WOOD RESEARCH Volume 67, Number 6, 2022
Manish Ranjan, Anand Nandanwar, and Pradeep Kumar Kushwaha

Comparative study on physical-mechanical properties of plywood produced from eucalyptus grandis and populus deltoids veneers. Short notes

Nine-ply plywood panels were produced from Eucalyptus grandis and Populus deltoids using urea-formaldehyde (UF) and phenol-formaldehyde (PF) adhesives. The physical and mechanical properties, such as moisture content, density, modulus of rupture (MOR) and modulus of elasticity (MOE) of the eucalyptus and poplar boards, were compared in this study. Samples were tested on both, along and across the grain. Higher values of MOR and MOE were observed for eucalyptus as compare to poplar. Density of ply board was observed as 500-560 kg.m-3 in plywood from poplar and 700-720 kg.m-3 in plywood from eucalyptus species. These differences were attributed to the variation in properties of veneer wood species. The effect of veneer wood species on some physical and mechanical properties of plywood was found statistically different.

WOOD RESEARCH Volume 67, Number 3, 2022
Huijun Dong, Mohammad Dahmardeh Ghalehno, Leila Fathi, Elham Ghehsare Ardestani, Miha Humar, and Mohsen Bahmani

Comprehensive evaluation of hawthorn wood characteristics in relation to soil physicochemical properties

Characteristics of hawthorn wood concerning soil physicochemical properties were studied. Physical properties such as dry wood density and volumetric swelling and fiber dimension parameters like fiber length, fiber diameter, and cell wall thickness were investigated. Soil properties including clay, silt soil, sand soil, electrical conductivity, pH, nitrogen, phosphorus, potassium, and organic matter content were determined. Pearson correlation was applied to explore the relationship between soil and wood properties. The mean wood density and volumetric swelling obtained were 0.71 g.cm-3 and 18%, respectively. Moreover, the mean values of fiber length, fiber diameter, and cell wall thickness were 0.80 mm, 20.50 μm, and 5.78 μm, respectively. Pearson correlation analysis showed a significant and positive correlation between wood dry density, cell wall thickness and volumetric swelling with percentage of silt, while a negative relationship between fiber length and percentage of silt were found.

WOOD RESEARCH Volume 66, Number 6, 2021
Mohammad Dahmardeh Ghalehno, Babak Nosrati Sheshkal, Farhad Kool, Miha Humar, and Mohsen Bahmani

Characterization of anatomical, morphological, physical and chemical properties of konar (ziziphus spina-christi) wood

The goal of this research is to investigate some morphological (fibre length, fibre diameter, cell wall thickness, Runkel coefficient, flexibility coefficient, slenderness coefficient, rigidity coefficient, Luce’s coefficient, solid coefficient), physical (dry wood density, volumetric shrinkage) and chemical (cellulose, hemicellulose, lignin, ash and acetone soluble extractives contents) composition of Konar (Ziziphus spina-christi) wood grown in Hormozgan province, Iran. For this purpose, three normal trees were selected randomly and a disk was cut from each one at breast height. Anatomical inspection revealed that the species was diffuse porous, with distinctive growth rings, simple preformation plate, with polygonal openings, and banded or diffuse-in aggregates parenchyma. The average values of wood dry density, fiber length, fiber diameter, cell wall thickness, Runkel coefficient, flexibility coefficient, felting coefficient, Luce’s coefficient, solid coefficient, rigidity coefficient were 0.926, 52.1, 77.85, 0.57, 163 ×103 μ3 and 0.48. Cellulose, hemicellulose, lignin, acetone soluble, extractives, ash contents were 43.34, 19.98, 33.9, 6.42 and 2.78%, resp.

WOOD RESEARCH Volume 61, Number 2, 2016
Cosmin Spirchez, Aurel Lunguleasa, and Tatiana Griu (Dobrev)

Testing model for assessment of lignocellulose-based pellets

This paper aims to find a simple testing and assessment model applicable to lignocellulose-based pellets, for the purpose of making the appropriate selection from the market. It is analysed the main tests of pellets, as density, caloric value and shear strength, for three different types of pellets bought from the competitive market. Afterwards is detailed the method of operation for the shear strength due to its not so frequent use. Finally, based on the tested values and limits required by the existing standards, it is determined a simple method for assessing for pellets, pointing out the closeness of each tested value to the standard limits.

WOOD RESEARCH Volume 62, Number 2, 2017
Szabolcs Koman, Sandor Feher, and Andrea Vityi

Short note. Physical and mechanical properties of Paulownia tomentosa wood planted in Hungaria

The Paulownia tree (or to its well-known name Chinese empress tree; Paulownia tomentosa) is classified among the most variable wood species of the world concerning usability. Its cultivation in Hungary in form of research plantations has just started in the last decade, first of all for the investigation of energetic properties. Due to this the information related to the physicalmechanical properties of the wood was still not determined, from which aspect this study is essential. The investigated wood with an air-dry density of 0.3 g.cm-3 has shown low bending (42 MPa), compressive (22 MPa), shear (7 MPa), tensile (33 MPa) and impact strength (1.6 J.cm-2) values, based on which its wooden material properties can be compared to poplars considering tree species in the region.

WOOD RESEARCH Volume 63, Number 4, 2018
Mohammad Mehdi Ramezanpoor Maraghi, Asghar Tabei, and Mostafa Madanipoor

Effect of board density, resin percentage and pressing temprature on particleboard properties made from mixing of poplar wood slab, citrus branches and twigs of beech

In this study, construction conditions of homogenous particleboard manufactured from mixing of poplar wood (Populus alba) slab, citrus branches and beech (Fagus orientalis) twigs have been investigated. The density of particleboard at three levels of 0.65, 0.7 and 0.75 g.cm-3, the amounts of resin at two levels of 9 and 11% and the amounts of pressing temperature at two levels of 160 and 170° C were considered. Increasing the density from 0.65 to 0.75 led to an increase in MOR, MOE and IB. By increasing the density, water absorption of particleboard decreased but its thickness swelling increased. By increasing the resin percentage the mechanical properties of particleboard improved, although this improvement was not statistically significant. Furthermore, by increasing the resin percentage the dimensional stability of particleboard improved partially. Not only did increasing the pressing temperature have any significant effect on the improving of mechanical properties of the particleboard, but also it has even led to a decrease in IB. Increasing the pressing temperature reduced the water absorption of particleboard in the short term (2 hours) while this increase led to a further increase in the thickness swelling of particleboard.

WOOD RESEARCH Volume 66, Number 4, 2021
Veronica Drăguşanu (Japalela), Lunguleasa Aurel, and COSMIN SPÎRCHEZ

The briquettes properties from seed sunflower husk and wood larch shavings

The paper aims to use the residue of sunflower seed hulls to obtain organic briquettes and to improve their properties by using larch shavings obtained in the process of solid wood planning. The physical-mechanical properties of briquettes made on a hydraulic machine, calorific value, ash content and volatile content were evaluated. The obtain results highlighted the briquettes obtained from larch waste, but also the acceptable characteristics of the briquettes obtained from sunflower seed husks. The main conclusions of this study is that briquettes obtained from unprocessed sunflower seed husks are acceptable in terms of physical-mechanical and calorific characteristics, even if they do not reach the level of briquettes obtained from larch shavings.

WOOD RESEARCH Volume 64, Number 3, 2019
Cosmin Spîrchez, Aurel Lunguleasa, and Liviu Gaceu

Researches on grape husk waste obtained from the winery and its use as pellets for combustion

Nowadays, there is a tendency to find new sources of biomass and to efficiently use old sources, especially to find renewable fuels. The paper aims to use grape husks resulting from the preparation of wine as pellets for combustion. Oven dry grape husk were used to be crushed and graded with the sieve of 1×1 mm in order to obtain dust for pelletizing. The pellets obtained from grape husk winery have a good density of 979 kg. m-3; a good ash content of 4.53% and a better high and low calorific value of 20.150 MJ. kg-1 and 19.850 MJ. kg-1, respectively. All over, the obtained results showed that this kind of raw material (pellets) can be use successfully when they are pelletized.

WOOD RESEARCH Volume 64, Number 2, 2019
Shuo Xue, Haibin Zhou, Xiaona Liu, and Weibin Wang

Prediction of compression strength of wood usually used in ancient timber buildings by using resistograph and screw withdrawal tests

Ultimate compression strength parallel to grain (UCS) of wood is one of important performance to evaluate the structural security of old wood buildings. Poplar wood (Populus tomentosa Carrière), Chinese larch wood (Larix gmelinii (Rupr.) Kuzen.) and Chinese fir wood (Cunninghamia lanceolata (Lamb.) Hook) were selected as the models in this paper. The aim of study is to predict UCS of wood by using resistograph and screw withdrawal methods. Compared with the screw withdrawal method (SW), resistograph method (RM) is generally more reliable, but because of the expenses involved, SW should also be considered as a much cheaper alternative. The results showed that the correlation coefficient between the RM and the UCS ranged from 0.5 to 0.7. The correlation coefficient between the double-start thread screw withdrawal force (SWDST) and the UCS distributed from 0.1 to 0.65, while the values of coefficients for the singlestart thread screw withdrawal (SWSST) differed from 0.4 to 0.65. In screw withdrawal method, greater pitch of screw resulted in higher correlation coefficient.