Influence of topography on the scratch and mar visibility resistance of randomly micro-textured surfaces

In this research, the influence of the macro- and micro-topography on randomly micro-textured polypropylene surfaces has been studied. An initial characterization of the underlying surface was carried out using three-dimensional (3D) technologies such as chromatic and white light confocal microscopy. A multi-scale analysis methodology was employed for analysing the surface at either macro- or micro-scales. Among others, topographic characteristics such as peak-to-valley symmetry and the amount of micro-asperities were analysed to quantitatively determine the scratch and mar visibility resistance. The results show that surfaces with higher symmetry in their functional height distributions yield lower lightness variation (ΔL*) between the scratch pattern and its residual background height (RBH). This allows for a better suitability in hiding the scratch damage. On the other hand, topographies with less amount of micro-asperities on top of the texture provided a better mar resistance. In these cases, deformation mechanisms such as ironing are minimized, resulting in a lower gloss variation and lower contrast between the damaged area and its surroundings. [Display omitted] •The topographic characterization of textured surfaces was essential for understanding its scratch and mar behaviour.•Textures with peaks and valleys symmetry were better suitable for hiding the scratch damage.•The imposed pattern by the groove shoulders was the main reason of lightness variation with its background.•The larger the amount of micro-asperities the larger the gloss and contrast variation was.