engleski

Analysis of Natural and Artificial Aging Influence on UV Inkjet Prints on Printing Substrates with Straw Pulp

Paper substrate, as the most common used substrate for printing labels or packaging, is traditional produced from cellulose fibres derived from wood. The growth of a large number of industries has led to a significant increase in the use of such resource, which consequently led to a global awareness of the possibility of forest exploitation and the importance of reusing waste paper as a source of fibres. Hence, paper fibres can be recycled up to seven times and it is important to enrich paper pulp with virgin fibres during paper production. In such a way, the characteristics of the paper and the quality of the printed elements are improved. In this paper, cereal straw as an alternative resource of virgin fibres was turned into pulp and mixed with recycled wood pulp to conduct printing substrates using laboratory equipment. Since aging is an inevitable process of any printing substrates and prints, and the degradation of print quality due to aging largely depends on the properties of the printing substrate, ink and type of printing. This research was focused on analysing optical stability of prints made on printing substrates with straw pulp by UV inkjet technique after natural and artificial aging. From a comparison of the aging processes based on the Euclidean difference results, it was observed that natural aging of UV inkjet prints yields less colour changes compared to artificial aging. Greater or equal optical stability after aging was perceived for prints on printing substrates with wheat, barley and triticale pulp compared to prints on substrates made with recycled wood pulp.

aging, optical stability, printing substrate, straw pulp, UV inkjet printing

ACKNOWLEDGMENT This work has been supported in part by Croatian Science Foundation under the project „Printability, quality and utilization of substrates with non-wood fibres“ (UIP-2017-05-2573) and by the University of Zagreb.