Influences of the design and production on the characteristic properties of multipolar bonded magnets

Abstract

Multipolar polymer bonded magnets can be used for several applications, as for example in electric drives or sensors. The particular application determines the requirements regarding the properties of multipolar magnets, as for example the accuracy of the pole pitch. The injection molding process of polymer bonded magnets allows a cost efficient production of complex design of the magnets' shape and its magnetizing structure. The final properties of injection molded magnets are influenced by the magnetic compound, the injection mold design and thus, the magnetic field in the cavity, as well as the process parameters. This paper deals with the design and production of multipolar magnets in the injection molding process. In a first step an overview of the requirements of multipolar magnets in different applications is given and important characteristic parameters are identified. In a second step the influences during the manufacturing process on the important characteristic properties of multipolar magnets are evaluated. This evaluation focuses on the injection molding tool design by using a magnetostatic simulation.