• Awais, Muhammad
• Varis, Juha
• Matthews, Sami
• Tanninen, Panu
• Sorvari, Joonas
• Leppänen, Teemu
• Backfolk, Kaj

Abstract

Press forming process is an important manufacturing process to produce paperboard tray packages. During the press forming, sever deformation occurs at the intricate shapes that can cause localized strains and the fracture. The formability can be improved by the crease lines and controlling parameters. Creases reduce the confine stiffness and assist the folding of the paperboard into the complex shapes. In this paper, the press forming process is modelled and simulated with the aid of finite element method. We focus especially on control parameters such as blank-holding force, friction and the behavior of creases at different forming levels. A stress-based failure criterion is also designed and modelled to analyze the rupture. The FE-model consisted of the male die, female die, blank holder and paperboard blank. A commercial material with the grammage of 290 g/m2 and thickness of 0.353mm is used in this study. The paperboard is modelled as an elastoplastic material and Hill’s yield criterion with isotropic hardening is used to interpret the hardening behavior. The creases are modelled as hinge connectors (one rotational degree of freedom). The failure criterion is implemented by the user-defined subroutine in Abaqus. In conclusion, the developed model can be used to analyze the crease behavior, strain mapping and the prediction of failure, which enables the better understanding of the paperboard converting in the press forming process.

Topics

• impedance spectroscopy
• forming
• isotropic