Relation between physical property of massage creams and skin surface smoothness.

The product performance of cosmetics is determined mainly by the sensory evaluation of users, and the objective measuring method and equipment to measure it haven't yet enough established. We applied KES-SE measuring instrument to the objective measuring method for evaluating the hand touch feeling of cosmetics.<br>In this study, we focused on the massage cream, especially whose hand touch on the skin surface is the decisive factor to determine the product performance among various cosmetics. As for the physical property, we used KES-SE measuring instrument and derived the coefficient of friction (MIU) and mean deviation of MIU (MMD) when massage creams are applied on an artificial leather. And, we measured the compressional force and energy, and stress alleviation of the hand touch feeling of creams, using KES-G5 (HANDY MOTION) Finger Robot Arm Motion Instrument. We examined the correlation between these measuring data and the result of the sensory hand evaluation test performed by aestheticians, such as the spreadability, permeability, smoothness, and stickiness of creams. The correlation between each physical property value and the sensory evaluation value differ according to various measuring conditions, varying application quantity, area of cream, number of times of the reciprocation action and load of contactor. And MIU of cream with application quantity 0.05ml and load 30gf showed a correlation with the result of the sensory hand evaluation of spreadability, permeability, and smoothness of creams. MIU of cream with application quantity 0.1ml and load 50gf showed a correlation with stickiness. And the compressional properties showed a good correlation with softness and skin touch feeling of creams.<br>As the results, we confirmed that we could grasp the hand touch feeling of massage creams by physical quantity, using the objective measuring method.