Packaging plays important part of the visual communication and in consumer’s choice of purchasing goods. To enhance visual appearance, packaging material is often coated. Beside enhancement of visual appearance, additional coating often improves other packaging properties. The COVID-19 pandemic stressed the importance of the antimicrobial properties of goods that encounter consumers. During purchasing, consumer first meets the packaging making it significant in the consumer’s protection. The aim of this research is to determine antimicrobial properties of nanocomposite coating which includes nanosized TiO2. For the purpose of the research a set of offset cardboard prints was coated with nanocomposite coating composed of water-based varnish (WD) and nanoscale TiO2 particles. The prepared samples were characterized by determining CIE L*a*b* coordinates of primary colours (CMYK), detecting colour fading after the accelerated ageing process by density measurements and by determining inhibition of microorganisms’ growth by using smear test. The change in chroma affected by UV radiation (accelerated ageing) is most visible on yellow samples while both, cyan and magenta proved to be more resistant to UV radiation. UV radiation did not cause significant change on the L* coordinate of black, although its values were affected with initial varnishing as TiO2 is also used as a white pigment. Although increase of the TiO2 concentration in nanocomposite causes increase of the colour change, only the one with the highest concentration (2%) proved to be unacceptable. On the other hand, as the beneficial effects of nanocomposites increase with increase of the TiO2 concentration, the nanocomposite with 1% of TiO2 should be the choice.
ANTIMICROBIAL PROPERTIES OF TiO2 NANOCOMPOSITE COATING
Cardboard packaging, nanoparticles, titan dioxide, functional coating, antimicrobial properties