Polyester resin (more loosely referred to as ‘laminating resin’ or ‘fiberglass resin’) is a polymer. Simple to use and economical, it is a major component in many industries, from construction to aerospace. Offering incredible physical and chemical properties, it’s also comparatively cheap compared to other resins like epoxies and urethanes, yet it offers similar – if not superior – performance in many cases.

Polyester resins have high thermal and heat stability, low shrinkage and good mechanical strength when combined with glass fiber to create composite structures.

Types of polyester resins:

Four main types of polyester resins are available as vinyl ester, alkyd, saturated polyester and unsaturated polyester.

Unsaturated polyester resin is a thermoset resin amenable to curing from a viscous liquid to a solid under the correct conditions. Unsaturated polyester resins are known as ‘polyester resin’ and even ‘polyester’ for short.

Today, a wide range of polyester resins have been created from different acids, glycols and monomers, each having different properties and can be applied to everything from marine vessels to fiberglass flat roofs.