Transformer Insulator Horizontal Rubber Injection Molding Machine for Substations

          300ton Clamp Force Transformer Insulator Injection Molding Machine for Substations
 
 
Difference Between Liquid Silicone Insulator & Polymer Insulator :

• The reliability of an insulator depends upon its electrical and mechanical strengths.. With the advent of modern manufacturing, mechanical molding and fixture technique, the mechanical strength is quite reliable.The modern style polymeric insulators were introduced about 25 years ago with most recent version about 13 years ago.The reason for this was not failure of ceramic insulators, but the other benefits such as 90% weight reduction, better pollution performance and low associated costs of polymeric insulators over ceramic ones.
• xperience of outdoor insulation started from the introduction of telegraphic lines.The pin and cap type insulators have been used since the last quarter of the 18th century. These insulators are very reliable. Glass and porcelain insulators were the only type available before the introduction of newer polymeric insulators and thus had fully ruled over the market till late second half of the 20 th century. The polymeric insulator has a fiber rod structure covered with weather resistant rubbers and fillers and fitted with end fittings. Such a type of insulator is also called composite insulator.
• The most critical thing to be considered in outdoor insulators is the interface between the solid insulting body and the surrounding air. The problem appears at the interface because it is the interfering point of air and the solid insulator. This problem arises due to the effects of pollution, rain, dust, salt, corona, arcing over surfaces, nitric acid in air, etc.

Molding Techniques of Polymer Insulators:

• The early developments of modern polymeric insulators started in 1964, and prototypes for field installations started in 1967, and a report from 1996 stated that insulators installed in 1969 were performing well. The early types had an epoxy bonded E-glass fiber core covered with a thin room temperature vulcanized (RTV) silicon rubber housing. A major change in production technology occurred in 1978, when the housing material was replaced with ATH-filled high temperature vulcanized (HTV) silicon rubber. Composite insulators can be manufactured by different techniques. One way is to first manufacture the sheds separately and push them onto the core.

• The whole insulator housing is then injection molded directly around the core in one piece.  In this way, the housing can be chemically bonded to the core, and the number of interfaces where moisture can penetrate is minimized. This technique is the most attractive to manufacturers because of the lower number of steps involved and short time of processing. There are three main types of silicone rubbers used in high voltage insulation applications: high temperature vulcanizing (HTV) silicon rubber, room temperature vulcanizing (RTV) silicone rubber and liquid silicone rubber (LSR). HTV is cured at high temperature and pressure, catalyzed by peroxide induced free radicals or by hydrosilylation catalyzed by a noble metal, ie platinum. HTV RTV is cured at lower temperature, ie around room temperature, by condensation reaction as one component system.