Overview
FRP (fiberglass-reinforced polymer) insulating plates are structural composite panels that combine high mechanical strength with excellent electrical insulation. Made from glass-fiber reinforcement in an epoxy, polyester, or vinylester matrix, they are widely used as mounting plates, terminal boards, and structural insulators in switchgear, transformers, and electrical equipment where metal parts would conduct or corrode.
ORRO Manufacturing machines FRP plates to final dimensions with CNC routing, drilling, and edge finishing. Because the glass reinforcement is abrasive, we use diamond and carbide tooling with controlled feeds to deliver clean edges, accurate hole patterns, and sealed surfaces that resist moisture and tracking.
Material Properties
| Property | GFRP (Epoxy / Glass) |
|---|---|
| Density (g/cm³) | 1.80 - 2.00 |
| Tensile Strength (MPa) | 200 - 400 |
| Flexural Strength (MPa) | 200 - 400 |
| Compressive Strength (MPa) | 250 - 350 |
| Dielectric Strength (kV/mm) | 10 - 20 |
| Volume Resistivity (Ω·cm) | 10¹⁴ - 10¹⁵ |
| Thermal Conductivity (W/m·K) | 0.3 - 0.5 |
| Max Service Temperature (°C) | 130 - 155 |
Key Advantages
- Structural Strength Plus Insulation: Carries mechanical load while providing 10-20 kV/mm dielectric strength.
- Corrosion and Moisture Resistance: Unlike steel, FRP does not rust or degrade in humid or chemical environments.
- Low Thermal Conductivity: Reduces heat transfer between electrical and structural assemblies.
- Lightweight: Roughly 75% lighter than steel at comparable panel stiffness.
- Non-Magnetic: Suitable for applications sensitive to magnetic fields.
- Dimensionally Stable: Low water absorption and stable CTE keep hole patterns and clearances accurate.
Typical Applications
Switchgear and Control Panels
Mounting plates and barriers that isolate live busbars and terminals from enclosures.
Transformer and Motor Insulation
Structural insulating plates, spacers, and clamping boards in dry-type transformers and rotating machines.
Chemical and Marine Structures
Corrosion-resistant structural panels for chemical plants, desalination equipment, and marine platforms.
Machining Capabilities
| Parameter | Capability |
|---|---|
| Tolerance | ±0.1 mm (cut profiles), ±0.05 mm (drilled holes) |
| Surface Finish | Ra 3.2 μm (as-machined) |
| Plate Thickness | 1 mm to 50 mm |
| Key Processes | CNC routing, drilling, edge sealing, waterjet cutting |
Application Case
Switchgear mounting plate, GFRP — A switchgear builder required insulating plates with 40 precision holes for busbar mounting and a dielectric rating above 12 kV/mm. ORRO routed and drilled 15 mm-thick GFRP plates to a ±0.05 mm hole tolerance, sealed all cut edges, and delivered 900 plates in 12 days with dimensional and dielectric spot checks.
