Glass Polyester Overview

Glass polyester is a laminate composite often used for electrical insulation. It’s available in multiple shapes, including rods, tubes and sheets, all of which come in a range of thicknesses and sizes. Glass-reinforced composite is made from cost-effective polyester and glass. Due to the polyester resin and the glass strand orientation, the material has outstanding track resistance, good mechanical strength, and low conductivity. Atlas Fibre has expertise with a wide range of thermoset composite materials. We can help you determine which material will best meet your project needs.

What Is Glass-Reinforced Polyester?

Glass-reinforced polyester, or thermoset polyester glass, is a type of material similar to phenolic composites. It’s made from fiberglass-reinforced polyester, which provides various mechanical and insulative benefits.

Among the benefits of glass polyester are:

  • Low flame spread
  • Low smoke generation
  • Self-extinguishing
  • Good track resistance
  • Low conductivity
  • Good mechanical strength
  • Good stability
  • High impact and flex strength
  • Arc resistance

Types of Glass Fiber Reinforced Polyester Resin

Several types of glass polyester are available.


GPO-1 is the most general-purpose type of glass polyester. It’s suitable for applications that require good electrical properties and physical strength but only moderate heat resistance. GPO-1 Is the most cost-effective option.


GPO-2 also has good electrical properties, heat resistance, and physical properties. It’s ideal for projects that require flame or arc resistance.


GPO-3 is highly flame-resistant and self-extinguishing. Of the three types of glass polyester, it has the best arc and track resistance. This material is often used to make electrical components.

GPO-3 is also chemical, abrasion, and impact-resistant.

Glass Polyester Shapes

GPO-1, GPO-2, and GPO-3 are available in several shapes, including sheets, tubes, rods, and extruded profiles, such as channels, square tubes, and angles. Each shape has specific uses and benefits based on a project’s requirements. As your resource center, Atlas Fibre can help you select the right shape and size of glass polyester.

  • Sheets: Glass polyester sheets come in a range of thicknesses and dimensions, including custom measurements.
  • Tubes: Glass polyester tubes are also available in several diameters and lengths.
  • Extruded profiles: Extruded profiles are used for specific shapes where you can save money versus carving from a block.
  • Rods: Like tubes, solid glass polyester rods come in various thicknesses and lengths.

Regardless of the shape you require, our experts can help you choose the correct diameter and size for your project.

Uses for Glass Polyester Laminate

The applications for glass polyester depend on the type of material.

GPO-1, the most economical option, is ideal for applications that require some degree of heat resistance but not flame resistance. It’s suitable for electrical insulating components, such as:

  • Mounting panels
  • Barriers
  • Collars
  • Wedges
  • Brush holders
  • Dry-type transformers
  • Large switches


GPO-3 is the more advanced material. It offers superior arc, track and flame resistance to GPO-1 and GPO-2. It’s often the material of choice for transit applications and switchgear panels. It also performs well in:

  • High-voltage appliance insulation
  • Power distribution
  • Switchgear mounting panels and barriers

Get a Quote for Glass Reinforced Polyester

If you need a thermoset composite material that is heat, flame and arc resistant, glass polyester may be right for you. We can help you choose the best material for your unique project needs. Contact us today for a quote.

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