Innovative Yale Study: Modified Wood Unlocks New Insulation Applications for Power Transformers

In common perception, wood has always been a classic building material. However, an innovative study from Yale University has completely broadened the boundaries of wood applications, successfully transforming it into high-performance insulation material for power transformers.

The research results were officially released by the Yale School of Engineering on June 10, 2026.

Power transformers are the core equipment of the power grid system. The key to transformer protection lies in the internal insulation layer. Current transformer insulation technology dates back to the 1890s, using kraft paper combined with insulating oil. However, this traditional solution has inherent flaws as the insulating oil forms interconnected micro-regions that can lead to electrical failures.

Compared to traditional processes, the high-density modified wood insulation material developed by Yale University has achieved a comprehensive upgrade in heat resistance, internal pressure resistance, wear resistance, and heat dissipation capacity.

Preparation Principles and Insulation Advantages

The research team reshaped wood's internal structure through a gentle chemical treatment to remove lignin and hemicellulose, followed by oil immersion and high-pressure densification.

Through high-pressure compression, the originally wide internal channels are transformed into tiny, independent closed channels. This structure "locks" the insulating oil within independent micro-channels, preventing the formation of a continuous failure path.

Measured Performance Fully Surpasses Traditional Materials

• Mechanical Strength: Tensile strength is 3.5 times that of traditional oil-impregnated insulating paper.
• Heat Dissipation: Thermal conductivity in the thickness direction is increased by 1.6 times.
• Aging Resistance: In 150°C aging tests for 6 weeks, the modified wood retained over 70% of its tensile strength.

Industry Value

This technology is particularly significant for the aging US power grid, where many large transformers have been in service for over 25 years. The core principle can also be extended to dry-type transformers, industrial motors, and printed circuit boards.

Source: Yale Engineering, Web