Advanced Infrared Drying of Industrial Coatings: Process Optimization and Evaluation of Protective Properties

The tendency of metals to corrode is a major challenge regarding economic costs, safety, and the durability of various structures. Organic coatings represent the most widely used technology for metallic protection and are subject to continuous research to achieve superior anti-corrosive properties and extended service life. Concurrently, there is a growing industrial demand for more efficient curing methods that do not negatively affect coating performance. One such method is infrared (IR) drying, which reduces curing time and increases production rates.
This study evaluates infrared (IR) drying against conventional atmospheric drying. Three-layer coating systems consisting of an epoxy primer, an epoxy intermediate coat, and a polyurethane topcoat were applied to carbon steel samples. The coatings were cured using either catalytic IR emitters or standard atmospheric conditions. A comprehensive comparison of their physical, mechanical, and electrochemical properties was conducted. The corrosion protection performance was characterized using salt spray chamber exposure, pull-off adhesion testing, hardness measurements, electrochemical impedance spectroscopy (EIS), and open-circuit potential (OCP) monitoring. Furthermore, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) was utilized for detailed microstructural and chemical composition analysis, while abrasion and erosion tests evaluated the coatings' mechanical resistance. The results demonstrated that infrared technology significantly reduces drying times while maintaining the protective performance compared to conventionally cured coatings.