Thermal Insulation Fabrics
can keep body warm in the cold day.
There are two kinds of thermal insulation fabrics. One is fleece that is brushed treatment and it reduce air convection between fibers. Reducing air convection will cut off the cold air to take heat away from human body and keep warm. The other one is fabric with nanoparticles. The nanoparticles can absorb light energy from solar and transform it to heat and store them. Then release the heat slowly to human body to make warm.