Corrugated Fiber is used for electrical insulation in power generation and transmission applications. It is a dense material having high strength imparted by the retained fibrous structure it is made of. This material is free from foreign matter that might impair electrical properties.

Corrugated Fiber is used in distribution transformers as a duct through which cooling oil flows. The number of corrugations needed per transformer is a function of the rating of the transformer and the amount of oil flow needed to keep the operating temperature below failure levels.

Square Corrugated Fiber, with corrugations perpendicular to the grain, possesses superior mechanical strength and maintains the height of the corrugations under pressure, allowing the proper amount of cooling oil to flow freely.

Tests have shown that our Square Corrugated Fiber is compatible with transformer oil and after aging, gains compressive strength.

Sinusoidal (rounded) or sine-wave configurations tend to deflect as the load is increased, thus reducing the height of the corrugation and the amount of cooling oil that can be passed through.

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    Nominal thickness (inches) 1/32"

    Bursting strength (PSI), minimum 325

    Water absorption % IN 24 hours, maximum 63

    Specific gravity, typical 1.12 TO 1.25

    IZOD impact strength (foot pounds/inch of notch 1.0 minimum

    Rockwell hardness, minimum R-80

    Dielectric strength, VPM minimum 175

    Ash content % maximum 1.5

    Silica content % maximum 0.3

    Zinc chloride content % maximum 0.1

    Compressive strength (of flat sheet) PSI typical 30,000


    HeightTypeGrain DirectionWidthLengthCompressive Strength
    3/16″SquaredCross corrugation6″ to 48″1′ to 200′245-300 PSI
    1/4″SquaredCross corrugation6″ to 48″1′ to 200′180-215 PSI
    1/4″RoundedWith corrugation32″48″Averages min:120 typ:175
    • Made-to-Order Sizes Available
    • All Base Material 1/32″ Thick Vulcanized Fiber