scholarly journals Optimization of the Hot-Pressing Regime in the Production of Eco-Friendly Fibreboards Bonded with Hydrolysis Lignin

2021 ◽  
Author(s):  
Ivo Valchev ◽  
Yvailo Yordanov ◽  
Viktor Savov ◽  
Petar Antov
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Adhesive System ◽  
Hydrolysis Lignin ◽  
Dry Process ◽  
Second Stage ◽  
Pressing Cycle ◽  
Good Retention

This research was aimed at studying the potential of using residual lignin from acid hydrolysis as a binder in manufacturing eco-friendly, dry-process fibreboards. For that purpose, a modification of the adhesive system and hot-pressing regime was conducted. The adhesive system applied was composed of 2 % phenol-formaldehyde (PF) resin and 10 % hydrolysis lignin (based on the dry fibres). The PF resin does not only act as a binder but generally contributes to the even distribution and good retention of the main binder – hydrolysis lignin. A specific hot-pressing cycle was used. In the first stage, the pressure was 1.0 MPa, followed by an increased pressure of 4.0 MPa, and subsequent cooling. The purpose of the initial lower pressure was softening the lignin and reduction of the material moisture content. The effect of the second stage of hot-pressing on the properties of eco-friendly fibreboards was investigated. It was determined that the fibreboards produced with 2 % PF resin and 10 % hydrolysis lignin have similar physical and mechanical properties to those of the control panels, produced with 10 % PF resin at a standard hot-pressing cycle. The findings of this work demonstrate that residual hydrolysis lignin can be effectively utilized as a binder in the production of eco-friendly, dry-process fibreboards with acceptable physical and mechanical properties.

scholarly journals Environmentally-Friendly High-Density Polyethylene-Bonded Plywood Panels

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1166 ◽  
Author(s):  
Pavlo Bekhta ◽  
Ján Sedliačik
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
High Density Polyethylene ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
High Density ◽  
Pressing Pressure ◽  
Pressing Time

Thermoplastic films exhibit good potential to be used as adhesives for the production of veneer-based composites. This work presents the first effort to develop and evaluate composites based on alder veneers and high-density polyethylene (HDPE) film. The effects of hot-pressing temperature (140, 160, and 180 °C), hot-pressing pressure (0.8, 1.2, and 1.6 MPa), hot-pressing time (1, 2, 3, and 5 min), and type of adhesives on the physical and mechanical properties of alder plywood panels were investigated. The effects of these variables on the core-layer temperature during the hot pressing of multiplywood panels using various adhesives were also studied. Three types of adhesives were used: urea–formaldehyde (UF), phenol–formaldehyde (PF), and HDPE film. UF and PF adhesives were used for the comparison. The findings of this work indicate that formaldehyde-free HDPE film adhesive gave values of mechanical properties of alder plywood panels that are comparable to those obtained with traditional UF and PF adhesives, even though the adhesive dosage and pressing pressure were lower than when UF and PF adhesives were used. The obtained bonding strength values of HDPE-bonded alder plywood panels ranged from 0.74 to 2.38 MPa and met the European Standard EN 314-2 for Class 1 plywood. The optimum conditions for the bonding of HDPE plywood were 160 °C, 0.8 MPa, and 3 min.

scholarly journals RESEARCH OF PHYSICAL AND MECHANICAL PROPERTIES OF BLENDED BRICKS WİTH FLY ASH BASED, BLAST FURNACE SLAG ADDITION

2019 ◽  
Vol 7 (1) ◽  
pp. 126-136
Author(s):  
Hakan Çağlar ◽  
Arzu Çağlar
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Physical And Mechanical Properties ◽  
Industrial Wastes ◽  
Second Stage ◽  
Volume Weight ◽  
History Of ◽  
Furnace Slag

In this study, it is aimed to make improvements on blended brick (1) which is the first building material has a history of at least 10,000 years. To the blended brick which is a traditional material was kept constant at 5% the addition of fly ash which is industrial waste. It was aim of determine of the effect on the physical and mechanical properties of the blended brick using different ratios (5%, 10%, 15% and 20%) blast furnace slag. In the first stage, the production of fly ash-based blast furnace slag doped sample of blended brick was performed. In the second stage, a variety of experiments were applied to determine the physical and mechanical properties of the blended brick sample. As a result; It has been determined that unit volume weight and compressive strength decreases with the use of industrial wastes in blended brick production. They have occured an increase in porosity and capillary water absorption values. The use of industrial wastes in the production of blended bricks will contribute both improve the properties of the bricks and   the reduction of wastes left to the environment.

Preliminary Research on Manufacturing Technology of Thin Bamboo Veneer Consolidated Composite Floor

2012 ◽  
Vol 503-504 ◽  
pp. 74-77
Author(s):  
Nan Hu ◽  
Xian Jun Li ◽  
Yi Qiang Wu ◽  
Xin Gong Li ◽  
Zhi Cheng Xue
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Bond Strength ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Pressing Pressure ◽  
Pressing Temperature ◽  
Decorative Material ◽  
Preliminary Research ◽  
Surface Bond

In this paper, the new bamboo-based consolidated composite floors were fabricated with thin bamboo veneers which used as decoration layers, wear resistant layers, high density fiberboards and equilibrium layers through assembling and scuffing. The effect rules of the composite floor on properties were preliminarily studied by three factors: hot-pressing temperature, pressure and time. The results showed that the wear resistance and surface bond strength of the thin bamboo veneer consolidated composite floor significantly increased with the rise of hot-pressing temperature. In the scope of resources, the effect of hot-pressing pressure and time on properties of the floor is not significant. The optimizing technology is hot-pressing temperature 170°C, pressure 3MPa and time 40s/mm in this study. The thin bamboo veneer consolidated composite floor is an excellent floor decorative material, which has good physical and mechanical properties.

Evaluation of the Influence of Pre-Alloyed Powder Fe65Nb on the Production of Metal Matrices by Powder Metallurgy

2020 ◽  
Vol 1012 ◽  
pp. 3-8
Author(s):  
A.C.G. Silva ◽  
Hellen C.P. Oliveira ◽  
Thales Eduardo Leal ◽  
Paulo Santos Assis
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Chemical Composition ◽  
Solid State ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Toxic Element ◽  
Alloyed Powder ◽  
Eds Analysis ◽  
Porosity Measurements

The objective of this paper is to study Fe65Nb-Cu metal matrices, thus varying the content of the pre-alloyed Fe65Nb powder from 10% to 100%. Therefore, powders of Fe65Nb and Cu were used, innovating in the chemical composition of the commonly used matrices. The objective is to evaluate the substitution of Co (toxic element, commonly used) by Nb (98.2% of reserves are Brazilian). For the sintering of the samples it was used hot pressing technique. The parameters were set at: 850°C / 35MPa / 3min. The sintered bodies underwent SEM/EDS analysis and density and porosity measurements were performed. From the results it is possible to say that the compositions of (10% and 30% Fe65Nb) presented the best physical and mechanical properties. The relative density decreases for the compositions with 40%, 50% and 60% Fe65Nb is justified by the presence of fragile particles in metal matrices, since they require more energy in order to efficiently transport matter (diffusion) in a solid state.

Study on Physical and Mechanical Properties of Cu/MoS2 Composites

2013 ◽  
Vol 575-576 ◽  
pp. 156-159
Author(s):  
Dou Qin Ma ◽  
Jing Pei Xie ◽  
Ji Wen Li ◽  
Ai Qin Wang ◽  
Wen Yan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diffraction Analysis ◽  
Electric Conductivity ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacuum Hot Pressing

Cu-3wt. %MoS2-7wt. %Mo and Cu-3wt. %MoS2 composites were prepared by repressing, re-sintering and vacuum hot pressing, respectively. Microstructures were characterized by optical metallographic microscope, EDS, SEM and X-ray diffraction analysis, respectively. The micro hardness, electric conductivity and density of samples were separately measured as well. Results show that the micro hardness of Cu-3wt. % MoS2-7wt. % Mo composites is about 33.3% higher than that of Cu-3wt. %MoS2 composites. The increase in micro hardness is attributed to the presence of Mo. The electric conductivity of Cu-3wt. %MoS2 and Cu-3wt. %MoS2-7wt. % Mo prepared by vacuum hot pressing were 80.6 % and 63.8% IACS, respectively, which is an increase compared with values of 80.2 % and 57.3% IACS of samples obtained by repressing and re-sintering.

scholarly journals INFLUENCE OF THERMAL MODIFICATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OF Eucalyptus badjensis MIXED PARTICLEBOARD / OSB PANELS

FLORESTA ◽  
2021 ◽  
Vol 51 (2) ◽  
pp. 419
Author(s):  
Giuliano Ferreira Pereira ◽  
Setsuo Iwakiri ◽  
Rosilani Trianoski ◽  
Polliana D'angelo Rios ◽  
Renan Zunta Raia
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Dry Mass ◽  
Thermal Modification ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Swelling Properties ◽  
Different Temperatures

The objective of this research was to evaluate the effects of thermal modifications, at different temperatures and exposure times, on the technological properties of mixed particleboard / OSB panels made out of Eucalyptus badjensis. Using the wood of Eucalyptus badjensis, Particleboard, OSB and mixed Particleboard/OSB panels (control and thermally modified) were manufactured. The mixed panels’ thermal modification was carried out under three temperatures (180ºC, 200ºC and 220ºC) and two exposure times (10 minutes and 12 minutes). For the panels’ manufacturing, 6% of phenol-formaldehyde adhesive and 1% of paraffin were employed, which was calculated based on the particles’ dry mass. The water absorption and thickness swelling properties were evaluated after 2 and 24 hours of immersion, in addition to the panels’ modulus of elasticity, modulus of rupture and internal bond. Based on the results, we were able to conclude that the thermal modification affected most of the physical properties positively. From the different exposure times studied, the most effective one was the period of 12 minutes, especially for water absorption after 2 hours, which caused a reduction of 11.27%. In turn, the most effective temperature was of 220ºC, highlighting the thickness swelling after 24 hours, which caused a swelling decrease of 23.76% in comparison with the control panels. Regarding the mechanical properties, the thermal modification, in terms of the studied exposure times and temperatures, did not affect the results of the mixed particleboard /OSB panels. 

scholarly journals Effects of Addition of Prosopis Juliflora Fiber on the Physical and Mechanical Properties of Wood Dust and Coir Pith Particle Reinforced Phenol Formaldehyde Hybrid Composite

2017 ◽  
Vol 13 (10) ◽  
pp. 6558-6562
Author(s):  
A. Athijayamani ◽  
A.Sujin Jose ◽  
K. Ramanathan ◽  
S. Sidhardhan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Hybrid Composites ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Prosopis Juliflora ◽  
Wood Dust ◽  
Weight Percentage ◽  
Coir Pith

In this study, Wood Dust (WD)/Phenol Formaldehyde (PF) and Coir Pith (CP)/PF composites were hybridized with the Prosopis Juliflora Fiber (PJF) to obtain the hybrid composites. Composites were prepared by hand moulding technique. The weight percentage of particles and fibers are fixed in the ratio of 1:1. Mechanical properties such as tensile, flexural and impact strengths were evaluated as a function of the particle and fiber loadings. The results show that the properties of both the WD and CP composites obviously improved by the addition of the PJF. The improvement in WD/PF composites was obviously higher than the CP/PF composites for all loadings. The WD/PJF/PF hybrid composites exhibited better tensile (strength of 48.9 MPA and modulus of 1262.1 MPa, respectively), flexural (strength of 55.4 MPa and modulus of 1344.3 MPa, respectively), and impact properties (1.32 KJ/m2). 

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