Modelling of PET bottle process using natural element method

Abstract

he modeling of the stretch-blow molding process for PET bottle is very complex. The most challenging problems need to be solved such as the bi-axial large deformation of the PET during the molding process, the choice of the appropriate material behavior law, the determination of the optimal control parameters. In order to overcome these issues, in this paper, the stretch-blow molding process is modeled by using the Natural Element Method (NEM). Also, the non-linear and visco-elastic material behavior law is used in the computation thanks to its capacity of describing the real material behavior. The computational results based on an axisymetric model show that the proposed method can be used to investigate the effects of the control parameters on the thickness distribution of the bottle as well as the temperature, stress and strain distributions. These results will be used to study the performance of the produced bottles. In perspective, the extension of the model to 3D and the application of the model to determine the optimal control parameters for the real bottle will be considered.