Comparative investigation into the interfacial adhesion of plywood prepared by air spray atomization and roller coating

Plasma treatment combined with air spray atomization (ASA) can improve the resin spread rate while manufacturing plywood and reduce the manufacturing cost and consumption of chemicals. To provide a mechanistic understanding of the interfacial adhesion of plywood with reduced resin spread rate, plywood prepared by ASA and roller coating (RC) was compared. The obtained results suggest that atomized resin penetrated plasma-treated poplar veneer and resulted in annular filling of vessels. The plasma treatment enhanced the penetration depth of atomized resin and further strengthened the cell walls in the interphase. The reduced elastic modulus (Er) and hardness (H) of the cell wall in plasma-treated ASA interphase were 17.48 GPa and 588.41 MPa, respectively. The plasma treatment further promoted a uniform distribution of shear strain in the shear section of plywood, indicating an enhanced stiffness and load-bearing capacity of the plywood interphase. A comparison between plywood prepared using ASA and RC revealed that massive amounts of resin consumption did not enhance the mechanical properties of the interphase and the resulting plywood. The results reported herein are beneficial for reducing the manufacturing cost and consumption of chemicals. Thus, a relatively sustainable development can be achieved in the wood composites industry.