Dielectric strength of the blends of virgin and recycled HDPE

This work evaluated the incorporation of recycled high-density polyethylene (HPDE) in the virgin polymer by measuring its dielectric strength. Post-consumer containers of HDPE were collected and passed through the basic processes of plastics recovery: washing, grinding, and drying. Formulations were elaborated containing 0, 25, 50, 75, and 100% of recycled material incorporated to the virgin resin by extrusion and injection processes, stabilized with 0.2% Irganox B215. Samples of these materials were submitted to dielectric breakdown analysis by using an electrodetype sphere-plane and ramp of positive electric tension. The data were treated and analyzed by using the statistical distribution of Weibull, and the Maximum Likelihood method. The degree of crystallinity was measured by X-ray diffraction. Atomic absorption spectrophotometry was employed to identify metallic residues present in the samples. The results showed that there is a 17% decrease in the values of the dielectric strength when we compare the virgin HDPE with the 100% recycled. Therefore, formulations containing up to 50% of recycled material may be taken into consideration in the development of products in electric insulating systems. (C) 2003 Wiley Periodicals, Inc.