Multi-stage and Multi-technology Forming of Paper for Sustainable Packaging
摘要
Forming of paperboard enables great design freedom, high productivity and sustainable packaging solutions. The limiting factor in forming processes is the low ductility of the natural fiber material. Not only does this often lead to unwanted cracks, but also to an insufficient control of wrinkle formation. Compared to packaging manufactured from plastics, visual deficiencies have been unavoidable so far. In order to extend the process limits and improve the product appearance, two-stage processes as well as the combination of different forming methods are promising process routes and are therefore discussed in this paper. So far, research in paperboard forming has mainly focused on forming with rigid tools. Recently, forming with active-media is gaining interest. Investigations of process combinations of active-media based forming followed by deep drawing show that both maximum forming depth as well as the wrinkle compression are enhanced. In order to explain the findings scientifically and to develop a numerical model, the materials used have been characterized. Subsequent investigations were carried out numerically and validated experimentally using optical analysis methods. The findings open up new approaches in design and process planning for sustainable, formed packaging.