WOOD DRYING QUALITY AND TRANSVERSAL PERMEABILITY OF CHILEAN SECOND-GROWTH NOTHOFAGUS ALPINA (RAULÍ) WERE EVALUATED. TWO CHARGES OF RAULÍ SAWNWOOD WERE DRIED IN A EXPERIMENTAL KILN. ONE OF THE CHARGES WAS PREPARED WITH SAWNWOOD FROM PINTO THE SECOND ONE WAS PREPARED WITH SAWNWOOD FROM COLLIPULLI. THE TRANSVERSE PERMEABILITY TO AIR OF THE MATERIAL AFTER DRYING WAS DETERMINED. THE RESULTS SHOWED THAT THE DRYING RATE WAS 25% HIGHER AND DRYING TIME WAS ABOUT 18% SHORTER FOR COLLIPULLI SAWNWOOD (FROM GREEN TO 12%) DUE TO THE EXTENT OF HEARTWOOD. THE SHRINKAGE, COLLAPSE AND DRYING STRESS WERE LESS IN THE WOOD DRIED FROM COLLIPULLI, WHILE THE TRANSVERSE PERMEABILITY WAS LOWER IN THE SAMPLES FROM PINTO.

INTRODUCTION: PARTICLE BOARD PRODUCTION IS BASED ON THE USE OF SAWMILL AND REMANUFACTURING RESIDUES; HOWEVER, THE AVAILABILITY OF THIS RAW MATERIAL HAS DECREASED SIGNIFICANTLY DUE TO ITS USE AS BIOMASS FOR FIREWOOD FUEL. OBJECTIVE: TO EVALUATE THE EFFECT OF THE REPLACEMENT LEVEL OF MAIZE (ZEA MAYS L.) AND PINUS RADIATA D. DON RESIDUES ON PHYSICAL AND MECHANICAL BOARD PROPERTIES. MATERIALS AND METHODS: MAIZE AND P. RADIATA RESIDUE PROPORTIONS BETWEEN 0 % (CONTROL) AND 30 % MAIZE WERE EVALUATED. UREA-FORMALDEHYDE ADHESIVE WAS USED IN PROPORTIONS OF 7.5 % AND 9.5 % FOR FINE AND THICK PARTICLES, RESPECTIVELY; PRESSING WAS BASED ON INDUSTRIAL PARAMETERS WITH A THICKNESS OF 10 MM AND 0.77 G?CM-3 DENSITY. PHYSICAL AND MECHANICAL PROPERTIES WERE DETERMINED ACCORDING TO PARTICLE BOARD STANDARDS. RESULTS: THICKNESS, DENSITY, MOISTURE, MODULUS OF ELASTICITY AND MODULUS OF RUPTURE WERE SIMILAR AMONG MAIZE RESIDUE PROPORTIONS AND MET THE INDUSTRIAL REQUIREMENT. AT 2 AND 24 H, ABSORPTION AND SWELLING MET THE INDUSTRIAL AND REGULATORY REQUIREMENT, EXCEPT FOR SWELLING AT 2 H WHEN 30 % MAIZE RESIDUES WAS USED. THE INTERNAL BOND (IB) MET THE INDUSTRIAL REQUIREMENT WITH ALL PROPORTIONS, BUT FROM 20 % ONWARDS THERE WAS A SIGNIFICANT DECREASE (P < 0.05). CONCLUSIONS: MAIZE RESIDUE PROPORTIONS BETWEEN 0 AND 10 % HAD SIMILAR PERFORMANCE. A PROPORTION OF UP TO 20 % MAIZE PROVIDED REGULATORY AND INDUSTRIAL COMPLIANCE, SO IT HAS POTENTIAL FOR THE PARTICLE BOARD INDUSTRY.