Research Articles

Wood cladding is used in the residential market. However, the use of wood cladding in nonresidential and large multi-residential projects can sometimes be difficult. This paper highlights the barriers to the use of this material and draws recommendations to overcome them. A triangulation approach was used to enhance the validity of the findings with a deep literature review, interviews with different stakeholders, and analysis of several websites. The cross-compared analyses indicated that four main obstacles have hampered the use of wood cladding in non-residential projects. In order of importance, these obstacles are the recurring maintenance needed, restricting regulations (building code fire-safety and architecture implementation), appearance issues, and technical considerations regarding detailing and installation. To overcome the barriers of wood use in the non-residential market, three development axes are proposed based on communication with stakeholders, product adaptation for non-residential markets, and new product development with regards to product maintenance performance. These recommendations can guide manufacturers in adapting their product development strategies.

The mode II fracture toughness of bamboo scrimber was evaluated. A compact shear specimen was chosen as the specimen, while the stress intensity factor K_IIC was chosen as the index for the mode II fracture toughness. In total, 54 specimens containing two different grain modes and three different thicknesses were manufactured and subjected to static loading with specially designed loading clamps. The failure modes were observed, and the crack initiating loads were obtained. The stress intensity factor was calculated and analyzed. The failure of all specimens was due to brittleness and occurred instantaneously. Thus, the linear elastic fracture mechanics is applicable to the mode II fracture of bamboo scrimber. The stress intensity factor K_IIC was 459.9 MPa·m^1/2 for the F-L grain mode and 358.0 MPa·m^1/2 for the S-L grain mode. There was no significant difference in the stress intensity factor K_IIC of specimens where the thickness ranged from 10 mm to 30 mm; a specimen with a thickness of 10 mm can be used to determine the fracture toughness of the bamboo scrimber.

The properties of irradiated and non-irradiated recycled polypropylene (RPP)/peanut shell powder (PSP) composites were investigated relative to the effects of 6 months exposure to natural weathering. RPP/PSP composites were prepared by melt-mixing and compression molding with 0 to 40 wt.% PSP loading. The fabricated composites were then irradiated using a 2.0 MeV electron beam accelerator at a fixed dose of 20 kGy. The properties of non-irradiated and irradiated composites after exposure to natural weathering were compared and characterized by tensile properties, scanning electron microscopy (SEM), carbonyl indices (CI), differential scanning calorimetry (DSC), and weight loss analysis. The results in tensile strength and tensile modulus of irradiated RPP/PSP composites increased, while elongation at break decreased. The thermal stability of irradiated composites was also improved compared with non-irradiated composites. Pores and fungus penetration were observed from the SEM morphology, while an increase in carbonyl index and weight loss of both composites were evidenced that degradation occurred. The overall results indicated that the irradiated RPP/PSP composites were more resistant to natural weathering degradation than the non-irradiated RPP/PSP composites.

The pyrolysis characteristics of untreated pine and fire retardant-treated pine (Pinus densiflora) were measured by using thermogravimetric analysis according to the ASTM E1131-08 (2012) regulation. Fourier transform infrared spectroscopy was used to monitor changes in chemical groups of fire-retardant treated specimens before and after the combustion test. In addition, the microstructures of the untreated specimen and the fire-retardant treated specimen after cone calorimeter testing were determined by scanning electron microscopy. Combustion gas toxicity was evaluated according to the test method described in Naval Engineering Standard 713 (1990). The emitted combustion gases of all specimens were carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxide (NOX), and acrylonitrile. The thermal decomposition rate was reduced by about one-third that of the fire-retardant treated specimen compared to the reduction rate of the untreated specimen. These results are useful for guiding the safe utilization of fire retardant-treated wood and wood-based materials for building applications.

Wood-based industries are an important part of the European Union (EU) manufacturing sector because their growth can help in achieving EU’s industrial policy goal of raising manufacturing’s gross domestic product (GDP) to 20% by 2020. In this paper, special emphasis is placed on the influence of macro-economic factors on small and medium enterprises (SMEs) employment in the wood industry. The research objective was to test whether traditional macroeconomic indicators of economic growth are significant determinates of SMEs employment dynamics. For estimation of employment dynamics, a two-step Arellano-Bover/Blundell-Bond (a system generalized method of moments) estimator with robust standard errors was used. The model contained the following independent variables: real GDP growth rate; industrial production of wood processing industry; the number of wood processing enterprises; and exporting of manufactured goods of wood processing. The findings confirmed that the increase in GDP growth rate, the industrial production of wood processing, and exporting of manufactured goods of wood processing had statistically significant and positive impacts on SMEs employment. It was also found that the existence of a high number of enterprises had a positive impact on employment.

The current extraction of carboxymethyl cellulose (CMC) from wood has created competition with wood industries. Interest in alternative sources is critical to ensure the sustainable production of CMC. Therefore, the extraction of CMC from oil palm empty fruit bunch (OPEFB) stalk fibres was evaluated. CMC extracted from OPEFB stalk fibres was characterized for chemical composition as well as by spectroscopic, microscopic, physicochemical, and rheological tests. Highest cellulose content was obtained from raw stalk fibres with the least amount of lignin and residual oil as compared to the empty fruit bunch (EFB) and spikelet. The XRD analysis revealed that the native cellulose was transformed into an amorphous phase, as evidenced from the characteristic peaks that had almost disappeared. Likewise, the FTIR analysis showed that major peaks in the lignin and hemicellulose were absent, which enabled the cellulose to be converted to CMC. Microscopy analysis showed notable changes in the fibres’ morphology throughout the extraction process. In addition, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), physicochemical studies, and rheological tests on extracted CMC showed that there was a significant difference between each phase of the extraction process and this showed that OPEFB stalk fibre was feasible to produce CMC that was comparable to those of commercial CMC.

Five types of alternative sandwich composite structures designed for building walls were investigated in this study using various core materials such as wood shavings, recycled acrylonitrile butadiene styrene panels, and rock wool. The sandwich structures were designed for exterior walls with a thickness of 175 mm. The experiment simulated the conditions for inside and outside temperatures during winter and summer seasons. The thermal conductivity coefficient associated with winter was lower by about 55% than those registered for summer. Wood shavings and one ABS panel as core components led to the most thermally stable structure. The best insulation solutions were the rock wool core structures with a mean thermal conductivity coefficient between 0.0564 W/mK and 0.0605 W/mK for the entire testing cycle. The two ABS panels from the core configurations had a negative impact on the thermal performance. The lowest thermal performance was recorded by the pure wood shavings core structure, with a maximum value of thermal conductivity coefficient of 0.150 W/mK. Compressed wood shaving core structures can compete with rock wool as thermal insulation solution.

Twelve strains of fungi from residues of Agave durangensis were isolated and identified by molecular techniques for evaluation of their hydrolytic enzyme production capability. A proportion (50%) of the fungal strains belonged to the Aspergillus genus and the other strains used belonged to Alternaria, Neurospora crassa, Mucor sp, Rhizopus sp., Botryosphaeria sp., and Scytalidium sp. The isolated strains were evaluated for their potential to produce extracellular enzymes using different substrates (cellulose, xylan, inulin, Agave fructans, starch, and tannic acid). It was observed that most of the tested strains were capable of simultaneously secreting cellulases, xylanases, inulinases, fructanases, and laccases. Botryosphaeria sp. ITD-G6 was selected for its evaluation in the production of inulinase, using different substrates. Showing high inulinase activities (5.22 U / mL for Agave waste, 4.37 U/ mL for inulin and 5.00 U / mL for Agave fructans).

Orange is a fruit of the Citrus genus in the family Rutaceae. It is assumed to have originated in southern Asia, and to have been first cultivated in China around 2500 BC. There is little knowledge on the quality of wood from orange trees, which is occasionally used in fine woodwork, tool handles, mosaics, and marquetry. This work aimed to evaluate the possibility of using orange wood from agricultural conversions and orchard plantation renewals to make products with a high value. Logs from plantations located in southern Italy were collected, and the key aspects for determining the suitability of using the wood as flooring were examined. Laboratory tests were carried out to determine the shrinkage, dimensional stability, and surface hardness, which included an indentation test on the wood flooring. Drying trials were also performed, and prototypes of flooring were prepared so professionals and end users could evaluate the aesthetic value. The results confirmed that the wood from orange trees is fine-grained, and is characterized by a high density and shrinkage, average dimensional stability, and high surface hardness. The results of the tests suggested performing careful drying and following specific procedures according to the size of the elements. The wood was highly appreciated by the users, which confirmed the possibility of using this wood as a renewable raw material, despite the limited availability, for manufacturing high-quality products.

To develop construction and building materials from low-quality fast-growing wood, poplar laminated veneer lumber composites reinforced by E-glass fiber cloths (GFC) were prepared with phenol-formaldehyde adhesives. The GFCs were modified with γ-aminopropyltriethoxysilane solution (concentration: 0.8%, 1.3%, and 1.8%). Between each veneer, 260, 330, or 400 g/m2 adhesives were spread on one or both sides of veneers. The composites were hot-pressed under different temperatures (130, 145, and 160 °C) and gauge pressures (0.7, 1.2, and 1.7 MPa). The GFC dosages and positions in composites were varied. To evaluate the effects of variables on composites, analytical methods included the contact angle, scanning electron microscopy, and physical-mechanical measurements (flexural strength, flexural modulus, horizontal shear strength, internal bond strength, thickness swelling, and dip peel). The results showed that γ-aminopropyltriethoxysilane made GFC more hydrophilic and compatible with adhesives, enhancing their interfacial adhesion. Considering most of the physical-mechanical and interfacial properties, the optimum parameters for preparing composites were determined to be 1.3% (γ-aminopropyltriethoxysilane), 330 g/m2 (adhesive, double-sided gluing), 160 °C (temperature), and 1.2 MPa (pressure). Varying GFC dosages and positions in composites had positive or negative effects on different physical-mechanical properties. Models were developed to correlate flexural data with GFC dosages and positions.