Product Construction - Goldstone Power

Product Construction

Silicone Rubber Extra High Voltage Insulators

The different tests that are carried out in our Laboratory:

Mechanical & Physical Tests on our Silicone Compound

  • Tensile Strength
  • Elongation at Break
  • Tear Strength
  • Hardness
  • Specific Gravity

Study of process ability and Curing Characteristics at a particular temperature with the help of Oscillating Disc Rheometer

  • The report from this study helps us to know the processing characteristics and total spectrum of curing characteristics of our Silicone rubber compound, which in turn guide the production department to maintain consistent quality

Electrical Tests on our Silicone compound

  • Volume Resistivity
  • Break down Voltage
  • Tracking and Erosion Resistance Test

Resistance to Corona

  • Here a cured sheet from our Silicone compound is put in a cell under corona generating electrodes, thereby exposing the Silicone rubber under corona. In this test the Silicone rubber is subjected to combined stress from electrons, ozone, UV and high temperature simultaneously.

UV Resistance Test (ASTM G53)

  • We are equipped with the facility for exposing the vulcanized sheet made from Silicone rubber to UV light (315 nm) and dry heat simulating normal day condition.

Test for Hydrophobicity

  • We have sophisticated camera based instrument for measuring contact angle of liquids on solids. This instrument is interfaced to PC. Liquid drop shape analysis makes the instrument an error free. By measuring contact angle, we can assess the state of hydrophobicity character of Silicone rubber under various conditions.

Facilities available for carrying out different tests on FRP rod & Viscosity of Resin Mixture:

  • Measurement of viscosity of epoxy mixture in the impregnated bath is very important, as the viscosity of resin mixture will control the impregnation of the bunch of glass fibers. Our quality control department in their process control collects samples from resin bath time to time and checks the viscosity and gives their feedback to the production department to maintain the required viscosity.

Glass Content

  • We have the facility for measuring glass content in FRP rods. Our Quality Control department collects the samples time to time from production line and measures the glass content.

Dye Penetration Test

  • It is one of the very basic tests to assess the quality of the FRP rod. We regularly carry out this test on our FRP rod.

Water Diffusion Test

  • This is a critical test for FRP rod. Though it is quite time consuming, we are carrying out this tests on our FRP rod on regular basis.
  • Besides the above-mentioned tests, we carry out the following tests regularly on our FRP rods:
  • Water absorption test
  • Specific gravity

All these are to convey that we understand the importance of role of composite insulators in power transmission and the importance of their long term uninterrupted performance. We believe a thorough testing of components and in-process can ensure the quality of this new generation product to give service for years together.

Silicone Rubber Extra High Voltage Insulators

Hydrophobicity effect of silicone housed composite insulators

The intrinsic hydrophobic property in combination with very good uv, tracking and erosion resistances of well designed silicone rubber formulations make this kind of rubber superior to all other electrometric and duromeric polymeric housing materials. Further on, a phenomenon well known as “Hydrophobicity transfer” to different kinds of pollution layers offer great benefits regarding the electrical insulation capability even under heavy pollution conditions. The ability to transfer the hydrophobic effect to pollution layers located on insulator surfaces can be regarded as an “intelligent” or “advanced” property and can only be observed for silicone rubbers. Coastal or marine environments are characterized by increased ESDD (Equivalent salt deposition density) values due to salt pollution. Especially in the Mediterranean countries a combination of salt pollution from the sea and dusty and sandy pollution can be observed on insulator surfaces. The latter kind of pollution results in increased NSDD (Non Soluble deposit density) values of the pollution layer. Silicone housed composite insulators show outstanding service experiences in environments where high ESDD and high NSDD values are existing. This positive service behaviour is based on the above mentioned transfer of the hydrophobic effect to pollution layers.

Hydrophobicity Transfer Mechanism

In the bulk of Silicone rubber there exists some quantity of highly mobile low molecular weight chains. It is a homologous compound of PDMS (Polydimethyl Siloxane), defined as LMW. Smaller units n=1 ~20 (or even higher) are called LMWS. Migration process of Silicone LMWS are mainly responsible for the hydrophobicity of PDMS surface and the hydrophobicity transfer to pollution layers. Due to the coating of the deposited pollutants by LMWS, the pollution layer behaves like a Silicone surface and becomes hydrophobic.

About Us

The intrinsic hydrophobic behavior of Silicone is caused by the orientation of – CH3 groups towards the Silicone/air interface and by the adhesion of LMWS on the surface. A generation mechanism of LMWS was found to work in Silicone where the LMW content is in an equilibrium state with PDMS backbone. This means that PDMS bulk material produces as much LMWS as needed for the external hydrophobicity transfer to pollution layer. This equilibrium reaction is also responsible for the excellent function of the hydrophobicity transfer to heavy polluted Silicone surfaces even after decades.

About Us

Considering this generation mechanism, there is no lifetime limitation for hydrophobicity transfer effect. Because of the hydrophobicity transfer behavior there is no need to wash the Composite Insulator having specially formulated Silicone rubber housing.

Silicone Rubber Extra High Voltage Insulators


Self – Cleaning Function

The specially designed Polymeric material used in making the housing of these insulators have a self-cleaning property by recovering the Hydrophobic characteristic due to migration of low moleculor weight / oligomeric PDMS, making it possible to maintain anti-tracking performance over an extended period.

About Us

Shatter Resistance

Composite Insulators are practically unbreakable.


Surface hydrophobicity is maintained throughout the lifetime of the insulator. This is very important in polluted environment.

High Tensile Strength

The composite FRP pultruded rod has a very high mechanical strength. Our special crimping technique allows this high strength to be maintained.

Light Weight

In a typical comparison, the Composite Insulator weighs 10-35% of a Ceramic Insulator. This ensures easy installation, less manpower, low transportation and installation cost.