Urethane cured polyester powder coating
Urethane cured polyester powder coating has excellent resistance to outdoor environments, toughness and very good appearance characteristics at 1 to 2 mil film thickness.A smooth, thin film that resists weathering and physical abuse makes the urethane polyesters a popular finish for high quality products.
It is common to block the crosslinker in urethane polyesters with ecaprolactam.To begin the cross linking process, the material must reach a temperature above the blocking agent threshold. With e-caprolactam, unblocking occurs at approximately 360 °F (182 °C). Therefore, temperatures must be higher than 360 °F to start the melt phase of the cure cycle.
Powders containing e-cap are usually sensitive to films thicker than 3 mils. Thicker films with these urethane may lose some of their mechanical properties and they may exhibit outgassing effects due to ecaprolactam evolution.
They are used for exterior applications such as patio furniture, automotive wheels and trim, lawnmowers and a wide range of other products requiring high quality, decorative finishes comparable to wet coatings.