IN THIS WORK, THE IMPREGNATION QUALITY AND MECHANICAL PROPERTIES OF PINUS RADIATA D.DON TREATED WITH DIFFERENT COPPER NANOPARTICLES (CUNP) SOLUTIONS (NAMED K1 AND K2) AND A COMMERCIAL PRESERVATIVE (M) WERE STUDIED. THE IMPREGNATION QUALITY OF RADIATA PINE WOOD WAS ANALYZED BY TWO INDICATORS, PENETRATION AND RETENTION. THE MICRO-DISTRIBUTION OF PRESERVATIVE IN THE TREATED WOOD WAS QUALITATIVELY EVALUATED BY SEM-EDS, BOTH IN THE SAMPLES CONTAINING CUNP AND IN THOSE TREATED WITH THE COMMERCIAL PRESERVATIVE. IN ADDITION, SOME MECHANICAL PROPERTIES WERE STUDIED IN THE PRESERVED WOOD INCLUDING MOE, MOR AND HARDNESS. THE RESULTS INDICATED VALUES BY ED XRF RETENTION OF 0.96 KG/M3 AND 0.86 KG/M3 FOR K1 AND K2, RESPECTIVELY, AND 1.01 KG/M3 FOR M WOOD IMPREGNATED. IN THE PENETRATION DETERMINED BY COLORIMETRIC TEST, THE WOOD SAMPLES IMPREGNATED (WITH K1, K2 AND M) SHOWED 100% PENETRATION. THE DISTRIBUTION OF CUNP AND MICRONIZED COPPER WITHIN THE WOOD NSTRUCTURE WAS CONFIRMED BY SEM EDS MAPPING. IN MECHANICAL PROPERTIES, A REDUCTION IN MOE WAS REFLECTED IN ALL WOOD TREATED. THE CONTROL SAMPLES WERE FAR SUPERIOR TO THE K1 AND M TREATED SAMPLES AND SLIGHTLY SUPERIOR TO THE K2 SAMPLES, WITH NO STATISTICALLY SIGNIFICANT DIFFERENCES. ON THE OTHER HAND, SAMPLES IMPREGNATED WITH K1 AND K2 SHOWED THE HIGHEST VALUES IN HARDNESS PARALLEL AND PERPENDICULAR TO THE GRAIN, REVEALING THAT THESE PRESERVATIVE SOLUTIONS TEND TO INCREASE HARDNESS. OVERALL, WHEN IT COMES TO THE SAMPLES IMPREGNATED WITH MICRONIZED COPPER (M), THE MECHANICAL PROPERTIES WERE CONSIDERABLY LOWER COMPARED TO THE CUNP TREATED AND CONTROL WOOD. THEREFORE, THE CUNP-BASED PRESERVATIVE DID NOT STRONGLY AFFECT THE MECHANICAL PROPERTIES OF THE PRESERVED WOOD.

THE SAWING OF HYMENAEA COURBARIL IS COMPLEX DUE TO ITS HIGH DENSITY AND ABRASIVENESS. THESE FACTORS ACCELERATE THE WEAR ON SAW BLADE TEETH, AND AS A CONSEQUENCE, INCREASE THE CUTTING VARIABILITY AND PROCESS COSTS. THE EFFECT OF CUTTING PARAMETERS ON STANDARD DEVIATION OF SAWN-WOOD THICKNESS WAS EVALUATED TO PROPOSE OPTIMAL SAWING CONDITIONS. A LOG CARRIAGE BANDSAW WITH TWO SAW BLADE GEOMETRIES, THREE LOG DIAMETER CLASSES, AND TWO FEED RATES WERE USED TO CARRY OUT THE SAWING TESTS. THE RESULTS SHOWED THAT THE SAWING VARIATION EXPRESSED BY THE TOTAL STANDARD DEVIATION OF BOARD THICKNESS WAS LOWER THAN 1 MM, WHEN LOG DIAMETER WAS LOWER THAN 0.79 M, AND THE LOG CARRIAGE FEED RATE WAS LOWER THAN OR EQUAL TO 10 M MIN-1 FOR BOTH SAW GEOMETRIES. THE SAWING THICKNESS WAS AFFECTED BY LOG DIAMETER AND LOG CARRIAGE FEED RATE, WHILE SAW GEOMETRY WAS NOT STATISTICALLY SIGNIFICANT. HOWEVER, THE GOAL OF THIS INITIATIVE WAS NOT AN ESTIMATION OF THE CHANGES ON SAWMILL PRODUCTIVITY. BEFORE THIS STUDY, ALL LOG CLASSES WERE PROCESSED WITH A LOG CARRIAGE FEED RATE OF NO HIGHER THAN 10 M MIN(-1). CONSEQUENTLY, GIVEN THE ESTIMATED TOTAL STANDARD DEVIATIONS, IT CAN BE SUGGESTED THAT THE LOGS OF CLASS 2 COULD BE SAWN AT A 50 % HIGHER RATE WITHOUT ALTERING THE CUTTING PRECISION, IMPROVING SAWMILL PRODUCTIVITY.

THE USE OF EUCALYPTUS NITENS HAS DIVERSIFIED THE CHILEAN LUMBER INDUSTRY IN UNPRECEDENTED WAYS. HOWEVER, GROWTH-INDUCED STRAINS CAUSE SPLITTING AND WARPING. THE OBJECTIVE OF THIS INVESTIGATION WAS TO DETERMINE THE EFFECT OF THE HEAT TREATMENT APPLIED TO LOGS OF EUCALYPTUS NITENS ON THE REDUCTION OF GROWTH STRESSES AND IMPROVEMENT OF QUALITY IN SAWN WOOD. LOGS WERE EXTRACTED AT DIFFERENT HEIGHTS OF THE TREE FOR 15-YR AND 20-YR-OLD TRESS. THE SAWMILL PROCESS WAS ALLOWED TO OBTAIN RADIAL, MIXED, AND TANGENTIAL PLANE PIECES, AT TWO THICKNESSES (25 AND 50 MM). THE EVALUATION OF MC AND WARPING WAS ACCORDING TO CHILEAN NATIONAL STANDARDS. THE RESULTS OBTAINED IN THIS RESEARCH SUGGEST THAT BY APPLYING THE HEAT TREATMENT TO EUCALYPTUS NITENS LOGS, A SIGNIFICANT REDUCTION IN GROWTH STRAINS CAN BE ACHIEVED. HEAT TREATMENT ALSO INCREASED THE QUALITY OF THE PIECES IN TERMS OF BOW, CROOKING, AND TWISTING. THEREFORE, THERE ARE SUBSTANTIAL BENEFITS OF USING HEAT TREATMENTS TO REDUCE DEFECTS CAUSED BY GROWTH STRAINS AND THUS INCREASE THE QUALITY OF THE WOOD AND REDUCE ITS WARP.

THE AIM OF THIS RESEARCH WAS TO PROPOSE MODELS TO PREDICT THE DRYING RATE OF EUCALYPTUS NITENS WOOD. FOR THIS, TANGENTIAL PIECES WITH A THICKNESS OF 36 MM, A WIDTH OF 100 MM AND A LENGTH OF 1000 MM WERE USED, WHICH WERE SUBJECTED TO ISOTHERMAL DRYING IN A SEMI-INDUSTRIAL CONVECTIVE CHAMBER, CONTROLLING THE MASS AT REGULAR INTERVALS OF TIME. THE TESTS CONSIDERED TWO CONDITIONS; CONDITION 1 (DRY / WET BULB TEMPERATURE 40/35 ° C) AND CONDITION 2 (55/50 ° C), WITH AIR VELOCITY 2 (M / S). THE EUCALYPTUS NITENS SHOWED DECREASING DRYING PHASES, WHILE THE CRITICAL MOISTURE CONTENT CORRESPONDED TO THE INITIAL MOISTURE CONTENT. THE SATURATION POINT OF THE EXPERIMENTAL FIBERS VARIED WITH THE DRYING TEMPERATURE, WITH AN ERROR OF UP TO 6.3% WITH RESPECT TO THE THEORETICAL VALUE. THE DRYING RATE WAS SIGNIFICANTLY AFFECTED BY MOISTURE CONTENT AND DRY BULB TEMPERATURE. THE RESULTS SHOWED THAT THE SIMPLE AND MULTIPLE REGRESSION MODELS (P-VALUE:

APPRAISING AND PROTECTING FORESTS REQUIRES A MANAGEMENT PLAN AND THE CREATION OF INNOVATIVE PRODUCTS FOR THE MARKET. THE DEVELOPMENT OF THE GREEN GLUING TECHNIQUE COULD ADD VALUE TO NATIVE TIMBER. HOWEVER, THERE IS A LACK OF KNOWLEDGE CONCERNING THE RESPONSE AND THE PRODUCTIVE PROCESS OF NOTHOFAGUS SPECIES USING THIS TECHNIQUE. THIS WORK INVESTIGATED THE VIABILITY OF IMPLEMENTING THE GREEN GLUING METHOD USING THREE TYPES OF NOTHOFAGUS. WOOD PIECES WERE MADE USING A ONE-COMPONENT POLYURETHANE ADHESIVE. DELAMINATION, SHEAR TESTS, MORPHOLOGICAL CHARACTERIZATION, AND BOND LINE THICKNESS ANALYSIS TESTED THEIR CAPACITY. THE RESULTS SHOWED A VARIABLE RESPONSE DEPENDING ON THE NOTHOFAGUS TYPE, WHERE THE SURFACE TREATMENT COULD IMPROVE THE GREEN GLUING PERFORMANCE. THE FINDINGS HIGHLIGHT THE RELEVANCE OF INCREASING KNOWLEDGE ABOUT THE ESSAYED SPECIES AND THEIR PREPARATION TO MAINTAIN THEIR NATURAL MOISTURE CONDITION.

EUCALYPTUS NITENS HAS A GREAT POTENTIAL FOR ITS USE IN HIGHER VALUE-ADDED PRODUCTS, MAINLY DUE TO ITS GROWTH RATE AND ADAPTABILITY TO DIFFERENT SOILS AND CLIMATES. HOWEVER, ITS USE IS STILL LIMITED, DUE TO LACK OF KNOWLEDGE OF ITS PHYSICAL PROPERTIES THROUGHOUT THE LOG. IN THIS SENSE, THE OBJECTIVE OF THE RESEARCH WAS TO MODEL THE PHYSICAL PROPERTIES AT DIFFERENT HEIGHTS AND AGE OF THE TREE. TO DO SO, 40 TREES OF 13 YEARS, 12 OF 15 YEARS AND 5 OF 20 YEARS WERE SELECTED, EVALUATING THEIR PHYSICAL PROPERTIES FROM THE BASE (0.3 M) TO THE USABLE FREE DIAMETER OF 8 CM. THE BASIC DENSITY AND MOISTURE CONTENT WERE DETERMINED BY STANDARD NCH176/2 OF. 86 AND NCH176/1 OF. 86, RESPECTIVELY. THE RESULTS SHOWED A BASIC DENSITY AT 13 YEARS OF 474 KG/M 3 , WITH A MOISTURE CONTENT OF 116%, AT 15 YEARS IT WAS 496 KG/M 3 AND 108% AND AT 20 YEARS IT WAS 521 KG/ M 3 AND 104% RESPECTIVELY. THERE WAS AN INCREASE OF 4.6% AND 9.7% IN THE BASIC DENSITY AT 15 AND 20 YEARS COMPARED TO 13 YEARS. THE MODEL DETECTED AN INVERSE RELATIONSHIP BETWEEN THE BASIC DENSITY AND MOISTURE CONTENT, BOTH PRESENTING A HIGH CORRELATION WITH THE HEIGHT AND AGE OF TREE. FINALLY, THE MODEL PREDICTED WITH HIGH LEVEL OF PRECISION THE PHYSICAL PROPERTIES IN EUCALYPTUS NITENS TREES. SO, IT CAN BE USED AS A TOOL TO SUPPORT DECISION-MAKING WHEN DEFINING THE USE OF LOGS ACCORDING TO THE TYPE OF PRODUCT TO OBTAIN.

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.

THE OBJECTIVE OF THIS RESEARCH WAS TO DEVELOP REGRESSION MODELS, WITH THE PURPOSE OF ESTIMATING THE GROWTH STRESSES AND END SPLITTING, IN 12-YR-OLD EUCALYPTUS NITENS TREES LOCATED IN THE PROVINCE OF VALDIVIA, CHILE. A TOTAL OF 40 TREES WERE SAMPLES. THEIR LONGITUDINAL RESIDUAL STRAIN (LRS) WAS MEASURED USING THE CIRAD-FORÊT METHOD AND COMPARED WITH THE COUNCIL OF SCIENTIFIC AND INDUSTRIAL (CSIR) INDEX AND WITH A NEW INDEX PROPOSED IN THIS INVESTIGATION, CALLED THE SPLITTING INDEX. PHYSICAL AND DENDROMETRIC PROPERTIES OF EACH SELECTED TREE WERE MEASURED TO IDENTIFY POSSIBLE CORRELATIONS BETWEEN THESE VARIABLES. THESE PREDICTORS WERE ANALYZED STATISTICALLY, ALLOWING THE DEVELOPMENT OF REGRESSION MODELS, WHICH SHOWED A COEFFICIENT OF DETERMINATION (R2) OF 0.783 AND 0.770 TO PREDICT THE LRS AND CSIR INDEXES, RESPECTIVELY. FINALLY, A RELATIVELY ROBUST REGRESSION MODEL WAS DEVELOPED TO PREDICT END SPLITTING IN LOGS USING LRS AND PHYSICAL AND DENDROMETRIC PARAMETERS.

STRUCTURAL LUMBER IS DESIGNED TO MEET THE TECHNICAL STANDARDS THAT ENSURE SAFETY, COSTEFFECTIVENESS, AND SUSTAINABILITY. HOWEVER, SOME TREE SPECIES FACE LIMITATIONS IN THEIR GROWTH, WHICH RESTRICTS THEIR WIDESPREAD USE. AN EXAMPLE OF THIS IS NOTHOFAGUS ALPINA, WHICH HAS EXCELLENT MECHANICAL PROPERTIES BUT IS NOT UTILIZED MUCH DUE TO THE CHALLENGES IN EXTRACTING ITS TIMBER AND POOR UTILIZATION, MAINLY BECAUSE OF THE LENGTH OF THE WOOD. THERE IS LITTLE INFORMATION CONCERNED WITH THE USES AND BETTER MANAGEMENT OF SMALL PIECES USING NOTHOFAGUS SPECIES, BUT IT IS STILL INSUFFICIENT. THIS STUDY INVESTIGATES THE ADHESION PERFORMANCE OF GREEN-GLUED FINGER JOINTS WITH VARYING WOOD RING ORIENTATIONS AND MOISTURE CONTENTS RANGING FROM 21% TO 25% USING NOTHOFAGUS ALPINA. THE PRIMARY AIM IS TO ASSESS HOW RING ORIENTATION AND WET TIMBER AFFECT THE GREEN GLUING PROCESS FOR CREATING LARGER WOOD PIECES THAN SAWN WOOD. THE RESULTING PRODUCTS COULD MEET THE STANDARDS FOR WOOD SERVICEABILITY NUMBER THREE FOR NATIVE CHILEAN WOOD. THE FINDINGS INDICATE THAT FINGER JOINT PERFORMANCE IMPROVES WITH HIGHER TIMBER MOISTURE LEVELS. HOWEVER, THE ORIENTATION OF THE WOOD FIBERS DID NOT SIGNIFICANTLY AFFECT THE PERFORMANCE UNDER THE TESTED CONDITIONS. IT IS IMPORTANT TO NOTE THAT THIS EFFECT MAY BECOME MORE SIGNIFICANT NEAR THE FIBER SATURATION POINT. THESE FINDINGS EMPHASIZE THE NEED FOR A DETAILED PROTOCOL ON THE GREEN GLUING TECHNIQUE FOR NOTHOFAGUS ALPINA AND THE ASSOCIATED DRYING AND SURFACE PROCESSES IN FINGER JOINT CONSTRUCTION.