Drying tension and shrinkage in paper and board: Part 1 Single ply sheets of chemical and mechanical furnishes

The shrinkage and drying behaviour of paper furnishes was studied by examining the development of shrinkage and tension in separate individual plies during drying in a specially developed apparatus that can control restraint and/or shrinkage. Experimental results show large differences in dryness and drying stress/shrinkage behaviour between chemical and mechanical furnish plies throughout the drying process. In Part 2 of this study the hypothetical shrinkage and drying behaviour of a symmetric three-ply board was predicted using this information together with simulated moisture and temperature variations of such a board as it passes through a typical cylinder dryer section.