Design and optimization of plants and components for the production of polyurethane foams

In cooperation with a German manufacturer of polyurethane technologies, Fraunhofer Institute SCAI launched a publicly funded project with the intention to improve the development of polyurethane technologies by applying computational fluid dynamics and multi-criteria optimization methods for robust design. For this purpose SCAI employed STAR-CCM+ for fluid simulation and the in-house code DesParO for optimization. This approach was carried out for two procedures in polyurethane technology, namely the mixing of polyurethane components in high-pressure mixing chambers and the manufacturing process of foam slab-stock in conveyor belt facilities. In order to achieve an optimal mixing by minimizing applied pressure for a wide range of different polyurethane components, one has to develop well designed mixing jets, mixing chambers and chamber outlet geometries. In a script-based automated process chain effective geometric parameters were varied by a design of experiment and various simulations were carried out, which results were integrated in response surface methods to reveal parametrical dependencies. For the production of foam slab-stock the geometry of the system has a significant influence on the product quality. It is necessary to spread the polyurethane fluid evenly over a system of moving paper or plastic foils to achieve a constant product height. According to the mixing chamber procedure an automated process chain to carry out the simulations was applied here as well.