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Today, porcelain insulator production for high voltage application can be made
by two possible methods:
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 | The conventional (plastic) production process |
| The isostatic (developed within PPC group) production process |
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While the conventional (plastic) production process requires an operating time
(for insulators without fittings) of 7-8 weeks, the isostatic production process
requires only 1,5-2 weeks for the same insulator. The considerable time
necessary for extrusion and drying before and after profile turning – as necessary
in conventional production - is reduced to almost zero by using isostatic
production process.
Beside the avoidance of the most time consuming production steps, isostatic
production process also enables secure production of insulators with very difficult
geometries and design.
In the manufacturing process itself, the isostatic "part" is limited to the
manufacture of the "blank" only. The slip (porcelain body with app. 80% water
content) is dried to a very fine porcelain powder (granulate) by using huge spray
dryer. In the isostatic press, the granulate is pressed into cylindrical blanks at
very high pressure. |  |
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On turning machines - specially designed for insulators - the blanks receive their
dimensional design. After turning, the insulator are to be glazed - after firing
process the glaze protects against atmospheric pollution as well as contributes
to electrical and mechanical properties of the final insulator product).
In the final production steps the insulators are cut´ and grinded, electrically
controlled (if applicable), assembled with metal flanges (if applicable) and
mechanically tested. | |
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