In the field of electrical insulation materials, the choice of laminated sheet can directly determine the performance, durability, and safety of electrical equipment. Among the most widely used insulation boards are 3240 epoxy sheet, FR4 epoxy glass sheet, and G10 laminated sheet.
Although they are all made from epoxy resin reinforced with fiberglass cloth, their properties, standards, and applications differ significantly. In this article, we will compare 3240 epoxy sheet vs FR4 vs G10, helping you decide which material is best for your transformers, motors, PCB boards, or other electrical equipment.
3240 epoxy laminated sheet (also called epoxy glass cloth laminated sheet 3240) is produced by impregnating alkali-free glass cloth with epoxy resin and pressing it under heat and pressure.
Key Features of 3240 Epoxy Sheet:
► Excellent mechanical strength and toughness
► High electrical insulation and dielectric performance
► Good heat resistance (suitable for Class B insulation systems)
► Stable dimensions and easy to machine (cutting, drilling, milling)
Applications of 3240 Epoxy Laminated Sheet:
► Insulation components in dry-type transformers
► Structural parts in electric motors and switchgear
► Mechanical support plates in electrical control systems
FR4 is the industry standard for flame-retardant epoxy glass laminated sheet, widely recognized for its UL94 V-0 flame resistance.
Key Features of FR4 Epoxy Glass Sheet:
► Flame retardant and safe for high-voltage and electronic applications
► High mechanical and electrical strength
► Excellent moisture resistance
► Stable at a wide range of temperatures
Applications of FR4 Sheet:
► Printed circuit boards (PCBs) for electronics
► Electrical insulation in high-frequency devices
► Applications where fire safety and insulation reliability are critical
G10 laminated sheet is similar to FR4 but does not contain flame-retardant additives. It is valued for its strength, moisture resistance, and stability.
Key Features of G10 Epoxy Laminated Sheet:
► High mechanical strength and durability
► Excellent dielectric properties
► Strong moisture resistance compared to other epoxy sheets
Applications of G10 Epoxy Sheet:
► Structural and insulation parts in motors and transformers
► Aerospace, marine, and defense industries
► Components where flame resistance is not mandatory but strength is essential
Comparison: 3240 Epoxy Sheet vs FR4 vs G10
| Property / Material | 3240 Epoxy Sheet | FR4 Epoxy Sheet | G10 Epoxy Sheet |
|---|---|---|---|
| Resin Type | Epoxy resin + glass cloth | Epoxy resin + glass cloth | Epoxy resin + glass cloth |
| Flame Retardancy | Non flame-retardant | Flame retardant (UL94 V-0) | Non flame-retardant |
| Mechanical Strength | High | High | High |
| Electrical Insulation | Excellent | Excellent | Excellent |
| Moisture Resistance | Good | Excellent | Excellent |
| Main Applications | Transformers, motors, switchgear | PCBs, electronics, fire-sensitive parts | Motors, aerospace, marine |
| Cost Level | Medium-low | Higher (due to flame retardant) | Medium |
Choose 3240 Epoxy Sheet if you need cost-effective electrical insulation with high mechanical strength for transformers, switchgear, or motors.
Choose FR4 Sheet if your project requires flame retardancy and PCB compatibility in electronics or high-safety devices.
Choose G10 Sheet if your application needs excellent moisture resistance and strength in marine or aerospace industries.
When comparing 3240 epoxy sheet vs FR4 vs G10, the right choice depends on your application, safety requirements, and budget:
► 3240 epoxy laminated sheet → best for electrical insulation in transformers and motors
► FR4 laminated board → best for PCBs and flame-retardant applications
► G10 sheet → best for aerospace, marine, and structural parts without flame resistance requirements
At XuJue, we are a leading manufacturer and supplier of 3240 epoxy sheet, FR4 epoxy glass sheet, and G10 laminated insulation board. Our products are IEC and RoHS compliant, with thicknesses ranging from 0.5mm to 50mm and custom sizes available.
Contact us today to get a quote for 3240 epoxy laminated sheet wholesale, or consult our engineers for technical support on selecting the right insulation material for your project.
