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The conventional wood-based composites contain an unreacted free formaldehyde, which causes a cancerous effect on humans. To overcome this problem, citric-acid-modified corn and oil palm starches are proposed as ecobinders for wood-based composites in this study. Experimental rubber-wood panels were made using the ecobinders. The panels were subjected to FT-IR, TGA, DSC, and X-ray diffraction analyses, and then their modulus of elasticity, modulus of rupture, bond strength, water absorption, and thickness swelling were determined experimentally. The results obtained are shown in figures and tables.

Particleboards were manufactured using coconut fibers (Cocos nucifera). The panels were made using different green adhesives, i.e., native potato starch, citric acid, and glutardialdehyde modified potato starch, that were applied at 10%, 12%, and 15% based on oven-dry particle weight for each green adhesive type. The properties of the panels were determined according to the Japanese industrial standard. The results showed that the panels that were bonded with the 15% citric acid-modified starch green adhesive yielded the best mechanical properties (the modulus of elasticity, modulus of rupture, and internal bonding strength). The modified potato starch had potential as a green adhesive used for the production of particleboards from coconut fibers.

Contact angles quantify the wettability of the rough or smooth surfaces of board materials. The aim of this study was to experimentally verify the Wenzel and Cassie theory and evaluate the essential properties of the binderless bio-composite particleboard fabricated from oil palm trunk and Acacia mangium wood. The particleboard properties were explored through contact angle surface morphology, fractal dimension, and surface roughness measurement. The hydrophilic and hydrophobic natures of the particleboard surface were established through Wenzel and Cassie theory. The contact angle and fractal dimensions showed that particleboards with a high proportion of oil palm trunk (OPT) followed the Wenzel theory and hydrophilic in nature. The increase of Acacia mangium wood (AM) proportion in the particleboard increased the fractal dimension and consequently hydrophilicity decreased. These results are well supported by the reduced percentage thickness swelling and water absorption properties of the binderless particleboard.

Oil palm trunk is a kind of biomass rich in starch content. Oil palm trunk waste was available throughout the year in Malaysia and Indonesia due to continuous felling of nonproductive, over 25-year-old trees. Even though some manufacturers were using it in plywood and veneer production, they are hard to handle which later becomes less favorable raw materials due to a high moisture content where combination with a high starch content quickly attracts fungus and wood-decaying agents. The objective of this work was to evaluate properties of experimental wood composite panels, manufactured using oil palm-extracted starch modified with glutardialdehyde (OPSMG) as a binder. Different analyses were employed to characterize the properties of the samples besides evaluation of bending, internal bonding strength, and dimensional stability of the panels. Characterization on the functional group using the FT-IR analysis showed presence of aldehyde groups and ketone stretching vibrations at 1736.05 cm−1 and 1596.25 cm−1, which proves the presence of glutardialdehyde besides formation of bonding between the OPSMG and the woody materials. The XRD analysis showed the starch modification had lowered the crystallinity index which in turn increased the strength of the manufactured wood composites. The OPSMG wood composites were also found to have lower thermal stability, as evaluated using the TGA analysis. It was recorded that the maximum modulus of rupture for OPSMG wood composites was achieved at the 0.80 g/cm3 density level with an average value of 15.446 N/mm2 which showed 38.00% increment in strength between those two types of wood composites. Thickness swelling after immersion in water can still be improved by incorporating the moisture-repellent material later. After analyzing the results, it was concluded that modified oil palm starch has the potential to be used as an environment friendly binder for wood composite making.

The physico-chemical analysis of bark-free oil palm trunk (OPT) in comparison with rice husk (RH) was evaluated for their suitability in building construction. The results showed insignificant differences in both chemical and proximate analysis of the two fillers. The optimum value for flexural and nail-pull hardness test was at 20% OPT loading. The OPT mixed gypsum composite shows good thermal stability suitable to be used as a new type of filler for the reinforcement of gypsum composite. The limitation however is its hygroscopic properties that might affects the dimensional stability of gypsum composite when contact with water.

Photon absorption parameters such as mass attenuation coefficients ( $${\mu }_{\mathrm{m}}$$ ), molar extinction coefficients ( $$\varepsilon$$ ), total molecular ( $${\sigma }_{\mathrm{t},\mathrm{m}}$$ ), atomic ( $${\sigma }_{\mathrm{t},\mathrm{a}}$$ ) and electronic ( $${\sigma }_{\mathrm{t},\mathrm{el}}$$ ) cross sections, half-value layers $$({X}_{1/2})$$ , tenth-value layers ( $${X}_{1/10}$$ ), mean free paths $$(\lambda )$$ , effective atomic numbers ( $${Z}_{\mathrm{eff}}$$ ), and effective electron densities ( $${N}_{\mathrm{el}}$$ ) were estimated for defatted soy flour (DSF), soy protein concentrate (SPC), and soy protein isolate (SPI)-based Rhizophora spp. particleboard composites substituted with 10 wt% sodium hydroxide (NaOH) and 0, 5, 10, and 15 wt% itaconic acid polyamidoamine-epichlorohydrin (IA-PAE) adhesives. Elemental composition was assessed using ultrahigh-resolution field emission scanning electron microscopy-energy dispersive X-ray spectrometry (UHR-FESEM-EDX). The interaction parameters were evaluated for $${\mathrm{K}}_{\mathrm{\alpha }1}$$ photons at 16.59, 17.46, 21.21, and 25.26 keV, employing a low-energy germanium (LEGe) detector system and an 241Am $$\gamma$$ -ray source. X-ray diffraction characterization revealed an amorphous phase in the developed particleboard composites. Samples DSF15′, SPC15′, and SPI15′ exhibited the highest values of $${\mu }_{\mathrm{m}}$$ , $$\varepsilon$$ , $${\sigma }_{\mathrm{t},\mathrm{m}}$$ , $${Z}_{\mathrm{eff}}$$ , and $${N}_{\mathrm{el}}$$ among all of the studied particleboard samples, within the range of measured photon energies. In addition, all of the modified samples exhibited lower $${X}_{1/2}$$ , $${X}_{1/10}$$ , $$\lambda$$ , $${\sigma }_{\mathrm{t},\mathrm{a}}$$ , and $${\sigma }_{\mathrm{t},\mathrm{el}}$$ than the unmodified samples, with DSF-, SPC-, and SPI/NaOH/Rhizophora spp./IA-PAE (15 wt%), indicating insignificant changes. The current results of the particleboard samples’ analysis can be useful for medical radiation applications and shielding research.

Experimental particleboards are made from Rhizophora spp. wood trunk with three different percentages of lignin and soy flour (0%, 6% and 12%) as adhesives. The objective was to investigate the equivalence of Rhizophora spp. particleboard as phantom material with human soft tissue using Computed Tomography (CT) number. The linear and mass attenuation coefficient of Rhizophora spp. particleboard at low energy range was also explored using X-ray Fluorescence (XRF) configuration technique. Further characterization of the particleboard was performed to determine the effective atomic number, Zeff using Energy Dispersive X-Ray (EDX) method. Adhesive-bonded Rhizophora spp. particleboard showed close similarities with water, based on the average CT numbers, electron density calibration curve and the analysis of CT density profile, compared to the binderless particleboard. The effective atomic number obtained from the study indicated that the attenuation properties of all the particleboards at different percentages of adhesives were almost similar to water. The mass attenuation coefficient calculated from XRF configuration technique showed good agreement with water from XCOM database, suggesting its potential as phantom material for radiation study.

This study investigated the efficacy of epichlorohydrin-modified oil palm starch as an adhesive in addition to urea formaldehyde, to minimise the use of urea formaldehyde adhesive in particleboard manufacturing. A single-layer particleboard was fabricated from rubberwood particles and urea formaldehyde resin supplemented with modified oil palm starch adhesive. The adhesive performance was analysed by studying the physical properties (actual density, moisture content, thickness swelling and water absorption) and mechanical properties (bending strength and internal bond strength) of the prepared panels. The panels of two target densities were manufactured (600 and 800 kg/m3) at two different pressing times (15 min and 20 min). The performance of manufactured panels were analysed by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, thermogravimetric analysis and differential scanning calorimetry. The panels manufactured in this study met the minimum required strength as stated in Japanese Industrial Standards (JIS) but a lower water resistant property. Furthermore, a panel with a density of 800 kg/m3 had improved mechanical properties in comparison to a panel exhibiting a density of 600 kg/m3 when manufactured with a 15 min pressing time.

This study aims to evaluate the attenuation properties of epoxy resin and Rhizophora spp. particleboards bonded with epoxy resin as tissue equivalent phantom materials. The calculated linear and mass attenuation coefficients of epoxy resin and Rhizophora spp. particleboards bonded with three different weight percentages of the epoxy resin (5%, 10% and 15%) were compared with theoretical (XCOM) and experimental measurements of human liver tissue and water at the same energy levels. The 241Am and 109Cd point sources were used to measure the linear and mass attenuation coefficients of the samples at gamma energies; 26.3, 59.5 and 88.0 keV. The computed tomography (CT) scanner was employed to determine the mean attenuation values (CT number) for the fabricated samples and water at CT tube energy 120 kVp. The linear and mass attenuation coefficients of epoxy resin and fabricated Rhizophora spp. particleboard bonded with 15% of epoxy resin provided excellent agreement to the values of XCOM calculated in the human liver tissue and water, respectively. The CT number results showed that the epoxy resin and the Rhizophora spp. particleboard bonded with15% epoxy were in a good agreement with those of human liver tissue and water, respectively. Therefore, the overall attenuation measurements of this study verify the applicability of epoxy resin as a phantom material to mimic the human liver in CT examinations and the epoxy–Rhizophora spp. particleboard fabricated with 15% epoxy resin can be used as a tissue equivalent material corresponding to CT energy range.

Particleboard from renewal agricultural residues or waste offers a significant effect toward ecological problem. However, hygroscopic nature of waste material contributes to a lower dimensional stability and lower strength properties in comparison to conventional particleboard. Therefore, the objective of this study was to convert oil palm waste, namely oil palm trunk, into particleboard with the addition of polylactic acid (PLA), a type of biodegradable thermoplastic, as a natural binder. Particleboard of oil palm trunk made with a target density of 0.8 g/cm3, at a pressing temperature of 180 °C, a pressing time of 20 min, and a pressure of 5 MPa was added with 10% of PLA. The PLA was added into different thickness particleboards, namely 5 mm, 10 mm, and 15 mm. The mechanical and physical properties of particleboards with the addition of PLA in comparison to binderless particleboards made from oil palm trunk were then evaluated. Thus, thermal degradation, spectroscopic characterization, crystallinity properties, and morphological properties of such types of boards were also examined. The mechanical properties, such as modulus of rupture and internal bond strength, and physical properties, such as thickness swelling and water absorption, had significantly improved with the addition of PLA compared to binderless particleboard. Particleboard with the addition of PLA exhibited satisfactory mechanical properties based on Japanese Industrial Standard for Particleboard Type 8. The thermal stability, spectroscopic characterization, crystallinity, and morphological results indicated that the addition of PLA improved the basic properties of the particleboards made of oil palm trunk.

Oil palm trunk (OPT) is one of the alternative resources for building materials. This research investigated the drying characteristics of OPT blocks of dimension 43.91 mm × 19.73 mm × 15.82 mm by controlling the relative humidity under an isothermal condition. The isothermal temperature condition selected for this study were 25, 30, 35, and 40°C. The obtained drying data were applied to Logarithmic, Wang-Singh, Page, Midilli-Kucuk, Henderson-Pabis, Newton, and Nadhari models. The drying kinetics were evaluated through these models. The suitability of these models was assessed based on the sum of square error, the coefficient of determination (R2), the reduced chi-square (χ2), and root mean square error. The Nadhari model was found to be a suitable model for explaining the drying behavior of OPT at various isothermal temperature conditions. The effective diffusivity, drying rate, porosity, and shrinkage were found to be increasing with the increasing of isothermal drying temperature. The activation energy of OPT during drying was found to be 35.56 kJ/mol. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1244–1252, 2017

The study evaluates the suitability of tannin-added particleboards made of Rhizophora spp. woods as phantom material for photon beams. The particleboards were fabricated at different particle sizes and target density of 1.0 g/cm 3 . The mechanical properties and dimensional stability of the particleboards were evaluated according to Japanese Industrial Standards ( JIS A 5908:2003 ). The microstructure, elemental composition and effective atomic number of the particleboards were studied using Scanning Electron Microscope and Energy Dispersive X-ray Analysis. Computed tomography (CT) images were obtained to determine the CT numbers and density profiles of the particleboards. The results indicated addition of tannin had improved the IB strength and MOR of the particleboards between 5 and 48%. The value of effective atomic number showed good agreement of tannin-added Rhizophora spp. to water with percentage different of 3.7%. The autocondensation of tannin also had improved the compactness of the particleboards. The CT number and density profile of tannin-added Rhizophora spp. were close to water shown by the lower χ 2 of 0.041. The results indicated the suitability of tannin-added Rhizophora spp. particleboards as phantom materials for photon beams.

Crystallinity of cellulosic fiber directly affects the physical and chemical behavior of the individual fiber and ultimately the product made from. In a controlled condition, if the natural fiber is exposed to enzymatic hydrolysis, its crystallinity improves without affecting the cellulose component of the fiber. In this work, four basic factors for enzymatic reaction, i.e., temperature, time, pH, and enzyme amount, were optimized using response surface methodology (RSM). The response was taken as the fiber crystallinity index, measured by X-ray diffraction method. The optimum treated fiber was further analyzed for the field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA) and results were compared with untreated fiber. Medium density fiberboards (MDF) were manufactured from optimum treated fiber and its tensile properties and water resistance properties were compared with MDF made from untreated fiber. The observation revealed a maximum of up to 14% increment in fiber crystallinity index (CrI) as compared to untreated fiber. The MDF prepared from optimum treated fiber exhibits improved tensile property and lower water absorption property as compared to MDF prepared from untreated fibers.

This research aimed at investigating the effect of epoxy resin and flame retardant additives on oil palm trunk particleboard. The oil palm trunk was used as a raw material with epoxy resin as a binder, which was synthesized by a reaction of epichlorohydrin and phenolphthalein, while aluminium hydroxide and magnesium hydroxide were used as flame retardant additives to manufacture particleboards. Four different types of particleboards were produced, control board, board with 10% epoxy resin, board with 10% epoxy resin and 6% aluminium hydroxide and board with 10% epoxy resin and 6% magnesium hydroxide, based on a target density of $$0.80~\hbox {g}~\hbox {cm}^{-3}$$, at a temperature of $$180^{\circ }\hbox {C}$$, a pressure of 5 MPa and a pressing time of 20 min. The mechanical, physical, functional group, spectroscopic, morphological and elemental analysis properties were determined in comparison with control particleboard. Thermal degradation and flame retardant analyses were also carried out to analyse the thermal properties of particleboards. The results indicated that particleboard bonded with epoxy resin and flame retardant additives had improved mechanical, physical, thermal and flame retardant properties compared to control oil palm trunk particleboard. Overall results showed that epoxy resin as a binder and aluminium hydroxide and magnesium hydroxide as additives have the potential to be incorporated into the particleboard to improve flame retardant properties.

The objective of the study was to evaluate the dimensional stability of experimental particle board panels made from rubberwood (Hevea brasiliensis) using modified starch as binder. Panels were manufactured using 15% corn starch modified with glutardialdehyde and 13% modified starch with 2% Urea Formaldehyde resin as improvement. The particle boards were tested for their dimensional stability towards moisture. Results found that the 2% replacement of modified starch with urea formaldehyde resin showed increment in dimensional stability compared to using glutardialdehyde modified corn starch only as the binder, recorded at 39.38 % and 23.47 % for particleboard with 0.80 g/cm3 density after exposed to 75% and 95 % relative humidity. Therefore, this study indicated that combination of modified corn starch and urea formaldehyde resin can have a potential to be used as an improved binder to produce particle board panels with accepted properties.The objective of the study was to evaluate the dimensional stability of experimental particle board panels made from rubberwood (Hevea brasiliensis) using modified starch as binder. Panels were manufactured using 15% corn starch modified with glutardialdehyde and 13% modified starch with 2% Urea Formaldehyde resin as improvement. The particle boards were tested for their dimensional stability towards moisture. Results found that the 2% replacement of modified starch with urea formaldehyde resin showed increment in dimensional stability compared to using glutardialdehyde modified corn starch only as the binder, recorded at 39.38 % and 23.47 % for particleboard with 0.80 g/cm3 density after exposed to 75% and 95 % relative humidity. Therefore, this study indicated that combination of modified corn starch and urea formaldehyde resin can have a potential to be used as an improved binder to produce particle board panels with accepted properties.

The aim of this study was to optimize the processing variables of producing compressed veneer panel from oil palm trunk without synthetic adhesive using response surface methodology. Based on the analysis, the optimal pressing temperature was at 186.6 °C and pressing time at 30 min and using outer part of oil palm trunk veneer to produce compressed veneer panel from oil palm trunk with acceptable mechanical strength and dimensional stability. The panel was produced by stacking 5 layers of 0.45 cm veneer to achieve final target thickness of 10 mm. The statistical analysis indicated that bending and shear block strength of the panel from optimal manufacturing condition were 36.07 MPa and 5.20 MPa respectively with 35.4% of delamination. It was shown that certain manufacturing parameters including pressing temperature, pressing time and part of oil palm trunk veneer could bind the oil palm trunk veneers without the need of synthetic adhesives with acceptable mechanical and physical properties.

The aim of the study was to produce and characterize the modified starches and their suitability as wood adhesive for the particleboard manufacturing. The adhesive properties and particleboard manufactured from rubberwood using the modified starch and modified starch mixed with polyvinyl alcohol (PVA) were evaluated. Mixing of PVA with modified starch reduced the viscosity but increased the solid content and thermal property of the modified starch. Particleboard bonded with modified starch mixed with PVA also had improvement in physical and mechanical properties, showing great potential of modified starch and PVA as an adhesive for the green particleboard with good properties.

The large availability and cheap price of oil palm (Elaeis guineensis) trunk makes it an attractive raw material for value-added applications, but its low density and high carbohydrate content are highly undesirable. In this work, oil palm trunk (OPT) was steam-pretreated and compressed at high temperature. The compressed OPT was laminated using polyvinyl acetate (PVAc) using either 250 or 500 g/m2 adhesive spread rate (ASR). Soil burial testing was performed for three months on two different samples to study the deterioration and weight loss by bio-organisms. The laminated, compressed OPT formed with high PVAc ASR was found to be more durable against bio-organisms. The thermal stability of the compressed OPT was studied by thermogravimetric analysis (TGA), and it was observed that the weight loss was lower for steam-pretreated samples compared to those without steam pretreatment. Moisture absorption-desorption testing of compressed OPT was performed, and a hysteresis curve was generated. It was found that laminated, compressed OPTs with 500 g/m2 ASR had lower moisture absorption than those with 250 g/m2 ASR.

In this study cellulose nanocrystals were isolated from oil palm trunk (Elaeis guineensis) using acid hydrolysis method. The morphology and size of the nanocrystals were characterized using scanning electron microscopy and transmission electron microscopy. The results showed that the nanocrystals isolated from raw oil palm trunk (OPT) fibers and hot water treated OPT fibers had an average diameter of 7.67 nm and 7.97 nm and length of 397.03 nm and 361.70 nm, respectively. Fourier Transform Infrared spectroscopy indicated that lignin and hemicellulose contents decreased. It seems that lignin was completely removed from the samples during chemical treatment. Thermogravimetric analysis demonstrated that cellulose nanocrystals after acid hydrolysis had higher thermal stability compared to the raw and hot water treated OPT fibers. The X-ray diffraction analysis increased crystallinity of the samples due to chemical treatment. The crystalline nature of the isolated nanocrystals from raw and hot water treated OPT ranged from 68 to 70%.

The objective of this study was to optimize the press temperature and time of binderless particleboard manufactured from oil palm trunk biomass with different thicknesses using rotatable central composite design of response surface methodology. A set of experiments was designed with two numerical factors including press temperature and time ranging from 160 to 200 °C and from 20 to 30 min, respectively at three target thicknesses, namely 5, 10 and 15 mm. Based on the findings in this work internal bond strength, thickness swelling and water absorption of the panels improved with reduction of the panel thickness. However panels made with 15 mm thickness had higher modulus of rupture values. The optimum press temperatures were found 191 °C, 196 °C and 195 °C, for corresponding press times of 23 min, 24 min and 30 min for 5, 10 and 15 mm board thickness levels, respectively.

The objective of the study was to characterize and to evaluate physical and mechanical properties of experimental particleboard panels made from rubberwood (Heveabrasiliensis) using modified starch-urea formaldehyde as binder. Panels were manufactured using 13% corn starch modified with glutardialdehyde with addition of 2 % urea formaldehyde resin and tested for their physical and mechanical properties. All of the particleboards satisfied the Japanese Industrial Standard which required 2000 N/mm2, 8.0 N/mm2and 0.15 N/mm2for modulus of elasticity, modulus of rupture and internal bonding strength, respectively. The mechanical properties were comparable to those made using 15 % urea formaldehyde resin with reduction of formaldehyde fume was over 50 %.

The objective of this study was to evaluate layering effects and adhesive rates of laminated compressed panels manufactured from oil palm (Elaeis guineensis) fronds. Nine types of panels, namely 6-layer, 8-layer and 10-layer bonded with adhesive spread rates of 200 g/m 2 , 250 g/m 2 and 300 g/m 2 were manufactured. The results showed that both bending and internal bonding strength properties all types of panels increased with increasing number of layers and adhesive amount with an exception of 10-layer panels bonded with 300 g/m 2 . Mechanical properties of such samples were slightly reduced due to their possible brittleness as a result of effect of densification, high resin content and temperature. Thickness swelling and water absorption of the samples enhanced with increasing number of layer and adhesive content. 2014 Elsevier Ltd. All rights reserved.

The objective of this study was to evaluate some of the mechanical and physical properties of experimental particleboard panels manufactured from rubberwood (Hevea brasiliensis) bonded using oil palm starch, wheat starch, and urea formaldehyde (UF) at a density of 0.60 g/cm3. Bending characteristics, internal bond strength, thickness swelling, and water absorptions of the samples were determined based on Japanese Industrial Standard (JIS). Overall mechanical properties for natural binder oil palm starch resulted in higher values than those made from wheat starch. The highest internal-bonding strength (IB) value of 0.41 N/mm2 was determined for the samples made from oil palm starch. Dimensional stability in the form of thickness swelling of the samples made from oil palm starch had higher values, ranging from 4.24 to 22.84% than those manufactured from wheat starch. Natural adhesive showed comparable strength with panels manufactured with UF. Overall results meet the Japanese Industrial Standard (JIS) requ...

Juvenile Neolamarckia cadamba or kelempayan tree has been harvested from forest plantation and converted into sawn timber. Some basic properties of timber such as physical and mechanical were determined from different parts of the tree namely lower, center and upper. The physical properties were evaluated. The mechanical properties were conducted using small test clear specimens. The results indicated that the physical and mechanical properties of the lower portion of the trunk were significantly superior compared to the upper portion of the trunk. The investigation revealed that the wood be able to use as a substitute material of the furniture components after some modification undertaken on its properties.

Cellulose is a multilevel, complex molecular structure built from superfine fibrils having diameters in the nanoscale. These nanofibrils contain highly ordered nanocrystallites and low-ordered whiskers in nanodomains. The cellulose in nanosize can be recovered from the cellulosic biomass by the top-down technique involving various physical and chemical processes followed by refining technique. At present, nanocellulose synthesis is an entirely established technique; however, it involves harsh chemical treatments that are perpetually hazardous to humans and the environment. Various green techniques for nanocellulose synthesis have been proposed such as enzymatic hydrolysis, ionic liquid, and so forth. Although nanocellulose is derived from cellulose, it possesses completely diverse characteristics from original materials. It shows enhanced crystallinity, high surface area, rheological properties, alignment and orientation, biodegradability, biocompatibility, low toxicity, and so on. Nanocellulose has gained much attention for various biochemical applications due to its remarkable physical properties, exceptional surface chemistry and superb biological properties. Its biomedical applications include wound dressings, drug conveyance, medicinal inserts, tissue building, nourishment, and beautifying agents. Whereas its composite materials applications include preparation of biodegradable plastics, aqueous coating, and materials creation.

The objective of this study is to evaluate the mechanical and physical properties of the particleboard manufactured from Rhizophora spp. in three particle sizes bonded with powdered Eremurus spp. root as a bio-based adhesive in two adhesive treatment levels. The samples acquired high internal bond strength values when the Rhizphora spp. particle size was reduced and the adhesive treatment level was increased. Dimensional stability normally increased with the reduced Rhizophora spp. wood particle size. The hydrophilic property of Eremurus spp. indicates that dimensional stability also increased with decreased adhesive treatment level. However, dimensional stability is affected by the adhesive treatment level when the wood particle size is smaller than that of the adhesive particle. The density distributions of the fabricated particleboards were evaluated using Surfer8 software, which showed significant homogeneity in all samples. The microstructures of the fabricated particleboards were investigated by field emission scanning electron microscopy, which refers to the better surrounding adhesive with bigger particles than Rhizophora spp. particles. This study indicates the potential of Eremurus spp. root as a bio-adhesive, which improved the characterization of Rhizophora spp. particleboard.

Gum Arabic (GA) was used as a binder for the fabrication of Rhizophora spp. particleboards. The physical and mechanical properties of the bioadhesive bonded particleboards, including moisture content, internal bond (IB) strength, thickness swelling (TS), water absorption (WA) and field-emission scanning electron microscopy (FESEM) were used to characterize the manufactured particleboards. Three different particle sizes of the Rhizophora spp. with four adhesive levels were utilized. Results revealed that the addition of GA into the particleboards noticeably improved panel overall properties. The GA bonded particleboards resulted in smoother surfaces, more rigid texture and better internal bonding strength compared to binderless particleboards made without using any adhesive. All specimens had internal bond strength of more than the minimum requirement of the Japanese Industrial Standard JIS A-5908 Type-8 of 0.15 N/mm 2 and were noticed to increase by increasing the adhesive level. However the GA bonded particleboards had higher percentage of WA and the TS compared with the binderless boards. Microscopic study also revealed that particleboards bonded with the gum had better contact compared to the binderless boards. Based on these results, it could be concluded that gum Arabic is an effective natural substance that could be added to manufacture particleboards to improve some of panels’ physical and mechanical properties.

In this study, the green animal-based, which has been prepared by prolonged boiling of the inedible connective tissues of domesticated ungulates, was investigated for adhesive properties. The viscosity of green animal-based wood adhesive was measured and compared with that of urea-formaldehyde (UF) and phenol-formaldehyde (PF) which are widely used synthetic glues in the wood industry. Also, the crude protein, crude fat, crude fiber, nitrogen free extract (NFE) that represents carbohydrate, and ash as the organic components of green animal-based glue was measured. According to the results, the green animal-based wood glue was found suitable to be used in wood industry.

The objective of this work was to evaluate properties of experimental particleboard panels manufactured from oil palm ( Elais guineensis ) trunks and Acacia mangium . Samples were made having five different ratios of two types of raw materials without using any adhesives. Both physical and mechanical properties of the specimens were evaluated based on Japanese Industrial Standards (JIS). Panels made with 100% oil palm particles had the highest modulus of rupture and internal bond strength values of 22.91% MPa and 0.59 MPa, respectively. Addition of A. mangium particles in the panels adversely influenced their mechanical properties while improved both thickness swelling and water absorption of the specimens. All panels made in this work met minimum strength requirements stated in JIS. Based on the findings in this work it appears that both types of underutilized species could have a potential to be used as raw material to manufacture binderless value-added panels.

The objective of this study was to determine the isothermal drying kinetics of Acacia mangium wood blocks by employing a relative humidity-controlled drying chamber. A model was developed based on solution of Fick's second law and evaluated through the coefficient of determination (R 2 ), sum of square error (SSE), root mean square error (RMSE), and reduced chi-square (χ 2 ). This model was compared to semi-theoretical models which are commonly used to describe the drying behavior of biomass in previous studies. The porosity and shrinkage characteristics of dried specimens were also evaluated. Based on the findings in this work, it was determined that the proposed model resulted in an excellent fit with experimental data for all four drying temperature levels of 30, 35, 40, and 45 ∘ C to describe the isothermal drying kinetics of Acacia mangium . It appears that volumetric shrinkage of the samples decreased quadratically with decreasing moisture ratio. The activation energy of the drying process was deter...

 Abstract—For the first time, Gum Arabic (GA) is used as a binder in particleboards preparation and the attenuation properties of the fabricated particleboards were evaluated to check their suitability as tissue equivalent material. Gum Arabic was added into Rhizophora spp. particleboards of four particle sizes at three different GA adhesive levels. The X-ray fluorescence (XRF) technique was used to measure the linear and the mass attenuation coefficients of the fabricated particleboards at effective energy range of 17.4 - 26.7 keV. This was achieved by determining the attenuation of Kα1 X-ray fluorescent (XRF) photons from niobium, molybdenum, palladium, silver and tin targets. The results were compared with theoretical values of water calculated using XCOM computer program. The mass attenuation coefficients of the GA bonded Rhizophora spp. particleboards were found to be close to the values of water calculated in XCOM at the same photon energies. Luckily, fabricated particleboards showed tissue equivalent results which optimistically can open a new window on the consumption of such a natural adhesive in particleboards as phantom material in dosimetric phantoms and quality control applications.

The objective of this study was to evaluate both physical and mechanical properties of particleboard panels manufactured from steamed material of oil palm trunks without using any adhesives. Experimental panels from fine particles and vascular strands of oil palm were manufactured. Modulus of rupture (MOR), internal bond strength (IB), thickness swelling (TS) and water absorption (WA) of the samples were tested based on Japanese Industrial Standards. Bonding quality of such binderless samples was also evaluated by using scanning electron microscope (SEM). Based on the findings on this work steaming of the raw material enhanced overall mechanical and physical characteristic of the samples. The highest MOR values of 8.12 MPa and 25.84 MPa were found for the samples made from fine particles and strands steamed at a temperature of 130 °C for 30 min, respectively. It appears that mechanical properties of the panels reduced when they exposed to beyond 30 min steaming time.

The objective of this study was to evaluate variation of mechanical and physical properties of binderless particleboard panels manufactured from raw material of young and old oil palm (Elaeis guineensis) trunks. Results revealed that such experimental panels made from particles of young oil palm trunks had higher mechanical characteristics than those of made from old trunks. Addition of sugar compounds in the samples produced having particles from young trunks with and without extracted material enhanced their bending and internal bond strength values. Overall dimensional stability in the form of thickness swelling and water absorption those panels made from young trunks was adversely influenced. However adding sugars in the samples improved their thickness swelling and water absorption in both cases of with and without applying of extraction process.

This research investigated the effect of steam treatment on the properties of particleboard panels manufactured from oil palm trunk with addition of polyhydroxyalkanoates (PHA) at different percentages. Particles were treated by steam at a temperature of 130 °C for 30 min. The mechanical and physical properties of the experimental panels including modulus of rupture (MOR), internal bond strength (IB), thickness swelling (TS), water absorption (WA) and surface quality were investigated. Further analyses of the specimens were also conducted using gas chromatography, thermogravimetric analyzer, Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscopy. Addition of PHA to oil palm particles enhanced MOR and IB as well as dimensional stability of the panels. The highest MOR and IB values of 8.76 MPa and 1.02 MPa were determined for the panels made with 10% pure PHA, respectively. It appeared that all properties of the specimens minimally increased with increasing PHA content in the panels. Based on the results of this work PHA could be considered as a potential additive to improve overall properties of such composite panels from oil palm which is an important agricultural crop in Malaysia.

This study evaluated physical and mechanical properties of laminated panels made from compressed oil palm trunk (OPT). The OPT were steamed at 130 °C before being compressed and laminated using polyvinyl acetate adhesive at 250 g/m2 and 500 g/m2 spread rates. The modulus of rupture and compression strength values of laminated panels made from compressed OPT was greater than those of laminated panels made from uncompressed OPT. Surface roughness, water absorption, and thickness swelling of laminated panels made from compressed OPT significantly improved. The findings in this study indicated that compressing of OPT would be considered as an alternative to produce value-added material with enhanced properties.

The objective of the study was to evaluate physical and mechanical properties of experimental particleboard panels made from rubberwood (Hevea brasiliensis) using modified starch as binder. Panels were manufactured using 15% corn starch modified with glutardialdehyde and tested for their properties based on Japanese Standard. The modulus of rupture and the internal bond strength of the panels met the requirement of the specified standard. Based on the findings in this work modified corn starch can have a potential to be used as binder to produce particleboard panels with acceptable properties.

The objective of the study was to evaluate some properties of experimental binderless particleboards produced from various processing parameters. Three different temperatures (160, 180, 200 °C), two different hot pressing times (15, 20 min) and two different pressures (5, 10 MPa) were applied in manufacturing the binderless particleboard. Three replications of each of the 12 different types of boards with a target density of 0.60 g cm−3 were produced. The thickness swelling, dimensional changes associated with changes in relative humidity, bending strength, internal bonding strength, and soil burial decay test were evaluated. Increase of temperature, duration of hot pressing and pressure increased the properties of specimens. Thickness swelling nearly met the requirement of European Standard for use in humid condition. Some of the specimens showed promising mechanical properties and met the requirement of European Standard.

The objective of this investigation was to evaluate optimum manufacturing parameters to produce compressed lumber from oil palm ( Elaeis guineensis ) trunks. Experimental samples were made using steaming time, pressure, pressure time and temperature ranging from 2 to 4 h, from 5 to 12 MPa, from 20 min to 60 min and from 100 °C to 200 °C, respectively. Compression and recovery ratios of the specimens were determined employing Response Surface Methodology (RSM) approach within the scope of Central Composite Design (CCD) computer program. Experimental and calculated values were compared to each other. Based on the results of the work, the specimens steamed for 2 h before they were compressed using a pressure of 11.16 MPa at a temperature of 200 °C for 60 min resulted in optimum conditions. Measured and calculated compression and recovery ratios of the samples showed 0.70 and 0.83 correlation coefficient values, respectively.

The objective of this investigation was to evaluate the properties of binderless particleboard manufactured from oil palm trunk as a function of press temperature. Particleboard samples were manufactured with a target density of 0.80 g/cm 3 using press temperatures of 160 °C, 180 °C and 200 °C. The modulus of rupture, internal bond strength, water absorption and thickness swelling of the boards were determined based on Japanese Industrial Standards (JIS). Thermal gravimetric analysis, Fourier transform infrared spectroscopy and field-emission scanning electron microscopy coupled with energy dispersive X-ray analysis were employed to characterize the properties of the raw materials and the manufactured panels. The moduli of rupture of the samples were observed to increase with increasing press temperature, but they did not meet the standard values. However, the internal bond strength of the samples attained satisfactory values according to the JIS standard for all three temperature levels. Water absorption and thickness swelling of the boards decreased with increasing pressing temperature. Based on the findings in this study, increasing the pressing temperature may be considered a potential way of improving the properties of binderless particleboard.

The objective of this study was to examine the extractive, holocellulose, alpha cellulose, lignin, starch, and sugar contents of oil palm biomass and to evaluate its suitability in binderless particleboard production. In this study, bark, leaves, fronds, mid-parts and core-parts of the trunks were used to produce experimental binderless particleboard panels. Binderless particleboard panels were made with a target density of 0.80 g/cm 3 at a temperature of 180 C and a pressure of 12 MPa in a computer controlled hot press. The modulus of rupture, the internal bond strength, the thickness swelling and the water absorption of the panels were evaluated. Fourier transform infrared spectroscopy and field emission scanning electron microscopy were used to characterize the properties of the raw materials and the manufactured panels. The chemical composition of the oil palm biomass consisted of high holocellulose, lignin, starch and sugar contents that have been found to aid in the production of binderless particleboard. The core-part of the trunk contained the highest amount of starch and total sugar. Samples made from the core-parts and fronds had sufficient modulus of rupture and internal bond strength to meet the Japanese Industrial Standard. The internal bond strength of the mid-part panels also met the standard. However, binderless board prepared from bark and leaves showed poor modulus of rupture and internal bond strength. Samples from the core-parts had the lowest thickness swell and water absorption but did not meet the above standard. The Fourier transform infrared spectroscopy spectra did not show any substantial difference between the raw materials and the manufactured panels. Field emission scanning electron microscopy indicated that the compressed cells varied between raw material types and showed the presence of compressed cells with some starch granules that facilitated adhesion. Based on the findings of this study, oil palm has the potential to be used to manufacture binderless panel products, and further study is required to improve its dimensional stability.

This study investigated certain aspects of physical and mechanical properties and resistance against biological deterioration of particleboard panels treated with extractives from different parts of Cerbera odollam trees. Particles of rubber-wood ( Hevea brasiliensis) treated with extracts of leaf, fruit, wood, bark, flower, and seed of Cerbera odollam were used to manufacture panels in laboratory conditions. Two types of adhesive, namely melamine urea formaldehyde and phenol resorcinol formaldehyde were used as binder for the panels. Treated panels had higher resistance against powder post beetle in laboratory as well as field exposures. Both thickness swelling and internal bond strength values of treated samples satisfied requirements for P4 Type particleboards stated in European Standards (EN 312). It appears that such extractives possess potential to enhance resistance of particleboard against insect damage in tropical countries.

This study investigated some physical and mechanical properties of experimental particleboard panels manufactured from different parts of oil palm including bark, leaves, fronds, and trunk consisting of mid-part and core-part using phenol formaldehyde adhesive. Two types of panels with target densities of 0.80 and 1.0 g/cm 3 were manufactured using pressure levels of 5 and 12 MPa, respectively. Both types of panels were pressed at a temperature of 180°C for 20 min. The findings indicated density and pressure level had an influence on the overall properties of the panels. Samples from the core-part had the highest modulus of rupture (MOR) values followed by those panels made from fronds and bark particles. Such samples satisfied MOR characteristics for particleboard type 13 listed in the Japanese Standard. Similarly, panels made from mid-part and leaves also showed satisfactory MOR values for particleboard type 8 based on the same standard. All panels met the IB strength requirement for type 8 except panels made from leaves made at a target density of 1.0 g/cm 3 pressed at 12 MPa. None of the samples satisfied the thickness swelling requirements. The scanning electron microscopy and Fourier transform infrared spectroscopy study indicated positive effect of the resin on interfacial bonding between the particles. Different parts of oil palm may have potential to manufacture exterior particleboard panels with acceptable strength properties. Dimensional properties of the samples need to be enhanced by using different chemicals such as wax or application of various treatments including heat treatment.

Experimental binderless composite panels were manufactured using fine particles and strands of oil palm ( Elaeis guineensis ) trunks. Modulus of rupture (MOR), internal bond strength (IB), dimensional stability, and surface roughness of the panels made with a target density of 0.80 g/cm 3 were evaluated. Strand type samples had MOR and IB values of 24.95 and 0.95 MPa, respectively. Corresponding values for the fine particle type samples were 4.04 and 0.49 MPa. Panels made from strands met MOR requirement stated in Japanese Industrial Standard (JIS). Enhanced bonding between strands observed by micrographs taken using scanning electron microscopy (SEM) also supported the findings. However, the samples having fine particles had lower MOR values than minimum requirement listed in JIS. Strand type panels had 41.6% thickness swelling which is only 4.6% lower than that of the panels made from fine particles. It appears that dimensional stability of both types of panels exhibited insufficient results according to JIS. Surface roughness quality of the samples made from fine particles had average surface roughness values comparable to those of panels made in past studies. Based on initial results of this work, raw material from oil palm trunks can have some potential to be used to manufacture binderless panels without using any adhesives. This study revealed that mechanical and physical properties of such experimental panels were influenced by the particle geometry. It would be important to consider possible addition of chemical or wax in the particles to improve their dimensional stability in further studies.

In this study, the properties of laminated veneer lumber (LVL) made from oil palm trunks (OPT) were evaluated in comparison with rubberwood using cold setting adhesives, namely, emulsion polymeric isocyanate (EPI) and polyvinyl acetate (PVAc). The evaluations were based on either dry or after cold water, hot water and cyclic pre-treatment. The density of the OPT LVL was slightly higher than that of solid OPT. Thickness swelling and water absorption of OPT LVL were greater than of rubberwood LVL. Pre-treatment increased the water absorption and thickness swelling. The OPT LVL bonded with EPI without toluene showed greater water absorption and thickness swelling than EPI with toluene. Pre-treatment significantly reduced the tensile strength of OPT LVL. The OPT LVL bonded with EPI without toluene showed higher tensile shear strength, but a greater reduction of tensile shear strength after pre-treatment, than the OPT LVL bonded with EPI and toluene. The PVAc adhesive had greater wettability than the EPI. The EPI without toluene showed a lower contact angle than the EPI with toluene. The loose side of the OPT veneer was found to have greater wettability than the tight side.

Laminated veneer lumbers from oil palm trunk were manufactured using urea formaldehyde, phenol formaldehyde, melamine urea formaldehyde, and phenol resorcinol formaldehyde adhesives. The density of the oil palm laminated veneer lumber was slightly higher than the solid oil palm trunk. The thickness swelling and water absorption of laminated veneer lumber of oil palm were higher than those made from rubberwood. Laminated veneer lumber bonded with phenol resorcinol formaldehyde showed higher shear strength compared to other adhesives. The contact angle on the loose surface was lower than on the tight surface. Phenol formaldehyde adhesive has a higher contact angle compared to the other adhesives.

The objective of this research was to study the effect of sanding on surface roughness of rubberwood. Surface roughness was measured using stylus profilometer. Sessile water drop technique was used to determine contact angle of the surface. The results indicated that sanding process could improved surface roughness. Lower grit size gave rougher surface. The radial surface of rubberwood was found to be rougher compared to tangential surface. The roughness value across the grain was higher compared to the longitudinal section. The contact angle on the tangential surface was higher compared to the radial surface and this indicated that the radial surface was rougher than the tangential surface.