Binderless bamboo sawdust panels reinforced with bamboo fiber bundles: Effects of hot-pressing temperature, pressure and reinforcement architecture

Bamboo sawdust was converted into binderless panels by hot pressing, and the effect of bamboo fiber bundle reinforcement on strength and water resistance was evaluated. Panels of 300 × 300 × 12 mm were molded at 160, 180, or 200 °C under 4.5 MPa, and reinforced panels were additionally prepared at 200 °C under 10 MPa using unidirectional or orthogonal fiber-bundle architectures. Mechanical and physical properties reported in the experimental dataset included tensile strength, modulus of rupture (MOR), modulus of elasticity (MOE), density, thickness swelling, water absorption, and internal bond strength. Raising temperature from 160 to 200 °C markedly improved the dimensional stability of unreinforced panels, reducing water absorption from 104.14% to 27.95% and thickness swelling from 44.90% to 19.26%, although tensile strength decreased from 8.71 to 6.03 MPa. At 200 °C and 4.5 MPa, unidirectional bamboo fiber bundle reinforcement increased tensile strength to 26.61 MPa, MOR to 31.17 MPa, and MOE to 4014 MPa, while lowering water absorption to 13.83%. High-pressure pressing at 10 MPa produced denser reinforced panels with further gains in flexural performance. The orthogonal architecture showed lower directional strength than the unidirectional configuration but higher internal bond strength, lower thickness swelling (3.72%), and lower water absorption (6.12%). These results show that bamboo sawdust can be upgraded into adhesive-free panel products through thermo-mechanical densification, and that the preferred reinforcement architecture depends on whether directional strength or dimensional stability is prioritized. The reinforced panels used 30 wt% bamboo fiber bundles calculated on the total oven-dry furnish mass.