ACACIA DEALBATA LINK, KNOWN AS MIMOSA IN PORTUGAL, IS AN INVASIVE HARDWOOD SPECIES WITH POTENTIAL FOR CONSTRUCTION USE, BUT RESEARCH IS LIMITED. THE AVAILABLE STOCK OF SMALL-DIAMETER JUVENILE WOOD LOGS CAN HELP REDUCE THIS GAP, BUT TANGENTIAL CRACKING AT LOG ENDS CHALLENGES FASTENER CONNECTIONS. THIS STUDY EVALUATED DIFFERENT TREATMENTS TO CONTROL AND REDUCE END-FACE CRACKING IN SMALL WOOD LOGS DURING AIR DRYING, AN ECONOMICAL AND ENVIRONMENTALLY FRIENDLY PROCEDURE. THE EXTREME TWO-THIRDS OF SIXTEEN MIMOSA LOGS WERE SUBJECTED TO TWO TREATMENTS: ONE WITH LONGITUDINAL KERFS 15 MM DEEP ALONG THE LENGTH (TWO AND THREE KERFS) AND THE OTHER WITH A HOLLOW IN THE CENTER UP TO HALF THE LENGTH (16 MM AND 30 MM DIAMETERS). OVER 219 DAYS OF AIR DRYING AND COMPARED WITH THE CENTRAL PART, KERFING TREATMENTS SIGNIFICANTLY REDUCED OUTER-WOOD TANGENTIAL CRACKING (P < 0.001), WITH THE THREE KERFS ALSO REDUCING CRACK NUMBERS (P < 0.05) BUT INCREASING SIGNIFICANTLY CRACKS NEAR THE PITH (P < 0.01). THE 30 MM CENTRAL HOLLOW SIGNIFICANTLY REDUCED CENTRAL PERFORATION CRACKING (P < 0.05). PROSPECTIVELY, THE RESULTS SUGGEST THAT A COMBINED TREATMENT APPROACH INVOLVING CROSS-CUTS COULD HELP REDUCE AND/OR CONTROL END CRACKING, THEREBY IMPROVING THE SUITABILITY OF WILD MIMOSA LOGS FOR CONSTRUCTION USE.

THIS STUDY DEALS WITH THE EFFECT OF HEAT TREATMENT ON PINUS OOCARPA SPECIMENS FROM FOREST PLANTATIONS IN COLOMBIA. THE EFFECTS OF TWO HEAT TREATMENTS AT 170 AND 190 °C FOR 2.5 H IN SATURATED VAPOR WERE EVALUATED BASED ON THE COLOR, DIMENSIONAL STABILITY, AIR-DRY AND BASIC DENSITIES, MODULUS OF ELASTICITY (MOE), AND MODULUS OF RUPTURE (MOR) IN STATIC BENDING OF SAMPLES. THE EVALUATIONS WERE CARRIED OUT FOLLOWING THE COLOMBIAN TECHNICAL STANDARDS NTC 290 AND 663, AND THE COLOR CHANGES RESULTING FROM HEAT TREATMENTS WERE MONITORED USING THE CIE-LAB, AS WELL AS OTHER STANDARDS FROM THE LITERATURE. THE RESULTS SHOW THAT THERE WAS 2.4% AND 3.3% MASS LOSS OF WOOD MODIFIED AT 170 AND 190 °C, RESPECTIVELY. THE AIR-DRY AND BASIC DENSITIES WERE HIGHER IN 170 °C TREATMENT THAN AFTER 190 °C TREATMENT, AND THE THERMAL MODIFICATIONS APPLIED INCREASED THE DIMENSIONAL STABILITY OF THE TREATED WOOD. AFTER TREATMENT AT 170 AND 190 °C, THE LIGHTNESS TO DARKNESS (L*) WAS REDUCED BY 10% AND 22%; THE A* COORDINATE INCREASED BY 11% AND 26%, CAUSING REDNESS IN THE TREATED WOOD; THE B* COORDINATE INCREASED BY 14% AND 17%; AND THE VALUES OF THE WOOD COLOR SATURATION (C*) INCREASED BY 14% AND 18%, RESPECTIVELY. THE GENERAL COLOR CHANGE (?E*) INCREASED GRADUALLY WITH THE INCREASE IN THE TREATMENT TEMPERATURE, RESULTING IN A HIGH COLOR CHANGE TO A VERY DIFFERENT COLOR. THE BENDING STRENGTH OF THERMALLY MODIFIED WOOD WAS IMPROVED AND SIGNIFICANTLY INCREASED TO VALUES HIGHER THAN THOSE OF UNMODIFIED PINUS OOCARPA WOOD. THE HIGH AIR-DRY AND BASIC DENSITIES, IMPROVED DIMENSIONAL STABILITY AND RESISTANCE TO BENDING, AND ATTRACTIVE APPEARANCE OF THE TREATED WOOD INDICATE THAT THERMAL MODIFICATION IS A PROMISING ALTERNATIVE FOR THE TRANSFORMATION OF PINUS OOCARPA WOOD INTO A RAW MATERIAL WITH A HIGH ADDED VALUE

TO EVALUATE EVOLUTION OF PHYSICAL AND MECHANICAL PROPERTIES DUE TO DRYING AND HEAT MODIFICATION, A LOAD OF RADIATA PINE WOOD WAS SELECTED AND PROPERTIES WERE MEASURED AFTER EACH DRYING PROCESS. THE RESULTS REVEALED INTERESTING CORRELATIONS BETWEEN INTRINSIC FACTORS AND PROPERTIES; THE VALUES OF DENSITY WERE HIGHLY DISPERSED AFTER DRYING OR THERMAL TREATMENT AND UNCORRELATED WITH OTHER PARAMETERS, BUT THE MINIMUM DENSITY VALUES WERE KEPT CONSTANT AFTER HEAT TREATMENT. MOREOVER, WEIGHT LOSS (WL) AND MOISTURE CONTENT (MC) WERE DECREASING PROPORTIONALLY TO THE TREATMENT INTENSITY, DUE TO WOOD?WATER INTERACTIONS, CELL WALL CHANGES, AND THERMAL DEGRADATION OF WOOD FRACTIONS. WL AND MC WERE REASONABLY CORRELATED WITH THE DIMENSIONAL STABILITY, IMPROVING THE DIMENSIONAL STABILITY AFTER DRYING TREATMENTS, BUT KEEPING THE SAME ORDER OF ANISOTROPY. REGARDING THE WOOD STIFFNESS (MODULUS OF ELASTICITY, MOE), IT WAS UNAFFECTED BY THE DRYING TEMPERATURE, AND THE CORRELATIONS BETWEEN MOE AND MC OR WL APPEAR TO BE ACCEPTABLE, AND THE VALUES OF MC OR WL DID NOT ADVERSELY AFFECT THE MOE. HOWEVER, THE MODULUS OF RUPTURE WAS DROPPED DURING THE DRYING PROCESS, OBTAINING THREE DIFFERENTIATED GROUPS WITH A DECREASE IN AROUND 59% AFTER THERMAL MODIFICATION.

IN THIS STUDY, THE EFFECTS OF THE WOOD QUALITY USED FOR THERMAL MODIFICATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OBTAINED AT TWO TREATMENT TEMPERATURES COMMONLY USED AT THE INDUSTRIAL LEVEL WERE EVALUATED IN ORDER TO VALIDATE EXPERIMENTALLY THE PILOT SCALE PROCESS FOR ITS FUTURE INDUSTRIAL SCALING. THE QUALITY OF THE INPUT RADIATA PINE REFERS TO THE PRESENCE OF NATURAL DEFECTS OF WOOD, AS WELL AS THE AMOUNT OF JUVENILE WOOD. SELECTED THERMALLY MODIFIED SAMPLES WERE USED TO MEASURE SOME QUALITY MARKERS (PHYSICAL, MECHANICAL, OPTICAL) AND TO FIND THEIR CORRELATIONS DUE TO QUALITY OR TREATMENT, SO AS TO OBTAIN THE BEST CHARACTERISTICS OF THE HEAT-TREATED PRODUCTS. THE RESULTS INDICATED THAT THE QUALITY OF THE INPUT WOOD WAS ONLY RELEVANT TO THE MILD TREATMENT (190 °C), FINDING AN ACCEPTABLE CORRELATION BETWEEN THE WEIGHT LOSS AND THE QUALITY USED (FIRST QUALITY). AFTER BOTH TREATMENTS, THE ORDER OF ANISOTROPY WAS KEPT AND THE DIMENSIONAL CHANGES WERE SIGNIFICANTLY REDUCED; THUS, THE WEIGHT LOSS DURING TREATMENT DID NOT DRAMATICALLY AFFECT ITS ANATOMICAL STRUCTURE. CLUSTERING THE DATA BY STATISTICAL PROCEDURES WAS POSSIBLE TO OBSERVE THAT SAMPLES OF LOWER QUALITY WERE ORDERED ACCORDING TO THE TREATMENT TEMPERATURE, INDICATING A STRONG INFLUENCE OF THE TREATMENT ON THE PROPERTIES OBTAINED. THE MECHANICAL PROPERTIES REVEALED THAT UP TO 190 °C THE CHEMICAL CHANGES THAT OCCUR ON WOOD AFFECTED POSITIVELY THE VALUES (MOE INCREASED BY ABOUT 15?32% AND MOR SLIGHTLY DECREASED?

THIS IS A SUMMARY OF A STUDY CARRIED OUT IN CHILE TO CERTIFY INDUSTRIAL KILN DRYING OF RADIATA PINE TO COMPLY WITH THE INTERNATIONAL PHYTOSANITARY STANDARD ISPM 15. THE DRYING TESTS WERE PERFORMED IN 100-M3 INDUSTRIAL KILNS LOCATED AT FOUR DIFFERENT SAWMILLS OF THE VIII REGION IN CHILE. THE OBJECTIVE WAS TO DEVELOP A STANDARD PROTOCOL TO CERTIFY INDUSTRIAL DRYING OF RADIATA PINE DEPENDING ON THE DRYING SCHEDULE AND WOOD THICKNESS. IN PART, THE RESULTS WERE USED TO DEVELOP A MULTIPLE REGRESSION EQUATION THAT PERMITS SAWMILLS TO SELECT THEIR DRYING SCHEDULES IN SUCH A WAY THAT THE LUMBER CAN BE OFFICIALLY STAMPED AS BOTH KILN-DRIED AND HEAT-TREATED FOR INTERNATIONAL TRADE.

THE THERMAL MODIFICATION OF WOOD IS A POTENTIAL ALTERNATIVE METHOD FOR IMPROVING WOOD DIMENSIONAL STABILITY AND INCREASING THE RESISTANCE OF WOOD TO DECAY. HOWEVER, DURING THERMAL MODIFICATION, MORPHOLOGICAL CHANGES OCCUR WITHIN THE MICROSTRUCTURE OF THE CELL, AND THESE CONFER DIFFERENT PROPERTIES TO THE WOOD. THIS STUDY INVESTIGATED THE EFFECTS OF THE THERMAL MODIFICATION PROCESS ON THE MICROSTRUCTURE OF RADIATA PINE JUVENILE WOOD. THEREFORE, ANATOMICAL MEASUREMENTS WERE PERFORMED VIA OPTICAL MICROSCOPY IN SELECTED EARLYWOOD AND LATEWOOD SAMPLES AFTER EACH TREATMENT, AND THE RESULTS WERE COMPARED TO UNTREATED WOOD SAMPLES. IN THIS STUDY, TWO TEMPERATURES (190 °C AND 210 °C) WERE CONSIDERED FOR THE THERMAL MODIFICATION PROCESS. THE RESULTS SHOWED THAT THE LEVEL OF TEMPERATURE OF MODIFICATION AFFECTED TO MICROSTRUCTURE OF CELL WALL. THE CELL WALL THICKNESS DECREASED AS TREATMENT TEMPERATURE INCREASED, WHEREAS THE AVERAGE LUMEN DIAMETER INCREASED SLIGHTLY AS TEMPERATURE INCREASED. THERMALLY MODIFIED RADIATA PINE SHOWED SIGNS OF DAMAGE (CRACKS, BROKEN CELLS AND DEFORMATIONS IN THE WOOD CELL WALL). THE PROPORTION OF DESTROYED AREA INCREASED AS TEMPERATURE INCREASED, AND SIGNIFICANT DIFFERENCES WERE EVIDENT FOR THE THERMAL TREATMENT AT 210 °C.

THIS PAPER STUDIES THE RELATIONSHIP BETWEEN APPARENT DENSITY AND SOME ANATOMICAL PROPERTIES OF EUCALYPTUS NITENS SUCH AS VESSEL FREQUENCY, VESSEL AREA, RING WIDTH, FIBER CELL WALL THICKNESSES, AND FIBER LENGTH. THE STUDY INVOLVED 29 TREES FROM 10 FAMILIES OF EUCALYPTUS NITENS CUT FROM A 17-YR-OLD PLANTATION IN SOUTHERN CHILE. THE PROPERTIES WERE DETERMINED ALONG THE RADIAL DIRECTION OF THE TREES BY USING X-RAY EQUIPMENT AND AT SELECTED POSITIONS THROUGH MICROSCOPE AND FIBER QUALITY ANALYZER EQUIPMENT. THE RESULTS SHOWED THAT THE ANATOMICAL PROPERTIES OF E. NITENS DID NOT CHANGE GRADUALLY FROM PITH TO BARK, BUT THEY WERE BETTER DESCRIBED BY DIVIDING THE TREE RADIUS INTO THREE DIFFERENT WOOD-ZONES REFERRED AS * CORRESPONDING AUTHOR ? SWST MEMBER INNER-, MIDDLE-, AND OUTER-WOOD. THE APPARENT DENSITY OF E. NITENS WAS DEPENDENT OF THE VESSEL AREA, CELL WALL AREA, RING WIDTH, AND LATEWOOD WIDTH. THE CORRELATION COEFFICIENT BETWEEN APPARENT DENSITY AND VESSELS AREA WAS NEGATIVE AND THE CORRELATION COEFFICIENT BETWEEN APPARENT DENSITY AND CELL WALL AREA, LATEWOOD RING WIDTH, AND TOTAL RING WIDTH WERE POSITIVE. THESE MEANS THAT E. NITENS WOOD WITH LOWER DENSITY TENDED TO HAVE HIGHER VESSEL AREA, AND LOWER FIBER CELL WALL AREA, RING WIDTH, AND LATEWOOD WIDTH.

WOOD DRYING IS AN IMPORTANT PROCESS FOR ADDING VALUE AND MANUFACTURING INNOVATIVE PRODUCTS. EUCALYPTUS NITENS WOOD IS INHERENTLY DIFFICULT TO DRY BECAUSE OF ITS NATURAL PROPENSITY FOR CHECKING AS WELL AS COLLAPSE AND SHRINKAGE. LUMBER RECOVERY AFTER INDUSTRIAL DRYING OF EUCALYPTS IS ALSO VERY LOW. THIS STUDY MEASURED THE WOOD QUALITY OF E. NITENS JUVENILE WOOD (13 MM THICKNESS) AFTER RADIO-FREQUENCY VACUUM (RFV) DRYING AND WOOD DRIED IN A CONVENTIONAL KILN DRYER (KD). DRYING CYCLES WERE PERFORMED USING A RADIO FREQUENCY VACUUM DRYER WITH A 3 M3 OF CAPACITY AND CONVECTIVE KILN-DRYER EQUIPMENT WITH A 3.5 M3 OF CAPACITY. THE RESULTS SHOWED THAT THE DRYING TIME USING THE RADIO FREQUENCY VACUUM METHOD WAS REDUCED BY 47% WHEN COMPARED TO CONVENTIONAL KILN DRYING. THE SHRINKAGE WAS SIGNIFICANTLY LOWER IN THE RFV THAN IN THE CONVENTIONAL KD. THE VOLUMETRIC COLLAPSE DECREASED BY APPROXIMATELY 60% IN THE RFV DRYING. RFV DRYING OF E. NITENS JUVENILE WOOD IMPROVES THE WOOD QUALITY FOR SOLID WOOD PRODUCTS BECAUSE THE INTENSITY OF SURFACE CHECKING AND COLLAPSE ARE REDUCED.

RADIATA PINE WOOD PACKAGING NEEDS TO BE STERILIZED ACCORDING TO INTERNATIONAL PHYTOSANITARY STANDARDS. IN THIS WORK THE HEAT STERILIZATION TIME OF GREEN RADIATA PINE PACKAGING MATERIAL STACKED WITHOUT SEPARATORS WAS STUDIED ON AN INDUSTRIAL SCALE, CONSIDERING AS VARIABLE FACTORS THE STEAM TEMPERATURE (80, 90 AND 100) °C, THE THICKNESS OF THE WOOD (16, 38 AND 53) MM AND THE HEIGHT OF THE WOOD PILE (150, 200 AND 400) MM. THE PILOT EXPERIMENT WAS CONDUCTED IN A 40 M3 INDUSTRIAL OVEN. SUBSEQUENTLY THE EXPERIMENT WAS SCALED TO 100 M3OVENS. THE RESULTS SHOWED THAT THE HEAT STERILIZATION TIME IN THE ANALYZED TEMPERATURE RANGE DEPENDS SIGNIFI-CANTLY ON THE THICKNESS AND HEIGHT OF THE STACK. THE MINIMUM TIME TO OBTAIN HEAT STERILIZATION CONDITIONS OF RADIATA PINE PACKAGING MATERIAL VARIED FROM 123 MIN TO A MAXIMUM OF 2275 MIN

PERMEABILITY FUNCTIONALITIES ARE NOTICEABLE IN THE WOOD DRYING AND IMPREGNATION PROCESSES BECAUSE IT HAS AN EFFECT ON THE BULK FLOW OF A FLUID THROUGH THE WOOD STRUCTURE. THE AIM OF THIS WORK WAS TO MEASURE THE RADIAL AND TANGENTIAL SPECIFIC GAS PERMEABILITY OF EUCALYPTUS NITENS WOOD FOR 10 DIFFERENT PROVENANCES. FURTHERMORE, THE EFFECT OF THE RADIAL POSITION (DEFINED AS INNER-WOOD, MIDDLE-WOOD, AND OUTER-WOOD) ON THE MEASUREMENTS WAS INVESTIGATED. THE SPECIFIC GAS PERMEABILITY OF E. NITENS RANGED IN ORDER OF MAGNITUDE FROM 10?20 TO 10?16?M2. THE RESULTS SHOWED THAT THE RADIAL POSITION HAD A STATISTICALLY SIGNIFICANT EFFECT ON THE SPECIFIC PERMEABILITY IN BOTH FLOW DIRECTIONS AND, IN GENERAL, THE PERMEABILITY VALUES INCREASED FROM INNER-WOOD TO OUTER-WOOD. MOREOVER, THE SCANNING ELECTRON MICROSCOPY IMAGES SHOWED OBSTRUCTION OF VESSELS BY TYLOSES WHICH EXPLAINED THE LOWER PERMEABILITY VALUES OBTAINED IN THE INNER-WOOD OF E. NITENS. DIFFERENCES IN THE MAGNITUDE OF THE PERMEABILITY VALUES COULD EXPLAIN THE DIVERSE DRYING AND IMPREGNATION BEHAVIOR ACCORDING TO THE WOOD ZONES, THE LOW PERMEABILITY VALUES IN THE INTERNAL WOOD-ZONE COULD SUGGEST AN OPPORTUNITY FOR IMPROVING IT, THROUGH CHEMICAL MODIFICATION OR STRUCTURAL CHANGES TO INTRODUCE NEW FUNCTIONALITIES OF THIS RADIAL WOOD-ZONE IN EUCALYPTUS NITENS.

THE OCCURRENCE OF INTERNAL CHECKS AND THEIR RELATIONSHIP WITH ANATOMICAL STRUCTURE AND BASIC DENSITY IN THREE CLONES OF EUCALYPTUS NITENS PLANTATION TREES GROWN IN THE EIGHTH REGION OF CHILE WERE STUDIED. TWO TREES PER CLONE WERE SAMPLED. THE NUMBER, RADIAL LOCATION, AND LENGTH OF INTERNAL CHECKS WERE DETERMINED IN SAMPLES OVEN-DRIED AT TEMPERATURES INCREASING FROM 50 TO 100?C. WOOD ANATOMICAL FEATURES INCLUDING VESSEL FREQUENCY AND DIAMETER AND ANNUAL GROWTH RING WIDTH WERE MEASURED BY IMAGE ANALYSIS. RESULTS SHOW THAT INTERNAL CHECKS WERE GREATER FOR CLONES WITH LOWER BASIC DENSITY. INTERNAL CHECK FREQUENCY DECREASED WITH HEIGHT IN THE TREE AND INCREASED FROM PITH TO BARK. A LOW WOOD BASIC DENSITY WAS RELATED TO GREATER RING WIDTH AND VESSEL FREQUENCY, WHICH CONTRIBUTED TO THE DEVELOPMENT OF INTERNAL CHECKS.

A TREATMENT IS PROPOSED TO SANITIZE WOOD FOR EXPORT PACKAGING USING RADIO FREQUENCY EQUIPMENT THAT IS CAPABLE OF TREATING WOOD. THIS WAS ACHIEVED BY OPTIMIZING THE SANITIZATION PROCESS AND DEVELOPING AN EQUATION TO PREDICT THE TOTAL SANITIZATION TIME. STATISTICAL ANALYSIS DETERMINED THAT THE SEPARATION OF PLATES AND THE POWER DENSITY OF THE EQUIPMENT SIGNIFICANTLY INFLUENCED THE DURATION OF A SANITIZATION PROCESS USING RADIO FREQUENCY HEATING, WHEREAS THE THICKNESS OF THE MATERIAL WAS NOT AS INFLUENTIAL FOR THE OVERALL PROCESS. FURTHERMORE, THE SANITIZATION PROCESS DID NOT INFLUENCE THE QUALITY OF THE WOOD; THEREFORE, THE PROPOSED SANITIZATION PROTOCOL PROVIDED A BALANCE BETWEEN DURATION AND THE QUALITY OF THE FINISHED RADIATA PINE PACKAGING MATERIAL.