Thermal reflectance of fabric in color temperature spectral domain

Purpose This study aims to explore the thermal reflectance of fabrics under sunlight or other thermal radiation sources at various color temperatures. Design/methodology/approach This study analyzed the spectral distribution of sunlight at different solar altitude angles as well as the spectral distribution characteristics of other light and thermal radiation sources, pointing out that their color temperatures can be used to identify their spectral distribution domains. Reflectance, transmittance, absorptance and color temperature domain reflectance of 35 different fibers and color fabrics were tested in a wide spectral range. The different behavior of these optical parameters in the segmented spectrum is discussed. The temperature rise tests demonstrate that the reflectance corresponding to the color temperature of the radiation sources is highly correlated with the temperature rise results. Findings The reflectance in the color temperature domain shows a strong correlation with the radiation source at same color temperature. The correlation coefficients for the 6,000 K xenon lamp test are −0.96 and −0.90 in two groups, and for the 3,200 K tungsten iodine lamp test are −0.87 and −0.90 as well. Originality/value The concept of fabric thermal reflectance in the color temperature domain was first introduced to match different thermal radiation sources. Validation of temperature rise is conducted through a self-constructed tester with unidirectional adiabatic heating. This new discovery could serve as a basis for developing functional fabric or clothing, such as sun-proof clothing, fire protection clothing, etc.