Printing inks containing a certain reactive substance indicating oxygen, and suitable for printing onto plastic materials have been produced. This kind of indicator signals for package leakage and can be used for perishable foods in packages with modified atmosphere. Another type of oxygen indicator has been designed to be activated during the sterilisation process, and is most suitable for medical applications. In addition to oxygen indicators, attention was paid to the concept of freshness indicators. Humidity indicator and ethylene indicator developments were started in the project and, later on, advanced in separate projects. Every indicator system is based on a distinctive chemical reaction. Thus, several active substances were identified and tested, and the most promising systems were chosen for further development. The formulation and design of the ink-jet ink has been carried out. A large number of raw material combinations have been tried out to find a viable system. Preliminary reliability studies in real operational environment in food or medical packages have been performed. Two types of oxygen indicators are under evaluation at potential customers.
|Title of host publication||Intelligen Products and Systems|
|Subtitle of host publication||Technology theme - Final report|
|Place of Publication||Espoo|
|Publisher||VTT Technical Research Centre of Finland|
|Publication status||Published - 2007|
|MoE publication type||D2 Article in professional manuals or guides or professional information systems or text book material|
Sipiläinen-Malm, T., Hurme, E., Smolander, M., Rajamäki, T., Heilmann, J., & Hakola, L. (2007). Printed indicators. In O. Ventä (Ed.), Intelligen Products and Systems: Technology theme - Final report (pp. 50-61). VTT Technical Research Centre of Finland. VTT Publications, No. 635 http://www.vtt.fi/inf/pdf/publications/2007/P635.pdf