Comparison of different abrasion mechanisms on aesthetic properties of organic coatings

Organic coatings are the most commonly used system for protection from corrosion. In many applications, the protective properties against corrosion are associated with several other properties, including resistance to abrasion and good aesthetic appearance. This is particularly important for the automotive and transport industry, building trade, domestic products and packaging. The aim of this work is to compare two different test methodologies to characterize mar performances of organic coatings. Taber test and Falling Abrasive test were chosen. In both tests sodium chloride and sucrose were used as abrasive agents in order to simulate a possible damage occurring in domestic environment. These abrasives produce a limited damage, due to the low hardness, that influences only the aesthetic aspect of the organic coating. The level of damage was evaluated through gloss measurements. The correlation between the changes of gloss and the damage was investigated using optical microscopy and environmental scanning electron microscopy. The two tests showed a different morphology of the damage of the organic coating due to the different mechanism of damage: abrasion in Taber test and erosion in the Falling Abrasive test