Comparison of Methods for Estimating Mechanical Properties of Wood by NIR Spectroscopy

Near-infrared (NIR) spectroscopy provides a rapid alternative to traditional methods of wood property assessment. For organizations who assess wood properties on a large scale, multisite, multispecies calibrations are of practical interest. We examined NIR spectroscopy for the estimation of density (at 12% moisture content), modulus of elasticity (MOE), and modulus of rupture (MOR) using clear wood samples obtained from several pine species (Pinus caribaea var. bahamensis, var. hondurensis, and var. caribaea, P. chiapensis, P. maximinoi, P. oocarpa, P. taeda, and P. tecunumanii). We compared different methodologies for collecting spectra, that is, benchtop instrument versus benchtop fiber-optic probe and field portable fiber-optic probe, and different wood surfaces (radial and transverse). Calibrations based on the benchtop instrument were superior to those obtained using the fiber-optic probe systems. Difficulty with adequately representing the sample when collecting spectra using a fiber-optic probe and lower quality spectra explain the differences among the data sets. Spectra collected from radial and transverse surfaces provided similar calibration statistics. The calibrations obtained for density (R2 = 0.81, SECV = 38.5 kg/m3) and MOE (R2 = 0.81, SECV = 1124 GPa) using benchtop instrument spectra demonstrate that it is possible to obtain general calibrations for estimating the wood properties of a number of tropical, subtropical, and temperate pine species

Coir and Sisal Fibers as Fillers in the Production of Eucalyptus Medium Density Particleboards - MDP

The aim of this study was to evaluate the potential use of sisal and coir fibers in combination with Eucalyptus particles for the production of particleboard. The particleboards were produced in three layers. The first and third layers (face) were made with small Eucalyptus particles. The second layer (core) was made with big Eucalyptus particles in combination with coir or sisal fibers. The particleboards were prepared with the substitution on Eucalyptus wood for sisal and coir fibers in the particleboards core, in doses of 0, 10, and 20%, relative to the total mass of particles. The particleboards were characterized by mechanical, physical and thermal properties. The results were not satisfactory for particleboards with sisal. However, for coir particleboards the physical-mechanical properties were very similar to those particleboards produced only with Eucalyptus. This work demonstrates the potential use of the coir that is commonly disposed in landfills on the Brazilian beaches

Uso potencial de la fibra de curauá (Ananas acutifolius) para la fabricación de compuestos cementicios

This study aimed to characterize and evaluate the performance of the Amazonian plant fiber curaua (Ananas erectifolius) as reinforcement in the cementitious composite panels’ production process. For the production of these panels were determined extractives content and bulk density of the fibers. The panels were produced with curaua fibers, varying the contents (5%, 10% and 20%). Also, as a methodology, vegetable fibers were treated through immersion in cold water for 24 hours, immersion in hot water for 6 hours, and finally immersed in NaOH solution for 2 hours at a concentration of 1%. The panels were manufactured in the dimensions of 500x500x15 mm, a nominal bulk density of 1.60 g/cm3 and kept under pressure (4 MPa) for 24 hours. After pressing the panels were conditioned for 28 days for cement cure. As a result, it was observed that the incorporation of 10% curaua fibers is possible as reinforcement in the cementitious matrix, in the manufacture of wood-concrete panels. It was also found that the chemical treatment of the fibers provided the improvement in the physical properties of the composites.  El objetivo de este estudio fue caracterizar y evaluar el rendimiento de la fibra amazónica de curauá (Ananas erectifolius) como reforzamiento en el proceso de producción de paneles de fibrocemento. Para la fabricación de estos paneles se determinó el contenido de sustancias extraíbles y la densidad aparente de las fibras. Se fabricaron paneles con fibras de curauá, variando su contenido (5%, 10% y 20%). Asimismo, como metodología, se trataron las fibras vegetales a través de la inmersión en agua fría durante 24 horas, inmersión en agua caliente durante 6 horas y, finalmente, se sumergieron en una solución de NaOH durante 2 horas a una concentración del 1%. Los paneles medían 500 x 500 x 15mm, con una densidad aparente nominal de 1,60g/cm3 y se mantuvieron bajo presión (4 MPa) durante 24 horas. Después de prensarlos, los paneles se acondicionaron durante 28 días para el curado del cemento. Como resultado, se observó que la adición de un 10% de fibras de curauá es idónea para reforzar la matriz cementicia en la fabricación de paneles de madera-cemento. También se encontró que el tratamiento químico de las fibras mejora las propiedades físicas del material. &nbsp

Comparison of Methods for Estimating Mechanical Properties of Wood by NIR Spectroscopy

Near-infrared (NIR) spectroscopy provides a rapid alternative to traditional methods of wood property assessment. For organizations who assess wood properties on a large scale, multisite, multispecies calibrations are of practical interest. We examined NIR spectroscopy for the estimation of density (at 12% moisture content), modulus of elasticity (MOE), and modulus of rupture (MOR) using clear wood samples obtained from several pine species (Pinus caribaea var. bahamensis, var. hondurensis, and var. caribaea, P. chiapensis, P. maximinoi, P. oocarpa, P. taeda, and P. tecunumanii). We compared different methodologies for collecting spectra, that is, benchtop instrument versus benchtop fiber-optic probe and field portable fiber-optic probe, and different wood surfaces (radial and transverse). Calibrations based on the benchtop instrument were superior to those obtained using the fiber-optic probe systems. Difficulty with adequately representing the sample when collecting spectra using a fiber-optic probe and lower quality spectra explain the differences among the data sets. Spectra collected from radial and transverse surfaces provided similar calibration statistics. The calibrations obtained for density (R2 = 0.81, SECV = 38.5 kg/m3) and MOE (R2 = 0.81, SECV = 1124 GPa) using benchtop instrument spectra demonstrate that it is possible to obtain general calibrations for estimating the wood properties of a number of tropical, subtropical, and temperate pine species