Microwave curing of multi-layer coatings

摘要

A method for providing a coated strip, which includes the steps of providing a metal or metal alloy strip, applying one or more coating layers on the metal or metal alloy strip and irradiating one or more of the applied coating layers with electromagnetic radiation, wherein one or more of the applied coating layers includes dielectric particles capable of absorbing microwave radiation and wherein microwave radiation is used to selectively heat one or more of the coating layers containing the dielectric particles to dry and/or cure and/or sinter the coating layer.

主权项

1. A method for providing a coated strip, which comprises the steps of providing a metal or metal alloy strip
applying two or more coating layers on the metal or metal alloy strip by coil coating, and irradiating one or more of the applied coating layers with electromagnetic microwave radiation, wherein each said one or more of the applied coating layers being irradiated comprises at least 1 wt % of dielectric particles capable of absorbing the microwave radiation and wherein the microwave radiation has a fixed microwave frequency between 0.9 GHz and 7.0 GHz to selectively heat at least the second coating layer of the coating layers containing the dielectric particles to cure and/or sinter the second coating layer, wherein a first said coating layer applied adjacent to the metal or metal alloy strip is dried and/or cured in a convection oven or by using infrared, near infrared or ultraviolet radiation and a second coating layer applied on the dried and/or cured first coating layer is cured or sintered by the irradiating using the microwave radiation without substantially heating the first coating layer.