Understanding the mechanical processes in deep-drawing and press-forming of compacted paper laminates

Compacted paper laminates can be formed by deep-drawing or press-forming to produce packaging solutions with height to diameter ratios not reachable with conventional thermoforming machines. These processes involve complex interactions of the fibres in the compacted paper layers and between these layers, including the bonding between them, which can be made either with glue or polyethylene (PE). To optimise the processing by deep-drawing or press-forming requires a more in-depth understanding of the mechanics at the scale of the individual materials, the interfaces and their interactions. This project will study the micro-mechanisms that are at play in deep-drawing and press-forming to identify ways to optimize the materials and overall laminates for improved forming and to mitigate mechanisms that can lead to product failure.

The main objective of this project is to increase the knowledge about the behaviour of fibre-based laminates in press-forming and deep-drawing processes towards developing materials with sufficient ply strength for such forming and to optimise the processing procedures. This will involve structural characterisation of the different laminates using 3D imaging by high-resolution x-ray tomography to investigate how the layers are bonded, as well to evaluate the fibre structure of the FibreForm. This characterisation will be made in un-formed and formed materials. To deepen the understanding of the mechanisms and material interactions, mechanical testing will be performed “in-situ” with x-ray tomography imaging. These tests will include tensile, compression and drawing-simulation tests with 3D x-ray tomography images acquired during the loading process.