Improvement of Dimensional Stability of Paper in a Drying Process (Second Report)

Hiroaki Kuno, Makio Hasuike, Akira Sanada, Kazutoshi Yokoo, Kazuhito Ohhira
2000 JAPAN TAPPI JOURNAL  
Most of mechanical properties of paper regarding dimensional stability are determined by repetition of restraint in a drying process. In order to grasp the mechanical properties of paper in the actual paper drying process, dynamic experiments were conducted. Restraint ratio during drying remarkably affected paper shrinkage as compared with results of static experiments. 87% of restraint ratio made CD shrinkage reduce 3.4% which is 36% reduction to free drying. Also, increase of heating
more » ... re results in more reduction of the shrinkage. Drying in an open draw section provides non-uniform CD shrinkage profile in the cross machine direction due to Poisson' effect. The edge CD shrinkage was almost same as that of free drying. It was verified by FEM analysis that the cause was due to less CD stress of the edge in the open draw section. On the other hand, curl tendency in the drying process depended on the moisture level after switched top and bottom and which side was dried first. A cross point of curvature between top side dried first and bottom side dried first coincided with that of alternated drying. This indicated that it was possible to solve a curl problem due to one side drying in a single
doi:10.2524/jtappij.54.1098 fatcat:l565uw6q4fe53ev4qqxf7xgnoa