Volume 19 Issue 4

Wood scrimber as a promising eco-friendly material in wood technology. This study evaluated the physical and mechanical properties of ginkgo scrimber, focusing on density, moisture content, water absorption, thickness swelling, flexural modulus of elasticity, bending strength, tensile modulus of elasticity, tensile strength, compressive modulus of elasticity, compressive strength, and shear strength. The results showed that the material had low variation in density and moisture content, indicating good homogeneity of the material. Mechanical properties tests showed that the material’s mechanical properties met high-quality standards, although variability in bending strength suggested potential issues with adhesive application. Some specimens experienced fractures perpendicular to adhesive layers, affecting strength. Despite this, ginkgo scrimber exhibited mechanical properties comparable to or exceeding those of reconstituted bamboo and laminated veneer lumber. The findings highlight its potential for construction, with recommendations for improved adhesive application and manufacturing processes to enhance performance stability.

The aim of this research was to investigate the effect of false heartwood of beech wood on the shear strength of glued joints for thermoplastic and reactoplastic adhesives for plywood production. The tensile shear strength of the lap joints was tested for four different types of adhesives according to EN 204 (2016) and EN 205 (2016). The results showed that for lap joints assembled with polyvinyl acetate, urea-formaldehyde, and phenol-formaldehyde adhesives, there was no significant difference in shear strength between beech sapwood and false heartwood. However, for joints bonded with polyurethane adhesive, the shear strength was lower for heartwood compared to the reference sapwood, particularly after exposure to water immersion.

Agro-residues, including banana peel, pineapple peel, mango peel, apple peel, and coconut husk, were utilized to produce extracellular polysaccharide (EPS) via solid state fermentation(SSF) by the fungus, Trichoderma hamatum. EPS production was highest in pineapple peel (84.2 ± 0.4 mg/g), followed by mango peel (70.3 ± 0.41 mg/g) (p<0.01). The SSF bioprocess was optimized via a two-level full factorial design and response surface methodology. The effects of five selected variables on EPS biosynthesis, namely, the concentrations of glucose (10 to 30%), ammonium sulphate (0.1 to 1%), yeast extract (0.5 to 2%), MgSO₄ (0.01 to 0.1%), and medium pH (4.5 to 6.5), were analyzed via a full factorial design (FFD). The EPS production ranged widely from 15.3 to 576.2 mg/g substrate. Three significant variables affecting EPS production were assessed in central composite design (CCD) to optimize concentrations of MgSO₄, and glucose, and the pH. The designed CCD model was fitted to the quadratic model and was significant (p<0.0001). For 50 μL of EPS, the scavenging ratio was 43.4 ± 4.1% at a concentration of 200 μL (78.5 ± 6.9 μL) (p<0.01). The extracted EPS exhibited an alpha-glucosidase inhibitory effect (p<0.001). Solid-state fermentation allows the utilization of low-cost biomass for EPS production and the application of T. hamatum EPS as a natural antioxidant and α-glucosidase inhibitor.

This article presents results obtained for the chipless cutting of wood using different cutting heads. Wood processing in forestry and the demand for firewood are currently increasing, so it is necessary to apply appropriate tools to the existing process, which will be sufficient for fast and high-quality operations. Four groups of cutting knives were used for experimental measurements, where the influence of the cutting knife edge on the cutting process was determined. The cutting knives were always made of the same material and with the same blade angle ∢ 30°. Measurements were made on spruce (Picea abies), beech (Fagus sylvatica), and willow (Salix caprea) trees. The size of the F_c cutting force was selected as the monitored variable, and then the dependent factors (kind of wood, wood diameter, cutting knife) were monitored in terms of their influence on the size of this F_c cutting force and thus also on the energy consumption. Based on the statistical evaluation, the most suitable shape of the cutting edge of the knife was selected, with this shape of the cutting edge, a reduction in the cutting force F_c was achieved for selected woods.

Rattan is an important non-wood forest product, which shows a natural gradient in its structure from cane cortex to core. Toughness is its main characteristic, which is closely related to resistance to fracture. In this study, based on the principle of linear elastic fracture mechanics, the fracture toughness of Plectocomia kerrana Becc., was studied in two directions whose cracks were prefabricated from the cane cortex and from the cane core, respectively. The results showed that the average fracture toughness of pre-cracked from the rattan cane core was 0.476 MPa·m^1/2 measured by the SENB method. This value is much smaller than bamboo, as well as fir, Masson pine and other woods. Nominal fracture toughness of pre-cracks from cane cortex measured by flexibility method was 0.263 MPa m^1/2, which was less than the nominal fracture toughness value for pre-cracks from the core. When the rattan was bent, the crack in the rattan extended along with the prefabricated crack plane. Within the parenchymatic tissue, the crack extended transversely and changed its direction when the crack stretched into fiber sheath. The distribution density of vascular bundle was positively correlated with the fracture toughness.

In the post and beam structure, the post and beam play a crucial role in directly supporting and transmitting loads, thus making them essential elements in structural design. In cases where the moment resistance performance of the post-beam joint is inadequate, a shear wall and bracing are frequently installed to provide support for horizontal load on the posts and beams. The structural insulated panel (SIP) is increasingly utilized and studied as shear walls alongside light-frame timber construction, owing to its insulation properties as well as its high shear strength. In this study, when using SIP as a shear wall between post and beams, three composite wall structures were considered based on the installation location of the SIPs on the post-beam structure and lateral resistance performance of the hybrid shear wall was evaluated according to the SIP installation location. Depending on the installation location SIPs on the posts and beams, shear strength for I-SIP 150, E-SIP 150, and M-SIP 150 were 23.2, 24.6, and 26.0 kN, respectively. In case of the shear stiffness, I-SIP 150, E-SIP-150, and M-SIP 150 were found to be 4.32, 3.99, and 2.74 kN/mm, respectively.

In the contemporary era of quality and personalization, this article explores how soft sofa fabrics enhance users’ emotional experience and convey perceptual images. Users’ visual-tactile perception data on 10 common soft sofa fabrics were gathered by questionnaire surveys, utilizing the Kansei engineering approach, and the visual-tactile evaluation theory. With SPSS software, the data were processed and examined in-depth using a variety of techniques, including cluster analysis and factor analysis. The experiment screened fabric samples and emotional vocabularies via the KJ method and expert evaluation, and questionnaires were designed and implemented based on the semantic differential method and Likert scale. Fabrics were categorized into four groups based on cluster analysis, which are suitable for users pursuing different home environments. The two primary factors that comprise the fundamental aspects of the perceptual image of soft sofa fabrics were found to be the texture, quality experience factor, and the typical emotional reaction factor, which were extracted by factor analysis. Both theory and practice were considered, enriching the theoretical framework of emotional imagery and user emotion research while offering valuable practical guidance for the design, production, and marketing of soft sofas.

To improve the use experience of airport chairs, this study adopted morphological analysis to conduct systematic deconstruction, analysis, and statistics on the modeling features of existing airport chairs. The KJ method was used to determine the design requirements of airport chairs. The study combined the Kano model to classify the functional attributes and prioritize the requirements, and it merged the module and demand analysis to build a Function-Behavior-Structure mapping model. In this way, passengers’ demand for airport chairs can be clearly defined, and airport chair configuration planning can be carried out according to the difference in preferences. Further, different module combination schemes can be formed to improve the functional allocation efficiency of airport chairs, optimize the overall service quality of airports, and provide some basis and reference for the future design of airport chairs.

Fibers collected from the husk of areca nut trees were chopped to a length of 30 mm and were either used as such or subjected to alkaline treatment by immersion in a 5% sodium hydroxide (NaOH) solution. The untreated and treated fibers were investigated using thermogravimetric analysis (TGA) before the fabrication of composites using an epoxy matrix. Different amounts of fibers were introduced in the matrix, fabricating the composite by compression molding. The composites were subjected to tensile, flexural, and Charpy impact and Shore D hardness testing, which all demonstrated the considerable advantage obtained with the growing quantity of fibers, especially when employing treated fibers, except in the case of hardness, where limited advantages were encountered. Wear tests were carried out on treated fiber composites and the surface morphology of the worn-out samples was studied, which also demonstrated the improvement in fiber-matrix bonding obtained with the growing amount of fibers. The main limitation of the fibers was their low elongation even after treatment. The fibers hardly reached 4%, which might represent a quite normal value for this kind of fibers, possibly due to with tendency to fibrillation. This would somehow compare these composites with others with similar amounts and lengths of natural fibers.

Graphene was mixed with varnishes at different ratios and applied by spraying method on different cross-sections of various wood materials, and their wear and adhesion performances were determined. Graphene (0.25%, 0.50%, 1%); varnishes (water-based and polyurethane varnish) and wood materials (beech (Fagus orientalis Lipsky), chestnut (Castanea sativa Miller), yellow pine (Pinus sylvestris L.), and spruce (Picea orientalis (L.) Link.)) were used. Adhesion and abrasion tests were performed. A total of 480 test specimens were prepared, 5 specimens for each wood type, cross-sectional direction, graphene ratio, and varnish type for adhesion and abrasion tests. The adhesion of the samples was determined by ASTM D 4541-09E1 pull-off test and abrasion resistance was determined in accordance with ASTM 4060-10. The data obtained were statistically analyzed and the significance values within and between groups were determined. As a result, abrasion resistance and adhesion increased in graphene 2 (0.50%) in both varnish types.