New Scratch Measurement Technique for Exterior Body Systems

This paper will describe a novel method for quantifying the perceived scratch and mar susceptibility of polymer surfaces. For automotive applications the relevant parameter that determines customer satisfaction is the visual perception of scratch and mar. Visual perception of a discontinuity on a surface is based on the contrast between the damaged area and its surroundings. The observed contrast differences are a function of the way in which light is scattered from the damaged area, as well as the illumination and observation angles. We have developed an imaging system that uses two geometries to capture the major contrast elements differentiating a scratch from its surroundings. The data from the two geometries are processed to extract values for reflectivity of the sample surface as well as that of the damaged area under the two observation conditions. The optical imaging data will subsequently be related to data collected from visual assessments by test groups of people to generate a numeric assessment of Visual Quality.