GPO3 Fiberglass Polyester Sheet

GPO-3 / Fiberglass Polyester Composite Insulation Sheet

GPO-3 is a high-performance glass-fiber reinforced polyester composite insulation material, structurally optimized for electrical and mechanical applications under high humidity, high voltage, and arc-stress conditions. It is manufactured using a precision hot-pressing process to ensure consistent laminate density, rigidity, and long-term stability.

Products image

GPO-3 / Fiberglass Polyester Composite Insulation Sheet

Material Construction

Base substrate: Non-alkali glass fiber mat
Resin system: Unsaturated polyester resin matrix
Additives: Custom-formulated stabilizers and performance modifiers
Forming method: Hot-pressed under controlled temperature and pressure to form rigid laminated sheets

As a UL-recognized electrical insulation material, GPO-3 demonstrates excellent environmental stability, thermomechanical strength, flame retardancy, and arc resistance, making it especially suitable for low- and medium-voltage switchgear components.

Key Performance Advantages

Environmental Stability

GPO-3 maintains over 85% surface resistivity retention in 95% relative humidity environments, ensuring stable electrical performance even in tropical or high-moisture conditions.

Thermo-Mechanical Strength

The material retains high flexural strength at elevated temperatures, making it reliable under thermal stress caused by current interruption and short-circuit events.

Electrical & Safety Compliance

GPO-3 meets stringent international safety standards, offering excellent flame retardancy, arc resistance, and tracking resistance, significantly reducing fire and electrical erosion risks.

Product Details

Technical Performance Parameters

Property	Standard	Value
Surface Resistivity Retention (95% RH)	IEC 60093	≥ 85%
Flexural Strength @ 120 °C	ASTM D790	≥ 180 MPa
Flame Retardancy (3 mm)	UL 94	V-0
Arc Resistance	ASTM D495	≥ 180 seconds
Comparative Tracking Index (CTI)	IEC 60112	≥ 600 V
Dielectric Strength	—	> 20 kV/mm
Dielectric Loss (tan δ)	—	< 0.02
Heat Resistance (Long-term)	—	155–180 °C
Heat Resistance (Short-term)	—	≥ 200 °C
Smoke Toxicity	IEC 60707	Low smoke, non-toxic
Halogen Content	RoHS	Halogen-free (selected grades)

NEMA, IEC, Mil Spec Material Comparative Table
NEMA	IEC	Mil Spec	Resin	Substrate
NEMA G-10	EPGC 201, 21*	MIL-I-24768/2 GEE	Epoxy	Glass Cloth
NEMA FR4	EPGC 202, 23*	MIL-I-24768/27 GEE-F	Epoxy	Glass Cloth
NEMA G-11	EPGC 203, 22*	MIL-I-24768/3 GEB	Epoxy	Glass Cloth
NEMA FR5	EPGC 204	MIL-I-24768/28 GEB-F	Epoxy	Glass Cloth
—	EPGC 205	—	Epoxy	Glass Cloth
—	EPGC 306	—	Epoxy	Glass Cloth
—	EPGC 307	—	Epoxy	Glass Cloth
—	EPGC 308	—	Epoxy	Glass Cloth
—	EPGC 309	—	Epoxy	Glass Cloth
—	EPGC 310	—	Epoxy	Glass Cloth
—	EPGC 311	—	Epoxy	Glass Cloth
—	EPGM 203	—	Epoxy	Glass Mat
—	EPPC 301	—	Epoxy	Polyester Cloth
NEMA G-5	MFGC 201, 20*	MIL-I-24768/8 GMG	Melamine	Glass Cloth
NEMA G-9	MFGC 201	MIL-I-24768/1 GME	Melamine	Glass Cloth
NEMA C	PFCC 201, 23*	MIL-I-24768/16 PBM	Phenolic	Cotton Cloth
NEMA CE	PFCC 202, 22*	MIL-I-24768/14 FBG	Phenolic	Cotton Cloth
NEMA L	PFCC 203	MIL-I-24768/15 FBI	Phenolic	Cotton Cloth
NEMA LE	PFCC 204, 21, 24	MIL-I-24768/13 FBE	Phenolic	Cotton Cloth
NEMA X	PFCP 201, 21*	MIL-I-24768/12 PBM	Phenolic	Cellulosic Paper
NEMA XP	PFCP 201	MIL-I-24768/19 PBM-P	Phenolic	Cellulosic Paper
NEMA XXX	PFCP 204	MIL-I-24768/10 PBE	Phenolic	Cellulosic Paper
NEMA XX	PFCP 202, 23*	MIL-I-24768/11 PBG	Phenolic	Cellulosic Paper
NEMA XXP	PFCP 203	MIL-I-24768/21 PBG-P	Phenolic	Cellulosic Paper
NEMA XXXP	PFCP 204	MIL-I-24768/22 PBE-P	Phenolic	Cellulosic Paper
NEMA XPC	PFCP 207	MIL-I-24768/20 PBM-C	Phenolic	Cellulosic Paper
NEMA G-3	PFGC 201, 21*	MIL-I-24768/18 GPG	Phenolic	Glass Cloth
NEMA GPO-1	UPGM 201	MIL-I-24768/4	Polyester	Glass Mat
NEMA GPO-2	UPGM 202	MIL-I-24768/5	Polyester	Glass Mat
NEMA GPO-3	UPGM 203	MIL-I-24768/6	Polyester	Glass Mat
—	UPGM 205	—	Polyester	Glass Mat
—	PIGC 301	—	Polyimide	Glass Cloth
NEMA G-7	SIGC 201, 21*	MIL-I-24768/17 GSG	Silicone	Glass Cloth