| Pressing method is commonly used to produce all kinds of wood-base product. Veneer drying is an energy demanding process. This research is aimed to increase drying productivity and reduce energy consumption.Water loss during compressing was analyzed and calculated theoretically. Several factors influenced the MC removal were also analyzed, such as veneer surface roughness, lateral expansion etc. Mechanical energy was calculated experimentally and compared with the thermal energy assuming to evaporate same amount of water. We could find that squeezing method reduced thermal energy greatly.The drying behavior of compressed and control veneer was compared. The difference was analyzed and confirmed by permeability test. Compression method caused many mini-cracks of cell wall and crashed the pit structure of wood cell. Therefore, it increased the veneer permeability. For heartwood veneer, its permeability increased 2 times. For sapwood veneer, that increased 40%. The MOE and MOR were tested and the results show compressing method did not decrease veneer mechanical property. So did the 5-ply panels. Bonding tests showed that compressing method could improve 5% of panels' bonding strength and percentage of wood failure. |
PDF Full Text Request