Maderas:Ciencia y Tecnología 2(2):2000. Copyright © 2003, CAB International
ET- Automation of production for the wood industry. FT- Automatizacion de la produccion para las industrias de la madera. AU- Charpentier, P.;Ramos, M. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 225-231 AB- The paper starts with a brief general presentation on the characteristics of manufacturing enterprises in the industrial wood sector. Three parts follow that discuss the introduction of automation to the industry. These cover (1) the function of 'capture', which permits the characterization of the wood product, (2) the organization and development of flow in the enterprise, and (3) the monitoring of production. ET- System of reverse engineering for the design of furniture by means of the use of a portable coordinate measuring machine. FT- Sistema de Ingenieria de Reversa para el diseno de muebles mediante la utilizacion de una maquina de medicion de coordenadas portatil. AU- Moraga, R.;Baesler, F.;Harrison, O. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 218-224 RE- 12 ref. AB- The first part of the paper discusses the technique of reverse engineering using portable coordinate measuring machines (CMM), and the application of the technique to furniture design (with reference to its potential use in Chile). Finally the results are described of the practical application of the reverse engineering technique to an existing bentwood chair using the FAROArm (a CMM). ET- Heat-hardened and thermoplastic resins: a study of in situ setting in the manufacture of boards of MDF and laminates. FT- Resinas termoendurecibles y termoplasticas: estudio del fraguado in- situ en la fabricacion de tableros mdf y laminados. AU- Gacitua E., W.;Rials, T. G.;Ballerini A., A. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 207-217 RE- 23 ref. AB- The first part of the paper discusses the principal processes in the pressing of wood-based panels and in the setting of adhesives during heat pressing. Next, a laboratory study is reported of the manufacture of MDF (medium density fibreboard) and laminated panels made from fibres of Pinus radiata glued with urea formaldehyde (MDF), phenol formaldehyde (MDF, laminates) or polyvinyl acetate (MDF, laminates) resins. Resin curing was monitored in situ using a dielectric method, and the thermal properties of the resins were evaluated. The results are presented and analysed in detail. ET- Populus x euroamericana (Dode) Guinier: sawmilling, drying and mechanical properties. FT- Populus x euroamericana (dode) guinier: aserrio, secado y propiedades mecanicas. AU- Juacida P., R.;Cuevas D., H.;Saldivar G., E. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 185-195 RE- 25 ref. AB- Data are reported from a study of 3 clones of Populus euramericana [Populus canadensis] ('I-72', I-161' and 'I-488') introduced into the province of Valdivia, Chile in 1976. The 3 clones had similar wood densities (0.317-0.328 g/m3) and colour, the presence of false heartwood, splits at the end of logs, and irregular curvatures and transverse sections. The principal difference between the clones is in diameter and crown height. Clone 'I-488' was the best in terms of sawnwood production and quality. All 3 clones had wood of a very low mechanical resistance. ET- Conventional drying of alamo (Populus nigra). FT- Secado convencional de la especie alamo (Populus nigra). AU- Sanchez A., R.;Ruiz T., P.;Ramirez R., J. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 177-184 RE- 7 ref. AB- A laboratory-scale drying test was carried out using sawnwood of (Populus nigra), which was dried from green to 10% humidity under 38 mm pressure. Three trials were done using loads with pieces of the same size (38 x 110 x 900 mm) and number but with slightly different initial basic densities (300, 308 and 325 kg/m2) and humidity contents (170, 143 and 143%). A different drying schedule was used for each load; the differences involved the use of different temperatures, air speeds and time periods at different drying stages (details are given). For each load measurements were recorded of humidity gradients and final humidity, and defects were evaluated and classified. The best results were obtained with the 2 drying schedules that used air speeds of 3 m/s and minimum temperatures <60 deg in the first stage of drying. ET- Conventional drying of calden (Prosopis calden) as boards 25 mm thick. FT- Secado convencional de la especie calden (Prosopis calden), en tablas de 25 mm. de espesor. AU- Gutierrez D., M.;Carmona C., R.;Rallo de la B., M. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 196-206 RE- 6 ref. AB- Sawnwood of calden (Prosopis calden [Prosopis caldenia]) 25 mm thick, 70-145 mm wide and 0.6-2.0 m long was brought from Argentina to Chile to study the drying process. Some of the sawnwood was from stems and some from branches. Details are given of the 3 drying schedules used (which were designated as mild, moderate and strong) and of the results obtained from them, in terms of speed of drying, defect development and gradients of humidity. The drying speed was 10 days in the most extreme schedule, and 22 and 16 days, respectively, in the moderate and mild schedules. There were no important defects resulting from any of the schedules. ET- Relations between the period of pre-existence of biocontrol agents and the presence of blue stain in sawnwood of Pinus radiata, under laboratory conditions. FT- Relacion entre periodo de preexistencia de biocontroladores y presencia de mancha azul en madera aserrada de Pinus radiata, en condiciones de laboratorio. AU- Garcia, J. M.;Peredo, H. L. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 168-176 RE- 13 ref. AB- The protective effectiveness of the presence 3 biocontrol agents (Geotrichum candidum, G. roseum and Trichoderma viride) for various periods (1, 6 or 11 days) before inoculation with blue stain fungi (Aspergillus flavus, Aureobasidium pullulans, Ceratocystis pilifera, Graphium, Penicillium and Sphaeropsis sapinea [Diplodia pinea]), was tested using 70 x 20 x 7 mm samples of Pinus radiata sapwood prepared 2 days after harvesting. The samples were assessed for blue stain development 30 days after inoculation with the stain fungus concerned. The period of pre-existence of the biocontrol agent had a significant effect on the development of all 6 species of blue stain only in the case of Geotrichum candidum, which gave increasing control of stain development the longer it was present before blue stain inoculation. For the other 2 biocontrol agents (Trichoderma viride and Geotrichum roseum) the period of pre-existence had very little effect on the development of any of the stain fungi, which were either completely or well controlled for all the time periods of pre-existence concerned. Record - 14 ET- Determination of the elastic constants of wood for ultrasound. Part I: modulus of elasticity and modulus of rigidity. FT- Determinacion de las constantes elasticas de la madera por ultrasonido parte I: modulos de elasticidad y modulos de rigidez. AU- Fuentealba, C.;Baradit, E. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 161-167 RE- 17 ref. AB- The advantages and disadvantages of nondestructive testing for wood elastic constants using ultrasonic techniques are discussed and the fundamental theory involved outlined. A practical study is reported using wood samples from 20-yr-old Pinus radiata from Concepcion, Chile, in which mechanical and ultrasonic tests were carried out and the results compared. Twenty samples were obtained from each of 5 trees for testing (1) mechanical compression parallel to the grain (samples 50 x 50 x 200 mm), (2) mechanical compression perpendicular to the grain (samples 50 x 50 x 100 mm) and (3) the propagation velocity of ultrasonic waves (using cubes of dimensions 16, 20, 25, 30 and 50 mm cut in a radial direction). The moduli of elasticity in longitudinal (L), radial (R) and tangential (T) directions calculated from the ultrasonic measurements were within similar ranges to those obtained from the mechanical tests. Results are also reported of the ultrasonic determination of moduli of rigidity in 6 directions (LT, TL, RT [no data given], TR, LR, RL) but comparative results from the mechanical determinations are not provided. ET- Effect of knots and grain inclination on the propagation velocity and acoustic impedance of ultrasonic waves in wood of radiata pine. FT- Efecto de nudos e inclinacion de fibras en la velocidad de propagacion e impedancia acustica de ondas ultrasonicas en Madera de pino radiata. AU- Alejandro M., B. G.;Jose T., K. C. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 150-160 RE- 9 ref. AB- This study was carried out as part of a project on the utilization of ultrasonic techniques in the characterization and classification of wood and its basic composition. The principal objective was to determine the propagation velocity and acoustic impedance of ultrasonic waves in defect-free wood of radiata pine [Pinus radiata] at different grain inclinations (0, 15, 30 and 45 deg ) and densities (low, medium and high). The results showed that both propagation velocity and acoustic impedance were affected by wood density and grain inclination. The effect of wood density on propagation velocity varied with direction (longitudinal, radial or tangential), while acoustic impedance increased slightly with density in all 3 directions. The effect of grain inclination on propagation velocity also varied with direction (parallel or tangential to the grain in the radial axis, and parallel or radial in the tangential axis), each showing a decrease with increase in grain inclination. Acoustic impedance decreased with increasing grain inclination in all directions. ET- Radial and longitudinal variation of spiral grain in an adult stand of maritime pine (Pinus pinaster Ait.). FT- Variacion radial y en el fuste de la fibra revirada presente en un rodal adulto de pino maritimo (Pinus pinaster Ait.,). AU- Rodriguez M., R.;Valenzuela H., L.;Espinosa B., M. JN- Maderas: Ciencia y Technologia YR- 2000 VO- 2 NO- 2 PP- 140-149 RE- 13 ref. AB- Variation in spiral grain was determined in 9 trees (3 in each crown class - dominant, intermediate and suppressed) in a 44-61-yr-old unmanaged stand in the Bio-Bio region of Chile. Relationships were determined between the occurrence of spiral grain and distance from the pith, cambial age, percentage of summer wood (latewood), ring width and basic density. Spiral grain was radially distributed similarly in all the trees, with grain inclination diminishing from the pith to the cortex. Longitudinally, the inclination of spiral grain increased with stem height. There was more spiral grain inclination on the northern aspect, and this situation was more marked in the crown zone (from 11.3 to 14.4 m). The occurrence of spiral grain was most related to distance from the pith and cambial age; there were no statistically significant differences in occurrence between different crown classes.