Since 2024, the company has launched production of suspension and pin-type insulators using proprietary know-how in quenching and annealing technologies for high-alkali and borosilicate glasses
Polymer-Apparat Group, based on the Malovishersky Glass Plant, has opened new horizons in the production of glass insulators. Innovative annealing and tempering technologies ensure greater reliability and service life, which are critical for the safety and efficiency of power systems.
Overhead transmission lines (OHL) remain the backbone of the national power grid, and insulators have always been, and continue to be, the key element of their reliability. In recent decades, approaches to insulator materials and designs have changed significantly. Today, outdated solutions are being replaced by advanced manufacturing technologies that combine durability, reliability, and adaptation to the demanding conditions of the Russian market.
In the evolution of power systems, insulators made of alternative materials have also found application alongside glass insulators: porcelain and polymer. Porcelain insulators, valued for their high mechanical strength and good insulation properties, remain a popular choice, especially for medium-voltage lines. Polymer insulators, in turn, offer the advantage of reduced weight, making them ideal for certain operating conditions. Each material comes with both strengths and limitations:
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Porcelain – high mechanical strength, but prone to moisture absorption; damage to the enamel layer may lead to internal breakdowns and sudden failure.
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Polymer – lightweight and easy to install, but require strict aging and quality control.
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Glass – combines the availability of raw materials, long service life, and excellent resistance to environmental factors.
The diversity of materials is part of natural technological progress, as engineers and scientists continue to explore ways to improve product performance.
For Russia, import substitution is a particularly important issue. Glass is produced from locally sourced raw materials: quartz sand (SiO₂), soda (Na₂CO₃), dolomite (CaCO₃×MgCO₃), chalk (CaCO₃), and several other components. At the same time, production is transitioning from costly, energy-intensive Soviet aluminosilicate formulations to borosilicate technology (Pyrex/Duran), which is also relevant to the global market.
The mixture of all components in defined proportions is called a batch. The batch is loaded into a glass furnace, where it is melted at 1350–1600°C to form a molten glass mass, later processed into glass products. The key glass-forming substance is quartz sand, containing 98% SiO₂. In theory, glass can be made from quartz sand alone, but this requires extremely high melting temperatures (around 2000°C), which in turn demands costly furnaces and sophisticated equipment.
To obtain various other types of glass, modifiers are added to reduce the melting temperature. These include soda, chalk, dolomite, and others. For example, red lead oxide is used to produce special grades of crystal glass.
The history of glass insulators in Russia began with aluminosilicate glass (type 13V), characterized by very high energy intensity. Today, production of low-voltage pin-type insulators has been fully transitioned to borosilicate glass – comparable in physico-chemical properties to global brands such as Pyrex – resulting in optimal combinations of mechanical strength, thermal stability, and resistance to environmental impact.
Polymer-Apparat JSC, leveraging the facilities of the Malovishersky Glass Plant, has introduced next-generation formulations, enabling the production of compact pin-type insulators for OHL up to 20 kV. The company’s manufacturing technologies are based on a deep analysis of the advantages and operating experience of classical Soviet methods, while addressing the challenges of today’s global energy industry.
Electrotechnical glass is ideally suited for insulator production, offering the following key properties:
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Electrical insulation – high dielectric strength makes glass an excellent insulator, preventing breakdowns.
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Mechanical strength – despite its brittleness, glass has sufficient mechanical strength to withstand normal operating loads; compared with porcelain insulators, it is lighter, simplifying transport and installation.
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Weather resistance – highly resistant to environmental exposure, including moisture and UV radiation, ensuring long service life outdoors.
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Thermal stability – retains its properties across a wide temperature range, making it suitable for diverse climates.
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Visual inspection – transparency allows easy detection of cracks or defects, facilitating maintenance and fault detection.
At the same time, insulators made of electrotechnical glass using older technologies had a number of significant drawbacks that limited their performance and service life. These shortcomings highlighted the need for new glass formulations and innovative technologies to improve insulator properties and enhance reliability.
For more information, visit us at POWEREXPO ALMATY 2025
October 21-23, 2025.
Use promo code PWRX21MC7L for free exhibition entry
