How to choose epoxy equivalent weight for a coating system

Epoxy equivalent weight (EEW) describes how much resin is needed per epoxy group. A low EEW means more reactive groups per unit weight, so a denser crosslinked network forms after curing.

Low-molecular solid resins (EEW roughly 450-500 g/eq) are typically chosen for solvent-based anti-corrosion primers, prepreg laminating and electrical insulation, where crosslink density and substrate adhesion matter most.

Mid and high molecular weight grades (EEW around 700-2000 g/eq) give longer flow, better flexibility and improved compatibility in powder coatings and can interior lacquers. Tell us the curing agent and the required film flexibility, and we can narrow the choice to one or two grades.