Extended Data Fig. 5: Mechanical performance tests of seven-layer plywood.
a, The photograph of a whole piece of prepared seven-layer plywood. b, Photograph of elasticity and rupture modulus tests. c, Photographs of piled veneers or plywoods before (top row) and after (bottom row) 7.5-Kg or 80-Kg loading. The order of the deformation degree after the 80-Kg loading was UF resin > FPL ≈ PF resin, showing the excellent mechanical properties of FPL adhesive. d, The dimensions of seven-layer plywoods prepared at different hot-pressing conditions. The FPL used in this study was isolated from eucalyptus at 80 °C (extraction temperature), 5 h (extraction time), and 400 mg formaldehyde·g−1 biomass. The mass ratio of lignin, UF or PF resin to deionized water in prepared adhesive suspensions was 1: 4 (w: w). All plywoods in d were prepared under the hot-pressing conditions of 110 °C (hot-pressing temperature), 20 min (hot-pressing time), 2.0 MPa (hot-pressing pressure), and 100 g·m−2 (glue application level).
