Volume 20 Issue 3

This study explores the potential of porang flour (Amorphophallus muelleri) as a sustainable filler in urea formaldehyde (UF) and citric acid (CA) adhesives, highlighting its effect on enhancing plywood performance. The physical and mechanical properties of plywood bonded with varying compositions of porang flour (0%, 10%, 20%) were evaluated according to Japanese Agricultural Standard (JAS 233:2003) for plywood. Three-layer plywood panels were manufactured using sengon wood and both types of adhesives. The results showed that adding porang flour to UF and CA adhesives significantly increased the solids content and improved physical and mechanical properties. Plywood bonded with UF exhibited superior density, water absorption, thickness swelling, and shear strength properties. Conversely, plywood bonded with CA adhesive showed better results in moisture content, modulus of elasticity (MOE), and modulus of rupture (MOR). Overall, adding 10% porang flour was optimal for improving plywood’s physical and mechanical properties. These findings suggest that porang flour is an eco-friendly additive that can enhance the performance of natural adhesives in plywood manufacturing, providing a greener alternative to conventional adhesives.

Bleached kraft papers obtained from unbeaten (UB) and beaten (B) pulps were separately treated with zinc borate (ZB) and boric acid (BA) to improve their flame retardancy. The immersion method was chosen for application, and natural soy protein was added as a binder. The combined effect of soy protein (SP) and used boron compounds was observed. To investigate the thermal and fire resistance properties of the bleached kraft papers (BKP), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), limited oxygen index levels (LOI), and UL-94 burning test were performed.  The brightness and color parameters (L*, a*, b*, ∆L*, ∆a*, ∆b*, ∆E*) were also measured to determine the optical properties. The results showed that the combined effect of ZB and BA used with SP increased the flame resistance of kraft papers. The bleached kraft paper treated with BA had better flame retardancy in terms of LOI and UL-94 burning tests than paper treated with ZB. These results were also consistent with the TGA and DSC findings. Furthermore, the optical properties varied slightly depending on the chemical usage rates. Zinc borate and SP had a more positive effect on the brightness values of the bleached kraft papers compared to BA and SP.

Consumers rely on sensory perception to judge the appearance of furniture, often guided by intuitive associations with shape. This process allows furniture designers to better understand and respond to consumer preferences and expectations. This work used a questionnaire design and analysis survey by using the material, color, style, shape, and surface decoration of furniture as the main evaluation indexes. Additionally, consumers’ furniture appearance indicators were analyzed by combining quantitative and qualitative research methods. Satisfaction analysis (attitude index) of color, shape, material, style, and surface decoration of furniture for different consumers’ age, education level, and gender. Finally, consumers’ psychological and perceptual preferences were analyzed based on the correlation between indicators to form product imagery. This study can guide the appearance design of furniture and avoid design blindness, thus reducing the design risk.

The problem with plastic packaging is globally recognized, as plastic packages often end up in landfills without degrading. Using packages made from natural materials is the best choice to address and sustainably solve this issue. In this work, a single-use container (tray) was prepared from arecanut leaf sheath through a hot-compression molding process. The electrical energy required for the compression molding process was obtained from mainly electricity and 3 kW solar cells, reducing the cost by more than 50%, depending on the mold size and operating temperature. The pressing of arecanut leaf sheaths through a two-roll mill for 20 cycles at a high temperature (80 °C) before the compression molding process can increase the mechanical properties of the tray container. The tensile strength of the leaf sheath tray was higher than for polystyrene (PS) and polypropylene (PP) commercial trays. Reducing bacterial contamination of the plates can be achieved by using ultraviolet (UV) light. Almost all bacteria were reduced from 410 CFU/g to ˂10 CFU/g after UV exposure (40 μW/cm²) for 10 min. This suggests the possibility of using arecanut leaf sheath plates as food contact material, especially in single-use container applications.

Oriented strand board (OSB) was prepared from the strands of rubberwood (RW) and Acacia mangium (AC), with inclusion of kenaf core (KC). The KC was used as substitution, where 5% was added with RW and AC during the manufacturing process of OSB. Considering the expected negative impact of adding KC on the performance of the OSB, various levels of PF resin content were used. This study applied phenol-formaldehyde (PF) resin contents of 7%, 9%, and 11%. The OSB samples produced were evaluated for thickness swelling (TS), water absorption (WA), modulus of rupture (MOR), modulus of elasticity (MOE), and internal bonding strength (IB). Generally, incorporation of kenaf core reduced the mechanical and physical properties of the OSB. However, its mechanical and physical properties could be improved by increasing the resin content. Based on the findings, taking into consideration the properties of OSB as well as the cost of resin, 9% resin content is recommended.

The integrated strategy using coupling photocatalysis and adsorption to treat liquid waste has attracted increased attention. In this work, a carbon enhanced photocatalyst (BiOBr@PSBM) with dopamine bridge was constructed using porous straw biochar (SBM) as loading carrier for efficient, multitasking water purification engineering, enhancing adjustable adsorption and visible-light degradation. A cellulose-targeted etching strategy was used to construct porous biochar carriers. Benefiting from the synergy of dopamine and carbon enhancement, the electron migration ability of composites enabled the heightened visible-light catalysis activities, and the efficient visible-light degradation (96.5%) for various dye pollutants was achieved. The optimized porous structure, amino-rich surface, and pH control adjustable surface charge properties endowed composites with multitasking ability. They achieved excellent and rapid capture Cr(VI) through static-dynamic adsorption (157.7 mg·g^-1, 40 min). The theoretical calculation with DFT framework was used to study the proposed adsorption-degradation mechanism and the degradation pathway of organic polluted molecules. Significantly, multiple recycling and environmental experiments indicated that photocatalysts boasted stable structure and regeneration, supporting their cost-effective and efficient remediation of wastewater containing various polluted species. This work provided a feasible strategy for developing advanced water purification materials by the utilization of low-value solid-waste.

Identifying the transition age between juvenile and mature wood is key for designing more efficient silvicultural strategies and optimizing timber exploitation.  The objective of this study was to identify the juvenile wood transition age and analyze certain growth characteristics of Cuban Pinus caribaea M. var. caribaea B&G by comparing plantation and native populations. Radial variations in growth ring width, latewood proportion, and ultrasonic longitudinal speed were examined to identify the delimitation age from juvenile to mature wood. Visual assessment and statistical analyses, including segmented regression and k-means clustering, were applied. The findings indicated that juvenile wood is formed within the first 5 to 9 years, while mature wood develops after 21 to 26 years. Plantation trees exhibited higher variability and a wider juvenile wood zone (60 mm from the pith) than native trees (43 mm). The mean growth ring in the mature wood was 3.14 mm in native and 3.67 mm in plantation. The latewood proportion stabilized above 50% beyond the transition age, confirming the shift to mature wood, trees from native population developing 22% more latewood than trees from plantation. The ultrasonic speed pattern was similar between populations, validating its use as an indirect indicator of wood maturation.

Rotary friction welding of wood typically uses dowels made from the same material as the base wood or involves specific modifications to the dowels, but these methods have practical limitations and are complex. This study focused on commonly used dowel materials (softwood: Scots pine, hardwood: birch), with moisture content adjusted to 7 to 10%, and examined the welding performance and micro-mechanisms. Through orthogonal experiments, the influence of process parameters on the welding strength of both wood types was systematically investigated. The microstructures of the welded areas were analyzed using a depth-of-field microscope and scanning electron microscope (SEM) to explore the friction mechanisms. The results indicated that both Scots pine and birch dowels can be effectively welded using rotary friction. The optimal parameters were identified as follows: Scots pine dowels—hole diameter ratio of 8/12, rotational speed of 3000 r/min, feed rate of 25 mm/s; birch dowels—hole diameter ratio of 8/12, rotational speed of 2500 r/min, feed rate of 20 mm/s. Depth-of-field microscopy revealed larger weld areas and well-preserved surface structures. SEM images showed that during welding, the materials between the dowels and base wood melted, flowed, and re-solidified into a tightly bonded structure, ensuring a durable connection.

Most mushrooms are sensitive to ethylene, and exposure leads to degradation in mushroom quality, particularly in appearance and organoleptic properties. This study investigated the feasibility of using heated wood for ethylene removal. The hypothesis was that ethylene accumulation can be limited by using heated wood-based ethylene scavengers in mushroom packaging. The applicability and benefits of heated wood-based ethylene scavengers in mushroom home delivery are discussed. The heated wood-based ethylene remover used in the courier maintained the color of Lentinula edodes during transportation. These results were supported by quantitative analysis, in which the ethylene concentration in packaging headspace was significantly reduced (p < 0.05) by the wood-based scavenger, and rate of weight change also showed significant improvement (p < 0.05) compared to the control. Overall, this heated wood-based ethylene scavenger has potential in terms of mushroom packaging and food shelf-life extension.

Nutritional values and biological activity of Persicaria longiseta inflorescence extract (PLE) were assessed relative to the antioxidant, anticancer, and antibacterial impact of ethanolic extracts from the plant’s inflorescence. Using high-performance liquid chromatography (HPLC), the PLE ethanolic extract revealed that naringenin, chlorogenic acid, quercetin, rosmarinic acid, rutin, and gallic acid were all present in high concentrations (9780, 8250, 5190, 4320, 2520, and 2430 µg/g, respectively). Nutritional values assessment showed carbohydrates (166 mg/g), protein (53.2 mg/g), phenols (36.2 mg/g), and flavonoids (13.2 mg/g). When applied to pathogen species and cancer cells, the ethanolic extract of PLE showed inhibitory effects. Additionally, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for the tested microorganisms. The P. longiseta extract exhibited significant inhibition of hemolysis, particularly in the presence of B. subtilis (77.7, 90.8, and 95.9%) compared to K. pneumonia (54.1 ± 1.16, 75.8, and 85.3%) at varying doses (25, 50, 75% MIC, respectively). These results represent the beginning of the use of this extract in advanced medical aspects as an antimicrobial, antioxidant, antihemolytic, and antitumor agent, with some confirmatory and accurate experiments in vivo.