Water Flow Evaluation in Eucalyptus and Corymbia Short Logs

Abstract

The aim of this study is to evaluate the free and adsorbed water flow in short logs of Eucalyptus urophylla and Corymbia citriodora clones. 40 cm long, short logs were extracted from the base of the trees. Three trees each of C. citriodora and E. urophylla (A and B clones) were used. 27 logs were debarked and dried to achieve stabilization of mass. Free water (FWFR), adsorbed water (AWFR) and total water (TWFR) flow rates, and basic density were calculated. FWFR was greater than TWFR, which was superior to AWFR. The B clone wood showed a higher FWFR value and a lower AWFR value when compared to the other materials. On the other hand, the A clone wood showed a higher TWFR than the other materials. The TWFR was inversely proportional to density.

Water flow in different directions in Corymbia citriodora wood

“…The mean basic density of Corymbia citriodora wood equal to 647 kg/m 3 (Table 1) is consistent with the literature, for example, Zanuncio et al (2015) found values between 665 and 684 kg/m 3 for Corymbia citriodora wood from seven-years-old trees, and Monteiro et al (2018) report mean values of basic density for trees of the same species and age equal to 610 kg/m 3 . The comparison with the values of water flow in wood is more complex since few studies approach the rates of the free and absorbed water in a detailed way, as well as diverse methodologies, are used for measure permeability, for example, apparatus for testing the permeability to air and liquid in wood (Silva et al 2010, Tanaka et al 2010, Baraúna et al 2014, Rezende et al 2018, Brito et al 2019 and gravimetric techniques (Redman et al 2016, Thybring et al 2018.…”

“…Logs with 0,4m length, 17,88cm diameter and dried between 70,3 and 14,8% of moisture content obtained the following drying rates: 0,37; 0,72; and 0,17%MC day -1 for total drying, free water outlet (between 70,3 and 30%), and bound water outlet (between 30 and 14,8%), respectively (Monteiro et al 2018). The lower values of the total drying rate (TWFR) of Monteiro et al (2018) can be explained by their use of pieces of wood (Corymbia citriodora logs) with larger dimensions when compared to the specimens used in this study. Bramhall (1971) reports that wood permeability decreases as sample length increases.…”

“…Eucalyptus and Corymbia logs with a diameter in the range of 4,3 and 20,3cm showed R² for exponential models for drying as a function of time equal to 0,926; 0,921 and 0,892 for the evaluation times of 30, 60 and 90 days, respectively (Zanuncio et al 2015). Corymbia citriodora logs with a diameter of ~17,88cm, drying between ~70% and ~14%, found R² for linear models for moisture content as a function of time equal to 0,96; 0,97 and 0,95 for total log drying (between ~70 and ~14%), free water outlet (between ~70 and ~30%), and bound water outlet (between ~30 and ~14%), respectively (Monteiro et al 2018).…”

“…The relationship between water and wood has been scientifically studied for over a century, focusing mainly on softwoods (Engelund et al 2013). The greater importance of hardwoods in recent years, such as those from Corymbia genus, has led to increased studies on the water-wood relationship in these species (Zanuncio et al 2013, Zanuncio et al 2015, Redman et al 2016, Monteiro et al 2017, Monteiro et al 2018, Resende et al 2018, Rezende et al 2018, Brito et al 2019, Nascimento et al 2019.…”

Secagem ao ar livre da madeira serrada de eucalipto

“…Duarte et al (2015) encontraram valores de taxa de secagem superiores em média de 7,5 vezes maior na retirada da água capilar para Eucalyptus spp., enquanto que Santos et al (2003), encontraram taxa de secagem inferior de 4,6 vezes maior na retirada da água capilar durante a secagem da madeira de Eucalyptus grandis. A retirada da água livre por capilaridade apresenta maior taxa de secagem quando comparada com a água de impregnação ligada na parede celular (Klitzke e Batista, 2010;Monteiro et al, 2018;Nascimento et al, 2019), a qual é retirada por difusão, e que as características da madeira e o aproveitamento das condições climáticas irão influenciar na taxa de secagem (Santos et al, 2003;Klitzke e Batista, 2010). Para espécies do gênero Eucalyptus esse movimento de difusão sofre restrições pelas características anatômicas da espécie (Monteiro et al, 2017), com predomínio de pontuações de pequenos diâmetros e com vasos usualmente bloqueados por tilose, tornando a madeira impermeável (Vermaas, 2000).…”