The dynamic mechanical behavior of paper during drying

The dynamic mechanical properties of paper during restrained drying are reported in this article. The apparatus used was a servohydraulic material testing system (MTS), connected to a computer unit. It has been found that the ratio of drying stress to elastic modulus at a given dry solids content corresponds to the instantaneous linear contraction of the sheet when the drying stress is relieved. It is therefore deduced that paper behaves as a linear viscoelastic body during restrained drying. The finding of a maximum loss coefficient and the drastic change in elastic modulus during drying of paper are interpreted in terms of a transitional change in the amorphous regions of wood polymers plasticized by water.