Desorption isotherms of heavy (AZOBE, EBONY) and light heavyweight tropical woods (IROKO, SAPELLI) of Cameroon

Sorption behaviour of three African tropical woods (Sapelli, Sipo, Kosipo) with similar anatomical structures from Cameroon

“…The same pattern is also observed in the adsorption phase. In addition, the equilibrium moisture contents obtained on the same environment, vary slightly between woods (0.6–1.2% in desorption and 0.1–1.4% in adsorption), certainly due to the very small differences in the distribution of their main amorphous chemical constituents (Nsouandélé et al 2018), notably their cellulose content, which is relatively higher in Sipo (40.2%) followed by Sapelli (30%) and Kosipo (37.1%) (CTFT 1973, 1974, 1978). Moreover, the singular behaviour of Sapelli at high temperatures, which tends to contain more of water at equilibrium, could result from the expansion of their lumen dimensions during moisture sorption (Passarini 2015).…”

“…To express this relation, several mathematical models have been developed. Some of these models are more suitable for tropical woods (Bonoma and Simo-Tagne 2005; Jannot et al 2006; Fernández et al 2014; Nsouandélé et al 2018; Simo-Tagne et al 2016, 2019). These latter models were tested to assess which best fits the experimental points.…”

“…Works of Almeida et al (2007) and Almeida and Hernández (2007) also suggest that under given hygrothermal conditions, a wood whose are significant in these tissues has more water at equilibrium due to the higher surface of Lumina. In fact, less dense woods, which are a larger proportion of pores and therefore many sorption sites (Almeida and Hernández 2007), are more hygroscopic than denser woods (Nsouandélé et al 2018). Moisture sorption in wood is also influenced by the polymer's mobility, which is the diffusion and exchange process of water molecules in wood (Almeida et al 2007; Jakes et al 2019).…”

“…They found that there is a theoretical relation between water content at equilibrium and relative humidity of wood, and that this relation is greatly influenced by the nature of the wood. Unfortunately to date, tropical woods from Central Africa have scarcely been concerned by these studies despite their economic importance (Bonoma and Simo-Tagne 2005; Fotsing and Tchagang 2005; Jannot et al 2006; Nkolo Meze'e et al 2008; Ngono Mvondo et al 2017; Nsouandélé et al 2010, 2018; Simo-Tagne et al 2014, 2016, 2019).…”

Analysis of drying stresses in green-glued plywood of Bete (Mansonia Altissima) specie

“…In the literature, several authors conducted investigations concerning the mass transfer properties of wood (11) K D = K 0 exp(K 0w w), [25,26]. Concerning central Africa tropical woods, some results on species like sapelli (Entandrophragma cylindricum) and sipo (Entandrophragma utile) are available [27][28][29]. Such timber species present similar technological properties with Bete [30].…”