Study on improvement of polyethylene interfacial properties

In order to improve the withstand strength level of extruded cables, optimized additives were used to modify the semiconducting material so as to improve the interfaces between semiconducting shielding layers and the insulation of cables. The result of the treeing experiments showed that a 40% increase in treeing inception voltage could be expected when certain additives were used. It is found that additives in the semiconducting material diffused and formed diffusion layers when processed, hence creating a field-dependent electric conductivity which helped inhibit treeing. The mechanism analyzed provides an effective method for improving the withstand voltage in polyethylene cables.