Space charge injection in LDPE by semi-conductive electrode with different carbon black filling rates

Electrode materials may play an important role in space charge accumulations. Semi-conductive electrodes, carbon black (CB) with ethylene vinyl acetate copolymer (EVA) in three different filling rates, 27vol%, 32vol% and 34vol%, were studied on their space charge injection. Results show that higher CB filling rate induces lower space charge injection than the electrode with lower CB filling rate. It is in agreement with the theoretical analysis. Low CB filling rate can obviously lead to high local electric field near the surface of the CB particles and a large region of high field, which may cause more charge injection.