How to predict the three-dimensional formability of papers
A packaging’s geometry is one of the major design factors for creating a highest possible identification effect for a product or brand. Thanks to comprehensive research during the past few years, it has become possible to expand the limits of paper as a material in three-dimensional forming methods, such as deep-drawing or hydroforming, to such an extent that packaging products at high forming degrees can be produced in very good qualities thereby boosting the availability of a promising alternative to thermoformed plastic trays.
Project title: » Development of a universal method for predicting the formability of paper-based materials in deep-drawing and hydroforming (UniVorsUm)
Project period: » 2020/12/01-2022/11/31
Project sponsor: » IGF 21513 BG
Research locations: » TU Darmstadt, Institute for Production Engineering and Forming Machines (PtU),
» Steinbeis Hochschule
» Papiertechnische Stiftung (PTS)
Project leader: » Dr. Martin Zahel » Benjamin Hiller
However, a remaining impediment to broader application on an industrial scale is that a paper’s suitability for 3D forming processes is not standardised and cannot be predicted on the basis of conventional material parameters, and this makes it signifi cantly harder for paper converters and packagers to select the appropriate material.
Fig. 1: Flowchart for modelling the forming quality
This was the motivation for PTS to enter into cooperation with Steinbeis University and TU Darmstadt (PtU) for a joint project known as “UniVorsUm”. This cooperation brings together the German-wide 3D paper forming expertise in material development and process development for both deep-drawing and hydroforming of papers. The UniVorsUm project pursues the goal to develop a solution for standardising and predicting the formability of papers and paper-related materials in 3D forming processes with both rigid and fl exible holding-down devices by defi ning the essential material properties.
A first subgoal is to develop a new testing strategy as well as associated parameters in order to be able to attribute effects and defects to the underlying deformations or material impairments (acceptable to a reduced extent, but undesirable to a large extent) in the 3D forming process. Another sub-goal is to identify test scenarios and test conditions (near-process conditions) that are indicative of the formability of materials. The well-aimed combination of the input variables and output variables will then serve to predict the forming limits. Finally, the test methodology for the various deep-drawing and hydroforming variants of the 3D forming process is to be harmonised to provide a standard that characterises a paper material by its forming quality.
Fig. 2: Exemplary formed part and hydroforming
Dr. Martin Zahel,