As the transformer industry continues to evolve, so do its electrical insulation needs. For transformer manufacturers across Europe, sourcing the right insulation raw materials and components means meeting exact technical requirements consistently, while maintaining reliable production and delivery accuracy.
In this article three important materials used for transformer insulation has been explained: transformer wood (KP wood), laminated pressboard, and Nomex. Each material offers different electrical, mechanical, and thermal properties for specific transformer applications. Finvacon specializes in machining these materials into precision insulation components according to customer drawings and requirements.
Transformer Wood — KP Wood
Transformer wood, widely known as KP wood, is one of the technically demanding materials used in the transformer supply chain. It is a densified beech wood engineered for applications in oil-immersed transformers.
KP wood is used for clamping structures, pressure beams, support brackets, and other load-bearing components that help hold the transformer core and winding assembly firmly in place.
Its combination of high compressive strength, oil compatibility, and controlled dielectric properties makes KP wood well suited for transformer insulation and structural applications. It can offer large dimensions, very low moisture absorption, fast oil absorption, and can withstand high voltage under oil, depending on the material specification and application.
Finvacon stocks and machines KP wood in various dimensions and veneer qualities, including SQ and HQ, ready to be machined according to customers’ specific drawings.
Laminated Pressboard
Manufactured from refined cellulose fibres under high pressure, laminated pressboard is widely used as an electrical insulation material in oil-immersed transformers. When impregnated with transformer oil, it provides the required dielectric performance while also offering mechanical support within the insulation system.
Laminated pressboard can take many forms and serve different functions inside a transformer. It is used for barriers between windings, strips and spacers for oil passage and cooling, pressboard rings between winding layers, and other insulation structures designed for specific transformer applications.
Finvacon stocks laminated pressboard in various weights, dimensions, and thicknesses suitable for transformer applications across the European market. At our machining facilities, standard plates are converted into finished insulation components such as barriers, strips, rings, and profiled parts, precisely machined according to customer drawings while optimizing material use.
Nomex and Aramid Insulation Materials
Nomex, an aramid paper and board material, is used in transformer insulation applications where high thermal stability and mechanical performance are required.
Compared with conventional cellulose-based insulation materials, Nomex offers higher temperature resistance and can maintain its mechanical properties at temperatures where traditional materials begin to degrade. Its thermal performance also makes it suitable for transformer designs where higher operating temperatures, compact construction, or increased overload capacity are required.
Finvacon is experienced with materials like Nomex and other composite insulation materials into customized transformer components according to customer requirements.
Finvacon — Transformer Insulation Component Supplier for Europe
Finvacon is a Finland-based supplier of precision-machined transformer insulation components for the European transformer industry.
By combining access to quality insulation raw materials with advanced CNC machining capabilities, we manufacture components from KP wood, laminated pressboard, Nomex, and other insulation materials according to customer specifications.
Our technical team supports customers with raw material, component development, prototyping, and machining to achieve accurate components with minimal material waste and competitive pricing. This allows transformer manufacturers to source both insulation materials and precision-machined components from a single supplier.
Supporting Europe’s Energy Transition
The demand for transformers is increasing as European electricity grids expand and adapt to renewable energy generation, electrification, and growing energy demand.
As a supplier of precision-machined transformer insulation components, Finvacon continues to invest in material availability, machining capacity, and technical capabilities to support the changing needs of the European transformer industry.