Influence of different hot-pressing conditions on the performance of eco-friendly jabon plywood bonded with citric acid adhesive

The citric acid (CA)-based adhesive, as a new environment-friendly adhesive, has been developed and used for the manufacturing of plywood to resolve the problem of formaldehyde-based adhesive for human health. The effects of pressing time and temperature on physical and mechanical properties of plywood were examined. Three-layer plywood panels were bonded using CA adhesive with a 134 g/m(2) of single glue spread on White jabon wood veneer. The plywood panels were hot-pressed at 5 MPa with three different pressing temperatures, 180 degrees C, 190 degrees C, 200 degrees C, for 10 min, and also different pressing times, 4, 7, 10 min at 190 degrees C. The physical and mechanical properties, such as moisture content, delamination, and shear strength, were evaluated according to JAS 233:2003. The results show that the plywood with pressing temperature of 190 degrees C for 10 min had lower delamination and greater tensile shear strength than those of other plywood panels. Moreover, some properties of the plywood fulfilled the requirement of JAS 233:2003. Based on the FTIR analysis, citric acid plays an important role in the formation of ester linkages (R-COO-R) via esterification between carboxyl groups of citric acid and hydroxyl groups of White jabon wood veneer, resulting excellent properties of plywood.

Automated summary

The study developed a citric acid-based adhesive for manufacturing plywood, aiming to address the health issue associated with formaldehyde-based adhesives. Results showed that plywood with specific pressing temperature and time exhibited improved properties and met certain standards.