Title: Modeling and simulation of micro-structural material properties and reactive injection mouldingin polyurethane foams

Abstract

Products made of polyurethane foam are manufactured by the chemical reaction of various low-viscosity raw materials and additives. The diversity of different formulations to meet the requirements of the market makes the characterization of their processing and final product quality important for a simple and error-free production. The modeling and simulation of such processes as well as the detailed analysis of the resulting material properties are equally of great importance. This provides additional findings without the expense of real tests and makes it easier to design components. The talk will present modeling and simulation techniques carried out against this background. On one hand, we will demonstrate simulation tools and their application to perform virtual micro structural analysis of PU foam structures to characterize the mechanical and fluid dynamical properties of different foams. Especially, the material performance like flow resistivity, acoustic absorption and stability under different compression situation will be studied which depends strongly on the local foam density. On the other hand, we explain a mathematically model to simulate the reactive injections moulding process for the foam expansion. The reactive multiphase model parameters are automatically identified from well know tube expansion experiments. The simulation results in detailed information about the filling behavior and the foam density and temperature distribution during and at the final state of the injection process. The simulation tool FOAM can be applied for all kinds of PU foams as well as for quite different manufacturing applications (car seats, refrigerator, insulation panels and fiber reinforced sandwich structure) to optimize the layout, the injections paths or the venting positions. Finally, we will show how the two methods can be combined to o create a digital twin for foam components in the future.

Biography

Konrad Steiner a member of the Department Flow and Material Simulation at Fraunhofer ITWM in Kaiserslautern Germany. The strength of the department is the resident expertise in company-specific software solutions and the development, supply, and specific use of multi-scale and multi-physics methods suitable for industrial application. Our simulation tools combine actual research results of model reduction methods, automatic parameter identification and machine learning to increase efficiency. He is an Expert of Comp. Fluid Dynamics and Microstructure Simulation.