Resin Matrices used in Pultrusion

Two major families of resin matrices--thermosets and thermoplastics
Predominately thermosets in pultrusion--bulk of which is polyester
Choice of resin will determine:

Degree of corrosion resistance.
Upper operating temperature limit.
Performance in fatigue.
Mechanical properties.

Reinforcements primarily determine the stiffness, strength and electrical properties.
Fillers are added to improve flame retardancy, processability, surface finish and reduce cost.

Thermoset Resin Matrices used in Pultrusion

Polyester Vinyl ester Epoxy

Polyester resins are most versatile in their ease of processing, blendability, and low cost.  Vinyl ester resins have improved chemical resistance and laminate mechanical properties.  Epoxies resins generally yield better high temperature and shear properties, but processing is more difficult and resultant line speeds are slower.