New printing inks with barrier performance for packaging applications
Design and investigation
Barrier properties of packaging materials against moisture and oxygen penetration are of high relevance. Enhanced protection of existing materials against weather conditions can be achieved by application of printed coatings. To improve barrier performance of packaging materials, new inks for obtaining printed coatings with a layered structure were developed and investigated. The proposed ink compositions for flexographic printing on paper substrates are based on an environmentally friendly acrylic binder and contain inorganic fillers with platelet particles incorporated in the polymer matrix. Coatings based on the developed printing inks demonstrate significantly decreased water vapour permeability compared to traditional polymer inks. The effect of decreased permeability was investigated considering inks rheological behaviour, the coating structure, mechanical properties, surface energy and water uptake for different ink formulations. The developed inks provide variable optical properties including coatings with a relatively high transparency. The development of the functional barrier inks contributes to saving natural resources by prolonging life performance of packaging materials and goods.