QUALITY ASSESSMENT AND ANALYSIS OF THE CAUSES OF COATING DEFECTS IN THE POWDER COATING PROCESS

This paper addresses the topic of quality assessment and defect analysis in powder coating processes applied to metal structures, particularly galvanized steel. Powder coating is a widely adopted surface finishing technique used to enhance the protection and aesthetics of metal products, especially in the construction and manufacturing sectors. The study focuses on evaluating the quality of paint coatings produced in the powder coating process and analyzing the causes of defects. Research was conducted on products from several powder coating plants across different regions, mainly manufacturing galvanized steel structures, including fencing systems. Quality assessment involved visual inspection, optical and scanning electron microscopy, chemical composition analysis, corrosion resistance testing, and adhesion tests. To determine defect causes, quality management tools such as the Ishikawa diagram and the 5 Whys method were applied. The results identified common imperfections like poor adhesion, surface contamination, and coating porosity. These were primarily linked to improper surface preparation and process control. Based on the findings, specific recommendations were proposed to reduce the occurrence of defects and improve the overall coating quality. The study contributes to enhancing process reliability and product durability in the powder coating industry.