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

Abstract

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 Qmax. 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 Qmax. 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.

Effect of knitting structure and yarn composition on thermal comfort properties of bi-layer knitted fabrics

“…31 Many researchers have tried to further improve the thermal transfer properties through conducting metal sputtering, 39 adding nanoparticles to a nylon matrix 40–42 and modifying the fiber cross-section. 43–45 Considering the wide application of cool-touch polyester and nylon in textiles, developing bi-layer knitted fabrics made up of cool-touch polyester as the inner layer and nylon as the outer layer could be an effective way to improve the thermal comfort of clothing due to their different reactions to moisture. However, the thermal comfort properties of bi-layer knitted fabrics made up of polyester fibers as the inner layer and nylon fibers as the outer layer have not been investigated.…”

Advanced materials for personal thermal and moisture management of health care workers wearing PPE

“…The coolness of fabric can be influenced by different textile parameters, such as cross-section of fibers, twist level of yarns, yarn number, pore volume ratio, geometric roughness, stitch density, stiffness and weight of fabrics, etc. [ [245] , [246] , [247] , [248] ] In Park’s study [ 246 ], the optimal combination of textile parameters for the cool-touch property of knitted fabric was investigated. Through an optimization of textile parameters, the cooling performance of thermal conductive textiles might be further improved.…”

Detection of raised cloths characteristics by heat flow using a miniaturized warmth and force sensor

“…As regards studies on cloth discrimination using heat flow and contact force, there are reports on evaluation of thermal sensation and friction sensation using large-sized measurement systems. 14,15,19,20 Such large systems may be used for raising-part length recognition, but cannot be mounted on robot's fingertips.…”

“…However, force sensors are not sensitive enough to detect the contact start position, while precise position control is necessary; thus, one can expect a decline in recognition speed as well as practicability. As regards studies on cloth discrimination using heat flow and contact force, there are reports on evaluation of thermal sensation and friction sensation using large‐sized measurement systems 14,15,19,20 . Such large systems may be used for raising‐part length recognition, but cannot be mounted on robot's fingertips.…”