Datasheet

Thermochromic Liquid Crystal Reversible Temperature
Indicating Strips
The Thermochromic Liquid Crystal (TLC) range of reversible temperature indicating labels forms a
fast, easy to interpret indication of actual temperature. They are also convenient, easy to use and in-
expensive.
What They Are:
These self adhesive labels consist of a series of temperature-sensitive elements containing
microencapsulated TLC coated on a black backing. Each element changes colour distinctly as its rated
temperature is reached, passing through the colours of the spectrum in sequence (Orange, Yellow, Green,
and Blue before turning black at a higher temperature. The TLC strips are calibrated so that the indicator
that shows green indicates the actual temperature. The colour changes are reversible and the reflected
colours will be observed in the reverse order upon cooling.
How the labels work:
The temperature-sensitive elements contain TLC molecules that are very sensitive to temperature and
change position / twist in relation to changes in temperature. This change in molecular structure affects
the wavelengths of light that are absorbed and reflected by the liquid crystals, resulting in an apparent
change in the colour of each temperature event.
When the rated temperature of an indicator is reached the TLC molecules twist slightly causing the TLC
substance to absorb the red and blue portions of the visible light and reflect the green part. This causes the
temperature event to appear green. When the temperature decreases, the molecules begin to twist in the
opposite direction, and the TLC reflect a different portion of the spectrum.
Label Construction:
Component: Thickness
Polyester film >75, 125, 175µ
(Depending on label type)
Graphic Print 10-20µ
Liquid Crystal Ink 10-50µ
Black Backing 10-20µ
Adhesive & carrier 150-180µ
Release Liner 75µ
Example shown right is A523-01
Above values are general guides using the standard products as a representative example.
Label Accuracy:
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