Study of adaptive thermochromic camouflage for combat uniform

Abstract

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.

Smart Textiles for Visible and IR Camouflage Application: State-of-the-Art and Microfabrication Path Forward

“…The work of many researchers demonstrates the importance of wearer comfort, resistance to laundering, and maintaining the functionality of the garment over time [ 14 , 16 , 23 , 31 , 34 , 39 , 40 , 44 ]. There are benefits in avoiding the need for embedded electronics as this adds complexity in terms of washing and powering of devices, especially since energy harvesting capabilities are not ready for use in textile systems yet.…”

“…Viková and Pechová examined the camouflage properties of thermochromic inks on two different fabrics, one a plain weave cotton/polyester blend and the other a cotton/polyester blend with a Czech desert camouflage pattern [ 40 ]. Varying concentrations (10–600 g.kg −1 ) of thermochromic inks with transition temperatures ranging between 30 and 39 °C were dissolved with a dye precursor and color developer in a hydrophobic organic solvent, then encapsulated.…”

High sunlight resistant thermochromic smart textiles based on UV absorbing polymer

“…In recent decades, some reports on the stability of thermochromic materials have been carried out. Mojca Friškovec 26 found that ultraviolet rays and temperatures much higher than 150°C would make the thermochromic materials lose color, and the stability been improved by 3–4 times by treatment thermochromic fabrics with commercial UV absorbers 27 . Hironori ODA 28,29 synthesized a series of thermochromic materials with UV absorption functional groups which effectively improve the light resistance of fluorane dye, which confirmed that the anti UV technology is an effective way to improve the light fastness of fluorane dye.…”

Camouflage Fabric – Fabric for Today’s Competitive Era

“…The word thermochromic is the combination of two words: thermos and chromic, where thermos means heat and chromic means colour change. When the chromic materials change colour due to the application of heat such type of fabrics are called thermochromic fabrics [21]. This phenomenon is referred to as thermochromism.…”