If you're struggling to choose among various electrical insulation materials, this guide compares five commonly used laminated insulation sheets: 3240 epoxy sheet, FR4 Fiberglass Sheet, Bakelite Sheet, Phenolic Cotton Cloth Laminate, and Phenolic paper laminate, helping you quickly identify the most suitable material for your application.
Grade: 3240
Full Name: Epoxy Glass Cloth Laminated Sheet
Color: Typically yellow or aqua green; black and other colors are also available
Standard Sizes: 1000 mm × 2000 mm, 1220 mm × 2440 mm, etc.
Thickness Range: 0.5 mm – 100 mm
Manufactured from woven glass fabric impregnated with epoxy resin under heat and pressure. 3240 epoxy sheet offers excellent electrical insulation properties, high mechanical strength, good chemical resistance, and stable dimensional performance. It belongs to Thermal Class F insulation (155°C) and maintains reliable mechanical properties under elevated temperature conditions.
3240 epoxy sheet is widely used for electrical insulation structural components, transformers and transformer oil environments, electrical motors and generators, switchgear and distribution cabinets, PCB drilling backup boards, mold clamping plates, and various industrial insulation parts.
Grade: G10 / EPGC201
Full Name: High Pressure Epoxy Glass Cloth Laminated Sheet
Color: Yellow, green, black, etc.
Standard Sizes: 1220 mm × 2440 mm, 1000 mm × 2000 mm, etc.
Thickness Range: 0.1 mm – 100 mm
G10 is an international standard epoxy glass cloth laminate defined under IEC/EN systems, corresponding to EPGC201. It is produced from continuous glass fiber cloth impregnated with epoxy resin under high pressure.
G10 offers:
High mechanical strength
Excellent electrical insulation performance
Good moisture resistance
Stable performance under humidity and temperature variations
Good dimensional stability
Compared with general 3240 epoxy sheet, G10 is more strictly standardized in international markets and is widely used in export-oriented industrial applications.
Typical applications include electrical insulation structural parts, PCB support plates, electrical equipment insulation components, mechanical fixtures, aerospace and marine insulation parts, and precision industrial assemblies.
Grade: FR4, EPGC202
Full Name: Flame-Retardant Epoxy Glass Fiber Laminated Sheet
Color: Yellow, green, black, and customized colors
Standard Sizes: 1220 mm × 2440 mm, 1000 mm × 2000 mm, etc.
Thickness Range: 0.1 mm – 50 mm
FR4 Fiberglass Sheet is produced from glass fiber fabric reinforced with epoxy resin. It features excellent mechanical strength, superior dielectric properties, good heat resistance, excellent moisture resistance, and flame-retardant performance. It is also classified as Thermal Class B insulation (130°C), maintaining high mechanical strength even at temperatures near 130°C.
FR4 Fiberglass Sheet is commonly used in printed circuit boards, multilayer PCB substrates, electrical and electronic insulation components, FPC reinforcement plates, wave solder pallets, high-temperature insulation fixtures, and electrical equipment and motors.
Grade: 3722, 3723, 3724, 3725, etc.
NEMA Standard: C, CE, L, LE
IEC Standard: PFCC201, PFCC202, PFCC203, PFCC204, PFCC305.
Full Name: Phenolic Cotton Fabric Laminated Sheet
Color: Reddish brown or black
Standard Sizes: 1000 mm × 2000 mm, 1220 mm × 2440 mm, etc.
Thickness Range: 1 mm – 50 mm
Phenolic Cotton Cloth Laminate is made by impregnating cotton fabric with phenolic resin under pressure and heat. It offers good electrical insulation performance, high mechanical strength, excellent toughness, good wear resistance, and good machinability, with relatively strong impact resistance compared to Phenolic paper laminate.
It is commonly used in electrical insulation structural parts, switches and switchgear components, terminal boards, wear-resistant mechanical parts, gears, bearing retainers, and motor insulation systems.
Grade: PFCP201, PFCP202, PFCP203, PFCP206, etc.
Full Name: Phenolic paper laminated Sheet
Color: Orange-red or black
Standard Sizes: 1000 mm × 2000 mm, 1220 mm × 2440 mm, etc.
Thickness Range: 1 mm – 50 mm
Bakelite sheet is manufactured from insulating paper impregnated with phenolic resin. It provides good mechanical strength, reliable electrical insulation, good heat resistance, and a hard wear-resistant surface with excellent machinability and scratch resistance.
It is widely used in electrical insulation components, transformer insulation parts, PCB drilling backup boards, distribution boxes, switchgear, mold fixtures, tooling plates, and general electrical and mechanical equipment applications.
Grade: X, XX, XXX, XP, PFCP201, PFCP202, PFCP203, etc.
Full Name: Phenolic paper laminated Sheet
Color: Brown, orange-red, or black
Standard Sizes: 1000 mm × 2000 mm, 1220 mm × 2440 mm, etc.
Thickness Range: 0.5 mm – 50 mm
Phenolic paper laminate is produced from insulating paper impregnated with phenolic resin. It provides good electrical insulation, smooth surface finish, easy machinability, cost efficiency, and stable dielectric performance, with moderate mechanical strength.
It is widely used in electrical insulation parts, low-voltage electrical equipment, switches and sockets, terminal boards, instrument panels, insulation spacers, washers, and general industrial insulation applications.
|
Material |
Base Material |
Temperature Resistance |
Main Advantage |
|
3240 epoxy sheet |
Glass Cloth + Epoxy Phenolic Resin |
Class F (155°C) |
Excellent overall performance |
|
G10 Fiberglass Sheet |
Glass Cloth + Epoxy Resin |
Class B (130°C) |
Excellent in mechanical and electrical Moisture resistance |
|
FR4 Fiberglass Sheet |
Glass Fiber + Epoxy Resin |
Class B (130°C) |
Flame retardant and moisture resistant |
|
Bakelite Sheet |
Insulating Paper + Phenolic Resin |
Class E (120°C) |
Cost-effective and easy machining |
|
Phenolic Cotton Cloth Laminate |
Cotton Fabric + Phenolic Resin |
Class E (120°C) |
Excellent toughness and machinability |
|
Phenolic paper laminate |
Insulating Paper + Phenolic Resin |
Class E (120°C) |
Economical insulation solution |
YILONG specializes in insulation materials and CNC-machined insulation parts, including epoxy glass sheets, FR4 laminates, G10/G11 materials, phenolic laminates, and customized machined components. With stable quality control, precision machining capability, and export experience, YILONG provides reliable insulation solutions for electrical, electronic, mechanical, and industrial applications worldwide. Please contact us for more information.
WhatsApp: 86 15866869385
If you're struggling to choose among various electrical insulation materials, this guide compares five commonly used laminated insulation sheets: 3240 epoxy sheet, FR4 Fiberglass Sheet, Bakelite Sheet, Phenolic Cotton Cloth Laminate, and Phenolic paper laminate, helping you quickly identify the most suitable material for your application.
Is your microwave oven suddenly failing to work? Are high-temperature industrial machines experiencing frequent breakdowns? In many cases, the problem may be traced back to a critical component—the mica board.
In today’s electronic era, electronic products are deeply integrated into our daily lives and are evolving at a rapid pace. It is difficult to imagine modern life without them. Epoxy glass sheets are a key insulating material widely used in electronic products. There are many types, including FR-4 Epoxy Glass Sheet, 3240 Epoxy Sheet, G11 Epoxy Glass Sheet, and G10 Epoxy Glass Sheet, each designed to meet different application requirements. Among them, G11 Epoxy Glass Sheet is considered one of the higher-performance materials, and it is important to understand its characteristics before use.
YILONG provides high-quality epoxy glass laminates widely used as engineering insulation materials. Among them, G10 Epoxy Glass Sheet and G11 are two commonly referenced grades in electrical and industrial applications. Although they share similar base structures, their performance and working environments differ due to material composition and manufacturing variations.
Material selection in engineering and manufacturing plays an important role in product performance and service life. Epoxy glass sheets have become a preferred material in many applications due to their excellent electrical insulation and mechanical properties. In particular, the G10 Epoxy Glass Sheet stands out in high-performance applications thanks to its outstanding durability and reliability.
Phenolic Cotton Laminate is a widely used thermoset composite material manufactured by impregnating cotton fabric with phenolic resin and curing under controlled heat and pressure. It is designed to deliver reliable mechanical strength, electrical insulation performance, and machining stability for industrial environments requiring durable structural materials.
Phenolic Cotton Board (also known as phenolic cotton laminate in sheet and rod forms) is a widely used engineering material valued for its balanced mechanical strength, electrical insulation, and thermal stability. Below is a structured and professional overview of its key properties and applications.
NEMA LE Phenolic Cotton Laminate is a high-performance thermoset insulation material manufactured from fine linen or cotton fabric reinforced with phenolic resin under controlled heat and pressure. It is designed to provide improved electrical properties, stable mechanical strength, and excellent machinability for precision industrial applications.
NEMA L Cotton Phenolic Board is a widely used thermoset laminate designed for electrical insulation and structural support in industrial environments. It is manufactured from multiple layers of cotton fabric impregnated with phenolic resin under high pressure and temperature, forming a dense composite material with stable mechanical and electrical properties.
In industrial manufacturing, engineers and procurement teams often face recurring challenges when selecting structural and machining-grade insulation materials. Common issues include unstable machining performance, edge cracking during processing, excessive tool wear, and inconsistent dimensional tolerance after fabrication.
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