This study evaluates the characteristics of superior clones of Eucalyptus pellita and Acacia hybrid (Acacia mangium × A. auriculiformis) aged six years selected from a breeding program in Indonesia as materials for pulp and papermaking. Height, diameter, and wood density differed significantly between species and among the clones, with respective mean values 21.6 m, 12.57 cm, and 657 kg.m-3 for E. pellita and 19.5 m, 24.83 cm, and 567 kg.m-3 for Acacia hybrid. Most fiber morphologies were significantly different between species. Cellulose and lignin differed significantly only among Acacia hybrid clones. The mean value of screened pulp yield Acacia hybrid (52.50%) was higher than that of E. pellita (50.31%). Kappa number and brightness were significantly different between species and among E. pellita clones. Some correlations of growth and wood properties showed a better relationship to pulp properties. Handsheet properties varied between species, and some clones showed an outstanding one.
Eucalyptus urophylla was treated with melamine-urea-formaldehyde resin (MUF) after pretreatment with urea solution. The properties of the wood were then determined. The weight percent gain (WPG) and, antiswelling efficiencies (ASE) of the wood treated with urea+MUF were 14% and, 45% higher than those of untreated wood, respectively. The water absorption (WA) of the wood treated with urea+MUF was decreased approximately 50% lower than that of the untreated wood. However, the mechanical properties of the wood treated with urea+MUF were weakened due to the destruction of the structure of wood. An X-ray photoelectron spectroscopy (XPS) analysis revealed that the atomic concentration ratio of O/C was increased. The ratio of C1 was decreased as the lignin and extractives contents were decreased, while the ratios of C2 and C3 were increased. The urea solution pretreatment was conducive to the impregnation of wood functional modifiers.
The aim of this research was to determine radial variations of some wood properties from natural and plantation trees of Alnus glutinosa. Oven-dried wood density (WD), fiber cell features, and annual ring width (ARW) were determined in radial positions of stem at breast height of tree. The results showed that the cultivation methods had significant influence on the fiber length (FL), fiber diameter (FD) and ARW. The effect of interaction between radial position and cultivation methods on anatomical features was not significant, except for cell wall thickeness (CWT). Fiber cell features and WD increased with distance from pith for both cultivations trees. The ARW decreased with increasing the cambial age in both cultivation methods. The average of FL and ARW in plantation trees was higher than those in natural trees. Widest FD was found in natural forest. There were significant relationships between ARW-WD and WD-FD for natural forest and between ARW-WD, ARW-CWT and WD-FL for plantation forest. About 67 % of WD variation in natural and plantation trees were related to FD and ARW, respectively. Due to high FL and ARW, wood from planted trees could be suitable for paper production than wood from natural trees.
The aim of investigations was to determine whether the tested models for calculating forces in wood cutting, set up under strictly controlled laboratory conditions, can yield sufficiently accurate results for predicting wood behavior in real cutting conditions. Tests were carried out on oak wood (Quercus robur). On the basis of measured values for the required cutting power, cutting forces were calculated and used for comparison by applying the method of coefficient (Kršljak’s model) and Axelsson’s model. The analysis indicated that there is not a result, but there is similarity in the curve shape, i.e. changes in measured values are followed by corresponding changes in calculated values. It can be inferred that analyzed models are not suitable for the cutting forces quantification, but could serve for comparing different cutting modes. More accurate modeling of the cutting process requires, besides physical, wood mechanical properties as well.
The study on wood physical properties of Quercus robur L., Quercus petraea (Matts) Liebl., and Quercus pyrenaica Willd., to use in wine aging was also founded on the relationship between porosity and void ratio to assess its variation in the oak species under study. A total of 45 oak trees were chosen in 15 oak stands of the Lugo and Ourense provinces (Galicia, northwestern Iberian Peninsula). Altogether, were obtained forty-five fine slices of wood at 60 cm tall on the trunk, and 194 wood test specimens’ parallelepipeds of 20 × 20 × 40 mm ± 1mm. On average, oak species in Galicia have lower porosity than oaks of the French regions of Limousin and Vosges. With a width of growth ring and age similar, Quercus pyrenaica has porosity slightly lower than Q. robur and Q. petraea. Our objective is to carry out a complete description on the wood physical properties of the studied species for its possible use in the cooperage industry and wine aging. For that, the aim of this work was to estimate the porosity versus the void ratio.