Thermochromic inks

Thermochromic inks or dyes are temperature sensitive compounds that temporarily change colour with exposure to heat. They come in two forms, liquid crystals and leuco dyes.

Leuco dyes are easier to work with and allow for a greater range of applications.

Thermochromic inks are pigments that change colour to colourless at certain temperature. There are many different types of thermochromic pigments including textile inks for textile screen printing.

ThermoColour kettles come with colour changing properties. As water boils, one model changes from black to white, one from dark green to lime green and one from blue to pink.

Inks and dyes are used within packaging. Thermochromic inks can change from colourless to colourful or vice versa very quickly. They can be used in the food industry to indicate the freshness of a particular food product.

Properties

  • Range of colour
  • Change colour as temperature increases or decreases
  • Can be applied to most surfaces

Thermochromic and phosphorescent pigments

Thermochromic pigments are sensitive to temperature. They change colour when they are heated up or cooled down. This property is useful for indicating if the drink in a cup is hot, or if the water in a kettle is hot.

Phosphorescent pigments glow in the dark. They are able to absorb light energy and store it. This stored energy is released as light energy over a period of time.

Phosphorescent pigments are useful for watch faces that glow in the dark. They may also be used in fire safety signs placed near fire extinguishers. In the event of a fire, the position of the fire extinguishers can be seen, even if the lights fail.

Resources