scholarly journals Interrelations of Wood Physical and Mechanical Properties and Patterns of Their Change within the Birch Stem

2021 ◽  
pp. 150-159
Author(s):  
Vladimir I. Fedyukov ◽  
◽  
Vasilii Yu. Chernov ◽  
Maria S. Chernova ◽  
Olga V. Tsoy
Keyword(s):  
Mechanical Properties ◽  
Sound Propagation ◽  
Physical And Mechanical Properties ◽  
Tree Height ◽  
Productive Capacity ◽  
State University ◽  
Wood Fibers ◽  
Middle Volga Region ◽  
Birch Tree ◽  
Birch Trees

The physical and mechanical properties of standing wood are not constant along the tree height and diameter. They also differ depending on the tree species and conditions of its growth. So, the research purpose is to identify patterns of change and interrelations between the parameters of density, compressive strength and sound propagation velocity along the wood fibers inside the stem of a birch tree growing in the forests of the Middle Volga region of Russia, where such research had never been conducted before. The work was carried out on two sampling areas laid out by standard methods in birch forests of natural origin with average productive capacity on the territory of the Scientific-Experimental Forest District of the Volga State University of Technology in the Mari El Republic. The average age of the birch trees is about 70 yrs, breast height diameter is 30 cm, and height is 28.5 m; 14 sample trees were studied; 0.5 m long chucks were cut out from their stems at a height of 1.3 m from the butt end and at relative heights of 0.25H, 0.5H, and 0.75H. Experimental work was carried out in a laboratory environment with modern technical facilities using standard procedures. Mathematical models describing the changes in the parameters stated above and the interrelations between them with regard to the stem diameter at relative heights were obtained. The research results generally confirmed the findings of other researchers on densitograms and other physical and mechanical properties of wood within the tree stem. However, the features listed above were revealed for birch trees growing under such conditions; in particular, it concerns the ratio of strength and density, as well as the wood strength and the velocity of sound propagation through the fibers. The results obtained have both scientific and practical value as a basis for the development of a non-destructive method for predicting technical properties of standing wood as well as timber for producing assortments for special purposes. For citation: Fedyukov V.I., Chernov V.Yu., Chernova M.S., Tsoy O.V. Interrelations of Wood Physical and Mechanical Properties and Patterns of Their Change within the Birch Stem. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 150–159. DOI: 10.37482/0536-1036-2021-6-150-159

PEMANFAATAN KAYU AKASIA MANGIUM (Acacia mangium Willd) UNTUK MEBEL

2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical Properties ◽  
Treatment Process ◽  
Acacia Mangium ◽  
Physical And Mechanical Properties ◽  
Wood Fibers ◽  
Test Parameters ◽  
Mechanical And Physical Properties ◽  
Scale Scores

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.

PREPARATION AND CHARACTERIZATION OF REPROCESSED COMPOSITES OF POLYPROPYLENE REINFORCED BY WOOD FIBERS: PHYSICAL AND MECHANICAL PROPERTIES

2017 ◽  
Author(s):  
Thais Helena Sydenstricker Flores-Sahagun ◽  
Kelly Priscila Agapito ◽  
ROSA MARIA JIMENEZ AMEZCUA ◽  
Felipe Jedyn
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Wood Fibers

scholarly journals ADSORPTION OF NANOWOLLASTONITE ON CELLULOSE SURFACE: EFFECTS ON PHYSICAL AND MECHANICAL PROPERTIES OF MEDIUM-DENSITY FIBERBOARD (MDF)

CERNE ◽  
2016 ◽  
Vol 22 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Hamid Reza Taghiyari ◽  
Roya Majidi ◽  
Asghar Jahangiri
Keyword(s):  
Mechanical Properties ◽  
Density Functional ◽  
Medium Density Fiberboard ◽  
Physical And Mechanical Properties ◽  
Mechanical Tests ◽  
National Standard ◽  
Medium Density ◽  
Wood Fibers ◽  
Strong Adsorption ◽  
Cellulose Surface

ABSTRACT Effects of nanowollastonite (NW) adsorption on cellulose surface were studied on physical and mechanical properties of medium-density fiberboard (MDF) panels; properties were then compared with those of MDF panels without NW-content. The size range of NW was 30-110 nm. The interaction between NW and cellulose was investigated using density functional theory (DFT). Physical and mechanical tests were carried out in accordance with the Iranian National Standard ISIRI 9044 PB Type P2 (compatible with ASTM D1037-99) specifications. Results of DFT simulations showed strong adsorption of NW on cellulose surface. Moreover, mechanical properties demonstrated significant improvement. The improvement was attributed to the strong adsorption of NW on cellulose surface predicted by DFT, adding to the strength and integrity between wood fibers in NW-MDF panels. It was concluded that NW would improve mechanical properties in MDF panels as a wood-composite material, as well as being effective in improving its biological and thermal conductivity.

High-Density Fiberboard from Wood and Keratin Fibers: Physical and Mechanical Properties

2021 ◽  
Vol 14 ◽  
Author(s):  
Menandro N. Acda
Keyword(s):  
Mechanical Properties ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
High Volume ◽  
High Density ◽  
Wood Fibers ◽  
Solid Waste Disposal ◽  
Renewable Materials ◽  
Polyurethane Resin ◽  
Keratin Fibers

Background: High-density fiberboards (HDF) are widely used as a substitute for solid wood in furniture, cabinet, construction materials, etc. Wood fibers are often used in the production of HDF but the use of renewable materials has gained worldwide interest brought about by global pressure to pursue sustainable development. An abundant source of renewable fibers that can be used to produce HDF is keratin from waste chicken feathers. The goal of the study is to investigate the use of keratin fibers in combination with wood fibers to produce HDF. No or limited studies have been conducted in this area and if successful, it could offer an alternative utilization for the billions of kilograms of waste feather produced by the poultry industry. HDF is a high volume feather utilization that can reduce pollution and help solve solid waste disposal problems in many countries. Methods: A series of dry-formed HDFs containing varying ratios of wood and keratin fibers bonded by polyurethane resin were produced. The physical and mechanical properties of the HDFs were determined. Results : The properties of the HDFs were affected by varying ratios of wood particles and keratin fibers. Dimensional stability as indicated by low levels of thickness swelling (<4.6%) and water absorption (<10%) was observed. Internal bond (2.47 MPa), MOE (5.8 GPa) and MOR (45 MPa) values were higher or comparable to those reported in the literature. Conclusion: HDF formed using a combination of wood and keratin fibers bonded together by polyurethane resin to as much as 50% keratin fibers were dimensionally stable with stiffness and strength above the minimum requirements for general use HDF as prescribed by EN 622-5.

scholarly journals Thermo-Mechanical Properties of a Wood Fiber Insulation Board Using a Bio-Based Adhesive as a Binder

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 152
Author(s):  
Franz Segovia ◽  
Pierre Blanchet ◽  
Nicolas Auclair ◽  
Gatien Geraud Essoua Essoua
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Citric Acid ◽  
Crude Glycerol ◽  
Wood Fiber ◽  
Physical And Mechanical Properties ◽  
Acid Mixture ◽  
Wood Fibers

The goal of the present study was to develop a low-density thermal insulation board using wood fibers and a bio-based adhesive as a binder, which was prepared from a crude glycerol and citric acid mixture. The physical and mechanical properties of insulation boards manufactured using two ratios of crude glycerol and citric acid (1:0.66 and 1:1 mol/mol) and two adhesive contents (14% and 20%) were evaluated. The results show that the insulation boards with a range of density between 332 to 338 kg m−3 present thermal conductivity values between 0.064 W/m-K and 0.066 W/m-K. The effect of adhesive content was very significant for certain mechanical properties (tensile strength perpendicular to surface and compressive strength). The tensile strength (internal bond) increased between 20% and 36% with the increased adhesive content. In contrast, the compressive strength decreased between 7% and 15%. The thermo-mechanical properties obtained of insulation boards such as thermal conductivity, traverse strength, tensile strength parallel and perpendicular to surface, and compressive strength are in accordance with the requirements of the American Society for Testing and Materials C208-12 standard for different uses. The results confirm the potential of crude glycerol and citric acid mixture to be used as an adhesive in the wood fiber insulation boards’ manufacturing for sustainability purposes.

Investigation of selected properties of the black elder wood (Sambucus nigra L.)

2021 ◽  
Vol 116 ◽  
pp. 28-38
Author(s):  
Paweł Kozakiewicz ◽  
Marcin Dadon ◽  
Monika Marchwicka
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Sound Propagation ◽  
Water Extract ◽  
Physical And Mechanical Properties ◽  
Hot Water ◽  
Acoustic Properties ◽  
Sambucus Nigra ◽  
Acoustic Resistance

Investigation of selected properties of the black elder wood (Sambucus nigra L.). The work has defined the selected chemical, physical and mechanical properties of the black elder wood, such as content of non-structural substances, shrinkage and density, speed of sound propagation, dynamic modulus of elasticity, acoustic resistance and sound attenuation, modulus of elasticity, bending strength, compressive strength, Brinell hardness, cold and hot-water extractives content and pH of hot-water extract. The black elder wood is hard and moderately shrinking. Mechanical properties are reduced by going from the pith to the perimeter, which is most likely affected by the increasing twist of the fibres. The distance from the pith also affects the acoustic properties and the size of the shrinkage, while the density remains constant.

scholarly journals Cross-Linked Chitosan as an Eco-Friendly Binder for High-Performance Wood-Based Fiberboard

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Erzhuo Huang ◽  
Yanwei Cao ◽  
Xinpeng Duan ◽  
Yutao Yan ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Modulus Of Rupture ◽  
Wood Fibers ◽  
Promising Candidate ◽  
Pressing Method ◽  
Optimum Modulus

High-performance wood-based fiberboards with high strength and dimensional stability were fabricated by hot-pressing method using 2,5-dimethoxy-2,5-dihydrofuran (DHF) cross-linked chitosan (CS) as an eco-friendly binder. The effects of cross-linked chitosan on the mechanical properties and dimensional stability of wood-based fiberboards were investigated. It is evident that cross-linked chitosan addition was effective in improving mechanical properties and dimensional stability of wood-based fiberboards. The prepared wood-based fiberboard bonded by DHF cross-linked CS displayed optimum modulus of rupture (MOR) of 42.1 MPa, modulus of elasticity (MOE) of 3986.0 MPa, internal bonding (IB) strength of 1.4 MPa, and thickness swelling (TS) value of 16.3%. The improvement of physical and mechanical properties of wood-based fiberboards could be attributed to the amide linkages and hydrogen bonds between wood fibers and cross-linked chitosan. The high-performance wood-based fiberboards fabricated in this study may be a promising candidate for eco-friendly wood-based composites.

Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Cheng Xing ◽  
Siqun Wang ◽  
George M. Pharr ◽  
Leslie H. Groom
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Loblolly Pine ◽  
Cell Walls ◽  
Physical And Mechanical Properties ◽  
Wood Fibers ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Mechanical Refining ◽  
Atomic Force

Abstract Refined wood fibers of a 54-year-old loblolly pine (Pinus taeda L.) mature wood were investigated by nanoindentation and atomic force microscopy (AFM). The effect of steam pressure, in the range of 2–18 bar, during thermo-mechanical refining was investigated and the nano-mechanical properties and nano- or micro-level damages of the cell wall were evaluated. The results indicate that refining pressure has important effects on the physical and mechanical properties of refined fibers. No obvious damage was observed in the cell walls at pressures between 2 and 4 bar. Nano-cracks (most less than 500 nm in width) were found in fibers at pressures in the range of 6–12 bar, and micro-cracks (more than 5 μm in width) were found in fibers subjected to pressures of 14 and 18 bar. The damages caused at higher pressures were more severe in layers close to the lumen than on the fiber surfaces. Under special circumstances, the S3 layer was heavily damaged. The natural shape of the cross sectional dimensions of the cell walls was not changed at lower pressures (2 and 4 bar), but, as pressure was increased, the fibers tended to collapse. At pressures around 18 bar, the lumina were augmented again. The nano-mechanical properties in terms of elastic modulus and hardness were obviously decreased, while nanoindentation creep increased with refining pressure.

scholarly journals WOOD PULP FOR POLYMER COMPOSITES PRODUCTION

FLORESTA ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 044
Author(s):  
Erick Afonso Agnes ◽  
Tânia Vieira De Mello ◽  
Éverton Hillig ◽  
Ricardo Yoshimitsu Miyahara
Keyword(s):  
Mechanical Properties ◽  
Wood Flour ◽  
Physical And Mechanical Properties ◽  
Wood Pulp ◽  
Inorganic Materials ◽  
Wood Fibers ◽  
Mechanical Process ◽  
The Matrix ◽  
Wood Pulps ◽  
Strength And Stiffness

The use of cellulosic fibers in composites is advantageous compared to inorganic materials, because they present lower density, abrasiveness and cost, besides the renewable origin. This study aimed to evaluate the influence of wood pulp obtained by the chemical (bleached and unbleached) and mechanical process, and wood-flour of Pinus taeda as reinforcement in low density polyethylene (LDPE) matrix. The composites were extruded and the specimens molded by compression. The samples were characterized by thermal analysis, density, mechanical properties and scanning electron microscopy (SEM). The incorporation of the wood pulps and the wood flour in the matrix improved the composites mechanical properties and reduced the rate of material degradation. All fibers types acted as nucleating agents because the composites had better mechanical properties than pure LDPE. There was influence of the studied parameters on tensile and flexural strength and the interactions were significant. In general, the highest values of strength and stiffness were obtained with the use of thermo-mechanical process pulp as reinforcement and the lowest values with the use of unbleached chemical process pulp. micrographs analysis showed that the coupling agent was effective for compatibilizing the wood fibers with the LDPE in the composites. It was possible to produce composite materials with good physical and mechanical properties and improved thermal stability by experimental model.

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