HOT-PRESSING VENEER-BASED PRODUCTS - THE INTERACTION OF PHYSICAL PRECESSES

Internal vapor pressure, internal temperature, and compaction are quan tified during the laboratory pressing of five-layered Douglas-firplywo od panels. The techniques used to collect these data are described. So me interactions among the variables, and their effect on the attainmen t of product integrity, are considered. Most attention is given to the accumulation and dissipation of water vapor pressure within panels. I nterestingly, such pressures were found to be greatest within the core plane of panels at all but the early stages of the pressing cycle. It is suggested that the gas permeability of gluelines changes as pressi ng proceeds and that this may play an important role in affecting vapo r entrapment and therefore the efficiency of veneer-based systems' man ufacture.