Organic external insulation

represented by silicone rubber material

has been widely used in power systems. However

the long-term operation of silicone rubber external insulation material inevitably leads to aging problems

resulting in a decline in hydrophobic properties

which has become a bottleneck restricting the reliable operation of power systems. Consequetly

we proposed a novel approach to improve the hydrophobic properties of aged silicone rubber material using pulsed laser lift-off technique

and investigated the mechanism of laser lift-off for removing the aged surface layer of silicone rubber shed

as well as the reasons for the improvement in hydrophobic and electrical properties. The research findings indicate that

after 10 consecutive laser ablations

namely

a removal thickness of approximately 0.10 mm

the contamination

cracks and aged layer on the surface of the shed are essentially eliminated. As a result

the contact angle can reach up to 158.75°

achieving a superhydrophobic state. Although laser ablation does not change the types of elements

it creates a micro/nano composite structure on the ablated surface

and the height of the absorption peak of hydrophilic hydroxyl groups (—OH) decreases

both of which contribute to the improvement of hydrophobic properties. Therefore

compared with the unablated insulator strings

the average dry flashover voltage and wet flashover voltage of five insulator strings after ablation increase by 22.69% and 17.39%

respectively. Pulse laser lift-off process is the result of the combined action of the internal temperature field and thermal stress field of the material.