Abstract:The overlaying process of particleboard involves a compressive rheological behaviour to the particleboard itself. In order to get a better understanding of the process and controling the thickness tolerance of overlaid particleboard, a rheological analysis can be adopted to the study of the behaviours of particleboard under compression perpendicular to its surface.Four kinds of creep-recovery curves can be identified in the wide range of compressive stresses as the creep behaves differently at different stress levels. The statistical results reveal that: the standard error of instantaneous elastic deformation is smaller and relatively constant; that of instantaneous plastic deformation is relatively larger and increasing as the stress inereases; the standard error of time-dependant plastic deformation increases with stress, and similar to that of the retarded elastic deformation, which increases as the creep time prolongates; the changing pattern of standard error of thickness decrement is consistant with that of instantaneous and time-dependant plastic deformation.Because the big voids in the most wood particles have been compressed during the manufacture of particleboard, the values of compressive theological parameters of particleboard are smaller than those of the original poplar wood.