Effect of gas flow rate on the double gas-assisted extrusion forming of plastic pipes

2019 3rd International Workshop on Renewable Energy and Development

能源学;生态环境科学

Ren, Zhong^1 ; Huang, Xingyuan^2

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

330038, China^1

School of Mechanical and Electrical Engineering, Nanchang University, Nanchang

330031, China^2

关键词: Extrusion forming;    Extrusion method;    First normal stress difference;    Normal stress;    Numerical results;    Velocity changes;    Wall thickness;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/267/4/042059/pdf
DOI  :  10.1088/1755-1315/267/4/042059

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

To overcome the extrusion problems of plastic pipes, the double gas-assisted extrusion method was used in this paper. To investigate the effect of gas flow rate on the double gas-assisted extrusion forming of the plastic pipes, the numerical simulations based on the finite element method were performed. Numerical results show that with the increase of the gases flow rate, the inner radius increases and the outer radius decreases, which lead to decrease the wall thickness of plastic pipes. At the same time, the flow velocity changes of melt under the different gases' flow rate were obtained and compared. To ascertain the mechanisms of shrinkage phenomenon of wall thickness, the normal stress and first normal stress difference distribution nephograms of melt under the different gases flow rates were obtained. Results show that the normal stress effect of assisted gases on the melt is the main reason that the wall thickness is decreased by the larger assisted gases flow rates.