Microvoid formation and water generation in cross-linked polyethylene resulting from heat treatment

In this study, the behavior of water and microvoid formation in heat treated XLPE insulation was investigated. When XLPE is heated, water is generated from cumyl alcohol, a decomposition product of DCP. The water generation is intensified by the antioxidant agent contained in XLPE and the oxygen in the air. The water generation leads to the formation of microvoids in XLPE. After the heat treatment, XLPE becomes supersaturated with moisture resulting in moisture condensation and microvoid formation during the cooling process.