Comparison of Print Durability in Accelerated Weathering

Abstract

Many packaging applications set strict demands for printing. When digital printing is used in packaging applications, these demands have to be taken into account. Packages stored outdoors in points of sales in the summer and in some cases even over the winter is a special group of consumer packages. These packages, for example plastic sacks, are exposed to daylight and rain over a long period of time.In this article, the results of accelerated weathering test are presented. The test was conducted in order to compare the weather fastness on digitally printed samples and conventionally printed samples. The test was based on the ISO standard that specifies methods for exposing specimens to xenon-arc light in the presence of moisture to reproduce the weathering effects that occur when materials are exposed in actual end-use environments to daylight. In the test series, CIE L*a*b* and densitometric values of the colour test fields were measured. The measurements were carried out in the beginning of the test and several times during the test, approximately every 24 hours.Clear differences between digital printing and conventional printing methods were found in the tests. Some samples offered excellent print durability even in harsh test conditions, while other samples faded considerably during the test.