BASF now offers an additional service for polyurethane systems in automotive interiors. The company’s Ultrasim simulation tool has been expanded so that the behavior of PU systems during foaming can now be reliably predicted for both open and closed molds. The automotive supplier Yanfeng Automotive Interiors is using the virtual process design for the instrument panels it manufactures for current models such as the BMW X1.
Process design begins at purely virtual phase
Instrument panels are safety-relevant, large and complex components that vehicle makers approve individually for every car model. During manufacturing, the foaming process is crucial to ensure that carrier, skin, PU foam and the respective airbag design combine to produce a harmonious component. With Ultrasim the PU foam can be manufactured efficiently according to process and part. The crucial aspect is that the process design already begins at an early, purely virtual phase of the project. For customers, this is a significant help toward cutting project times, optimizing mold design and planning development work in a cost-effective and holistic way.
Simulation adds value especially in early project phases
Within the simulation tool, the manufacturing process for the component is an integral part of the calculation of the component behavior. Ultrasim contains tailor-made material models for PU systems, so that the injection, foaming and hardening of the polyurethane can be precisely predicted. The analysis thus takes exactly into account the typical properties of the relevant materials: the temperature-dependent reaction process and foam formation as well as the resulting density profile and flowability during foaming. This makes it possible to generate a location-independent calculation of the foaming process: from injection via the complete mold filling to the final part density.
Foaming process in both open and closed molds becomes transparent
Setting the right process parameters is just as important as having an exact description of the material behavior. Foam-fill simulation allows the injection position, the route of the mixing head and the orientation of the mold to be analyzed, but also flow aids, venting designs and closing times. Thus the foaming process in both open and closed molds becomes transparent and can be examined with a virtual magnifying glass. For closed mold processes, the simulation results can be used to evaluate different injection designs, so as to prevent e.g. air voids and weld lines. For open molds, the simulation can run a series of virtual simulations to optimize injection lines for the PU system. The simulation especially adds value in the early phase of a project, because it generally reduces development times. And if the simulation detects a problem, customers can adjust part geometry and venting designs at no extra cost.
Applications: from engine hoods to steering wheels
The new simulation service is currently being used in customer projects for other components such as engine hoods and steering wheels, i.e. for integral and flexible foams. The medium-term goal is to use Ultrasim to determine the ideal processing parameters of all PU systems for a mold but also to gain insight into the ideal PU system for a given mold.