JOANNA IZDEBSKA*, ZUZANNA ZOLEK-TRYZNOWSKA, TOMASZ KSIAZEK
*Corresponding author
Department of Printing Technology, Institute of Mechanics and Printing, Faculty of Production Engineering, Warsaw University of Technology, Konwiktorska 2, 00-217 Warszawa, Poland

Abstract

The article is an attempt to answer the question, how do the optical properties of biodegradable, compostable cellulose films change with time. Samples printed by a flexographic technique with using water-based inks and non-printed films were subjected to artificial aging. Two kinds of cellulose film were used in the experiments. Densitometry and spectrophotometric parameters were measured. It has been found that the type of film determined the resistance to ageing, and under the same conditions one sample almost maintained the measured parameters while the other one changed intensely. The period of artificial aging, equivalent to about three months of natural aging, can cause visible changes in the appearance of non-printed films as well in the quality of copies on those printing substrates. Spectrophotometric parameters better described the changes after ageing then those of densitometry. The tests revealed the resistance of printed and non-printed films to solar radiation.

INTRODUCTION

The problems of packaging waste and ecology have become of increasing importance and general interest to all European countries over the last few years. Biodegradable materials seem to be good alternative to traditional plastic. They degrade with time, from several months to several years depending on the condition, where traditional synthetic, petroleum-based plastics require hundreds or thousands years. The European market in biodegradable plastic is continuing its dynamic development and is changing. Biopolymers have a strong growth potential over the next decade. Over 50% of the global biodegradable plastics market in 2010 was contributed to by packaging. Nowadays, biodegradable materials occupy less than 1% of the plastic market, but a significant increase is anticipated. At present there are various biodegradable materials on the market which characterise different properties. Polylactide (PLA), starch and cellulose are the most important biodegradable polymers on the market (1–7).
Among them cellulose is the first agricultural, organic polymer in the biosphere. It is a linear polymer consisting of several hundred to over te ...