MODELING THE CREASING OF PAPERBOARD

Laminated paperboard is widely used in packaging products. It usually consists of multiple layers bonded to each other by starch or adhesive materials. To obtain the commercial cartons with high quality, the indentation of fold lines (creasing) plays a crucial role during the whole converting processes. Thus, the aim of this study is to describe the material behavior of a laminated paperboard during the creasing process. The paperboard was considered as a laminate of three different layers, each of which was modeled separately with an anisotropic elastic-plastic material model. The initial yielding was given by the Hill's 48 yield criterion, while the isotropic strain hardening was described by a power law hardening function. To calibrate the material parameters, a sequence of tensile tests was conducted for each layer in different directions to account for the material's anisotropy. Furthermore, tensile tests for the whole laminate were performed, such that numerical predictions could be validated against experimental data. Finally, the creasing process was investigated using a two-dimensional finite element model with a plane strain assumption.