When touching different materials, metal might feel “cold,” while wool fabric might feel “warm,” despite both having the same temperature. This difference in sensation arises from varying amounts of heat transfer between our skin and the material, resulting in the sensations of “warmth” or “coolness.” This tactile sensation is commonly known as the “warm-cool feeling.
(Figure 1) Measured values at KES-F7 Thermo Lab
Introducing the KES-F7 Thermo Lab, a testing machine that measures the “qmax” index to evaluate the cooling sensation upon contact.
Originally developed as a demonstration model by Professor Sueo Kawabata, the creator of KES (Kawabata Evaluation System), at Kyoto University in the 1970s, the KES-F7 Thermo Lab was commercially launched by Kato Tech in 1980.
Before Professor Kawabata’s research, tactile sensations and the perception of a cool feeling from touch relied solely on subjective human senses.
In around 1972, Professor Kawabata and Kato Tech introduced the KES-FB series to the market.
This system objectively evaluates the “texture” and “feel” by quantifying tactile sensations, replacing subjective judgments with objective numeric data.
Furthermore, Professor Kawabata’s research revealed the correlation between the maximum heat flux (qmax) and the sensation of coolness. The collaborative effort and broad research between Professor Kawabata and Kato Tech led to the development of today’s multifunctional KES-F7 Thermo Lab.
This upgraded Thermo Lab measures not only the coo feeling but also the thermal conductivity and heat retention properties of materials. Its applications range from evaluating garment coolness, warmth, insulation, and automotive interior thermal properties to assessing the refreshing feel of cosmetics.
(Image 2) List of the automobile interior materials that can be evaluated for tactile sensation by KES.
Furthermore, for fabric’s coolness testing, standards have been established globally and domestically based on the KES-F7 Thermo Labo:
Japan: JIS L 1927 – Textiles — Measurement method of cool touch feeling property.
China: GB/T 35263-2017 – Textiles — Testing and evaluation for cool feeling in contact instant
Taiwan: CNS15687, L3272 – Method of test for the instantaneous cool sensation fabrics
Kato Tech also conducts various evaluations focusing on the “texture” of materials. Utilizing the KES (Kawabata Evaluation System), which quantifies tactile sensations, we have supplied this technology to over 50 countries worldwide. If you require test sampling measurement for any material property or sensory evaluation, feel free to contact us.
For more information about this product, please click here (KES-F7 Thermo Labo | KATO TECH CO., LTD. | Pioneer of Texture Testers and Electronic Measuring Instruments (keskato.co.jp)).