As UV coatings continue to be applied to a broader range of substrates, the demand for scratch and abrasion resistance continues to grow. This is especially true with thin-film applications over flexible, semi-porous or hard substrates with varying types of gloss or haptic properties. There are a variety of ways in which damage can occur due to various geometries and forces of the objects scraping over the coating surfaces. There are many factors, such as resin composition, surface uniformity and irregularities, etc., that will influence the scratch and abrasion resistance performance of the coating. Different test methods highlight different aspects of a coating’s integrity, and often there is not consensus across test methods in regards to consistent performance. All these variables combined can result in a wide performance response from slight deformation, which may not be visually observable, to fractal failure of the polymer itself that leaves visually apparent damages.
To obtain continual improvements in scratch- and abrasion-resistant coatings, a variety of additive technologies have been developed to address this issue. In this study, the article examines additive technologies ranging from surface-active siloxanes and nanocomposite technology to synthetic amorphous silica and co-binders. These technologies are then evaluated side-by-side in a urethane UV-curable coating. The study will look at compatibility of these products in the coating formulation and provide relative ratings of their impact on scratch resistance. The scratch and abrasion resistance are measured using several common test methods. The results will provide a comparable overview of how these various technologies perform in improving scratch and abrasion resistance of the UV coating, and the variations that can occur across testing methods.