A Multifunctional Mineral Binder for Plywood Production: The Effect of Manufacturing Parameters on Bonding Quality

Geopolymers show great potential for use as binders in developing and manufacturingmultifunctional wood products. The objective of this study was to improve the bonding qualityof a geopolymer binder, with wood veneers, using different manufacturing parameters. To thisend, we produced five layered plywood panels treated with various lay-up times (1, 5, 10, 15 min),panel compressibility values during hot pressing (5%, 10%, 15%, and 30% compression), veneerroughness values (low, medium, and high roughness), press temperatures (120, 140, and 160◦C),and veneer layouts via changing the middle layer position of plywood relative to the surface layers.The results show that the shear strength and thickness swelling were negatively influenced byincreasing the lay-up time of resinated veneers and panel compressibility. Increasing the veneerroughness significantly increased the panels’ properties. Furthermore, the panels produced witha pressing temperature of 140◦C showed the best performances. The veneer layouts also significantlychanged the physical and mechanical properties of the plywood panels. Generally speaking, the resultsobtained in this study show that improving the bonding quality of geopolymer binders with woodcan be done through the manipulation of plywood manufacturing parameters.