Perpendicular-To-Grain Rheological Behavior of Loblolly Pine in Press Drying


  • Yifu Tang
  • William T. Simpson


Drying, press drying, loblolly pine, southern pine, shrinkage, creep


To predict the thickness loss of loblolly pine lumber during press drying, a model was developed to describe the perpendicular-to-grain rheological behavior as a function of pressure, temperature, and drying time. The strain-time curve was divided into four parts—initial elastic deformation, viscoelastic deformation, final elastic springback, and time-dependent springback—according to the characteristic responses of these behaviors to pressure, temperature, and drying time. The model was fitted to experimental data by nonlinear regression. Good agreement was obtained between the predicted and experimental thickness loss during press drying.


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