When designing insulation structures for high and low voltage electrical appliances, power equipment, motors, transformers and industrial control devices, 3240 Insulation Sheet, FR4 Insulation Sheet and GPO-3 Insulation Sheet are the three most widely used laminated insulating materials. Nevertheless, many engineers get confused during material selection: what are the essential differences among 3240, FR4 and GPO-3? Which material is more reliable and cost-effective under specific working conditions?
With over 30 years of R&D and manufacturing experience in insulating materials, YILONG will distinguish these Insulation Sheets from three dimensions including material essence, core performance and application scenarios, helping you avoid improper material selection and realize rational design.
Comparison of Material Essence
3240 Insulation Sheet
It complies with Chinese national standard GB/T 1303.1, without mandatory flame retardant requirements (generally non-flame retardant or low flame retardant grade). It features Class B temperature resistance of 155℃, is mostly yellow in color, contains halogen and boasts low cost.
FR4 Insulation Sheet
It carries UL94 V-0 flame retardant rating with self-extinguishing property. Its temperature resistance ranges from 130℃ to 155℃ depending on formulas, and it is generally water green. It achieves better environmental performance (certain halogen-free grades available), superior dimensional stability and electrical properties.
GPO-3 Insulation Sheet
Also known as GPO-3 laminated sheet or UPGM-203, it is a rigid flame-retardant insulating plate manufactured by hot pressing non-alkali glass fiber mat impregnated with unsaturated polyester resin paste and additives. Its thickness ranges from 0.8mm to 100mm, mainly white and reddish brown in color. This material obtains UL certified V-0 flame retardant grade, and some variants are halogen-free.
Core Performance Comparison
Electrical Properties
3240 : Excellent power frequency insulation performance at low cost, mediocre arc resistance and no flame retardancy.
FR4 : High dielectric strength, stable insulation under humid-heat environment and low high-frequency loss, medium arc resistance.
GPO-3 : Ultra-strong arc resistance (over 180 seconds), optimal arc extinguishing and arc isolating capacity, ideal for switchgear.
Mechanical Properties & Dimensional Stability
3240 : Sufficient mechanical strength, easy machining and outstanding cost performance.
FR4 : High strength, great rigidity, high dimensional precision and low deformation tendency.
GPO-3: Good toughness, crack-free processing, prominent advantages for thick plate machining with slightly lower mechanical strength.
Heat Resistance & Flame Retardancy
3240 : Class B heat resistance (130℃), non-flame retardant and combustible under open flame.
FR4 : Class F heat resistance (155℃), UL94 V-0 flame retardant with excellent self-extinguishing performance.
GPO-3 : Class B heat resistance (130℃), UL94 V-0 flame retardant for reliable safety.
Environmental Adaptability
3240 : Oil resistant and moisture resistant, suitable for general electrical working environments.
FR4 : Resistant to humid heat and chemical corrosion, the preferred option for harsh environments.
GPO-3 : Arc and tracking resistant, applicable to scenarios with arc and discharge risks.
Application Comparison
3240 : General-purpose, Economical, No Flame Retardant Requirements
Applicable scenarios: General motors, transformers, low-voltage switch cabinets, ordinary insulating gaskets, tooling fixtures and cost-sensitive projects.
FR4 : High-end, Flame Retardant, High Precision
Applicable scenarios: PCB substrates, high-frequency electronic insulation, new energy battery separators, high-voltage motor slot wedges, rail transit insulation parts and high-temperature & high-humidity environments.
GPO-3 : Arc Resistant, Arc Extinguishing, Special for Switchgear
Applicable scenarios: Phase separation plates for high and low voltage switch cabinets, arc extinguishing covers, circuit breaker insulation components, busbar supports, carbon brush holders and insulating structures with discharge risks.
YILONG provides complete series of 3240, FR4 and GPO-3 Insulation Sheet for high voltage equipment, supporting custom cutting, precision machining and free material performance comparison for engineering design. If you need sample supply, technical specification sheets or bulk order quotations, please feel free to contact us:
Email: yilong@yilonginsulation.com
Website: www.yilonginsulation.com
Mob/Whatsapp: +8615866869385
With over 30 years of R&D and manufacturing experience in insulating materials, YILONG will distinguish these Insulation Sheets from three dimensions including material essence, co
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We have shared full knowledge about GPO-3 insulation board in previous articles from YILONG. This article will focus on a widely concerned topic: simple identification methods to distinguish qualified finished GPO-3 insulation boards from inferior ones. Let’s take a closer look.
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