Influence of flow behavior of different matrix materials on the orientation of anisotropic magnetic particles during injection molding

Polymer-bonded magnets are showing great potential for applications in electrical drives and sensor applications by reducing production steps and costs as well as by their freedom in shape and magnetic design. The main factor for the magnetic performance of bonded magnets is the maximum filler content and the degree of orientation of the magnetic anisotropic particles. By using thermoset molding compounds such as Epoxy, the maximum filler content and the degree of orientation should be increased because of the lower viscosity of this material compared to commonly used thermoplastics such as PA12 or PPS. This should lead to enhanced magnetic properties. This paper deals with the differences in filling and orientation behavior of different matrix materials like PA12 and Epoxy filled with anisotropic magnetic particles (e.g. NdFeB particles).