GPO-3 Fiberglass-Reinforced Polyester

Despite its high similarity to phenolic materials, GPO-3 contains fiberglass and a polyester resin instead of a phenolic resin, making it a more cost-effective choice for many applications. GPO-3 is stiff, strong, impact-resistant, and dimensionally stable. Electrical insulation manufacturers prefer GPO-3 because of its exceptional flame, track, and arc resistance.

Of the three types of glass polyester — GPO-1, GPO-2, and GPO-3 — GPO-3 has better electrical properties and can withstand higher temperatures. GPO-3 is recognized by the National Electrical Manufacturers Association (NEMA) and complies with MIL-I-24768/6 standards.

GPO-3 Material Properties and Composition

GPO-3 glass polyester is ideal for applications requiring high arc and carbon-track resistance with low flammability properties. Its versatility makes it a practical choice for projects needing enhanced electric properties, sufficient physical strength, and moderate heat resistance. One of the few disadvantages of GPO-3 is that it can sometimes suffer slight cracking or brittleness because of its excellent strength and hardness.

GPO-3 glass polyester’s primary composition properties include the following:

  • Specific gravity: 1.81
  • Tensile strength: 8,000 pounds per square inch (psi)
  • Flexural strength: 22,100 psi
  • Shear strength: 11,600 psi
  • Hardness (Barcol Scale): 62
  • Flammability rating: V-0
  • Maximum operating temperature: 160 degrees Celsius (320 degrees Fahrenheit)
  • Izod impact strength (notched): 8.9 foot-pounds per inch
  • Water absorption over 24 hours: 0.2
  • Coefficient of thermal expansion in degrees Celsius (x10-5): 2.0

Types of GPO-3 Materials We Offer

At Atlas Fibre, we supply GPO-3 glass polyester in various forms, including sheets, rods, tubes, and extruded profiles like squares, channels, and angles. Extruded profiles provide significant cost savings over creating unique contours from a solid block. We stock sheets in an extensive range of colors, sizes, and thicknesses.

Our in-stock selection of ready-to-ship materials enables us to offer some of the industry’s fastest delivery times. Our experts can help you choose the shapes and sizes you need based on your unique project. Atlas Fibre also offers customization capabilities to meet the requirements of specialized jobs.

GPO-3 Applications

GPO-3 is the most advanced glass polyester thermoset. Other primary advantages of GPO-3 include satisfactory machinability, superior abrasion resistance, low smoke generation, and resistance to harsh chemicals. In addition to electrical insulation, GPO-3 is ideal for transit and switchgear applications.

Several examples of specific applications and uses include:

  • Power distribution.
  • High-voltage appliance insulation.
  • Switchgear mounting panels and barriers.
  • Bus bars and insulating supports.
  • Structural electrical components.

Find Out More About GPO-3 With Atlas Fibre

If your project requires a thermoset material with superior arc, heat, and flame resistance, GPO-3 glass polyester could be the perfect option. Our knowledgeable team has decades of experience helping businesses choose the most practical, cost-effective, and highest-performing materials that align with their specific needs. Regardless of the material you choose, we have a comprehensive selection of sheets, tubes, and rods ready to ship from multiple locations.

To obtain a price quote or request additional technical information, contact us online or call 847-565-1996 today.

*Atlas Fibre LLC provides this data as information only and does not imply any warranty for its use or application. Test results for a specific sheet or lot are available for a fee upon request.