Analysis of the injection moulding process of soft magnetic plastics compounds

Electric/electronic devices become increasingly more complex and are used in highly integrated assembly groups. Plastics bonded magnets can fulfil some of upcoming requirements with respect to design freedom and advantageous processability. However, the magnetic properties of plastics-bonded magnets are significantly reduced since the maximum magnetic filler content incorporated into plastics is limited. Due to a comparably high relative permeability soft magnetic plastics compounds allow for a further increase in magnetic flux density of conventionally used plastics-bonded hard magnets. In cooperation with industrial partners IKV further develops soft magnetic plastics compounds within a joint project called “Mikromag”. The paper deals with the injection moulding of soft magnetic plastics compounds. Achievable soft magnetic properties of different fillers are shown. The influence of process parameters, inductive heating and magnetic coils within an injection mould on the processing and magnetic properties is discussed.