EFFECT OF VARIOUS CONDITIONS OF ARTIFICIAL AGEING ON SELECTED PROPERTIES OF OVERPRINTED PLASTIC FILMS
Overprinted plastics films, which are mainly used as a packaging, may be exposed to the various factors during storage. The aim of this work was to study the influence of various conditions of ageing of overprinted plastic films. Laboratory printing was performed using various plastic films (PE, BoPP, PET) and three flexographic printing inks: water‐based, solventbased and biodegradable. The analysis was focused on two external factors: elevated temperature and UV radiation. The effect of temperature and UV radiation on printing ink colour was examined by studying the optical density of a full tone area and the total colour difference . The period of artificial aging, equivalent to nearly two months of natural aging, caused visible changes in the appearance of the quality of prints. The total colour difference increases with the time of artificial ageing, as it was expected. The changes of print quality during ageing are higher for PE prints than for PET and BoPP prints. Additionally, UV radiation causes major changes in the print quality than elevated temperature.