gas assisted length on polymer melt extrusion based on the gas-assisted extrusion technique

3rd International Conference on Advanced Materials Research and Applications

Wan, B.^1 ; Ren, Z.^2,3 ; Liu, G.D.^2 ; Huang, X.Y.^3

President's Office, Jiangxi Science and Technology Normal University, Nan-Chang-Jiangxi

330038, China^1

Key Laboratory of Optic-Electronic and Communication, Jiangxi Science and Technology Normal University, Nanchang

330038, China^2

School of Mechanical and Electrical Engineering, Nanchang University, Nanchang

330031, China^3

关键词: Extrudate swell;    Extrusion techniques;    Finite element numerical simulation;    Numerical results;    Polymer melt extrusion;    Slip boundary conditions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/170/1/012018/pdf
DOI  :  10.1088/1757-899X/170/1/012018

来源: IOP

【 摘 要 】

In this study, the gas-assisted technique was used into the process of polymer melt extrusion to overcome the extrudate swell problem. The gas length is an important factors in the gas-assisted extrusion technique. To ascertain the mechanism of the gas-assisted extrusion technique, and to determine the optimal gas length, the effect of gas length on the extrudate swell ratio of melt was numerically investigated. In finite element numerical simulation, PTT constitutive model and full slip boundary condition were used to achieve the gas-assisted mode. Compared with the traditional no gas-assisted extrusion, numerical results showed that the extrudate swell problem was well eliminated by the gas-assisted method. Moreover, the extrudate swell of melt decreased with the increasing of the gas length because the pressure and shear stress of melt were greatly decreased. Moreover, the flow velocity of melt is uniform at the die outlet.