Paper and board are complex materials which suffer from a number of features which can limit their usefulness. The defect sensitivity of the paper material can lead to web breakage in both the manufacturing and subsequent converting processes; creep during long-term loading can mean that paper-based packages break during transport and storage; weak layers in the thickness direction of the paper increase the risk that delamination may occur during the converting processes and the moisture sensitivity of the paper material can lead to a number of problems.

 

Exposure to moisture means that papers become softer and weaker, while desiccation makes the paper material brittle. Changes in the moisture content of the paper often means that the paper becomes cockled and looks unattractive.

 

Paper physics provides tools both for measuring and for designing the properties of paper materials. Test methods can be used not only to classify the properties of the materials but also to provide an understanding of the relationships between manufacturing parameters and material properties. Testing is therefore an excellent aid in the development of paper materials and paper products with improved properties. Moreover, the test data can be used to develop and calibrate models which can in turn be used to simulate, regulate and optimize the manufacturing and converting processes.

 

In order to be able to control and systematically improve a particular paper property it is essential that the property concerned can be measured and quantified. Over the years, Innventia has developed a number of methods for the testing of paper materials, both standardized methods for production control and world-unique methods and equipment for the testing of complex paper properties.