Electrical Grade Sheet Laminates 2018-06-04T21:38:17+00:00
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Electrical Grade Sheet Laminates

All grades of Polyply industrial sheet are produced using polyester reinforcements in and fiberglass reinforcement. They are U.L.recognized and are available in 36″x72″ and 48″x96″ sheet. Sheets are manufactured in thicknesses ranging from 1/32″ to 2″ with most sizes in stock for immediate shipment.

Polyply L-40. Low cost, general purpose flame retardant electrical laminate which meets or exceeds NEMA GPO-2 requirements. Polyply L-50. Track resistant, flame retardant laminate which meets or exceeds NEMA GPO-3 requirements. Polyply L-50HT. Track resistant, High Temperature laminate.

Typical Properties

General Information Unit ASTM/UL Test No.   Typical Average Values  
NEMA GRADE GPO-2 GPO-3 n/a
Polyply Grade L-40 L-50 L-50HT
Color Red Red NC
U.L. Recognized File Number E82624 E82624 E82624
Mechanical Properties
General Information Unit ASTM/UL Test No.   Typical Average Values  
Tensile Strength psi D638 9,800 10,000 10,820
Flexural Strength psi D790 22,000 23,200 26,092
Compressive Strength psi D695 32,000 32,800
Flexural Modules psi x 106 D790 1.2 1.23 1.28
Shear Strength psi D732 14,000 14,000
Izod Impact Strength (notched) ft-lb/in D256 8.0 8.2 11.3
Water Absorption % by weight D570 0.23 0.21 0.28
Barcol Hardness D2583 50 50 50
Specific Gravity D792 1.8 1.8 1.75
Electric Properties
General Information Unit ASTM/UL Test No.   Typical Average Values  
Dielectric Strength (- in oil) volts/mil D149 415 400 420
Dielevtric Strength (parallel in oil) kV D149 61 57
High Voltage Arc Resistance sec D495 200+ 200+ 181
Dielectric Constant @ 60Hz D150 4.6 4.8
Dielectric Constant @ M Hz D150 4.5 4.7
Dissipation Factor @ 60 Hz D150 .014 .013
Dissipation Factor @ M Hz D150 .012 .011
Comparative Tracking Index volts D3638 500+ 500+ 600+
Flame Resistance Properties
General Information Unit ASTM/UL Test No.   Typical Average Values  
U.L. Subject 94 UL94 VO VO HB
Thermal Properties
Coefficient of Thermal Expansion in/in/C x 10-5 D696 2.0 2.0
Thermal Conductivity btu/hr/ft2/in/°F C177 1.8 1.9
U.L. Temperature Index-Electrical °C UL746B 130 130 220
U.L. Temperature Index-Mechanical °C UL746B 160 140 210

All properties are based on 1/8″ thick sheet.
Unless otherwise indicated, all properties published are based on tests performed on standard ASTM test samples and according to ASTM test methods. Values shown are for test samples made from production materials and they are believed to be typical. No warranty is expressed or implied.

Nominal Thickness, Inches Plus or Minus Tolerance, Inches Nominal Tolerance, Inches Plus or Minus Tolerance, Inches
1/32 0.0075 1/2 0.024
1/16 0.0075 5/8 0.027
1/32 0.0090 3/4 0.029
1/8 0.0100 1 0.033
3/16 0.0125 1-1/2 0.041
1/4 0.0150 2 0.049
3/8 0.0200

At least 90 percent of the area of the sheet shall be within the tolerances given, and at no point shall the thickness vary from the nominal by a value greater than 125 % of this specified tolerance.