化粧用ブラシの物理特性測定法の開発

摘要

化粧用ブラシのような繊維集合体に関する研究例は少なく，客観的な評価方法が確立されていない.そこで，ブラシの客観評価方法を提案するために，力学特性とファンデーションの塗布性能を測定する装置を試作した.両装置の仕組みは，実際の使用方法を模擬している.力学特性は，ブラシを曲げる際のブラシの先の復元力と摩擦力を垂直と水平方向の力として計測でき，ファンデーションの塗布性能は，一定条件でファンデーションを取り込み，肌模型に対する塗布性を評価できるものである.さらに，これらで得られる結果がヒトの使用感にどのように寄与するのかを見出すために官能検査を用いた.結果，試料間の特徴が得られ，本装置でこれまで測定が困難であったブラシの物理特性が捉えられることが分かった.また，垂直方向の力はファンデーションの取り込み量と，水平方向の力はソフトさなどと関係があることが示唆された.%Few studies have been carried out on fiber assemblies such as cosmetic brushes, and thus there is a lack of objective evaluation. In order to perform objective evaluation, systems for measuring the mechanical properties and application properties of cosmetic brushes were devised. The systems were designed to simulate the actual usage of the brushes. A device for measuring mechanical properties was able to quantify the restoring force and the frictional force when bending a brush. The restoring force was the resultant of vertical and horizontal forces, and the frictional force was equivalent to the horizontal force. A device for measuring the application of foundation was created to take up and apply foundation to a skin model in controlled conditions. Sensory tests were then performed to consider how physical properties affected the usage of the brush. Results showed that the system could measure the physical properties of the brush, and suggested that there were correlations between vertical force and foundation quantity, and also correlations between horizontal force and softness.