The different tests that are carried out in our Laboratory:Mechanical & Physical Tests on our Silicone Compound
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.
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.
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.
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.
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.Shatter Resistance
Composite Insulators are practically unbreakable.Hydrophobicity
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.