How the labels work:
The temperature-sensitive elements are phase-change indicators which use the sharply defined melting points of a series of specially purified organic chemicals to give the unique, high precision, color change effects. Each temperature element uses a different chemical compound and is made separately by applying a coating containing the chemical to a special absorptive paper substrate which is usually black. When the rated temperature is exceeded, the chemical melts and is absorbed by the substrate, causing a permanent color change to black. Up to ten elements can be combined together on a single label.
Typical Label Construction:
Melinex Polyester Film (171ºC and below)
Kaladex Film (177°C to 204°C)
Kapton Polyimide Film (210¬ºC and above)
Adhesive & Carrier (without liner)
Black Coated Paper & Backing
75 - 85µ
Above values are general guides for illustration purposes only.
Process Temperature Indicator