Research project develops thermally agile extrusion tool for more efficient film production
The aim is to use targeted lightweight construction approaches to reduce the mass, flow paths and thermal set-up times of moulds in order to increase efficiency in film production. This innovative project promises customised solutions for different tool sizes and types.
© IKVExtrusion dies that are used for the continuous production of complex products such as a coextruded film several metres wide are usually very large and heavy. The combination of high pressures due to the high viscosity of the processed polymers, multiple flow channels in the coextrusion structure and large film widths means that extrusion moulds are subject to high mechanical loads. To ensure that the individual mould plates are properly sealed against each other despite these loads, they are generally dimensioned conservatively, i.e. very rigid and therefore very voluminous. The large volume and the resulting high mass in turn lead to difficulties in handling, high flow path lengths and long thermal set-up times, i.e. long waiting times when changing over to a product with a different target temperature. The new research project “Automated simulation-driven analysis of lightweight design strategies for the efficient design of film extrusion dies” aims to investigate which lightweight design strategies make sense in order to reduce masses, flow paths and thermal set-up times depending on the size and type of extrusion die. To achieve this goal, a simulation environment that describes the interaction between the flow in the flow channel and the bending of the die plates is to be created. In addition, this simulation environment must allow for an automatic adaption of plate geometry. For this purpose the immersed boundary surface method in the open source software OpenFOAM (OpenFOAM Foundation Ltd., Great Britain) is to be used. Conventional calculation methods and laboratory tests with a flexible mould made of PMMA are used for the validation of this approach. After that, lightweight construction strategies like substitution of steel with aluminium, increasing rigidity by bending, highly detailed mechanical dimensioning, ribbing and topology optimisation are automatically applied. Two fundamentally different types of extrusion dies and various sizes are investigated. The simulated improvements in terms of die mass, flow path length and thermal set-up time are analysed in detail and compared with typical industrial values. As a result, the extent to which lightweight construction makes sense for the majority of extrusion dies used in practice will be examined for the first time. Two optimised dies are manufactured and examined in laboratory tests so that the optimisation method is validated alongside the calculation method.
Project data and funding
We would like to thank the DFG for funding the project (funding code HO 4776/89-1) and the project partnersfor their cooperation.
Project duration: 01.01.2024 – 31.12.2025
Project partners and funding
