Characterisation of Packaging Material Surfaces

Abstract: As the packaging material (PM) becomes better defined from the results of technical development, its processing stages will be of greater complexity. The nip process is an example of one vital step in the lamination coating of PM, and this process is studied in the present thesis by analysing the surfaces of chill rollers (CR) and PM. Ideally, a laminated PM surface should be the perfect negative of a CR surface, and a correlation between the features of these surfaces is of significant importance. More specifically, a set of surface texture parameters was used to compare the corresponding surfaces and to reveal the dependence of PM properties on its surface texture. To determine the surface texture parameters, a focus variation microscope was used to study both CR and PM surfaces. The gloss of PM was studied by ocular observation for both inside and décor sides. These results were compared to the surface parameters for finding characteristics that can offer the explanation of difference in gloss. Such an explanation was found in the differences between CR and PM surface textures. The friction of PM against metal surface was studied for three PM samples, including both inside and décor sides. While no direct correlation between surface parameters and friction data could be found, a hypothesis explaining the differences is presented.