This article is focused on the research of particleboards (PB) composed of wood particles from spruce logs and recycled crushed plastic granulates. Crushed plastic granulates sized from 1.0 to 4.0 mm were obtained from worn automobiles by recycling, specifically painted and unpainted bumpers. The proportion of plastic granulate in the particleboards represented 10%, 15%, and 20% of the total weight of the composites. In the production of PB, urea-formaldehyde resin and paraffin emulsion were used as a binder and ammonium nitrate was used as a hardener. The aim of the article was to compare the selected properties of PB containing plastic filler with pure PB. Mechanical properties (tensile and bending strength), and physical properties (water absorption and thickness swelling) were evaluated according to EN 319, EN 310 and EN 317. Based on the results, it can be stated that the bending strength and physical properties of PB containing plastic filler were significantly better compared to pure PB. On the contrary, the tensile strength values were lower in most cases


The physical and mechanical properties of 40-year-old coconut stem were investigated in different radial directions and height positions. The results showed that in the radial direction, the properties of the number of vascular bundles (NVB), density, shrinkage, compressive strength parallel to the grain (CS), modulus of rupture (MOR), and modulus of elasticity (MOE) decreased continuously from the outer area to the inner area, except for the water absorption (WA) value which increased from the outer area to the inner area. The density and MOE decreased from the bottom to the top in the height direction while NVB and WA increased. The shrinkage, CS, and MOE first increased and then decreased from the bottom to the top. NVB in coconut stem affects the density and determines the main mechanical properties of CS, MOR, and MOE. The analysis of variance (two-way ANOVA) showed a significant difference in density, NVB, WA, CS, MOR, and MOE in radial direction and height position. These findings can be useful for the development of new applications for coconut stems, such as in construction, landscaping, or furniture manufacturing, as well as for improving our understanding of their structural characteristics

Suitability of Aspen (Populus Tremula L.) for Cross-Laminated Timber (CLT)

Cross-laminated timber (CLT) CLT is an excellent material for building and high load-bearing structural applications, but its fabrication and use are limited to softwood only. The suitability of aspen (Populus tremula L) wood for manufacturing CLT was assessed by using two adhesives, one-component polyurethane (1C-PUR) and melamine adhesive (ME). Physical properties like water absorption (WA), thickness swelling (TS), delamination, and mechanical properties like bond shear strength, bending modulus of elasticity, bending strength, and rolling shear strength were evaluated to examine its suitability. Compared to ME-bonded CLT, 1C-PUR bonded CLT panels displayed superior physical characteristics, with 70% passing the delamination test. CLT panels bonded with 1C-PUR adhesive also have better mechanical properties than ME-bonded CLT. CLT panels experienced three types of bending failure: rolling shear, delamination, and tension. Aspen CLT has similar or higher mechanical properties than traditional softwoods, making it suitable for CLT manufacturing.

Study on basic wood properties of critically endangered species Syzygium album

Syzygium album is a critically endangered species, and the wood basic properties haven’t been reported. Therefore, this paper analyzes the wood from the anatomical characteristics, physical properties, and secondary components. The results showed that observed S. album wood of a 46-year-old tree is diffuse-porous to semi-diffuse-porous wood. The maximum vessel tangential diameter is 127.47 μm, which is found at the beginning of the earlywood. The wood rays are heteromorphic type I and II, and the multi-column part is mostly 3 cells wide. In physical properties, the air-dry density is classified as “heavy”, whereas its air-dry and full-dry differential dry shrinkage are “small” and “medium”, respectively. This indicates that the wood performs better when dried. The content of benzene-ethanol extract from S. album wood is 2.10%. The benzene-ethanol extracts were analyzed by GC-MS, and the main components are 2,6,11,15-tetramethylhexadecane (3.29%), eicosamethyl cyclodecasiloxane (10.02%), octadecamethyl cyclononasiloxane (7.43%), and tetracosamethyl cyclododeca- siloxane (3.60%), etc.

The potential for using corn stalks as a raw material for production particleboard with industrial wood chips

In this study particleboards were manufactured from mixtures of corn stalks (Zea mays indurate Sturt.) and industrial woodchips at several ratios. The corn stalks and industrial wood particles were mixed at ratios 0, 25, 50, 75 and 100 % respectively. The suitability of corn stalks chips for particleboard production was examined. Urea formaldehyde resin was used as a binder in 3-layers particleboards. Produced panels were tested for certain mechanical and physical properties. The manufactured boards were tested according to EN standards. In addition, the chemical properties of corn stalks were evaluated. Experimental results indicated that increase in corn stalk chips in the mixture generally diminished the mechanical and physical properties.

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.

Testing of wood physical properties in oak species (Quercus robur L., Q. petraea (matts) liebl. and Q. pyrenaica willd.) for cooperage. Part II: Wood grain

Our research about wood physical properties of Quercus robur L., Q. petraea (Matts) Liebl., and Q. pyrenaica Willd., for cooperage was founded on the calculate of wood grain to estimate the change of this property in the Galician oaks. Overall, 45 trees were selected in 15 oak forests of the provinces of Lugo and Ourense (Galicia, NW Spain), of which we obtained 45 thin slices of wood at 60 cm tall on the trunk, and 194 wood samples parallelepipeds of 2 × 2 × 4 cm ± 1mm. The grain of Quercus pyrenaica and Q. robur are similar to oaks Limousin region, France. Quercus petraea is comparable to the Vosges oaks. Now, both regions are among the most important sources in quality oaks for manufacturing barrels. Our global objective was to realize a detailed description on the physical properties of wood of these species for its possible use in industry cooperage. For this, the aim of this second work was to continue with the study of wood grain.

Effect of tree diameter classes on the properties of persian oak (Quercus brantii Lindl.) wood

This study was conducted to investigate the properties of Persian oak (Quercus brantii Lindl.) wood, the most abundant tree species, harvested in the west and southwest regions of Iran. To the best our knowledge, there were no reported studies investigating the physical, chemical and biometrical features of Persian oak wood. For this purpose, 12 healthy trees in three diameter classes including 10-20, 20-30 and 30-40 cm were selected randomly and a disk was cut from each one at breast height. Results indicated that the highest basic densities are related to the diameter class 20-30cm (0.98 g.cm-3) and the lowest one at diameter class 10-20 cm (0.88 g.cm-3). The highest shrinkage was determined at oak wood samples from the diameter classes 10-20 cm (14.15%). Fiber length varied between 0.82 g.cm-3 (Dia. Class 10-20 cm, middle part) to 1.01 (Dia. Class 20-30 cm, bark). With increasing diameter, the cellulose content increased and the lignin content decreased while ash and extractive content was quite constant.

Comparison of selected properties of natural aged wood and contemporary timber of Pinus sylvestris L. investigated using standard methods and measuring of transition speed of ultrasounds along the fibre

Scots pine wood (Pinus sylvestris L.) is the most common wood material used in historical buildings in many parts of Central and Eastern Europe. Experiments were conducted natural aged wood (263 – 459 years old), extracted from construction elements of four historical buildings (from seven construction elements), and contemporary wood extracted from 5 construction elements. A strong relationship was observed between density and static bending strength (MOR) of natural aged wood (R2 = 0.5599), and also of contemporary timber (R2 = 0.7863). Antique wood compared to contemporary wood with the same average moisture content and density is characterized by significantly lower modules (static and dynamic), the speed of ultrasonic waves transitions, and bending strength. Differences in these properties increase with increasing wood density.

Mechanical and physical properties of medium density fibreboard with calcite additive

In this study, it is investigated that are calcite filler can be used in the production of medium density fiberboard. Chips have been to the process of cooking for 4-5 minutes in Asplund defibrator with the vapor pressure of 7-7.5 bar, and 180ºC temperature. 1.5% paraffin and 1% ammonium sulphate to be pulverized is added to fibers on the output of defibrillator and blowline line. Calcite fillers are prepared in a separate tank in order to use calcite instead of lignocellulosic fibers in the production of 1 m³ MDF. After that, urea formaldehyde glue is prepared as three different solutions which include the calcite, respectively with 3% (20 kg.m-3), 6% (40 kg.m-3), 9% (60 kg.m-3). The fibers are dried to moisture of 8%-12%. This press applies temperature about 185-190°C and pressure about 32-34 kg.m-2 to the mixture material for 270 seconds during pressing time. MDF panels (2100 x 4900 x 18 mm) were produced in the process. Both mechanical and physical experiments are performed on boards which are produced.

Characteristic features of the oil-heat treated woods from tropical fast growing wood species

This study aimed to evaluate the effect of oil-heat treatment on the anatomical, physical, and chemical properties of the tropical fast-growing wood species as gmelina (Gmelinaarborea) and mindi (Melia azedarach) wood. Vessel lumen area and diameter in radial and tangential direction of both species increased with increasing temperature. The fiber lumen areas in both woods were remarkably decreased by oil-heat treatment, and the fiber wall area increased considerably with increasing temperature. Both woods tended to gain weight after heat treatment at 180°C and 200°C, and then lose weight after heat treatment at 220°C. The density of mindi increased greatly at 180°C and 200°C and slightly decreased at 220°C. The dimension of the specimens in tangential direction increased with heat treatment, but the rate decreased with increasing temperature. The relative crystallinity and crystallite width of the heat-treated woods were greater than those of the untreated wood. In the Fourier transform infrared analyses, the peaks from the carbohydrates were changed after oil-heat treatment, mainly due to the degradation of hemicellulose. Consequently, it was revealed that the heat treatment affected various properties of gmelina and mindi woods. Differing characteristics between the species were also noted.

Alkaline solvent cooking treatment of cork and component analysis of filtrates

This study aimed to determine the effects of alkaline solvent treatment on the physical properties of cork, and to analysis the filtrate components of cork after cooking treatment. Potassium hydroxide (KOH), alkaline hydrogen peroxide (AHP), and ammonium hydroxide (AOH) were used as solvents. The properties of treated cork including color, volume, hardness, compression resilience ratio, and filtrate components of different solvent treatments were investigated. The results showed an increase in the cork’s volume, changes in color, and decrease in lightness after three solvent treatments. Hardness and compression resilience decreased after three solvents cooking, and the difference in the compression resilience ratio between 15 min and 24 h was at a minimum when cork was cooked in KOH solvent. The analyses of filtrate components after KOH and AHP cooking treatments indicated that the hemicelluloses content was generally higher than lignin content. Moreover, water-soluble lignin, obtained from the three solvent filtrates, consisted of a small amount of monosaccharides, such as arabinan, galactan, glucan, and xylan. Nuclear magnetism (NMR) spectra analysis demonstrated that the lignin in KOH and AOH filtrates consisted of G units and H units, while S units only appeared in KOHimmersed lignin. This study shows that solvent treatment changes cork’s physical and chemical properties based on the solvent type and concentration.

The effect of thermal modification by hot pressing on the some physical and mechanical properties in rubberwood (Hevea brasiliensis)

Rubberwood (Hevea brasiliensis) was thermal modified by hot pressing in an open system at three different temperatures (170, 185, 200°C) and two different durations (1.5, 3 h), and the effect on the physical and mechanical properties was studied. Results show that the thermal modification increased the oven-dried density and decreased the EMC (equilibrium moisture content) by 7.93% and 37.15%, respectively, and the dimensions stability was improved. Hardness, bending strength, modulus of bending and compressive strength parallel to grain of modified samples basically decreased with increasing temperature and time, but they showed a meaningful increase compared to control samples. However, impacting bending and nail withdrawal resistance decreased after hot pressing and thermal treatment, and the failure of the compensation for the impairment was the rubberwood hot pressed and thermal treated in the presence of air, and the participation of oxygen provoked rapid degradation reactions during the treatment.