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Degraded Paper Fiber From Transformer Oil Under the Microscope

Degraded Paper Fiber From Transformer Oil

This degraded paper fiber is from an oil sample collected from a 8400kVA transformer. This transformer was reportedly gas blanketed and sealed. The presence of this paper fiber and others similarly degraded indicates severe aging of the paper insulation in some areas.

Transmitted Oblique Off Crossed Circular Polarized Light


Paper is used as a primary insulation in the core of transformers. This material will degrade hydrothermally like other cellulose materials in a transformer over time.

Significance in the Environment:

This type of degradation indicates temperatures typically over 90 degrees Celsius and elevated moisture content.

Characteristic Features:

Hydrothermally paper fiber often exhibits tears normal to the long axis of the fiber. The birefringence is typically below 0.01 by the time these tears are evident. The paper fiber may be quite irregular in shape, having lost mechanical integrity in all layers of the fiber.

Associated Particles: