Thermochromic liquid crystal inks for printing
Thermochromic liquid crystal inks are inks changing colours in rainbow shades. Each colour of thermochromic liquid crystal inks indicates a different temperature.
The ink, sensitive to temperature, changes from colourless (black on a black background) to red in a given temperature and together with the temperature increase, goes through every colour of the visible light spectrum (orange, yellow, green, blue, violet) and then becomes colourless (black) again at an even higher temperature.
The colour changes are reversible. After cooling down, the sequence of colour change is reverse to the one observed during temperature increase.
Thermochromic liquid crystal inks are used for signing medical equipment, as thermometers to measure the temperature of a human body, a room or an aquarium.
They are also widely used in printing promotional and advertising materials. The functional markers printed with these inks, such as a gas level indicator in a propane container, also meet with acknowledgement.