Understanding Hydrophobicity Recovery of Silicone Rubber Material Post Corona Ageing

TLDR: Results indicate that surface potential and its decay time constant reduces drastically after the corona ageing, as compared to the virgin specimen, however, the test specimens regain their hydrophobicity, though at a different rate, with time.

Abstract: Surface hydrophobicity recovery of silicone rubber insulating material post corona ageing is reported in the present work. Recovery rate of hydrophobicity of uncleaned (S1) and cleaned sample (S2) after the corona ageing are compared. Results indicate that surface potential and its decay time constant reduces drastically after the corona ageing, as compared to the virgin specimen. However, the test specimens regain their hydrophobicity, though at a different rate, with time. Trap distribution characteristic shows that the characteristic time and charge trap depth reduces with the corona aged specimens and regain with rest period. A similar trend is observed with contact angle and corona inception voltage (CIV) of the test specimens. Pattern classification of Ultra High Frequency (UHF) discharge signal is done using modified Chaotic Analysis (CA).