Some insight on paper structure and properties with different drying conditions

This paper focuses on structural changes of paper caused by different drying conditions. Contact drying with and without hot air impingement was investigated at different temperatures. The main focus was on relating mechanical properties to the fine structure of the paper and the constituent fibres, measured by different methods including microtomography, high resolution formation measurement and other standard methods. When paper is dried under different drying conditions, with shrinkage prevented, significant differences are seen in surface roughness and elastic properties. Measurements of porosity, fibre wall thickness and pore volumes do not show such large changes when different drying boundary conditions are used. This indicates that changes happen more between fibres rather than within fibres - and also that bonding in the fibre network is altered. One of the practical results of this study is that the elastic properties and surface smoothness of paper can be improved by cooler paper temperature during drying process