engleski

INFLUENCE OF THE NANOCOMPOSITE COATING COMPOSITION ON THE CARDBOARD PACKAGING CHARACTERISTICS

The aim of this research was to compose a nanocomposite coating which will upgrade existing varnish and enable transfer of the visual message and function of the packaging throughout the product’s lifespan. To fulfil its role, packaging material is often coated. For this research, lithographic offset printed samples were coated with prepared nanocomposites in various nanoparticle’s weight ratios (0.25%, 0.5%, 1% and 2 hybrid types (two types of nanoparticles in same coating)). The base of nanocoating was commercial water-based varnish while chosen nanoparticle were zinc oxide (ZnO), titanium dioxide (TiO2) and silicon dioxide (SiO2). The prepared samples were characterised by determining colorimetric values, barrier properties, surface and adhesion properties, resistance to colour fading and antimicrobial effect. The results showed that ZnO nanocoating will have a smaller initial effect on the colour change of the printed image after coating than the TiO2 counterpart but will also provide lower protection against induced accelerated ageing (UV radiation) or barrier properties for water vapour. Both nanocomposite types showed that increase of nanoparticle weight ratio leads to higher protection benefits. The hybrids (ZnO + SiO2 and TiO2 + SiO2) provide better barrier to water vapour properties than the nanocomposites with single nanoparticle. All presented nanocomposites will upgrade varnish’s antimicrobial properties, where the Hybrid/Z (Zno + SiO2) showed the strongest inhibition potential overall. This research provided a new method of possible varnish modification via added nanoparticle that can upgrade the protective benefits of the varnish against outer environmental influence such as UV radiation. The newly formed nanocomposite coatings protected the printed image while having limited effect on the colorimetric values of printed inks. Moreover, the prepared nanocomposite coating provided an inhibition of microbial growth.

cardboard packaging, coatings, nanocomposite, zinc oxide, silicon dioxide, titanium dioxide

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