Insulating silicone

High voltage HTV silicone rubbers (Insulating Silicone) are a group of silicones that are specially designed to be used in making high pressure (high voltage) insulators in polluted and humid environments that are highly corrosive. The superiority of silicone rubber insulators over other plastic composite insulators and conventional insulators in terms of behavior in highly polluted atmospheres is due to two special features of silicone rubbers:

Silicone rubbers are waterproof, that’s why water flows on silicone rubber surfaces.
Silicone rubbers release low molecular weight siloxanes from their surface, which are also waterproof. When soil is placed on a silicone rubber surface, they transfer the low molecular weight siloxanes to the soil particles and hold them. They cover it so that the dirt particles are also hydrophobic.

Features of High voltage HTV Silicone Rubbers

High transparency
Resistant to breakage and erosion
Excellent dielectric strength
High hydrophobicity (water repellency)
Resistant to weathering and air pollution
Low leakage
Excellent injection molding

Applications of High voltage HTV Silicone Rubbers

Suspension Insulation
Line Post Insulator
Surge Arrestor
Cable Terminator and Connectors

Technical Specification Table

HVI-70	HVI-65	Grade No.
Insulator Surge Arrestors		Physical Properties / Application
1.54	1.52	ASTM D792	Specific gravity
Gray	Gray		Color
70	65	ASTM D2240	Hardness (shore A)
45	50	ASTM D412	Tensile strength (kgf/cm2)
200	250	ASTM D412	Elongation (%)
13	15	ASTM D624 "B"	Tear strength, "B"(kgf/cm)
24	24	ASTM D395	Compression Set (150°c/22hrs)
49	50	JIS K 6255	Rebound (%)
2.85	2.9	JIS K 6249	Linear Shrinkage (%)
94V-0 Level	94V-0 Level	UL-94	Flame Retardant
Electrical Properties
2.5*10^	2.5*10^	ASTM 257	Volume Resistivity (ohm.cm)
23	23	ASTM 149	Dielectric Strength (kv/mm)
4.0	4.0	ASTM 150	Dielectric Constant (1KHz)
0.03	0.03	ASTM 150	Dissipation Factor (1KHz)
4.5	4.5	IEC 587	Tracking Resistant (kv)
200 <	200 <	ASTM 495	Arc Resistant (second)