Knitted fabric properties influencing coolness to the touch and the relationship between subjective and objective coolness measurements

The aims of this study were to identify the optimal combination of knitted fabric properties that influence the sensation of coolness and to ascertain the relationship between subjective and objective coolness measurements. Test fabrics included eight cool-touch nylon knitted fabrics and four other knitted fabrics. The physical properties and surface characteristics of the fabrics were assessed. Coolness sensation was determined by the Thermolabo II instrument to provide an objective measurement, expressed as Q_max. A forearm test and palm-of-hand test were used as subjective measurements. Pore volume ratio and geometric roughness had a significant effect on coolness sensation expressed via Q_max. Stiffness and weight influenced the forearm test. Pore volume ratio and the coefficient of steel–fabric friction affected the coolness sensation measured by the palm-of-hand test. Nylon/spandex (78/22) tricot was the coolest of all samples, such that its characteristics were thought to represent the optimal combination of knitted fabric properties for a cooling fabric, that is, a high and balanced stitch density of 150 × 130, light in weight of 161.4 g/m², a pore volume ratio of 69.4%, medium geometric roughness, and a thin pliable knitted fabric. The objective measurements were highly correlated with the palm-of-hand test, but not with the forearm test because only the palm-of-hand test had a test set-up that was similar to the objective test. Although the objective and forearm test set-ups were only slightly different, coolness assessed with the forearm test was not correlated with coolness assessed with objective measurements.