Effect of Moisture Content on Thermal Physical Properties and Heat Transfer of Plywood during Hot-Pressing

Abstract

In order to investigate the effect of moisture content on thermal physical properties and heat transfer of plywood during hot pressing, the quasi steady method was applied to measure the thermal conductivity, specific heat and thermal diffusivity values of the resinated plywood assembly with a UF loading rate of 300g/m2 under different moisture conditions. Results showed that with the increase of moisture content in a range of 10-22%, the thermal conductivity and specific heat of the plywood assembly enhanced significantly, and that plywood hot pressing noticeably consisted of fast heating and slow heating phases: during the first phase the heating rate of the core ply was quickened with the increase of moisture content while the second phase did not show any significant impact of moisture content on the corresponding heating rate.