Phenolics and High-Pressure Laminates

Phenolics and high-pressure laminates such as Micarta, Texolite, and Bakelite are hard, dense materials made by applying heat and pressure to a series of layered materials, such as paper or fabric, and then impregnating them with a synthetic resin. These materials are extremely versatile because of their unusual combination of properties. All grades are lightweight (about half that of aluminum), structurally strong, and moisture-resistant. High-pressure laminates do not soften appreciably under reapplication of heat, and their high dielectric strength and strength in thin sections make them easy to punch and shear. Because no one grade can suit all applications, a variety of grades are available.

phenolic resins were used to impregnate paper and cotton fabric which were cured under pressure and high temperature to produce laminates.Common uses of modern high pressure laminates are as electrical insulators, printed circuit board substrates, and knife handles.

HPL is the direct descendent of the original plastic laminate. It is considered to be one of the most durable decorative surface materials and is available with special performance properties including chemical, fire and wear resistance. Special grades of HPL can be postformed around curved edges by application of heat and restraint.

HPL is produced by saturating multiple layers of kraft paper with phenolic resin. A layer of printed decor paper is pieced on top of the kraft paper before pressing. The restulting sandwich is fused together under heat and pressure (more than 1,000 PSI). Because phenolic and melamine resins are thermoset plastics, the curing process transforms the resin into plastic by a cross linking process that converts the paper sheets into a single, rigid laminated sheet. Thermosetting creates strong, irreversible bonds that contribute to HPL's durability.

HPL is laminated to a panel utilizing a variety of adhesives. Particleboard or MDF are the preferred substrate because they provides stable, durable, consistent and economical foundation.

 Due to its durabiity, HPL is a common choice for horizontal surfaces including Rooting, countertops and desktops. It also performs well in horizontal and vertical applications for high traffic settings such as hospitality, office furniture, healthcare, retail casework, commercial interiors and educational facilities.

A relatively new development in HPL technology is Double Belt Press (DBP) for the production of Continuous Pressed Laminate (CPL). CPL is decorative paper impregnated with resins and fused under heat and high pressure with resin-impregnated backer(s). Laminate properties are similar to standard HPL and typical thickness range is .4 mm to 1 mm. CPL is available in desired sheet lengths or continuous rolls. Flexible CPL is decorative paper impregnated with flexible thermosetting resins and fused under heat and high pressure with resin-impregnated backer(s). This engineered CPL offers a unique range of formable decorative laminates suitable for profile wrapping and edgebanding applications. Common thickness range is .2 mm through .4 mm. Surface properties are similar to vertical grade HPL and are used significantly to complement HPL and TFM laminates.

Key Properties

Excellent dielectric strength

Easy to punch and shear

High impact and tensile strength

Extremely versatile

High dimensional stability

Standard Shapes and Forms

Sheet: .010” – 4” thick

Rod: .062” – 6” (made from sheet) & .187” – 4.” (molded rod)

Tubular Bar: .094” – 48” ID

Wall thickness: .031” – 5”

Other Forms: GPO polyester laminated sheet, Copper clad sheet, Vulcanized fiber sheet, Glass polyester structural shapes

Color: Phenolic Grades: Natural (tan/brown) and black

The range of sizes and shapes are grade specific, order minimums may apply.

Grades

XX

PlasticsProduct_PhenolicXX

Phenolic XX (NEMA XX) is a paper based phenolic that is a machining grade with less robust electrical properties than those of Phenolic XXX (Phenolic XXX - not stocked, but can be special ordered). Designed for electrical insulation, the product can be used in dry or high humidity conditions. Applications include barriers, breaker arms, switch panel boards, and relay and switch bases.

Current Spec: Mil-I-24768/11 Type PBG

(LP 509, MIL P 3115, Type PBE)

XXX

Current Spec: Mil-I-24768/10 Type PBE

(LP 509, MIL 3115, Type PBE)

Grade XXX has similar mechanical properties as Grade XX but is considerably better electrically because of its high resin content. This material is ideal for use at radio frequencies and under very humid conditions.

C

Phenolic C consists of a cotton canvas fabric and general-purpose phenolic resin. The product is easy to machine and operates with less noise than metal. In addition, this material is not as abrasive as fiberglass alternatives when used in wear applications. The material is commonly used to make gears, pulleys, rollers, and guides.

Current Spec: Mil-I-24768/16 Type FBM

(LP 509, MIL P 15035, Type FBM)

CE

PHENOLIC CE (Canvas Electric)

Phenolic CE (NEMA CE) consists of a cotton canvas type fabric and electrically insulating phenolic resin system. Phenolic CE is easy to machine and operates with less noise than metal. In addition, this material is not as abrasive as fiberglass alternatives when used in wear applications. This material is commonly used to make gears, pulleys, rollers, and guides, as well as electrically insulated parts such as control boards.

Current Spec: Mil-I-24768/14 Type FBG

(LP 509, MIL P 15035, Type FBG)

L

Current Spec: Mil-I-24768/15

(LP 509, MIL P 15035, Type FBI)

Grade L is a fine-weave cotton cloth reinforced with a phenolic binder. Weighing not more than 4 ounces per square yard, Grade L is recommended for fine punchings or threading or for close-tolerance machining.

LE

PHENOLIC LE (Linen)

Phenolic LE (NEMA LE) is used where better machining is needed compared to that offered by canvas grades . This product consists of a fine-weave linen fabric and electrical grade of phenolic resin. Suitable for smaller and more intricate shapes than those made with Phenolic C, this product is commonly used to make gears, pulleys, rollers, and guides, as well as electrical insulating parts.

Current Spec: Mil-I-24768/13 Type FBE

(LP 509, MIL P 15035, Type FBE)

Grade LE is similar to Grade L but with better moisture resistance and increased dimensional stability. It is also acid-resistant. Grade LE is recommended for fabricated parts that need smooth edges and good mechanical strength.

N-1

Current Spec: Mil-I-24768/9 Type NPG

(LP-509, MIL P 15047, Type NPG)

Grade N-1 is a staple-fiber nylon-fabric impregnated with a phenolic resin. It has good electrical properties and mechanical toughness, and it is very humidity-resistant. Grade N-1 is excellent for high-voltage electrical insulators requiring low dielectric loss, high insulation resistance, and fungus resistance.

G-9 (G-5)

Current Spec: Mil-I-24768/1 Type GME

(LP 509, MIL P 15037, Type GMG)

Grade G-9 (also known as Grade G-5) is a continuous-filament, woven-glass fabric reinforced with melamine resin. It has excellent strength under wet conditions and is ideal for applications requiring arc and flame resistance. It retains its shape and size and works well in wet environments.

G-7

PHENOLIC G-7 (Glass Silicone)

A continuous glass fabric laminated with a silicone resin. Grade G-7 is unequalled for high heat and arc resistance applications, and where good mechanical and electrical properties must be exhibited in humid conditions in excess of 500°F.

Current Spec: Mil-I-24768/17 Type GSC

(LP 509, MIL P 997, Type GSG)

G-10 & FR-4

PHENOLIC G-10 / FR4 (Glass Epoxy)

G-10 / FR4 is a continuous-filament, woven glass fabric laminated with an epoxy resin. This grade is extremely high in mechanical strength, has low water absorption and dissipation factors and has superior electrical characteristics, which are exhibited over a wide range of temperatures and humidity. Grade G-10 is used for terminal boards, washers, sleeves, structural components, and parts where the strength to size ratio is critical.

Current Spec G-10 Mil-I-24768/2 Type GEE

Current Spec FR-4 Mil-I-24768/27 Type GEE-F

(LP 509, MIL P 18177, Type GEE)

G-11

PHENOLIC G-11 (High Temp Glass Epoxy)

Phenolic G-11 is a grade similar in composition and properties to Grade G-10 but more suitable for continuous use at elevated temperature. G-11 retains at least 50% of its structural strength at continuous operating temperatures in excess of 300°F. Due to its high cost, G-11 applications are limited to only the most critical high heat situations.

Current Spec: Mil-I-24768/3 Type GEB

(LP 509, MIL P 18177, Type GEB)

Phenolics and High-Pressure Laminates Pictures