Paper in a non-homogeneous material as to composition and structure. The STFI Formation is a powerful method to describe the in-plane variability of mass dstribution in a paper structure but its response cannot account for profiles in the thickness direction of the sheet.

 

We have developed a layerwise optical formation method to describe and study specific structural features that appear at one specific depth from the paper surface. Flocculation patterns and the occurrence of wire markings are two examples of structural properties that can be studied with this method.

 

The heat seal lamination splitting technique is a fundamental step in this method. Image analysis of the individual splits is used to provide quantitative descriptions of the phenomena observed.