Study of adaptive thermochromic camouflage for combat uniform

Adaptive camouflage refers to the adaptation of an object, such as a military vehicle or soldier, to its surroundings. Although the use of camouflage by military forces dates back to the First World War, this research will address the development of an adaptive color changeable system based on selected thermochromic inks following the colors used in Czech woodland and desert combat uniforms. The printed color pattern mimics leaf design, which transforms into desert design based on thermal conditions (hot air and body temperature). Target colors were prepared using six thermochromic inks, which were combined into a suitable mixture based on measured spectral and colorimetric data. The transition temperature of each thermochromic ink was measured together with the fastness properties of the printed color pattern. The data on rubbing fastness were satisfactory. Nevertheless, at high concentrations, thermochromic ink in the printing paste caused an unacceptable decrease in fastness. The wash property of printed fabrics showed reasonably good fixation of colors to the fabric surface. From the point of view of light fastness, the results confirmed that commercial thermochromic pigments are less resistant against solar radiation, and the resulting light fastness is between 1 and 2 on the blue scale. The special hydrophobic and UV treatment applied by the knife-over-roll method improved light fastness by 3–4 times. In this research, we demonstrated the potential to create a complex and dynamic range of patterns on textiles, with the promise of using one uniform for camouflaging in different types of environment.