A Methodology to Quantify Surface Mar 2012-01-0542

Understanding scratch and mar damage performance of materials is important in the automotive industry. Hence there is need to develop a suitable method to quantify them and relate back to product performance. This paper elucidates a method to quantitatively evaluate mar defects. The method involves marring the surface of a sample with a crockmeter and the damaged surface characterized using a two-camera optical imaging system. These results were then correlated with visual survey results and a transfer function was generated using Design expert DX6net. In the validation stage, a set of newly marred samples were investigated to generate both visual rank and mar index using the transfer functions. Excellent agreement between mar index and visual survey rank reconfirmed the method's effectiveness. Mar performance of different materials (black and high gloss) can be compared using this technique on a 0-100 scale. This method can also be used to characterize polycarbonate glazing surfaces. Mar quantification tool is robust, quantitative, measures visual perception and free from human bias.