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Mango being a climacteric fruit undergoes various metabolic processes after its harvest that affect the fruit quality. Henceforth, an investigation was undertaken to preserve the postharvest quality and extend the shelf life of mango fruit by preharvest putrescine application. Mature plants of mango cv. Dashehari were sprayed with four different concentrations of putrescine; 1, 2, 3, and 4 mM at 14 and 7 days before harvesting respectively. Physiologically developed mango fruits were taken from treated plants, packed in corrugated fiberboard boxes, and stored at 12 ± 1 °C and relative humidity of 85–90%. Research findings indicated that in comparison to untreated fruits, fruits treated with 3 mM putrescine 14 days before harvesting resulted in reduced weight loss (12.10%), fruit spoilage (8.83%) along with retention of higher firmness (44.54 N), titratable acidity (0.58%), antioxidant activity (54.55%), TSS (18.84 °Brix), and total sugars (14.86%) by the end of storage. Overall, it could be inferred that 3 mM putrescine application 14 days before harvest could be used to maintain the physicochemical attributes and extend the shelf life of mango fruit under low-temperature conditions. [ABSTRACT FROM AUTHOR]

This study determined the factors affecting peeling strength performance of edge bands, an important element of the furniture industry, and improved peeling strength performance by optimizing these factors. The independent variables were material types, amount of adhesive, feed speed, and temperature, while the dependent variable was the peeling strength. A central composite design (CCD) was used to investigate the optimal process parameters to achieve a maximum peeling strength for medium-density fiberboard (MDF) and particle board (PB). These materials were prepared using different feed speeds, temperatures, and amounts of adhesive. The CCD design based on the desirability function approach successfully achieved the optimal process parameters. An analysis of variance (ANOVA) determined the significant parameters on the peeling strength of edge banding. Maximum MDF and PB edge banding peeling strength values were calculated as 0.0706 and 0.0673 N/mm2, respectively. In the edge banding process applied using optimum parameter levels, an increase of 8.8% and 7.17% was achieved in the peeling strength of PB and MDF samples, respectively. [ABSTRACT FROM AUTHOR]

This study aims to develop, enhance, and characterize the qualities of recycled jute fiber and kraft pulp as reinforcement for use in cement composite boards for building applications in developing countries. In many African countries, jute fiber (Corchorus capsularis) is readily available but faces challenges in achieving a strong bond with the cement matrix. To address this, mild treatment with different alkali concentrations was employed to modify the fiber properties before reinforcement. Alkali treatment significantly improved fiber characteristics such as tensile strength, Young's modulus, thermal stability, and surface morphology, as confirmed by the single fiber tensile test, thermogravimetric analysis, and scanning electron microscopy, respectively. Using a laboratory-simulated Hatschek process, cement composite boards were produced with varying percentages (2–6 wt.%) of treated and untreated jute fiber. The mechanical properties and fractured surface morphology of the boards were examined through a three-point bending test and scanning electron microscopy. Results showed that the composites reinforced with treated fibers exhibited significantly improved flexural strength and ductility compared with the untreated ones. SEM examination revealed that the untreated fiber-reinforced composite experienced fiber pull-out due to poor bonding at the fiber–matrix interface. In contrast, the composites reinforced with treated fibers displayed optimal strength, meeting the minimum requirements for fiber cement flat sheets according to relevant standards. An optimum flexural strength of 9.57 MPa was achieved for composite boards containing 10 and 4 wt.% of kraft pulp and treated jute fibers, respectively. Overall, this study demonstrates that recycled jute fibers could be successfully enhanced and reused as reinforcement in cement composite boards, leading to improved properties and mechanical performance in cement composite boards. Hence, it provides environmental benefits and contributes to the circular economy. [ABSTRACT FROM AUTHOR]

Currently, wood-based panels are mainly made from wood and adhesives containing formaldehyde. With the growing demand for raw materials and increasing concern for human health, the use of residues from annual crops to manufacture binder-free biodegradable biomass boards has attracted increasing interest. The aim of this study was to develop a biodegradable bio-board without any adhesives using eggplant straw fibers. The bio-boards were produced via simple mechanical refinement of eggplant straw fibers and were formed under pressures of 2.0 MPa, 3.5 MPa, 5.0 MPa, 6.5 MPa, and 8.0 MPa. The mechanical properties and dimensional stability of the manufactured bio-boards were evaluated. With increasing applied pressure, the bending rupture stress of the bio-boards increased from 27.69 MPa to 45.29 MPa, the tensile rupture stress varied from 12.45 MPa to 24.62 MPa, the water absorption decreased from 91.45% to 88.29%, and the contact angle increased from 89.67° to 90.45°. The bio-boards were subjected to morphological analysis (SEM) and porosity and crystallinity measurements (XRD), and the results indicated that the water absorption of the bio-boards was due to a combination of porosity and crystallinity. The results showed that eggplant straw is suitable for manufacturing bio-boards. [ABSTRACT FROM AUTHOR]

The need for environmentally friendly and affordable building materials has sparked researches for materials to use in the construction industry. This paper therefore, studied the characterization of ceiling boards manufactured from plaster of Paris (POP) reinforced with banana fibres (BF) and coconut shell (CS) particulates. The samples were produced by adding different ratios of BF and CS to the POP matrix. To evaluate the effectiveness of the samples, several tests, were conducted. The results demonstrated that the addition of reinforcements improved the properties. The sample with a mixture of POP, BF, and CS demonstrated superior properties with the lowest water absorption (2.77%), high compressive strength (7.74 MPa), least thermal conductivity (0.2157 kW/mK) and hardness value of (23.2 HVN), these are within the standard range. The Scanning Electron Microscopy (SEM) analysis confirmed the results obtained. This study established the possibility of using local accessible materials to produce high quality ceiling boards. [ABSTRACT FROM AUTHOR]

Self adhesion is a simple and effective bonding technique that can be used to produce environmentally friendly and green straw-based fiberboard (CLS) through deep eutectic-like solvent (DES) treatment. This article mainly introduces the use of DES composed of choline chloride and oxalic acid. DES is diluted with deionized water and straw is immersed in it, and finally dried into pretreated fiber raw materials. Fiber boards are prepared by adjusting the hot pressing parameters and the preset moisture content of straw itself for hot pressing solidification. The aim of this study was to investigate the effects of different processing parameters (hot pressing temperature and straw moisture content) on the microstructure, physical properties, and mechanical properties of CLS. Straw-based fiberboard heated at 180 ° C exhibited the best mechanical and water resistance performance. The fiberboard reached its highest mechanical performance at a moisture content of 50%. The bending performance of fiberboard produced at 180 °C reached 13.5 MPa, and compared with the board manufactured at 120 °C, the bending strength, tensile strength, and internal bonding strength increased by 320%, 224%, and 280%, respectively.

Sanding in medium-density fiberboard (MDF) often encounters unstable quality and premature failure, primarily because there is currently no abrasive belt specifically suitable for MDF sanding characteristics. We designed two precision-shaped abrasive belts (PSAs) for MDF and herein report on the characteristics. The material removal process for PSA was divided into three phases; the most stable, phase II, represents the effective working period. Compared to the contrast accumulated abrasive belt, PSAs achieve 16.12 and 11.10 times higher surface quality based on the mean value of roughness parameter Sa, achieving 1.34- and 2.0-, and 15.61- and 8.54-times-higher stability in material removal and surface quality based on the mean deviation. Wear patterns on PSAs include large abrasive wear, micro-abrasive fall-off, fracture, and wear, avoiding premature failure due to blockage and promoting long-term and efficient sanding. The uniform shape, height, and distribution of particles in PSAs results in excellent sanding performance. This study provides the foundation for further research on sanding mechanisms and PSA design for MDF. [ABSTRACT FROM AUTHOR]

This study investigated the effects of shredded waste office paper as a raw material on the physical and mechanical properties of fiberboard. Two amounts of urea formaldehyde (UF) resin (10 and 15%) and five shredded waste office paper/wood fiber mixing ratios (0/100, 25/75, 50/50, 75/25, and 100/0) were selected. The findings showed that all characteristics of boards were improved with an increase in resin content at various wastepaper participation ratios. The 15% UF-bonded board with 100% wood fiber had the highest modulus of rupture (MOR) value, but there was no statistically significant difference between it and the board with 50% wastepaper. The modulus of elasticity (MOE) values of the 15% UFbonded boards increased as the wastepaper participation ratio increased, and the highest was obtained from the board with 75% wastepaper. The highest internal bond (IB) strength value was also recorded from the 15% UF-bonded board with 50% wastepaper. This was due to the presence of sufficient bonding potential and smoother surfaces in the shredded wastepaper, which allowed for a synergistic interaction between the wastepaper and wood fiber. [ABSTRACT FROM AUTHOR]

The hot pressing process for 100% coriander-based fiberboards was optimized using an induction RocTool system, which offers rapid mold heating and cooling. The fiberboards were made using deoiled press cake as a protein binder and extrusion-refined straw as reinforcement. Doehlert's experimental design was used to evaluate the influence of pressure (10–50 MPa), molding time (60–300 s), and mold temperature (155–205 °C) on fiberboard properties, energy consumption, cost, and environmental impact. The results showed that the RocTool device allows for better temperature control during shaping throughout the mold, resulting in mechanical properties that are both more homogeneous across the entire surface of the panel and, more importantly, substantially improved. Using the isoresponse curves, the optimal hot pressing conditions were 35 MPa, 300 s, and 205 °C, corresponding to a 40.6 MPa flexural strength. However, it was observed that to achieve an MDF-like fiberboard with minimal production costs, much less restrictive molding conditions were sufficient, i.e., 32.5 MPa, 170 s, and 160 °C. The study revealed that maximum thermopressing conditions emitted 3.87 kg of CO2 eq., while conditions leading to the MDF-like board reduced emissions to 1.45 kg CO2 eq., resulting in a more environmentally friendly material. [ABSTRACT FROM AUTHOR]

Cellulosic fiber board (CFB) is a lightweight form of sheathing that contains 94% post-consumer recycled materials. The viability of CFB sheathed shear walls as an alternative to Oriented Strand Board (OSB) walls is the focus of this study. A total of 23 walls and 10 connection samples were tested under cyclical loading to determine their overall behavior and capacity. The walls consisted of 2.44 m high by 3.66 m long CFB and OSB sheathed walls with and without openings. The design capacity of each wall was calculated and compared to the experimental results. For the walls with openings, the effects of blocking and strapping on their behavior were also evaluated. It was found that CFB is a viable alternative to OSB; however, some adjustments to the current design values and processes are required as the current procedure results in safety factors that are significantly lower than those for OSB walls. [ABSTRACT FROM AUTHOR]

Local agro-industrial wastes-based particleboards and fiberboards in Egypt are manufactured mainly from sugarcane-bagasse and flax shives. These panels are used in decorations and interior claddings. This paper aimed to broaden their market to be utilized in local low-cost and simple building envelope retrofitting packages instead of conventional packages that depend on imported expanded polystyrene and wet-rendered gypsum boards. Thermal conductivities of various existing sugarcane-bagasse and flax-shives-based panels were measured to be used in developing multilayered interior claddings with adequate thermal insulating performance to increase the thermal mass of a validated non-insulated case-study residential building as recommended by the Egyptian Code for Energy Efficiency of Residential Buildings. Models retrofitted using the developed cladding assemblies were simulated using Design Builder to determine their achieved annual energy savings and predict their profitability. Thermal conductivities of sugarcane-bagasse and flax-shives-based particleboards were lower than wood-based cladding panels, with the range of 0.05-0.1166 W/mK. Moreover, the thermal conductivities of sugarcane-bagasse fiberboard had the range of 0.0926-01,111 W/mK which is significantly lower than wood-based fiberboards. Simulation results showed that both models retrofitted, sugarcane bagasse-based and flax shives-based, achieved better energy savings, 5.07% and 5.04%, than the conventionally retrofitted model, 3.73%. Furthermore, the flax-shives-based model showed higher profitability, with positive income achieved in the 15th year, than a conventionally retrofitted model, achieved in the 20th year, and the sugarcane-bagasse-based model, achieved in the 19th year. Thus, it was recommended that although flax-shives-based wall claddings were usually 14-20% thicker than sugarcane-bagasse-based claddings, they provided similarly high annual energy savings with lower initial costs and higher profitability. [ABSTRACT FROM AUTHOR]

Abstract This study presents an experimental and numerical comparison between the mechanical performance of a lightweight corrugated sandwich panel based on the tea oil camellia shell (TOCS). Hence, TOCS was mixed in two groups with Poplar particles and fibers. After that, in the experimental part, the conventional mechanical tests, including the 3-point bending test, flatwise compression, dowel bearing, and screw resistance, and in the numerical part, finite element analysis (FEA), including the normal, maximum principal, and equivalent (von Mises) stress by Ansys Mechanical software carried out. The specimens for experimental and numerical tests were prepared in transverse and longitudinal directions. Before that, the engineering data (shear modulus, Young's modulus, and Poisson's ratio) for improving the FEA simulation were obtained from TOCS-based flat panels fabricated with a mixture of Poplar particles and fibers. The results of FEA are used to compare the mechanical behavior and failure mechanism with the results of experimental tests. According to the mean values of bending stiffness and maximum bending moment, sandwich panels made with 100% particles demonstrated an advantage in both directions. Nevertheless, the compression strength and screw resistance showed the same trend, but the dowel bearing showed higher values for panels made with fibers. The observed results of equivalent (von Mises) stress indicated a coloration with the results of failure mechanisms.

Free formaldehyde is released due to the addition of aldehyde-based adhesives during the production of fiberboard. This is harmful to human health and pollutes the environment, and for that reason binderless fiberboard has become a research hotspot. There have been reports about pretreatments with white-rot fungi or lignocellulase to produce binderless fiberboard, but there have been no such reports about optimizing the bio-pretreatment conditions. In this study, poplar wood shavings were used for fiberboard production, and the bio-pretreatment conditions with Coriolus versicolor were studied using response surface methodology. After single-factor optimization, the central levels of bran, molasses, and magnesium sulfate were obtained. Further optimization was carried out using Box-Behnken design to study the influence of the factors. A second-order polynomial equation was obtained, and the low p-value (0.001) implied that the model was highly significant. The optimized bio-pretreatment conditions for modulus of rupture (MOR) of the fiberboard were obtained by ridge analysis as 3.021 g of bran, 8.907 g of molasses, and 0.27 g of magnesium sulfate. Under the optimized conditions, MOR of fiberboard reached 27.21±0.64 MPa, which was 2.2 times that of the control fiberboard. Bio-pretreatment with C. versicolor should be a good choice to produce a high-strength binderless fiberboard.

Although gypsum-based building materials exhibit many positive characteristics, solutions are still being searched for to reduce the use of gypsum or improve the physico-mechanical properties of board materials. In this study, an attempt was made to produce gypsum boards with hemp fibers. Although hemp fibers can be a specific reinforcement for gypsum-based board materials, they negatively affect the gypsum setting process due to their hygroscopic characteristics. Fibers impregnated with derivatives based on polyvinyl acetate, styrene–acrylic copolymer and pMDI (polymeric diphenylmethane diisocyanate) were used in this study. Gypsum–fiber boards produced with impregnated fibers showed approximately 30% higher mechanical properties as determined by the 3-point bending test. The positive effect of the impregnates on the hemp fibers was confirmed by FTIR (Fourier-transform infrared spectroscopy) and TG/DTA (thermogravimetric analysis/thermal gravimetric analysis) analysis. [ABSTRACT FROM AUTHOR]

The pressing need to develop eco‐friendly polymer materials for building applications has led to increased interest in modifying existing polymer systems. In this study, a sustainable approach to augmenting urea‐formaldehyde (UF) resins, widely employed in wood‐based panels is introduced. Addressing this, formaldehyde‐scavenger demethylated lignin nanoparticles into UF resins, aiming to produce a green and enhanced medium‐density‐fiberboard (MDF) with minimal formaldehyde emissions is incorporated. The results indicate that increasing concentrations of demethylated lignin nanoparticles in the UF adhesive, there is not only a reduction in formaldehyde emissions from MDF composites but also a significant decrease in thickness swelling. The highest reduction in formaldehyde emission is observed in the MDF composite prepared with UF resin containing 7% lignin nanoparticles (UF‐7NL), with an emission of 2.9 mg/100 g, marking a substantial decrease of 74% compared to emission of 11.2 mg/100 g from neat resin. Importantly, this reduction does not compromise physical and mechanical properties of the MDF; they remain comparable to boards bonded with unmodified UF. Molecular modeling revealed that lignin effectively traps formaldehyde, incorporating it as ‐CH2OH groups, leading to a notable decrease in formaldehyde emission from MDF. This approach offers an eco‐friendly modification to a common polymer, showcasing lignin nanoparticles as innovative additives. [ABSTRACT FROM AUTHOR]

Many factors (material properties, drill bit type and size, drill bit wear, drilling parameters used, and machine-tool characteristics) affect the efficiency of the drilling process, which could be quantified through the delamination factor, thrust force, and drilling torque. To find the optimal combination among the factors that affect the desired responses during drilling of wood-based composites, various modelling techniques could be applied. In this work, an artificial neural network (ANN) and response surface methodology (RSM) were applied to predict and optimize the delamination factor at the inlet and outlet, thrust force, and drilling torque during drilling of prelaminated particleboards, medium- density fiberboard (MDF), and plywood. The artificial neural networks were used to design four models—one for each analyzed response. The coefficient of determination (R2) during the validation phase of designed ANN models was among 0.39 and 0.96. The response surface methodology was involved to reveal the individual influence of analyzed factors on the drilling process and also to figure out the optimum combination of factors. The regression equations obtained an R2 among 0.88 and 0.99. The material type affects mostly the delamination factor. The thrust force is mostly influenced by the drill type. The chipload has a significant effect on the drilling torque. A twist drill with a tip angle equal to 30° and a chipload of 0.1 mm/rev. could be used to efficiently drill the analyzed wood-based composites. [ABSTRACT FROM AUTHOR]

The commonly used ultraviolet ray (UV) curing coatings have the characteristics of fast curing speed, high hardness, strong abrasion resistance, etc. However, the self-healing properties of UV coatings after being damaged still need to be improved. Self-healing microcapsules can alleviate this problem. The UV top coating itself has good properties, so it can be directly chosen as the core material of microcapsules. UV top coating microcapsules can be added to the UV top coating to increase the self-healing properties of the UV coating to achieve the purpose of better protection of the UV coating and fiberboards. UV top coating microcapsules were prepared and added in different contents to characterize the effect on the physical, chemical, and self-healing properties of the UV coating on a fiberboard surface. The 1#, 2#, and 3# UV top coating microcapsules that were prepared with emulsifier HLB values of 10.04, 10.88, and 11.72, respectively, were added to the UV top coating at contents of 2.0%, 4.0%, 6.0%, 8.0%, and 10.0%. The UV coatings were applied to the fiberboard using a method of two primers and two top coatings, in which no microcapsule was added in the primer, and were tested and analyzed. The results showed that when the content of microcapsules was greater than 6.0%, close to 8.0%, the excessive density of microcapsules produced stacking and extrusion between the microcapsules. As a result, the core material could not flow out smoothly when part of the microcapsule was ruptured. The outflow of the core material was not efficiently utilized, thus leading to a decrease in the self-healing rate. The 2# UV top coating microcapsules of 4.0% made the UV coatings reach the self-healing rate of 26.41%. The self-healing rate of the UV coatings prepared with the 3# UV top coating microcapsules with 6.0% was up to 26.58%. The UV coatings prepared with the 1# UV top coating microcapsules of 6.0% had the highest self-healing rate among the three groups, up to 27.32%. The UV coatings of this group had the best comprehensive properties with a chromatic aberration ΔE of 4.08, a gloss of 1.10 GU, a reflectance of 17.13%, an adhesion grade of 3, a hardness of 3H, a grade 3 of impact resistance, and a roughness of 1.677 μm. An investigation of the UV coatings on fiberboard surfaces with the content of UV top coating microcapsules can provide support for the optimization of the self-healing properties of UV coatings and can also provide innovative ideas for the preparation of the self-healing coatings on fiberboard surfaces. [ABSTRACT FROM AUTHOR]

Silphium perfoliatum, an energy crop with a high fiber content but low concentrations of fermentable carbohydrates, presents challenges for complete fermentation in biogas production. To overcome this, a bioeconomic approach proposes the use of the fibers for paper and board production, which requires high-quality silage with minimal butyric acid, which affects the marketability of the fibers. This study aims to optimize the silaging process of Silphium perfoliatum by investigating the effects of harvest date, bacterial cultures and additives on fermentation results. Laboratory experiments were conducted to evaluate the effect of three harvest dates on fermentation acid composition, with a focus on increasing lactic acid production to inhibit butyric acid formation. Results indicate that an early harvest date (early September) is critical for achieving stable fermentation and minimizing ensiling losses. The addition of sugar-rich additives, such as syrup, was found to be essential, especially for later harvest dates. Despite these interventions, a late harvest (early November) consistently resulted in suboptimal fermentation. The results suggest that optimizing harvest timing and incorporating appropriate additives are key strategies for producing high quality silage and ensuring the suitability of Silphium perfoliatum fibers for industrial applications. [ABSTRACT FROM AUTHOR]

Novel research has been conducted to characterize fiberboards made from palm frond fibers and polyester resin. In this study, polyester resin served as the matrix, and palm frond fibers with a size of 80 mesh were employed as the filler. The fiberboard composites were produced using a hot press at 70°C for 20 minutes, with varying mass compositions of polyester resin to palm frond fibers: S1 (60%:40%), S2 (65%:35%), S3 (70%:30%), S4 (75%:25%), and S5 (80%:20%). Parameters observed include physical properties (density and porosity), mechanical properties (impact, tensile, and flexural strength), and microstructure analysis using scanning electron microscope (SEM) and differential scanning calorimetry (DSC). The results indicate that S5 exhibits optimal properties, including a density value of 1.197 g/mL, low porosity at 0.232%, and mechanical characteristics with an impact strength of 271.251 J/m2, tensile strength of 23.221 MPa, and flexural strength of 149.837 MPa. However, according to the DSC data, S1 stands out with a higher temperature water evaporating point at 82.48°C, indicating greater thermal stability. In addition, SEM results for the S5 sample reveal minimal voids, enhancing the fiberboard composites' physical and mechanical properties and demonstrating high stability. This fiberboard can be classified as a High-Density Fiberboard (HDF) according to JIS A 5905:2003. It is a viable alternative for household furniture, offering a substitute for traditional wood. [ABSTRACT FROM AUTHOR]

In order to achieve antibacterial properties in water-based coatings, two types of antibacterial pomelo peel flavonoid microcapsules were added to water-based coatings and decorated on the surface of fiberboard. The surface coatings of the substrates were tested and analyzed. The antibacterial rate of the surface coatings of the two groups of fiberboards gradually increased with the increase in the content of the microcapsules. The color difference of the surface coatings of both groups increased slightly, the glossiness decreased, the gloss loss rate increased greatly, and the reflectivity increased slightly. The adhesion of the surface coatings of the two groups of fiberboards did not change significantly, the roughness gradually increased, the hardness of the melamine-resin-coated pomelo peel flavonoid microcapsules gradually increased, and the impact resistance slightly improved. Compared with the antibacterial results of the coating without substrate at the same content, the antibacterial effect of the fiberboard surface coating was slightly decreased. Overall, the surface coating on the fiberboard with 9.0% chitosan-coated pomelo peel flavonoid microcapsules demonstrated superior performance, superior coating morphology, and enhanced antibacterial properties. The antibacterial rate was 73.7% against Escherichia coli, and the antibacterial rate was 77.4% against Staphylococcus aureus. The color difference was 3.85, the gloss loss rate was 90.0%, and the reflectivity was 20.19%. The hardness was HB, the adhesion was level 1, the impact resistance level was 3, and the roughness was 1.94 μm. This study explored the effect of antibacterial microcapsules on coating performance, providing a technical basis for the application of the antibacterial microcapsules. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) coatings are widely used because of their good performance. However, the self-healing performance of UV coatings can be further improved. Microcapsule technology can be used to solve this problem. To investigate the effects of the compound use of two UV coating microcapsules on coatings of a fiberboard surface, three kinds of UV primer microcapsules (1#, 2#, and 3# microcapsules) with different contents were added to a UV primer, and a UV top coating was prepared with UV top coating microcapsules at a consistent ratio. The UV coating was used to coat the fiberboard surface by way of a two-primer and two-top coating method. The results show that as the content of the UV primer microcapsules was increased, the self-healing rates of all three groups of coatings increased and later decreased. The color difference ΔE of coatings with the content of the UV primer microcapsules at 4.0% and top coating microcapsules at 6.0% was 3.59, the gloss was 1.33 GU, the reflectance was 21.17%, the adhesion grade was 2, the hardness was 2H, the impact resistance grade was 5, the roughness was 1.085 μm, and the self-healing rate was 30.21%. Compared with the self-healing rate of the blank control group, the increase in the self-healing rate was 10.07%, and the improvement rate was 50.00%. The comprehensive performance of the coating was better. The results provide a technical reference for the application of the UV coating microcapsules in the UV coating on fiberboard surfaces. Incorporating the self-healing UV coating microcapsules into the UV coatings and applying the UV coating microcapsules on the fiberboard surfaces supports the microcapsule technology of self-healing UV coatings, lays the foundation for extending the service life of furniture while improving the furniture's quality, and promotes the sustainable development of the coating industry. [ABSTRACT FROM AUTHOR]

Medium-density fiberboard (MDF) waste generation has increased steadily over the past decades, and therefore, the investigation of novel methods to recycle this waste is very important. The potential of repurposing MDF waste as an adsorbent for the treatment of Cd(II), Cu(II), Pb(II), and Zn(II) ions in water was investigated using MDF offcuts. The highest adsorption potential in single-metal ion solution systems was observed for Pb(II) ions. The experimental data of Pb(II) ions fit well with the Freundlich isotherm and pseudo-second-order kinetic models. Complexation and electrostatic interactions were identified as the adsorption mechanisms. The adsorption behavior of multi-metal ion adsorption systems was investigated by introducing Cd(II) ions as a competitive metal ion. The presence of the Cd(II) ions reduced the adsorption potential of Pb(II) ions, yet the preference for the Pb(II) ions remained. Regeneration studies were performed by using 0.1 M HCl as a regeneration agent for both systems. Even though a significant amount of adsorbed metal ions were recovered, the adsorption potential of the MDF was reduced in the subsequent adsorption cycles. Based on these results, MDF fines have the potential to be used as an economical adsorbent for remediation of wastewater containing heavy metal ions. [ABSTRACT FROM AUTHOR]

Calcium lignosulfonate (CLS) (C20H24CaO10S2) is widely used in various industries today, including wood, construction, food, agriculture, and textiles. There are currently few studies on the addition of CLS chemicals to various fiberboards. This study was designed to explore the outcomes of the interaction between CLS and the boards, with the aim of expanding the potential applications of this chemical. We incorporated CLS at varying percentages (6%, 8%, and 10%) as an adhesive additive in high-density fiberboard (HDF) produced using urea-formaldehyde (UF) resin in a laboratory setting. We assessed its impact on several physical properties - thickness swelling (TS), density, and water absorption (WA) - and mechanical properties: modulus of rupture (MOR), internal bond strength (IB), modulus of elasticity (MOE), and surface soundness (SS). A control group was created using prepared boards, enabling the comparison of results between boards made with and without CLS additives. According to the results of a multivariate analysis of variance, the CLS percentage showed no significant effect on density, MOE, and SS. However, it significantly influenced TS, WA, IB, and MOR, resulting in reductions of 4-12% for SS, 6-12% for MOR, and 2-22% for IB, while increasing TS by 20-130%, WA by 25-84%, and MOE by 1-3%. It was observed that the use of CLS led to differing results in the tests conducted on the produced HDF materials. [ABSTRACT FROM AUTHOR]

This study presents an experimental and numerical comparison between the mechanical performance of a lightweight corrugated sandwich panel based on the tea oil camellia shell (TOCS). Hence, TOCS was mixed in two groups with Poplar particles and fibers. After that, in the experimental part, the conventional mechanical tests, including the 3-point bending test, flatwise compression, dowel bearing, and screw resistance, and in the numerical part, finite element analysis (FEA), including the normal, maximum principal, and equivalent (von Mises) stress by Ansys Mechanical software carried out. The specimens for experimental and numerical tests were prepared in transverse and longitudinal directions. Before that, the engineering data (shear modulus, Young's modulus, and Poisson's ratio) for improving the FEA simulation were obtained from TOCS-based flat panels fabricated with a mixture of Poplar particles and fibers. The results of FEA are used to compare the mechanical behavior and failure mechanism with the results of experimental tests. According to the mean values of bending stiffness and maximum bending moment, sandwich panels made with 100% particles demonstrated an advantage in both directions. Nevertheless, the compression strength and screw resistance showed the same trend, but the dowel bearing showed higher values for panels made with fibers. The observed results of equivalent (von Mises) stress indicated a coloration with the results of failure mechanisms. [ABSTRACT FROM AUTHOR]

Radiation shielding materials significantly contribute to various fields. In this research, a new eco‐friendly nanocomposite shielding material based on high‐density polyethylene (HDPE) and natural fiberboard (NF) with different concentrations of barium oxide nanowires (BaO), bismuth oxide nanorods (Bi2O3), and boric acid (H3BO3) is constructed and investigated for 137Cs, 60Co gamma ray, and 142Am–Be neutron sources. Mechanical and physical testing and thermal analysis were conducted to assess the impact of nanostructure incorporation on the structural integrity and thermal stability of the nanocomposite. The 60Co gamma and neutron attenuation properties were evaluated using the appropriate radiation sources. The transmission and absorption coefficients of the nanocomposites were measured. The results demonstrated that HDPE/NF filled with BaO, Bi2O3 nanostructure, and boric acid has higher tensile strength and thermal stability than unfilled HDPE/NF. The results displayed that the HDPE/NF filled with 1.5% Bi2O3 and 1.5% BaO improved gamma attenuation and also HDPE/NF/10% boric acid had a high value. The outcomes of this research provide valuable insights into the design and fabrication of radiation shielding materials by understanding the relationship between nanoparticle concentration, radiation attenuation properties, and the mechanical and thermal characteristics of the nanocomposite. This study aims to optimize the performance and applicability of HDPE/NF nanocomposites for radiation protection applications. Highlights: Synthesis of BaO nanowires and bismuth oxide (Bi2O3) nanorods by hydrothermal simple method.Fabrication and characterization of a new HDPE/natural fiberboard (NF) nanocomposite containing BaO/Bi2O3/H3BO3 as an eco‐friendly additive.The HDPE/NF/1.5% BaO/1.5% Bi2O3 nanocomposite has better tensile strength and more thermal stability.Usage of HDPE/NF/1.5% BaO/1.5% Bi2O3 nanocomposite that should be utilized for radiation shielding.Usage of HDPE/NF/1.5% BaO/1.5% Bi2O3/10% H3BO3 nanocomposite that should be utilized for neutron attenuation performance. [ABSTRACT FROM AUTHOR]

Mycelium-based fiberboards were evaluated as potential environmentally friendly substitutes for conventional wood-based composites. The goal of this study was to produce and test fiberboards out of yellow pine and poplar fiber mixtures without using any extra adhesive. Pleurotus ostreatus and Ganoderma lucidum fungi were used. The physical and mechanical characteristics of the fiberboards were tested under the influence of two different types of fungi and two different incubation periods. The key findings indicated that the mycelium-based fiberboards had higher water absorption and thickness swelling percentages compared to control boards produced with adhesives. The fiberboards produced from fibers inoculated with Ganoderma lucidum and incubated for 30 days had higher mechanical properties compared to other test fiberboards. This indicated the possibility of utilizing them in specific applications. Although the mycelium-based fiberboards did not fully meet all the EN 622-5 (2009) standard requirements for dry-condition use, the results highlighted their potential in sustainable material development. This study provided useful insights into the utilization of mycelium for the development of mycelium-based fiberboards.

Sugarcane (Saccharum officinarum L.) leaf is an abundant waste from agriculture. In this study, we prepared binderless fiberboards from sugarcane leaf with <3 % moisture (w/w) and <1 mm in size by hot‐pressing temperature in the 210–240 °C range, followed by surface coating with polyurethane. The effect of hot‐pressing temperature on the modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding (IB) strength, and thickness swelling of the binderless sugarcane leaves was investigated. An optimal pressing condition for preparing the binderless sugarcane leaf fiberboards was 230 °C for pressing temperature, 5 MPa for pressing pressure, and 600 s for pressing time, giving 1200 kg m−3 for board density, MOE of 657.1 MPa, MOR of 7.04 MPa, and IB strength of 0.277 MPa. The thickness swelling of the coated samples was almost completely eliminated by the surface coating. [ABSTRACT FROM AUTHOR]

Bio-based materials are becoming increasingly important as demand for conventional wood-based products raises environmental issues, potentially leading to deforestation. As a result, environmentally acceptable, cost-effective, and easily available alternative natural biomass materials for these intended utilizes are highly required. In this work, a waste wheat straw cellulose polymer matrix composite reinforced with sisal fiber through physical and chemical treatment methods for fiberboard application was synthesized and characterized. The composite materials were developed using the polymer solution casting method. Waste wheat straw composites with 0, 5, 10, 15, 20, 25, and 30 wt% of sisal fiber with respect to the matrix were prepared. Qualitative and quantitative approaches, as well as exploratory and experimental research methods, were employed. Fourier transform infrared (FTIR) spectroscopy was used to investigate the functional group of wheat straw cellulose, while scanning electron microscopy (SEM) was used to examine the sisal fiber morphology. Flexural strength was tested by using a universal testing machine, and impact strengths were measured by a V-notch Charpy tester based on medium-density fiberboard (MDF) and low-density fiberboard (LDF) as control samples. The water absorption of the samples was also studied. The work complied with ANSI A208.2–2002's general test standards for general usage. The results showed that the maximum flexural strength attained at 20 wt% of reinforcement was (56.83 MPa) and the impact strength at 20 wt% sisal fiber was (30.33 J), while the MDF and LDF control samples' flexural strengths were 35.5 MPa and 41.5 MPa, respectively, and the impact strengths were (20.16 J and 25 J), respectively. The lowest water absorption value was achieved at 5 wt% of sisal fiber, and the value was (2.09%). However, water absorption of (74.04%) for MDF and (106.98%) for LDF was measured. Thus, it was discovered that using waste biomass such as wheat straw instead of raw wood may provide a composite material with superior flexural strength, impact strength, and reduced water absorption for fiberboard applications. [ABSTRACT FROM AUTHOR]

Influence of décor paper raw (40 and 50 gr m-2) and final weight (105 and 115 gr m-2), and corundum (Al2O3) amount (8, 10, and 12 gr m-2) on surface abrasion count, abrasion resistance, impact resistance (small ball) and cure properties of the laminate floor with high-density fiberboard core was evaluated. Nine different types of laminate floor products were produced and tested. The averages of surface abrasion, abrasion resistance, impact resistance, and cure properties ranged from 2667 to 5000 revolutions, 4.5 to 5.5 N, 70 to 90 N, and level 4 to 5, respectively. According to the results, products meet both domestic and commercial levels of use regarding BS EN 13329:2023. The overall performance of B-type products was higher than A and C-type products. It should be noted that the products evaluated in this study were factorymade instead of laboratory applications. Furthermore, some production parameters are kept confidential due to marketing concerns. [ABSTRACT FROM AUTHOR]

The anti-electromagnetic interference capability of partial discharge (PD) acoustic signal conversion and collection circuits severely restrict the sensitivity of PD detection. The data acquisition (DAQ) systems available in the current market are costly and have limited functionality, making it difficult to satisfy the acquisition requirements for PD detection. This paper proposes a medium to high-speed fiber optic signal acquisition board with an adjustably controlled sampling rate and filter cutoff frequency. The circuit achieves a higher signal-to-noise (SNR) ratio by distributing the noise in each part of the signal acquisition chain reasonably. The temperature characteristics of the acquisition module are improved by utilizing the programmable T-type structure for transimpedance amplification of photocurrent. The DAQ card performs data acquisition and processing using STM32H743 internal ADC and caches data in bulk with an SRAM and SD card. A data uploading method based on time reference has been proposed, which enables full, effective information signal upload through a low-cost transmission interface. The research ultimately achieves a stable sampling of three channels at 1 MSps, SNR of 63 dB, and programmable gain amplification of the photocurrent with 0–60 dB. Finally, the system is used for PD acoustic signal acquisition in the frequency range of 20 Hz to 100 kHz. [ABSTRACT FROM AUTHOR]

Ultrasonic detection is currently used in the industry of medium-density fiberboard to detect blister defects. Due to the small detection area of a single sensor, multiple sensors need to be used, which results in high costs. Starting from elastic thin plate vibration theory, this paper builds a vibration dynamic model to detect blisters. The size and depth of the blister area can be established by determining the natural frequency of the thin plate vibration in the blister area. In this model, if the elastic modulus and density are known, the natural frequency of the thin plate vibration at the blister place is directly proportional to the blister depth and inversely proportional to the square of the blister radius. The size and depth of the blister can be determined by measuring the first third-order natural frequency of this area of research. A total of 25 specimens with blister sizes and depths were simulated, and the natural frequencies of the specimens were measured. Subsequently, the detection model was verified by comparing its experimental data with theoretical values. The theoretical value was highly consistent with the measured data. The measured values of the first, second, and third-order natural frequencies were slightly smaller than the theoretical calculated values, with average relative deviations of −1.6%, −1.34%, and −1.03%, respectively. As the order progressed, the deviation exhibited a downward trend, and the third-order natural frequency displayed the smallest deviation and highest accuracy. The proposed vibration dynamic model can detect larger blister areas by measuring the natural frequency, which can overcome the shortcomings of small ultrasonic detection areas in current actual industries. Thus, the practical online blister detection device is expected to be further developed. [ABSTRACT FROM AUTHOR]

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This study investigated converting abundant paper mill waste, de‐inked paper sludge (DPS), into value‐added medium‐density fiberboard (MDF) panels. The objective was to repurpose this solid waste into a valuable material that aligns with the principles of a circular economy. Previous research has examined the addition of paper sludge to wood composites, but there is limited information on the specific incorporation of DPS into MDF production. This investigation offers new insights into this application. MDF panels were manufactured using hardwood fibers, with varying levels of urea‐formaldehyde resin (10% and 12% by weight) and different loadings of DPS (ranging from 0% to 50% by weight). X‐ray diffraction analysis revealed the presence of defective DPS fiber crystals. Contact angle measurements confirmed that DPS had poor wettability, corresponding to increased water absorption. As more DPS was incorporated, the mechanical properties of the panels progressively weakened due to defective fibers and poor adhesion between the fibers and the matrix. This was evident in scanning electron microscopy micrographs, which showed an escalation in interfacial flaws. Increasing the resin dosage noticeably improved the internal bond strength and reduced moisture uptake across all levels of DPS. However, at a DPS loading of 50%, the properties of the panels deteriorated by 36%–57% compared to the control MDF. Additionally, thickness swelling and water absorption increased significantly with higher DPS content, primarily due to the hydrophilic nature of the fibers. Based on optimization, it was determined that a DPS loading of 20% with a resin content of 12% provided the best balance between performance, waste utilization, cost, and moisture resistance. The reuse of abundant paper sludge supports the goals of a circular economy. However, strategies are required to tailor the processing methods and enable higher levels of recycled material without excessively compromising the key attributes of the product. Further research should focus on enhancing the quality of DPS and its compatibility with wood fibers and resin to enhance the performance of the composite material. Highlights: DPS from recycled paper mill assessed for MDF production with wood fibers and resinIncreasing DPS loading caused reductions in strength and adhesion of panelsWater absorption and thickness swelling markedly rose with more DPS additionIt was attributed to hydrophilic fibers and disrupted fiber‐matrix bondingOptimal formulation was 20% DPS loading and 12% resin content, balancing performance, waste utilization, and cost. [ABSTRACT FROM AUTHOR]

A novel pretreatment strategy utilizing a combination of NaOH and 1-Butyl-3-methylimidazolium chloride ([Bmim]Cl) was proposed to enhance the enzymatic hydrolysis of abandoned Medium-density fiberboard (MDF). The synergistic effect of NaOH and [Bmim]Cl pretreatment significantly improved the glucose yield, reaching 445.8 mg/g within 72 h, which was 5.04 times higher than that of the untreated samples. The working mechanism was elucidated according to chemical composition, as well as FTIR, 13C NMR, XRD, and SEM analyses. The combined effects of NaOH and [Bmim]Cl led to lignin degradation, hemicellulose removal, the destruction and erosion of crystalline regions, pores, and an irregular microscopic morphology. In addition, by comparing the enzymatic hydrolysis sugar yield and elemental nitrogen content of untreated MDF samples, eucalyptus, and hot mill fibers (HMF), it was demonstrated that the presence of adhesives and additives in waste MDF significantly influences its hydrolysis process. The sugar yield of untreated MDF samples (88.5 mg/g) was compared with those subjected to hydrothermal pretreatment (183.2 mg/g), Ionic liquid (IL) pretreatment (406.1 mg/g), and microwave-assisted ionic liquid pretreatment (MWI) (281.3 mg/g). A long water bath pretreatment can reduce the effect of adhesives and additives on the enzymatic hydrolysis of waste MDF. The sugar yield produced by the combined pretreatment proposed in this study and the removal ability of adhesives and additives highlight the great potential of our pretreatment technology in the recycling of waste fiberboard. [ABSTRACT FROM AUTHOR]

The wood-based panel industry is experiencing an excessive accumulation of solid residues from the production of medium-density fiberboard (MDF) panels and moldings. It is possible to create new MDF products with acceptable physical and mechanical properties by revaluing MDF residues. Additionally, those products' thermal properties can be improved by incorporating phase change materials (PCMs). This study aims to develop a wood-based fiberboard made of MDF residues, capable of storing thermal energy. Two types of PCMs (liquid and microencapsulated), two PCM ratios (2% and 6%), and two types of adhesives (urea-formaldehyde and phenol-formaldehyde) were used to produce eight different types of panels. The vertical density profile, thickness swelling, water absorption, internal bond (IB), and static bending properties—modulus of elasticity (MOE) and modulus of rupture (MOR)—were determined for each panel type. The specific heat of the panels was also determined. The results show the panels' densities were greater than 700 kg/m3. Thickness swelling in water improved by 23% compared to the reference value of the control panel PCMs after PCM incorporation. The highest IB value was 1.30 MPa, which is almost three times the minimum required by regulation standards. The incorporation of PCMs reduced the panels' bending properties compared to the properties of the control panels. Even though the values obtained are sufficient to comply with the minimum values set out in ANSI standard A208.2 with an MOE value of 2072.4 MPa and the values obtained are sufficient to comply with the minimum standards with an MOE value of 2072.4 MPa and an MOR value of 16.4 MPa, when microencapsulated PCM is used, the specific heat of the panels is increased by more than 100% over that of the control panels. This study developed fiberboards with adequate physical and mechanical properties and capable of storing thermal energy. [ABSTRACT FROM AUTHOR]

Lignin is the natural binder in wood and lignocellulosic plants and is regarded as the main natural and renewable source of phenolic compounds. Its incorporation in the composition of fiberboards will enhance both the environmental performance of the panels and the complex use of natural resources. In recent years, the increased valorization of hydrolysis lignin in value-added applications, including adhesives for bonding fiberboard panels, has gained significant research interest. Markedly, a major drawback is the retention of lignin in the pulp until the hot-pressing process. This problem could be overcome by using a small content of phenol–formaldehyde (PF) resin in the adhesive mixture as an auxiliary binder. The aim of this research work was to investigate and evaluate the effect of the hot-pressing temperature, varied from 150 °C to 200 °C, in a modified hot-press cycle on the main physical and mechanical properties of fiberboard panels bonded with unmodified technical hydrolysis lignin (THL) as the main binder and PF resin as an auxiliary one. It was found that panels with very good mechanical properties can be fabricated even at a hot-pressing temperature of 160 °C, while to provide the panels with satisfactory waterproof properties, it is necessary to have a hot-pressing temperature of at least 190 °C. [ABSTRACT FROM AUTHOR]

Carbon fiber bracket can greatly reduce the weight of foldable display modules, making a significant contribution to the lightweight of foldable mobile phones. This article takes OLED display modules as the research object, and fully reveals the bulging mechanism of carbon fiber bracket through disassembly analysis, infrared analysis, SEM analysis of pre impregnated materials, FIB slicing analysis after boiling carbon fiber boards, and verification of process parameters. The results indicate that the bulging delamination interface mainly occurs between FEP adhesive and carbon fiber board, and the fundamental reason is that the carbon fiber board releases gas. Further analysis indicates that carbon fiber board contains a curing agent, which contains a dicyandiamide component. Under high temperature and humidity conditions, dicyandiamide reacts chemically, releasing ammonia gas and damaging the interface between the colloid and carbon fiber board, resulting in delamination between FEP adhesive and carbon fiber board, and bulging in the reliability testing. [ABSTRACT FROM AUTHOR]

Non-food use of solid residues from the dairy industry as a binder in dry-formed fiberboard technology. The research investigated the possibility of using solid residues from the dairy industry as a binder in dry-formed fiberboard technology. The scope of work included the production of boards with a mass content of milk powder of 0%, 10%, 12%, 15%, and 20% (concerning the totally dry mass of wood fibers) and studying their selected physical and mechanical properties. The results show that the properties of the produced boards are related to the mass amount of the binder, and that is, using the right amount of binder makes it possible to obtain values that meet the requirements of the relevant European standards. [ABSTRACT FROM AUTHOR]

This article analyzes the effect of the rehydration method on the physical–mechanical properties of accelerated carbonation-cured magnesium-based fiber cement boards. The rehydration process of the boards was analyzed in conjunction with the analysis of the pre-curing time before accelerated carbonation (24, 48, and 72 h before carbonation), resulting in eight different curing parameters used in this investigation. The physical–mechanical performance and microstructural characteristics of magnesium oxysulfate boards before and after carbonation were investigated by water absorption, apparent porosity, and bulk density using the four-point bending test, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. According to the results, the accelerated carbonation process improved the mechanical properties of the boards. The samples that carbonated after 48 h showed a higher modulus of rupture. The rehydration process of the composites before carbonation led to enhancements in the pre-cured boards for 48 and 72 h, demonstrating that carbonation occurred more effectively after water rehydration. The mechanical improvements were associated with the formation of hydration products, which preferentially formed in the pores and voids of the fiber cement matrix. These carbonation products altered the physical properties of the composites, increasing the density of the boards and reducing the void volume. The decomposition of the formed carbonates was confirmed by thermogravimetric analysis, which indicated that the rehydration process favored the carbonation of the composites. [ABSTRACT FROM AUTHOR]

Paperboard boxes represent a sought-after class of packaging products, where the use of recycled fibers offers a cost-effective and environmentally friendly alternative to virgin fibers. The presence of a significant proportion of recycled fibers in the paperboard leads to a number of limitations associated with the deterioration of its characteristics. In this study, the properties of coated and uncoated paperboards containing recycled fibers, wood pulp, and virgin cellulose fibers were investigated using a laboratory sample of paperboard produced from 100% recycled fibers without any chemical additives for comparison. Properties such as smoothness, bulk density, absorbency, and tensile strength, as well as colorimetric characteristics, were determined for the recycled paperboards; for the latter test, charts were printed using inkjet printing and UV-curable inks. Whiteness was calculated by three formulae (CIE, Berger, and Stensby), and all the paperboards had a relatively low whiteness (not exceeding 90 CIE), with a yellowish tint due to recycled fibers and mechanical pulp in the composition. The absence of optical brightening agents in the paperboards was experimentally confirmed. The color gamuts of the paperboards were in direct ratio to their whiteness, with the highest ones demonstrated by the coated paperboards. Color reproduction, according to the tone value increase curves, also depended on the whiteness. Uncoated paperboards demonstrated smaller color shifts than the coated ones, with the greatest increase in tone for yellow color. Coated recycled paperboards are suitable for packaging printing under the same conditions as virgin fiber boards, while uncoated boards are the recommended choice for digital printing with UV inks. [ABSTRACT FROM AUTHOR]

This study designed a planar carbon fiber composite collector plate with excellent conductivity and mechanical strength for use in the proton exchange membrane fuel cell (PEMFC). The collector plate is made of phenolic resin mixed with conductive particles such as graphite powder, and coated onto carbon fiber cloth. After the solvent is allowed to evaporate, the prepreg is cut and stacked layer by layer into a mold for the heat pressing process at 150 °C. The resin in the carbon fiber prepreg cloth is cured into a carbon fiber composite board. A computer numerical control (CNC) engraving machine was used to engrave the carbon fiber composite board into the current collector shape. The carbon fiber composite current collectors were placed into a high temperature furnace for the carbonization process. The resin between the carbon fibers is removed by the high temperature to increase conductivity. The carbon fiber composite collectors were assessed for conductivity, mechanical strength, and performance. Afterwards, a planar two cell fuel cell stack was assembled for testing performance and stability. A printed circuit board (PCB) was used to design the circuit and the planar two cell fuel cell module made using the heat pressing process. The planar two cell module was combined with a small hydrogen storage tank to form a portable power generation device. • The carbonized composite current collector plate show higher performance. • Carbonized twice collector plates reach the maximum carbonization. • Increasing back side conductivity of collector plates can improve the performance. • Planar 2-cell module with composite collector plates has stable performance. • Planar 2-cell module successfully assembled as a portable power generator. [ABSTRACT FROM AUTHOR]

Explosion accidents are one of the factors that impede urban underground space development and utilization, and it is imperative to study safety precautions in case of an explosion in an urban underground space. Given this problem, a polyurethane sponge and carbon fiber board with Blocking Rates (BR) of 0.2, 0.4 and 0.6 were used to explore the combustion and explosion characteristics of hydrogen/methane premixed gas in a confined space in the presence of a flexible and rigid obstacle. The results indicated that both the flame and pressure exhibit Helmholtz oscillation characteristics in case of a rigid obstacle. When the BR of both flexible and rigid obstacle were 0.4, the explosion intensity index was the highest. It first increased and then declined with the increase of flexible obstacle BR. In the presence of a flexible obstacle, the Helmholtz oscillation phenomenon was completely suppressed, and explosion intensity indices were minimized, as the flexible obstacle BR increased, it first increased and then declined. Under the rigid obstacle preset conditions, the explosion hazard significantly increased compared to the flexible constructions. The research results provide a theoretical basis for protective facilities to suppress combustion and explosion phenomena in underground spaces. • The risk of hydrogen and methane explosion were studied in urban underground space with the layout of rigid and flexible obstacle. • Revealed the Helmholtz oscillation characteristics of flame and overpressure, and the competitive characteristics between overpressure peaks. • Analyzed the hazards associated with the overpressure rise rate and explosion intensity index. • Ensured that the flexible obstacle should be fore-lying and the blockage rate of flexible obstacle is greater than rigid obstacle in protection mechanism. [ABSTRACT FROM AUTHOR]

Novel composite materials were made by combining micro-lignocellulosic fibrils and natural rubber applied as spray coated layers for building materials. The micro-lignocellulosic fibrils were produced based on the mechanical pulping process with jute bast as the raw material. The obtained micro-lignocellulosic fibrils had a good content of watersuspended materials with fibril widths of about 0.1 to 1.0 µm and fibril length of about 100 to 150 µm. The composites were produced using natural rubber mixed with the micro-lignocellulosic fibrils at 0, 5, and 10 parts per hundred of rubber, vulcanizing sulfur, and activated zinc oxide. The fibril-rubber suspension was formed in the composite sheets with a thickness of 0.5 to 1.5 mm using a spray coating technique and was ovendried at 100 °C. The rubber composite had a homogenous fibril distribution in the rubber composite matrix, with good bonding between the fibrils and the rubber polymers. The fibrils contributed to the strength reinforcement of the rubber composite layers. The application of the micro-lignocellulosic fibril rubber composites coated onto industrial fiber cement boards enhanced the thermal insulation properties, which had a lower degree of thermal conductivity and heat diffusivity and enhanced the toughness and waterproofing of the fiber cement boards. [ABSTRACT FROM AUTHOR]