Influence of processing conditions on the dielectric properties of PVC insulator

The dielectric properties, tan δ and dielectric constant, Ε, of PVC insulator were measured over a range of temperature and frequency for extruded and mould-pressed samples. The samples were prepared with a formulation containing locally produced CaCO3 filler. Peaks of tan δ were observed to change with frequency and tended to shift towards higher temperatures with increasing frequency. The peaks depend on type and temperature of the process involved. These conditions appeared to introduce internal stresses and crystallinity, as revealed by X-ray diffraction investigations.