GENERAL DESCRIPTION Phenolic Laminates are made by applying heat and pressure to layers of paper, canvas, linen or glass cloth impregnated with synthetic thermosetting resins. When heat and pressure are applied to the layers, a chemical reaction (polymerization) transforms the separate layers into a single laminated material with a "set" shape that cannot be softened again -- therefore, these materials are called "Thermosets". A variety of resin types and cloth materials can be used to manufacture thermoset laminates with a range of mechanical, thermal, and electrical properties.
GENERAL PROPERTIES Physical strength, resiliency, ease and versatility of fabrication, and excellent electrical properties make Phenolic Laminates useful as support components in a wide range of mechanical and electrical applications. Phenolic Laminates are strong, stiff, and have high impact and compressive strengths. And, they do not soften upon re-heating, so they are easy to saw, drill, tap, and machine with ordinary tools. "FR" grades are flame retardant.
Paper-based phenolics are the most economical of the laminates, yet provide significant electrical properties and good mechanical properties. For greater strength and machinability, cotton-fabric phenolics are often a good choice.
PHENOLIC GRADES
X, XX, and XXX (Paper Base / Phenolic Resin)
Mechanical and Electrical grades are available which are excellent choices for intricate punch parts, insulating washers, spacers, terminal boards, switch bases, and other electrical components. The "X" designations generally distinguish manufacturing processes which result in different levels of electrical properties (i.e., dielectric strengths). Paper-based phenolics are available in a variety of sheet, rod, and tube sizes.
C and CE (Canvas Base / Phenolic Resin)
Medium weave cotton cloth fabrics are mixed with phenolic resins to provide good wear resistance, low moisture absorption, and good mechanical strength at economical cost. Canvas-based phenolics are used for structural supports, piston rings, gears, spacers, and bearing surfaces. The "CE" grade has better electrical properties than the "C" grade. Canvas-based phenolics are available in a variety of sheet, rod, and tube sizes.
L and LE (Linen Base / Phenolic Resin)
Fine weave cotton cloth fabrics are mixed with phenolic resins to provide better machinability than provided by the "C" and "CE" grades. The Linen-based grades also have higher density and good moisture resistance. "L" and "LE" phenolics are used for fine tooth gears, relay bases, radio parts, terminal bases and strips, often in high-humidity environments. The "LE" grade has better electrical properties than the "L" grade. Linen-based phenolics are available in a variety of sheet, rod, and tube sizes.
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TYPICAL PROPERTIES of PHENOLIC LAMINATES (SHEET FORM) ( mechanical properties of rod and tube forms may differ ) | ||||
| ASTM or UL test | Property | Paper | Canvas | Linen |
| PHYSICAL | ||||
| D792 | Density (lb/in³) (g/cm³) |
0.049 1.35 |
0.050 1.37 |
0.048 1.34 |
| D570 | Water Absorption, 24 hrs (%) | 2.0 | 2.5 | 1.8 |
| MECHANICAL | ||||
| D638 | Tensile Strength (psi) -lengthwise -crosswise |
15,000 12,000 |
11,000 9,000 |
13,000 9,000 |
| D790 | Flexural Strength (psi)-lengthwise -crosswise |
16,000 13,200 |
17,500 15,000 |
22,000 16,000 |
| D790 | Flexural Modulus (psi)-lengthwise -crosswise |
1,100,000 900,000 |
1,600,000 1,500,000 |
1,600,000 1,200,000 |
| D256 | IZOD Notched Impact (ft-lb/in)-lengthwise -crosswise |
0.65 0.60 |
1.70 1.50 |
1.35 1.10 |
| D695 | Compressive Strength (psi) | 32,000 | 37,000 | 37,000 |
| D785 | Hardness, Rockwell M | M100 | M100 | M100 |
| THERMAL | ||||
| D696 | Coefficient of Linear Thermal Expansion (x 10-5 in./in./°F) -lengthwise -crosswise |
0.80 1.20 |
1.10 1.22 |
1.00 1.06 |
| - | Max Operating Temp (°F / °C) | 257 / 125 | 257 / 125 | 285 / 140 |
| C177 | Thermal Conductivity (BTU-in/ft²-hr-°F) (x 10-4 cal/cm-sec-°C) |
2.03 7.0 |
2.03 7.0 |
2.03 7.0 |
| UL94 | Flammability Rating | H-B | H-B | H-B |
| ELECTRICAL | ||||
| D149 | Dielectric Strength (V/mil) short time, 1/8" thick | 750(XX) | 550(CE) | 625(LE) |
| D150 | Dielectric Constant at 1 MHz | 5 | 5 | 6 |
| D150 | Dissipation Factor at 1 MHz | 0.045 | - | 0.045 |
| D495 | Arc Resistance (sec) | 110 | 15 | 15 |
NOTE: The information contained herein are typical values intended for reference and comparison purposes only. They should NOT be used as a basis for design specifications or quality control. Contact us for manufacturers' complete material property datasheets.
All values at 73°F (23°C) unless otherwise noted.
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