Effects of Element Size and Orientation in the Production of High Strength Resin Impregnated Wood Based Materials

Holzforschung ◽  
2000 ◽  
Vol 54 (4) ◽  
pp. 443-447 ◽  
Author(s):  
H. Yano ◽  
K. Mori ◽  
P.J. Collins ◽  
Y. Yazaki
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Hot Pressing ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Element Size ◽  
Resin Impregnation ◽  
The Difference ◽  
C 30

Summary The effects of low molecular weight phenolic resin impregnation and high pressure hot pressing (150°C, 30–100 MPa) on the physical and mechanical properties of wood were first investigated by using sawn wood prepared from a block of Japanese birch (Betula meximowicziana). Subsequently, the effects of element size and orientation were examined by using sliced veneers, particles and powder prepared from the remaining portion of the block. Due to the combination of resin impregnation and hot pressing under high pressure, the specific bending strength at 20°C and 65% RH of sawn wood increased 50% accompanied by enormous decreases in moisture content, and bending strength reached around 400 MPa. The mechanical properties of veneer laminated product did not differ significantly from those of sawn wood product. Among isotropic products, the highest bending strength at 20°C and 65% RH of plywood, particleboard and powderboard was 242 MPa, 166 MPa and 175 MPa, respectively. The difference of bending strength between plywood and other isotropic products could be explained by the difference in element orientation, cross lamination and random distribution. Furthermore, the results for the particleboard and powderboard showed that when the resin impregnated elements were hot pressed under high pressure, a decrease in element size did not result in a decrease in bending strength.

scholarly journals Effects of selected chemical admixtures on physical and mechanical properties of cement mortar

2020 ◽  
Vol 30 (3) ◽  
pp. 305-310
Author(s):  
SS Bethe ◽  
MN Haque ◽  
MR Islam
Keyword(s):  
Mechanical Properties ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Chemical Admixtures ◽  
Super Plasticizer ◽  
The Difference

This study was aimed to determination of appropriate dosage of selected chemical admixtures to reduce water cement ratio for mortar mix also to determine its effects on physical and mechanical properties of cement mortar. Amount of water used in concrete is very important for the physical and mechanical properties. Less amount of water increase the strength but reduce the workability. Water retarding admixture can reduce the water cement ratio with desired workability. In this experiment plasticizer (master pel 707) and super plasticizer (master polyheed 8632) was used. The used dosages of admixture were 0.5%, 1% and 1.5% according to cement weight. The test was done at 3 days, 7 days, 28 days and 91 days. 2.76″ cube mold was used for the work. The experiment was done to find the difference between with and without admixture used in mortar. Water used reduced with add of plasticizer and super plasticizer. In the experiment the workability of normal mortar and admixture used mortar remain same. The compressive strength is high for 1.5% super plasticizer used sample. So 1.5% super plasticizer is recommended for high strength. Progressive Agriculture 30 (3): 305-310, 2019

Evaluation of Physical and Mechanical Properties of Paulownia Wood Core and Fiberglass Surfaces Sandwich Panel

2011 ◽  
Vol 471-472 ◽  
pp. 85-90 ◽  
Author(s):  
Maryam Sobhani ◽  
Abolghasem Khazaeian ◽  
Taghi Tabarsa ◽  
Alireza Shakeri
Keyword(s):  
Mechanical Properties ◽  
Sandwich Panel ◽  
Bending Strength ◽  
Polyester Resin ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Modulus Of Rupture ◽  
The Core ◽  
Paulownia Wood

The purpose of this study was to determine some physical and mechanical properties of sandwich panels manufactured from the core of Paulownia wood and surfaces of multilayer of fiberglass and resins. Paulownia was selected among Hardwoods because of its s low density (0.26 g/cm3) and high strength/weight ratio. Eight treatments were used for experiments: Two kinds of fiberglass (needle and combination of the needle and curtain type), two various resins (polyester and epoxy) and two core thicknesses (9mm and 19mm). Physical properties including density, resistance to water absorption, Dimensional stability, and Mechanical Properties such as internal bonding, compressive and bending strength of panels were measured following ASTM Standard. The results indicated that panels with 19 mm thick core had lower density (0.5g/ cm3) compared to the 9mm thick panels (0.7g/cm3). Bigger volume of wood in the core of panels with higher thickness was the main reason of this result. The experimental results showed that thickness of wood was effective on the modulus of rupture, modulus of elasticity, and compressive strength, significantly. Epoxy resin presented higher internal bond compared to the polyester resin. The two kind of fiberglass (needle one and the combination of needle and curtain type) didn’t have noticeable differences on mechanical properties. It also was found that Paulownia is a promising species for manufacturing sandwich panel.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.

Influence of different concentrations of fibrinogen on the properties of a fibrin matrix for vascular tissue engineering

2021 ◽  
Vol 29 (1) ◽  
pp. 21-34
Author(s):  
Vera G. Matveeva ◽  
Mariam Yu. Khanova ◽  
Tatyana V. Glushkova ◽  
Larisa V. Antonova
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Metabolic Activity ◽  
Vascular Tissue ◽  
Physical And Mechanical Properties ◽  
Vascular Tissue Engineering ◽  
Test Machine ◽  
Fibrin Matrix ◽  
Before And After ◽  
The Difference

Aim. To evaluate the potential utility of fibrin matrices containing 10, 20, and 25 mg/ml of fibrinogen (fibrin-10, fibrin-20, and fibrin-30, respectively) in vascular tissue engineering (VTE). Materials and Methods. Fibrinogen was isolated using the method of ethanol cryoprecipitation and polymerized using a solution of thrombin and CaCl2. The fibrin structure was studied in a scanning electron microscope, and the physical and mechanical properties of the material were tested on a Zwick/Roell test machine. The metabolic activity of endothelial cells (EC) on the fibrin surface was evaluated by the MTT assay, and the viability of fibroblasts in the thickness of fibrin and possibility for migration by in fluorescent and light microscopy. Percent of fibrin shrinkage was determined from the difference in the sample volumes before and after removal of moisture. Results. The fiber diameter did not differ among all fibrin samples, but the pore diameter in fibrin-30 was smaller than those in fibrin-10 and fibrin-20. A possibility for migration of fibroblasts into the depth of the fibrin matrix and preservation of 97-100% viability of cells at a depth 5 mm was confirmed. The metabolic activity of EC on the surface of fibrin-20 and fibrin-30 exceeded that on collagen, fibronectin, and fibrin-10. All fibrin samples shrank in volume to 95.5-99.5%, and the highest shrinkage was seen in fibrin-10. The physical and mechanical properties of fibrin were inferior to those of human A. mammaria by a factor of 10. Conclusion. Fibrin with fibrinogen concentrations of 20 and 30 mg/ml maintains a high metabolic and proliferative activity of EC on the surface and also a high viability of fibroblasts in the matrix. Its availability, ease of preparation, and a number of other favorable properties make fibrin a promising material for VTE. However, the problem of insufficient strength requires further investigations.

Fabrication of Carbon Nanotube Reinforced Boron Carbide Composite by Hot-Pressing Following Extrusion Molding

2014 ◽  
Vol 616 ◽  
pp. 27-31 ◽  
Author(s):  
Tomohiro Kobayashi ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Boron Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Extrusion Direction ◽  
Sem Observation

The CNT/B4C composite with Al2O3 additive was fabricated by hot-pressing following extrusion molding of a CNT/B4C paste, and mechanical properties of the obtained composite were investigated. Many CNTs in the composite aligned along the extrusion direction from SEM observation. 3-points bending strength of the composite was slightly lower than that of the monolithic B4C. Elastic modulus and Vickers hardness of the composite drastically decreased with CNT addition. Fracture toughness of the composite was higher than that of the monolithic B4C.

scholarly journals Excellent Mechanical Properties of the Silicate Glasses Modified by CeO2 and TiO2: A New Choice for High-Strength and High-Modulus Glass Fibers

2021 ◽  
Author(s):  
Chao Chen ◽  
Qingong Zhu ◽  
Huanping Wang ◽  
Feifei Huang ◽  
Qinghua Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silicate Glass ◽  
Optical Fibers ◽  
Bending Strength ◽  
Glass Fibers ◽  
High Strength ◽  
Maximum Level ◽  
Compression Modulus ◽  
Co Doping ◽  
Optimum Approach

Abstract As is well known, silicate glass has a stable glass-forming region and mature drawing processes into fibers. In this study, to obtain enhanced mechanical properties, glasses with a composition of SiO2-Al2O3-MgO-CaO-B2O3-Fe2O3 were synthesized using TiO2 and CeO2. When the amount of TiO2 and CeO2 is less than 2 wt%, the mechanical properties increase with increases in the TiO2 and CeO2. However, as the amount of TiO2 and CeO2 increases from 2 to 3.5 wt%, the mechanical properties decrease. Co-doping with 1 wt% TiO2 and 1 wt% CeO2 was found to be the optimum approach, with a density, bending strength, compression strength, and compression modulus of 2.626 g/cm3, 108.36 MPa, 240.18 MPa, and 115.03 GPa, respectively. The optical band gap and Raman spectroscopy proved that, as long as the content of oxygen bonds reaches the maximum level, a kind of best structural stability and mechanical properties will be achieved. Hence, this type of high-strength silicate glass can be used in optical fibers for military defense, wind power generation, and transportation.

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

Sign in / Sign up

Export Citation Format

Share Document