Delamination of paperboard related to offset printing

Abstract: The relationship between the behavior of paper during converting operations and the mechanical properties of paper are a fundamental issue for both paper producers and converters. In the attempt to establish these relationships and thus be able to judge the performance of paper, several testing methods have been developed. The major obstacle to achieve this goal is the fact that the stress conditions acting on paper are not always clearly defined neither in converting operations nor during testing. The first step to achieve a better understanding of the problem is to determine the fundamental mechanical properties of paper.Secondly, the stress condition occurring during converting must be investigated. In this respect, the modeling of paperboard represents a fundamental tool, allowing for the definition of the stress acting on paper during virtually every stage of the converting process or testing. These two steps lead to a better choice of the testing methods that are more relevant for each specific converting operation. The studies presented in this thesis investigate the different aspect of out of plane resistance in paper materials, with particular attention to the problem of delamination during offset printing.