KRAFT INSULATION

Transformer Layer Insulation

General Description

Kraft Insulation is produced in multi-layer form on a modified wet machine from an electrical grade, unbleached Kraft wood pulp. The dry finished sheets contain no sizing, coloring or other materials which would contaminate natural or synthetic impregnating oils.

Kraft Insulation is used as transformer layer insulation, capacitor can liner and in numerous other applications where the ultimate in electrical and physical strengths are required.

Kraft Insulation is available in sheets, strips, mill rolls and slit rolls in thicknesses from .007” to .062”. Above .062” to .250” is available only in sheets and strips. Above .040” thickness Kraft is laminated from dry sheets with a polyvinyl-acetate-polyvinyl alcohol formulation having good electrical properties.

PHYSICAL, ELECTRICAL AND CHEMICAL PROPERTIES:

 Fiber Content  100% Unbleached Kraft Wood Pulp
 Ash Content (Max.)  .75%
 pH Water Extract  6.0 – 7.5
 Moisture Content  7.0% Avg.
 Chlorides  8 – 16 ppm
 Water Extract Conductivity Microhms/cm  7.5 Avg.

 

 Standard Thickness, ± 7% Inches .007 .010 .015 .020 .025 .031 .040
 Apparent Density, (Air Dry), ± 7% g/cc 1.00 1.00 1.05 1.05 1.05 1.05 1.05
 Weight, (Air Dry), ± 7% lbs./sq. ft. .036 .052 .078 .109 .136 .169 .216
 Tensile Strength, (Avg.) MD lbs./In. 135 195 340 500 575 700 800
CMD lbs./In. 25 50 75 85 115 140 160
 Burst Strength, (Avg.) lbs./sq. in. 120 185 320 440 510 580 625
 Tear Strength, (Avg.) grams MD 180 270 475 650 875 1000
CMD 300 450 800 975 1100 1200
 Dielectric Strength, (Avg.) grams AC, 25˚C (Avg.) volts/mil 250 250 250 250 250 250 250

Click here to download the Kraft Insulation Spec Sheet.

Click here to download the Kraft Insulation SDS Sheet.

“Values shown are typical, are not guaranteed, nor to be used for specifications without approval.”

NOTICE: The above information and data are believed to be accurate and reliable. Windsor Stevens assumes no responsibility for end-use applications and no performance warranty is expressed or implied.