Paper is the material of choice for a large range of packaging applications. Due to its inherent porosity paper is already the prime choice for packaging of dry goods and food. However, the use of paper in packaging solutions is also challenged because of its porous nature. When paper is used in packaging applications, migration and permeation rates must be within legal requirements and regulations. To comply with the requirements, the porosity of the paper must be adjusted to selectively promote or prevent transport processes. Therefore, the production process of paper has to be adjusted accordingly, and the pore network optimization strategies must rely on a fundamental knowledge of the nature of the pore network. Furthermore, the physical processes that govern the transport of packaged goods, contaminants, or carrier gases through this network need to be understood. At the moment, the properties of the pore network itself and the relations between the pore network and governing transport processes are still poorly understood. There are hardly any techniques probing transport properties of paper relying on particles in the gas or fluid phase. Rather, there are standardized measurement conditions for paper characterization, e.g. the Gurley test to infer paper porosity from air permeance.
The aim of this project is to gain a fundamental understanding of the interdependence of transport mechanisms and the pore network of paper. Therefore, representative gases and organic compounds capable of gaseous transport are selected and measured to determine the pore network of paper and its transport-relevant properties. The used analytical techniques include migration cells and gas chromatographic based methods
