Smart label monitors thermal load of packaging

A smart label fixed to the packaging for measuring the ambient temperature throughout the logistic chain. A possible application includes monitoring toners for the heat sensitive substrates in order to safeguard the quality of the ink.

Xeikon in Lier designs, develops and supplies digital colour printing systems based on rotary presses using LEDs and dry toner. A few years ago the company brought out a new dry toner for heat sensitive substrates and with it, introduced some extra quality controls. The ultra-fine powder particles of the new toner started to coagulate when stored at high temperatures, which could have a negative effect on the printing process. This suddenly made the storage temperature of the toner a problem.

A search was made to find a reliable measuring system for monitoring the toners: this turned out to be the Timestrip Plus smart label made by Innolabel. The label indicates whether the packaging has been exposed to high temperatures for excessive periods during storage or transportation. The customer can simply read this information on the label attached to the toner packaging.

How it works

The label has green, yellow and red zones that indicate the quality of the product. The label is activated with the simple press of a button when the temperature has been higher than the maximum temperature setting, so that the blue liquid contained in the label seeps into a membrane. The label can be kept at a lower temperature after activation and before the product is used. If during use, the liquid appears in the red window, the quality may be affected. The shelf-life of the label is two years, so that the temperature can also be monitored even during storage. Under normal conditions the toner is used within two months of delivery.

Tests carried out at one of the customers confirmed that the temperature sensor met both the customer's and the quality control requirements. The temperature accuracy was within 1%.