Electromagnetic Shielding Simulation with Injection Molded Carbon Fiber Reinforced Plastics

Effective shielding against electromagnetic interference (EMI) is essential to ensure the functionality of electronic systems and to limit their radiation. In automobiles, for example, where space is limited and many electrical components are used, such interference can affect safety-critical systems. To achieve required electromagnetic shielding, metals are often used. Due to lower carbon footprint and lower production costs, the use of plastics is increasing, either with electroplated conductive layers or conductive additives. These materials are suitable for injection molding, the most efficient production technology for plastics products. However, the precise design of such components is challenging due to factors such as filler content, geometry, and orientation of the additives. Simulation methods play a key role in optimization, but require a comprehensive understanding of the material properties. In addition, process-related effects with discontinuous fibers or particles, require detailed measurements of electrical properties and influence on the manufacturing process. Due to these challenges, the goal of this work is to measure the fiber content as well as the orientation dependent electrical conductivities and use them for the simulations. In addition, the local orientation differences across the thickness of the component must be correctly modeled and represented in the simulation in order to represent the true anisotropic material behavior.