Shrinkage of Recycled Paper Sheet During Drying

ABSTRACT

The properties of recycled paper are strongly affected by shrinking during drying, which depends on the drying conditions. An experimental study of the shrinkage phenomenon during drying of paper is presented. Drying experiments were conducted in a drying oven with controlled temperature. The temperature influence on shrinkage extent, porosity, and apparent density of the paper was evaluated. Structural changes on the paper surface after drying were analyzed by scanning electronic microscopy. Thickness contraction, surface, and volumetric shrinkage were correlated as a function of the moisture content. Lower apparent density values and more porous paper samples were obtained for higher temperatures.

Keywords:

• Convective drying
• Structural changes
• Structural properties
• Paper physical properties

ACKNOWLEDGMENTS

The authors acknowledge the financial support received from Foundation for Research Support of São Paulo State, FAPESP.