Estimation of the mechanical properties of wood from Eucalyptus urophylla using near infrared spectroscopy

Abstract

Mechanical properties studies of wood usually involve destructive wood assessments, with time-consuming tests that use large amounts of resource (wood). Although this is not a limiting factor, it could be attenuated by the use of a nondestructive technique known as near infrared spectroscopy (NIRS). This technique has been applied to evaluate compounds containing C-H, N-H, S-H or O-H bonds, and involves quick analyses and can be applied to process control tasks. The objective of this work is to use the NIRS technique to obtain calibrations for mechanical properties of Eucalyptus sp. wood. A natural E. urophylla hybrid at age 7 was used as obtained from V&M Florestal crops. Spectra were measured directly in solid wood (radial, tangential and transverse faces) and in ground wood, in diffuse reflectance mode, using a Bruker spectrometer in the 800 to 1,500 nm range. The NIRS technique proved suitable to estimate modulus of elasticity in solid wood, with values r=0.91 and RPD=2.6, and in ground wood, with values r=0.87 and RPD=2.0. Modulus of rupture and compressive strength presented r values below 0.9. First and second derivative pretreatments provided a slight increase in correlation values for the properties in question. Calibrations for different plank faces did not present a defined variation pattern. Solid wood and ground wood presented similar correlation values for all properties.Key words: NIRS, Eucalyptus, characteristics. ESTIMATIVA DE PROPRIEDADES MECÂNICAS DA MADEIRA DE Eucalyptus urophylla USANDO A ESPECTROSCOPIA NO INFRAVERMELHO PRÓXIMO RESUMO: O estudo das propriedades mecânicas da madeira comumente é realizado por meio de uma avaliação destrutiva na madeira demandando um extenso tempo para realização dos testes e com grande uso de recursos (madeira). Esse fator, embora não seja limitante para a realização dos ensaios poderia ser amenizado com o uso de uma técnica não-destrutiva como a espectroscopia no infravermelho próximo (NIRS). Essa técnica vem sendo aplicada na avaliação de compostos que contenham ligações C-H, N-H, S-H ou O-H, apresenta rapidez nas análises e pode ser aplicada no controle de processos. O objetivo, neste trabalho, foi utilizar a técnica NIRS para obter calibrações para as propriedades mecânicas da madeira de Eucalyptus sp. Foi utilizado um

Variations on growth characteristics and wood properties of three <i>Eucalyptus</i> species planted for pulpwood in Indonesia

“…4 and 5). The CS, MOE, and MOR estimated by NIR spectroscopy were 40.1 to 63.6 MPa, 11.1 to 20.2 GPa, and 69.9 to 115.8 MPa in seven-year-old E. urophylla grown in Brazil (Andrade et al 2010). Cademartori et al (2014) reported that the MOE of seven-year-old E. grandis obtained through a static bending test was 11.2 to 13.0 GPa from the heartwood to the sapwood.…”

PHYSICAL-MECHANICAL CHARACTERIZATION OF Eucalyptus urophylla WOOD

“…This species is also found in Indonesia (Vieira & Bucsan, 1980;Scanavaca Jr & Garcia, 2003a;Martins-Corder et al, 1996), Ivory Coast (Wencelius, 1983, Corbasson, 1986, Cameroon, Gabon, Guyana, Madagascar (Corbasson, 1986), Congo (Corbasson, 1986;Gouma 1998), Vietnam (Sein & Mitlöhner, 2011), Malaysia, Papua New Guinea (Soerianegara & Lemmens, 1993, among others. In addition, Eucalyptus urophylla is present in Brazil (FAO, 1981;Gonçalves & Passos, 2000;Oliveira et al, 2005;Andrade et al, 2010;Guimarães JR. et al, 2012) from its introduction during the 1970s, through seeds harvested in several islands belonging to Indonesia (Rocha et al, 2006). Perennial, Eucalyptus urophylla can reach heights of 45 to 55 m, however, in unfavorable environments this tree develops as a twisted bush (Sein & Mitlöhner, 2011).…”

Do the Growing Conditions of Trees Influence the Wood Properties?

“…Several researches have been developed in order to predict wood properties by nondestructive methods. Studies presented by , Downes et al (2002), Jones et al (2006), Hein et al (2009aHein et al ( , b, 2010a, Andrade et al (2010), Hoibo & Vestol (2010), Hein et al (2010b), Couto et al (2013), and Downes et al (2012) are some examples of using nondestructive methods in assessing timber properties.…”

“…Nondestructive methods or tests have great potential as analysis tools, since they are intended to qualify the material without impairing its future use (Couto et al, 2013). Most studies have been conducted using alternative methods for fast and reliable wood characterization that, along with traditional methods, can result both in quality analysis and time gains (Andrade et al, 2010).…”