Press-forming of paperboard has been previously studied by several authors. A point of interest regarding gas tight heat sealing of the packages are the creases in the package. The objective of this article was to study and compare different microscopic imaging methods to research an optimal imaging method for the formation of creases in the press-forming process of polymer coated paperboard trays. The studied methods were: Scanning electrode microscopy (SEM), X-ray Microtomography, Optical light microscopy and Polarized light microscopy. All four tested methods delivered clear images. Casting of the samples in an acrylic resin and light microscope imaging was found to be the most suitable method for the analysis of heat sealed creases and leakage detection.
Leminen, Ville; Mäkelä, Petri; Tanninen, Panu; and Varis, Juha
"Methods for Analyzing the Structure of Creases in Heat Sealed Paperboard Packages,"
Journal of Applied Packaging Research: Vol. 7
, Article 5.
Available at: https://scholarworks.rit.edu/japr/vol7/iss1/5