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Softwoods are the basic and traditional raw materials for medium-density fiberboard production. However, sustainable consumption of wood material in the production of wood-based products requires material variety. Therefore, the usability of hardwood species in the production and its effects on the board properties should be of interest. Considering this, the influence of oak utilization percentages (30 %, 50 %, 70 %, and 100 %) on the physical (density, thickness swelling-TS 2 and 24 h) and mechanical (modulus of rupture, modulus of elasticity, internal bonding, screw holding resistance, and Janka hardness) properties of medium density fiberboard was evaluated in this study. Boards were factory-made instead of laboratory-made using Quercus petraea (oak), Fagus orientalis (beech), and Pinus sylvester (Scots pine) fibers. According to the results, the modulus of rupture, modulus of elasticity, and Janka hardness values were increased when medium-density fiberboard was produced using only oak fiber. On the contrary, thickness swelling, screw-holding resistance, and internal bonding properties were decreased.

Electronics in furniture and construction materials, in particular technologies which allow for a flexible and cable-free connection of electronics in such materials, are gaining broader interest. This study shows a further development of a concept to obtain highly conductive medium-density fibreboard panels (MDF) for furniture application. MDF were produced using two mixing processes (wet and dry) for wood and carbon fibres to investigate the effects of resin type (urea formaldehyde (UF) and polymeric methylene diphenyl diisocyanate (pMDI)) and carbon fibre content on their mechanical, physical, and electrical properties. Overall, wet mixed fibres showed better electrical but reduced mechanical properties. Modulus of elasticity (MOE) and bending strength (MOR) values of 3500 MPa and 35 MPa, respectively, and internal bond (IB) values of 0.45 to 0.65 MPa with electrical conductivities of up to 230 S/m were achieved. The technology has been successfully implemented in a demonstration object showing the application in a small piece of furniture. [ABSTRACT FROM AUTHOR]

Medium density fiberboard (MDF) is widely utilized in furniture production. Most MDF in such applications has a surface laminate layer. The lamination process improves the physical and mechanical properties of the boards. The temperature, press time, and pressure values applied during the lamination process affect such properties. In this work, the lamination process was carried out using a constant temperature (180 °C), four different press times (18, 20, 22, and 24 s), and three different pressures (25, 30, and 35 kg/cm²). The raw weight of the decor paper was 90 g/m² and UF and MF glues were used in its production. The properties of the laminated panels were then determined for each variation. In general, the water absorption and thickness swelling properties were improved at the lower pressure and higher press times. The internal bonding strength exhibited a linear change at different press times depending on increasing pressure values, whereas the changes in the bending strength and modulus of elasticity in bending were not statistically significant. It was concluded that the BS increased with rising pressure in the short-term lamination process and that the effect of the pressure on the BS declined with increasing press time. [ABSTRACT FROM AUTHOR]

The main goal of the present research is to investigate the possibility of recycling agricultural residues for producing different types of pressed wood. All experimental work was conducted using a mixture of wood saw dust + linen sass + corn stalks with equal percentages, to produce samples of different types of pressed wood. The main experiments were carried out to control and study the effect of some different operating parameters (pressing pressure (1, 3, 5, 7 MPa), pressing time (5, 10, 15, 20 min.) and resin type (Urea formaldehydes and Speria formaldehyde) affecting the pressed wood production processes. The produced pressed wood was evaluated taking into consideration physical properties (Density, thickness swelling and water absorption), mechanical properties (Modulus of elasticity, modulus of rupture, and internal bond strength) and final product quality. The obtained data reveal that the produced pressed wood quality were meeting the required physical and mechanical properties as stated in the standard quality guidelines under conditions of 5 MPa pressing pressure and 15 min.. pressing time with the use of urea formaldehyde resin. The findings also illustrated that by controlling both pressing pressure and pressing time, a mixture of wood saw dust + linen sass + corn stalks with equal percentages could be used to produce different types of pressed wood (Particleboards, PB; Medium density fiberboards, MDF and High density fiberboards, HDF). [ABSTRACT FROM AUTHOR]

Background and Objective: Nowadays, in metropolitan areas, principled and hygienic waste management is very important. Recycling is one of the most appropriate options in waste management. Hereof, the present study was aimed to investigate the possibility of using textile waste fibers in the manufacture of Medium Density Fiberboard (MDF). Materials and Methods: This experimental study was performed on lab-scale. Fabric waste was prepared by separation method at source from a clothing manufacturer in Tehran and converted into fibers. Test boards were made with weight percentage of mixing textile waste fibers to industrial fibers at three levels of 0:100, 10:90 and 15:85, respectively, 10% urea-formaldehyde adhesive, with 16 mm thickness and 0.7 g/cm³ density by hot press. Then, properties of the boards were measured including bending strength, modulus of elasticity, internal bond, hardness, water absorption and thickness swelling. The results were analyzed with ANOVA test. Results: The results of ANOVA showed that the effect of textile waste fibers on the bending strength, modulus of elasticity and swelling thickness of 2 and 24 hours of boards made at 5% probability level was significant. Additionally, the highest values of physical and mechanical properties are related to made boards with 10% of textile waste fibers. Conclusion: The results showed that it is possible to make MDF with textile waste fibers. The use of wastes such as fabrics in the production of new functional products can be considered as one of the strategies to reduce waste and thus to maintain human health and the environment. [ABSTRACT FROM AUTHOR]

The paper investigates the addition of Nano-Al2O3 powder (alumina, Average Particle Size: 20 nm) on the characteristics of the Medium Density Fibreboards (MDF) made by the forest fibers. Some important physical, mechanical and quasi-static properties of the panels were measured according to the standard test methods and apparatus. Different percentages of alumina powder (0, 1, 2, and 3 weight percentage (wt.) based on the solid content of resin) were used and panels were made in three thicknesses (5, 10 and 14 mm). The experiments showed that the resultant properties of the new composites were improved. The greatest increase in Modulus of Elasticity (MOE) was achieved when 1% wt. alumina was added to the samples. Addition of alumina up to 1% wt. in 5 and 10 mm panels amplified energy absorption by 17% and 24%, respectively. The greatest increase in peak load and energy absorption was observed in samples with 2 and 1% wt. alumina, respectively. Finite element modeling was also used to validate the experimental results. The numerical modeling was in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Physical, mechanical, and formaldehyde emission properties were studied for medium density fiberboard (MDF) produced with oak (75%) and pine (25%) fibers that had been mechanically refined in the presence of calcite particles. The calcite slurry was prepared at two levels of solids, 1.5% and 3% (10 and 20 kg·m-3). Chips were cooked for 4 min at 185 °C, under 8 bar vapor pressure in an Andritz defibrillator. 1.8% liquid paraffin, 0.72% ammonium sulphate solution, and 11% urea-formaldehyde were added by percentage based on oven-dried wood fibers in the blowline at the exit of the defibrator. The fibers were dried to 11% moisture content. MDF boards (2100 mm × 2800 mm × 18 mm) were created using a continuous hotpress process. The addition of calcite in the course of MDF production resulted in improved physical properties, such as thickness swelling (ThS 24 hours) and water absorption (WA 24 hours). MDF boards prepared with calcite exhibited higher internal bond (IB), modulus of rupture (MOR), and modulus of elasticity (MOE). Resistance to axial withdrawal of screw also was increased by addition of 3% calcite. In addition, the lowest levels of formaldehyde emission were observed for MDF prepared with calcite at the 3% level. [ABSTRACT FROM AUTHOR]

Change of relative humidity (RH) in surrounding environment can greatly affect the physical and mechanical properties of wood-based panels. Commercially produced acetylated medium density fiberboard (MDF), Medite Tricoya®, was used in this study to predict strength and stiffness under varying humid conditions by separating samples in parallel (//) and perpendicular (⊥) to the sanding directions. Thickness swelling, static moduli of elasticity (MOEstat) and rupture (MORstat), and internal bond (IB) strength were measured at three different humid conditions, i.e., dry (35% RH), standard (65% RH) and wet (85% RH). Internal bond (IB) strength was also measured after accelerated aging test. A resonance method was used to determine dynamic modulus of elasticity (MOEdyn) at the aforementioned humid conditions. Linear regression and finite element (FE) analyses were used to predict the MDF's static bending behavior. Results showed that dimensional stability, MOEstat, MORstat and IB strength decreased significantly with an increase in RH. No reduction of IB strength was observed after 426 h of accelerated aging test. A multiple regression model was established using MOEdyn and RH values to predict MOEstat and MORstat. In both directions (// and ⊥), highly significant relationships were observed. The predicted and the measured values of MOEstat and MORstat were satisfactorily related to each other, which indicated that the developed model can be effectively used for evaluating the strength and stiffness of Medite Tricoya® MDF samples at any humid condition. Percent errors of two different simulation techniques (standard and extended FE method) showed highly efficient way of simulating the MDF structures with low fidelity. [ABSTRACT FROM AUTHOR]

High global production of medium-density fiberboard (MDF) in recent years could generate an equal quantity of waste MDF at the end of its service life, requiring recycling of waste MDF instead of landfilling or incineration. This study investigated effects of the addition of recycled fiber (RF) obtained from surface laminated MDFs with three different materials to the properties of three-layer recycled MDF (rMDF). Three types of surface laminates such as low-pressure laminate, polyethylene terephthalate, and polyester coating were hammer milled, and then went through a patent-pending fiber recovery system to obtain the resultant RFs that were added to the core layer of rMDF. These RFs at three contents (10, 20, and 30%) were blended with 12% of urea-formaldehyde (UF) resin prior to hot-pressing. Statistical analysis showed that the best internal bonding strength, modulus of rupture, and modulus of elasticity of rMDF panels were obtained for LPL-rMDF with a 20% RF content. Thickness swelling, water absorption, and formaldehyde emission of rMDF were reduced by increasing the RF content. These findings suggest that a minimum RF content of 20% can be replaced with virgin fibers for the rMDF manufacture, indicating the feasibility of recycling waste laminated MDF into three-layer rMDF. [ABSTRACT FROM AUTHOR]

The use of different mineral material types and contents in medium density fiberboard (MDF) production was investigated. Three different minerals (sepiolite, dolomite, and perlite) and five different ratios (3%, 6%, 9%, 12%, and 15%) were used according to the oven-dry wood fiber weight. These minerals were homogeneously added as powder between the wood fibers. Some physical, mechanical, limit oxygen index (LOI), and thermogravimetric analysis (TGA) tests of the boards were conducted. The mineral fillers negatively affected the physical properties such as water absorption (WA), thickness swelling (ThS), and mechanical properties such as modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond (IB). However, LOI and TGA test results showed a positive effect on combustion resistance depending on the type and rate of mineral fillers. [ABSTRACT FROM AUTHOR]

In this study, graphene oxide (GO) and ethylenediamine-functionalized graphene oxide (EDA-GO) materials were used as a multifunction additive in a UF resin to test the relevant effects on the release of formaldehyde from medium density fiberboard (MDF). The GO was synthesized from graphite using the modified hummers method. Then, the as-synthesized GO was functionalized with ethylenediamine (EDA). The as-synthesized and modified nanomaterials were characterized by XRD, Raman Spectroscopy, AFM, and SEM-EDS techniques. These tests confirmed that the nanomaterials were of the required quality, and they were added to the resin to make the relevant panels. After making the boards, they were tested to determine their physical and mechanical properties, as well as formaldehyde emission based on relevant standards. Modulus of elasticity and formaldehyde emission reduction of the EDA-GO 3 -treated MDF panel were with the highest values. On the contrary, the higher performance of GO than that of EDA-GO was observed in a thermal property (t 100°C). Microstructure and polar increase in the graphite planes network, due to oxidation, may be considered for its GO effects. Amino-functionalization of graphene oxide planes is suggested as the cause of the minimum formaldehyde emission and the maximum modulus of elasticity in the EDA-GO-incorporated MDF board since resin reaction sites with formaldehyde were enhanced by increasing the amine group content. [ABSTRACT FROM AUTHOR]

As a way of reducing the formaldehyde emission and improving the properties of medium density fiberboard (MDF), this study investigated the effects of nanoclay and modified nanoclay with 3-aminopropyltriethoxysilane (APTES) and l -Lysine (Lys) on the MDF. The XRD, FTIR, and CHN anaLyses showed that nanoclay was successfully modified with APTES and Lys. 1.5, 2, and 2.5% of nanoclay and modified nanoclay were added into UF resin (based on the dry weight), and the mixtures were used to produce MDF. Changes in formaldehyde emissions were determined by the desiccator method. In addition, the modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), thickness swelling (TS), and water absorption (WA) of the boards were measured. The results showed that adding nanoclay (5–25%) and modified nanoclay with APTES (42–61%) and Lys (38–50%) reduced formaldehyde emission. Meanwhile, the mechanical and physical properties of the boards also improved by adding nanoclay and modified nanoclay. [ABSTRACT FROM AUTHOR]

Synergic effects of different fire retardant compounds and zinc borate on wood-plastic composites filled with polypropylene (PP) and mediumdensity fiberboard (MDF) waste fibers were investigated. For this purpose, zinc borate, synergic compounds (antimony trioxide, ammonium phosphate, and magnesium hydroxide), and a coupling agent, i.e., maleic anhydride-grafted polypropylene (MAPP), were used in the production of wood-plastic composites (WPCs). The composite samples were characterized in terms of the burning rate and limiting oxygen index (LOI) analyses, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) along with mechanical tests, i.e., flexural properties, tensile properties, elasticity modulus, and impact strength. It was found that the synergic influence of the combination of zinc borate, antimony trioxide, and magnesium oxide on WPCs increased the heat resistance according to the burning rate, LOI, TGA, and DSC tests. Also, the mechanical properties of the WPCs decreased slightly, but their elasticity modulus increased. [ABSTRACT FROM AUTHOR]

The effect of temperature in the range from 25 ºC to 175 ºC on the bending performance of plywood and medium density fiberboard (MDF) has been studied with the ultimate purpose of optimizing the post-processing using radio frequency heating and improving the quality of the final products. Static 3-point bending tests were conducted on a universal testing machine inside a computer-controlled chamber. Results show that the bending strength (MOR) and modulus of elasticity (MOE) of plywood and MDF decrease with the increase of the temperature from 25 ºC to 175 ºC. The bending strength of plywood and MDF decreases with the increase of the exposure time. However, the effects of exposure time on MOE of plywood and MDF are not obvious. Plywood and 2.6 mm thick MDF show a typical elasto-plastic behavior, while 12 mm thick MDF does not exhibit any plastic behavior. It is recommended that the post-processing procedure should be completed within 15 minutes for both MDF and plywood.

The properties of medium density fiberboard (MDF) derived from different manufacturing plants were compared. Each plant provided 5 full-sized (2440 by 1220 mm) 155-grade panels that were tested according to ANSI A208.2-2009. None of the panels met the recommended value for Internal Bond (IB). Mean values for Thickness Swell (TS) were all significantly different, with one manufacturer below the standard. Three manufacturers exceeded the recommended face Screw Withdrawal Resistance (fSWR) values, one was equal to it, and one failed. Three manufacturers exceeded the edge SWR (eSWR) standard, and the remaining two fell below. Two manufacturers met the standard for Modulus of Rupture (MOR), and only one manufacturer failed to meet the Modulus of Elasticity (MOE) requirements. Linear Expansion (LE) was evaluated for a RH change from 50 to 90%. The panels made with pMDI-resin consistently had some of the highest mean values for MOR, MOE, fSWR, and IB and exhibited good performance in the TS test. [ABSTRACT FROM AUTHOR]

It is preferred to perform conformity assessment of wood-based panels on the whole panel without cutting it down to smaller pieces. The modulus of elasticity, a mechanical property of wood, was determined by longitudinal vibration testing with the full-size panel, and the results were compared with results of tests of prismatic beams. The Brancheriau's correction coefficient was used to compensate for errors from cross-sectional dimension variations and errors from Poisson's ratio. Longitudinal excitation of the panels along the length was shown to be successful in evaluating the modulus of elasticity. However, strong correlations obtained from plate and beam comparisons along the width of the panels are promising. [ABSTRACT FROM AUTHOR]

Glue-free fiberboard, as a substitute for traditional fiberboard, does not contain a large amount of synthetic resins, which can avoid harm to human health and environment. However, glue-free fiberboard still has some disadvantages of insufficient mechanical strength and excessive thickness swelling of water absorption. Here, corn straw lignin was co-modified by demethylation/hydrothermal degradation to obtain high hydroxyl content increased by 210.85% compared with raw lignin. The co-modified lignin was then introduced into freezing activated wood fibers to prepare the environment-friendly medium density fiberboard (MDF). The effect of co-modified lignin content on the properties of MDF was investigated. MDF with 3 wt% co-modified lignin exhibited the best comprehensive performance with the modulus of elasticity (MOE) of 5809 MPa, modulus of rupture (MOR) as high as 70 MPa, internal bonding strength (IB) of 2.29 MPa and thickness swelling (TS) as low as 16.65%, completely matching the requirements of the Chinese national standard GB/T 11718-2009 and EU national standard BS EN 622–5–2009. The interaction mechanism of co-modified lignin on the wood fibers was further explored by Fourier infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and scanning electron microscope (SEM) analysis. The phenolic structures of co-modified lignin could be chemically crosslinked with wood fibers during the hot-pressing process and the large amount of hydroxyl groups provided strong hydrogen bond interactions for the glue-free fiberboard. The glue-free fiberboard enhanced by co-modified lignin with excellent comprehensive performance exhibits a broad application prospect. 1 1 MDF: medium density fiberboard; MOR: modulus of rupture; MOE: modulus of elasticity; IB: internal bonding strength; TS: thickness expansion; DSC: differential scanning calorimetry [Display omitted] • Corn straw lignin was co-modified by demethylation and hydrothermal degradation. • Co-modified lignin with high hydroxyl content enhanced the performance of MDF. • Internal bonding strength of MDF was 2.29 MPa much higher than national standards. • Interaction mechanism of co-modified lignin and wood fiber was analyzed. [ABSTRACT FROM AUTHOR]

There is an increasing interest in using non-wood lignocellulosic materials for the production of wood-based medium density fiberboard (MDF). Agave durangensis Gentry bagasse is a waste product produced in large quantities in the mezcal industry. This study evaluated the incorporation of A. durangensis bagasse fibers (ADBF) to elaborate MDF wood-based panels. Three types of panels with different ratios (wood fibers: bagasse fibers) were investigated. The ratios evaluated were 100:0, 90:10, and 70:30. The density profiles, water absorption, and thickness swell of the panels were determined, as well as the modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond (IB), according to the ASTM D1037-06a standard. The results were compared to the ANSI A208.2-2016 standard. The effect of the addition of ADBF on the properties of the panels was analyzed. Density profiles were comparable among the three types of panels, while water absorption, thickness swelling, MOE, MOR, and IB were similar between panels with ratios of 100:0 and 90:10. Panels with 10% and 30% of ADBF meet the minimum ANSI requirements for quality grade 115. It is feasible to use up to 30% of ADBF in the manufacture of wood-based MDF panels. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate suitability of luffa (Luffa cylindrica) fiber for medium density fiberboard (MDF) production. For the experiment, luffa and commercially manufactured fibers (Pinus sylvestris (30%), Fagus orientalis Lipsky (35%) and Quercus robur L. (35%)) with 11% moisture content were used. Luffa was mixed with commercially manufactured fibers in the following fashion: a layer of luffa fiber (30 g) placed in the middle of the mat, two equidistantly placed layers (60 g) in the mat, three layers (90 g) instead of two in the mat, and homogenously (90 g) dispersed without a district pattern in the mat, respectively. In panel production the only variable tested was the addition of luffa fiber at various weights to the wood fibers. Commercial urea formaldehyde (UF) adhesive was used as a binder. Chemical properties, including holo-, α-cellulose, and contents, alcohol-benzene solubility in dilute alkali (1% NaOH), and hot and cold water solubility, were determined. In addition, some physical and mechanical properties, such as density, thickness swelling (TS), bending strength (BS), modulus of elasticity (MOE), and internal bond (IB) of the panel of MDF were also measured. The chemical composition and solubility of luffa were found to be similar to those of nonwoods in general. Thus, the results suggest that luffa (Luffa cylindrica Mill.) fiber can be used as an alternative raw material for MDF manufacturing. [ABSTRACT FROM AUTHOR]

Abstract: Influence of the temperature on the bending strength (BS) and modulus of elasticity (MOE) of three types of commercial wood-based panels (plywood, medium density fiberboard (MDF), and oriented strandboard (OSB)) was investigated at temperatures between −30°C and +30°C. The BS and MOE of the panels decreased with increasing temperature. Significant differences (p <0.01) were observed in both the BS and MOE of the panels. The strength properties of the panels changed more at positive temperatures than at negative temperatures. For example, when the temperature increased from −30°C to 0°C, the BS and MOE parallel to the plywood face grain were decreased by 9.8% and 7.4% while they were decreased by 12.5% and 9.6% when the temperature increased from 0°C to +30°C. Similar results were also observed for the MDF and OSB panels. [Copyright &y& Elsevier]

Taking medium density fiberboards (MDF) as samples, the feasibility of the applications of wavelet analysis in a nondestructive test is discussed in this paper. The main results are as follows: the modulus of elasticity of longitudinal resonance, measured by wavelet analysis, can replace the conventional static modulus of elasticity. Their correlation coefficient is significant ( p < 0.01). The defect of samples can be judged by wavelet analysis, which is superior because it is a nondestructive test. [ABSTRACT FROM AUTHOR]

In this research, the special effects of graphene oxide nanoparticle charging (0, 2, 4, 6, wt.%) on the properties of medium-density fiberboard were examined. Physical and mechanical properties of the panels were determined conferring the method of European Norm standards. The consequences exhibited substantial enhancement in mechanical properties, explicitly in modulus of rupture, modulus of elasticity and internal bonding for 2–6% nanoparticle addition in a urea–formaldehyde resin. The mechanical properties, i.e., internal bond, modulus of elasticity and modulus of rupture were improved by 28.5%, 19.22% and 38.8%, respectively. Results also show a clear enhancement in thickness swelling and water absorption. The physical properties of thickness swelling, water absorption and thermal conductivity were improved up to 50%, 19.5% and 39.79%, respectively. The addition of graphene oxide nanoparticles strongly affected the curing time of the urea–formaldehyde resin and improved its thermal stability. [ABSTRACT FROM AUTHOR]

In this research work effect of embedment of multiwall carbon nanotubes (MWCNTs) on the physical and mechanical properties of medium density fiberboard (MDF) have been investigated. The MWCNTs were embedded in urea formaldehyde resin (UF) at 0, 1.5%, 3% and 5% concentrations by weight for the manufacturing of nano-MDF. The addition of these nanoparticles enhanced thermal conductivity by 24.2% reduced curing time by 20% and controlled formaldehyde emission by 59.4%. The internal bonding (I.B), modulus elasticity (MOE), modulus of rupture (MOR), thickness swelling (Ts) and water absorption (WA) properties were improved significantly by 21.15%, 30.2%, 28.3%, 44.8% and 29% respectively as compared to controlled MDF. [ABSTRACT FROM AUTHOR]