engleski

Advanced quality and sustainability when printing irreversible thermochromic inks

Worldwide, there is a growing need for use of recyclable and biodegradable materials, made from natural resources, for a variety of applications. This trend is followed by the printing industry as well, which is trying to use environmentally friendly materials and reduce the consumption of environmentally unfriendly materials. In addition, the used materials should give the satisfying quality of the end -product. Thermochromic inks can be reversible (color change is multiple) or irreversible (color change is one-time and permanent). Irreversible printing inks are initially either colorless or colored and when exposed to high temperatures they get colored or change to another color. Therefore, the aim of this paper is to examine the possibilities of two printing substrates (uncoated and coated) for the application of irreversible thermochromic inks in order to find a more environmentally friendly option that gives a satisfactory print quality. The dynamics of color change was monitored through one heating cycle every few degrees. Their colorimetric characteristics were described using spectral reflection curves and the CIELAB color system. Based on the obtained results, it can be concluded that with the change of temperature, the color tone changes slowly and continuously. The differences are evident for the selected printing substrates due to their different properties. However, these variations are imperceptible to the eye of the observer and according to the obtained results, it can be concluded that the tested inks behave similarly on the used substrates. In addition, more environmentally sustainable materials can be a good option in the use of printing with irreversible water-based thermochromic inks.

thermochromic inks ; sustainable materials ; colorimetric characteristics

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