New technique for the quantification of scratch visibility on polymeric textured surfaces

Surface texturing plays a vital role in enhancing the look and feel of modern consumer goods and has recently shown promise as a means of increasing scratch resistance. Unlike smooth surfaces where scratch damage is immediately apparent, the introduction of texture can obscure scratches, making them harder to detect. This work presents a new technique for the automatic detection and characterisation of multiple scratches on textured polymeric surfaces. The program was tested on five different texture patterns with various features scales and directionality, with scratches applied in different directions. Charcoal and beige coloured samples were also tested to determine the effect of colour on accuracy and scratch visibility. The program was found to be highly accurate for the majority of samples and was able to detect scratches that were too faint to find by eye. The appearance of the scratches were characterised through a visibility score, which was in good agreement with the visual assessment by eye and results from the literature. Coarser textures and the beige coloured samples were found to have greater scratch visibility resistance overall. Directional textures also showed significant variation in visibility scores depending on whether scratches were parallel or perpendicular to the primary feature orientation.