COMPARATIVE STUDY ON THE HEAT TREATMENT OF DALBERGIA LATIFOLIA ROXB. WOOD UNDER ATMOSPHERIC PRESSURE AND VACUUM CONDITIONS

This study comparedatmospheric heat treatment (AHT) and vacuum heat treatment (VHT)of Dalbergia latifoliaRoxb. at 180°C for 6 hto improve dimensional stability. Through multiple tests, it analyzed their effects on the wood. Results showed VHT caused milder chemical changes, preserving hydroxyl and lignin structures while AHT severely degraded hemicelluloses. VHT led to lower weight loss 0.45% vs 1.25%, better dimensional stability with a greater reduction in radial swelling 0.84% vs 1.34%, higher mechanical strength (modulus of rupture: 118.22 MPa vs 95.83 MPa; modulus of elasticity 9361.50 MPa vs 8558.34 MPa), and a smaller color change ΔE*: 9.79 vs 18.65. Overall, VHT can balance performance improvement and minimize damage to the wood’s structure and aesthetics.