Properties and Colorimetric Performance of Screen-Printed Thermochromic/UV-Visible Fluorescent Hybrid Ink Systems

Abstract

In the present research, properties and performance of special effect printing inks were observed with the aim of obtaining a printed product with dual functional properties. Thermochromic liquid crystal-based printing ink (TLC) and UV-visible (daylight invisible) fluorescent inks (UVF), pure and as hybrid ink systems, were printed using a screen-printing technique on two types of uncoated paper substrates. Characterization of the paper substrates was performed, as well as detailed analysis of printed layers. Thickness, surface roughness, surface free energy, and adhesion parameters of printed layers were analysed. Spectral reflectance of pure UVF and TLC printing inks, as well as the spectral reflectance of the proposed hybrid ink systems were measured. The thermochromic effect of the TLC ink and hybrid systems was analysed. Microscopy was used to display the visual colour play effect and the effect of the fluorescence. Results of the measurements showed high compatibility of used materials in the proposed hybrid ink systems. Since the effect of luminescence and the colour play effect in the hybrid systems were preserved, it can be concluded that TLC/UVF hybrid ink systems can find their application in the development of functional packaging and in all other applications with special requirements for temperature monitoring and hidden information for different products.

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“…From the calculated SFE components, the adhesion parameters between the layers in the "board-primer-printing ink" system were calculated (Azarhoosh, Moghadas Nejad & Khodaii, 2017). The work of adhesion (W 12 ) (Equation ( 2)) between the layers in contact was defined in order to predict the strength of interactions (Żenkiewicz, 2007;Tomašegović et al, 2021):…”

“…Negative S 12 is present between the board and the primers, as well as between the unprimed board and WBI. Negative S 12 indicates that the spreading of the observed primer/ink layer on the board is not spontaneous, and could pose a problem with the mechanical properties and durability of the print (Tomašegović et al, 2021;Aydemir, Altay & Akyol, 2021).…”

Preliminary report on properties and interaction of layers in “board-biodegradable primer-printing ink” screen-printed system

“…The conductivity of water was γ = 2,0 μScm -1 , the dispersive component of the water's surface tension γl D = 21.80 mJm -2 , the polar component of the surface tension γl P = 51.00 mJm -2 and the total surface tension of the water was γl = 72.80 mJm -2 . Glycerol has equal amount of polar and dispersive surface tension components (γl P = 34.0 mJm -2 , γl D = 30.0 mJm -2 ) and total surface tension γl = 64.0 mJm -2 and diiodomethane is a dispersive liquid with total surface tension, γl = γl D = 50.8 mJm -2 ('Future Fibres: Coir', n.d.; Tomašegović et al, 2021).…”

“…Previous research on PCL and PLA as primers on paper substrates proved them as suitable solution for the improvement of print properties in offset printing technique (Hudika et al, 2020). Furthermore, PCL/PLA composites have been successfully applied as the materials for relief printing plate production (Poljaček et al, 2021;Priselac et al, 2022). PLA and PCL were used in this research as primers on the board substrate, with the motivation of having beneficial effect on reducing the permeability to water vapour, and possibly improving the characteristics of the print such as the edge of the printed motive and adhesion parameters between layers on the print.…”

Proceedings - The Eleventh International Symposium GRID 2022

“…The conductivity of water was γ = 2,0 μScm -1 , the dispersive component of the water's surface tension γ l D = 21.80 mJm -2 , the polar component of the surface tension γ l P = 51.00 mJm -2 and the total surface tension of the water was γ l = 72.80 mJm -2 . Glycerol has equal amount of polar and dispersive surface tension components (γ l P = 34.0 mJm -2 , γ l D = 30.0 mJm -2 ) and total surface tension γ l = 64.0 mJm -2 and diiodomethane is a dispersive liquid with total surface tension, γ l = γ l D = 50.8 mJm -2 ('Future Fibres: Coir', n.d.; Tomašegović et al, 2021). Sessile drop method was used for the contact angle measurement, and the volume of the drops was 1 μl.…”