Modeling the relationship between tactile sensation and physical properties of synthetic leather

Surface texture plays an important role in expressing the tactile sensation of leather. The purpose of this study was to develop a combinational panel of physical properties that express the tactile sensations of coarse/fine, uneven/flat, soft/hard, sticky/slippery, and moist/dry. Thirteen synthetic leather samples were fabricated from polyurethane, and eight physical properties were measured as storage modulus, loss modulus, surface roughness, waviness, mean frictional coefficient, apparent contact angle, contact angle hysteresis, and urethane thickness. Thirty adult women performed sensory evaluation of the five tactile sensations by using a semantic differential method based on a five-point scale. The tactile sensation–physical property model for each tactile sensation was explored with logistic regression analysis. Receiver operating characteristic analysis showed that the proposed models based on multiple physical properties clearly distinguish the tactile sensations with higher sensitivity and specificity compared to using a single physical property. The dynamic viscoelasticity contributed to all the tactile sensations when polyurethane was used as synthetic leather. Additionally, the difference of five tactile sensations might be caused by the surface roughness, the mean frictional coefficient, and the polyurethane thickness.