The subject of the present paper is improving sound absorption properties and protecting the dust generation of ceramic fiber boards. The two‐microphone impedance tube method measured the sound ...absorption coefficient (SAC) of ceramic fiberboards (CFB) with different shapes and sizes. The wood veneer was used to cover the ceramic fiberboard (VCFB) surface to improve the wall's appearance and prevent dust generation. The step‐shaped ceramic fiberboards with veneer attached (VCFBS) revealed improved SAC (.98, 2000 Hz) compared with CFB and VCFB. The noise reduction coefficient (NRC) and sound absorption average showed a 100% improvement compared to CFB. The surface morphology and air permeability were analyzed using a scanning electron microscope and a capillary flow porometer to correlate with the findings. Furthermore, the porosity and pore diameter of the CFB were also studied to gain a comprehensive understanding of its acoustic properties and sound absorption capabilities. Statistical T‐tests revealed significant variations in the SAC (p ≤ .005). Besides, the obtained SAC was compared with other reported sound‐absorbing materials. These findings suggest that using step‐shaped ceramic fiberboard covered with a wood veneer can significantly absorb sound and improve the living environment. This novel approach offers potential advancements in sound‐absorbing materials for building construction.
Very volatile organic compounds (VVOCs) are a group of important odor pollutants affecting indoor air quality that have been shown to be harmful to human health. A 15 L environmental chamber, ...combined with multi-bed tube was used to collect gases. Fifteen very volatile organic compounds (VVOCs), including 12 odor compounds, were identified from veneered medium density fiberboard coated with water-based lacquer (WB-MDF) using gas chromatography-mass spectrometry/olfactometry (GC-MS/O). The total very volatile organic compound (TVVOC) and total odor intensity (TOI) showed a decreasing trend over time, reaching equilibrium on day 28. TVVOC showed an overall slow-fast-slow emission profile, from day 3 to day 7, with a maximum decay rate of 29.7%. TOI showed the greatest rate of decline from day 1 to day 3, at approximately 12%. Alkane and alcohol VVOCs were the more abundant compounds, accounting for at least 60% and even up to 80% of the total. The major odor impression was fruity, with a highest odor rating of 6.6, followed by sweet, with an odor rating of 6.1. Although the odor impression changed from sweet to fruity over time, it seemed pleasant overall. The odor contributors were mainly alkanes, alcohols, esters, and ethers, which had relatively high odor intensities. The main odor-contributing substances were dichloromethane, ethanol, ethyl acetate, 2-methylacrylic acid methyl ester, and tetrahydrofuran. When WB-MDF is used for furniture or other decorative materials, it is strongly recommended that it be stored under ventilation for at least 28 days and the adoption of substitute solvents of lacquers, modified adhesives, and low-odor wood raw materials is recommended. These possible initiatives would contribute to the aim of building an environmentally friendly indoor environment.
The main objective of this study is to identify the suitability of Dehydrated Coconut Husk (DCH) and Particle Coconut Fibre Sheet (PBCS) for manufacturing the electrical insulation boards. The ...samples are collected and tested in two different approaches using Universal Testing Machine (UTM). The results show that the PBCS yield better results terms of tensile strength, impact strength, and flexural strength with values of 26.34 Mpa, 31.9 Mpa, and 44.9 Mpa, respectively. It is also evident that the PBCS based natural fibres having good mechanical properties and it is best suitable for making electrical insulation boards.
As a strategic new material with excellent performance, carbon fiber has attracted much attention in the wood structure industry. In this paper, the test modal and computational modal analysis ...methods are used to study the mode shape and modal parameters of carbon fiber board, calculate the elastic constants, i.e., the elastic modulus, shear modulus, and Poisson’s ratio, and analyze the coupling of the results. The conclusions show that the numerical results of the mode shape and elastic constants of the carbon fiber board obtained via the computational modal and test modal analysis are highly coupled. The first-order bending and first-order torsional modes of the carbon fiber board obtained via the two analysis methods are consistent, and the frequency error rate is less than 5%. The error rates of the elastic modulus and shear modulus are 0.7% and 7.8%, respectively. In addition, the research is conducive to strengthening the work of finite element computational modal analysis, and better promoting the application of non-destructive testing and quality grading of carbon fiber board. The above-mentioned optimization design work for improving the dynamic characteristics of carbon fiber board, and further research on the detection and optimization of the performance when the carbon fiber material is combined with wood, also has engineering application value for promoting the faster development of the wood structure market.
The study presents a possible innovative use of cement fiber boards (CFBs) reinforced with cellulose fibers for construction of an interior prefabricated staircase. Regarding the unusual use of ...traditional material that was used in all bearing elements of the staircase, a numerical simulation with the use of a material model SBETA was carried out and, subsequently, multiple experimental static loading was applied. In order to carry out experimental testing of static load capacity, a full-scale experiment method was chosen and performed on a real staircase structure for family houses. The full-scale experiment is considered the most precise method to test structures or material behavior. The obtained results show that the designed and tested staircase structure of CFBs is able to meet the requirements of technical standards related to static loading of staircases. The load test confirmed the potential use of cement fiber boards produced by the Hatschek process for real bearing structures under static loading.
The volume of global gross banana exports reached a record of 117.9 million tonnes in 2015 (FAO 2017), which agro-industrial wastes derived as the pseudo-stem, rachis and leaves do not have an ...industrial application instead they are discarded. This research study applies full factorial design and response surface methodology to determine the effect of pressing temperature and resin content on density (D), moisture (M), water absorption (WA), water swelling (WS), module of rupture (MOR), module of elasticity (MOE) and formaldehyde content (FC) of particle board made of banana pseudo-stem. A 22 factorial design was performed, factors considered were resin and temperature. The low level of resin was 15% in the coarse fiber (CF) and 35% in fine fiber (FF); high level as 25% CF and 45% FF. Temperature levels were 150ºC and 170ºC respectively. The boards met all quality parameters except ones with low resin content that didn't meet WS parameter. Furthermore, resin affected positively on WA, FC and MOE, and decreased D, WS and MOR values. Meanwhile, temperature affected negatively on D, WS, and increased FC, WA, MOE, MOR properties; none of the factors affected M response. Process conditions were optimized to 162.61°C and 43.15% FF, 23.97% CF.
Retrofitting of historical and traditional buildings is an effective thermal protection measure. The presence of thermal insulation in the composition of building envelopes might, however, bring some ...shortages due to a decrease of exterior surface temperatures or possible water vapor condensation. These shortages can improve living conditions for various microorganisms on the exterior surfaces, especially in the case of interior thermal insulation systems that are typical with thermal bridges and thus supply the surface with heat to a greater extent. This paper, therefore, aims at the investigation of hygrothermal conditions in selected critical construction details and evaluates the results from the point of view of potential biofilms growth. Two-dimensional modeling of coupled heat and moisture is applied and the hygrothermal patterns are evaluated based on an adjusted isopleth growth model. The results showed that the duration of favorable conditions for biofilms growth is relatively low, accounting for less than 180 h in the worst-case scenario. It means the exterior surfaces of historical buildings provided with interior thermal insulation systems are not threatened by biofilms growth. Anyway, other negative aspects have been revealed that should be treated individually. Possible wood decay or increased hygrothermal straining are the typical examples in that respect.
Zirconia fiber not only can be used for a long time in 1600°C, but also has low thermal conductivity at high temperature. Due to the excellent insulation performance, it has a broad application ...prospect in aerospace, aviation, energy and other areas. In the present study, we chose yttrium stabilized zirconia fibers and nanometer zirconia powder as main material and adding soluble starch, zirconium sol as low temperature and high temperature binder. Rigid zirconia fiber board was prepared by material slurry, filter shaping, stripping drying and high temperature calcination. After high temperature calcination of 1600°C for 12h, sample pore are mainly concentrated in 25-75μm, bending strength performance is best when the adding amount of nanometer zirconia powder was 7%, the thermal conductivity is only 0.132 W·m-1·K-1 at 1400°C.
Medium Density Fiberboard (MDF) has been one of the most rapidly growing composite panel products to enter world market in recent years. Optimization of drilling parameters for Medium Density ...Fiberboard (MDF) panel with multiple performance characteristics using Grey Relational Analysis (GRA) method was done. Drilling parameters, such as feed rate, spindle speed, drill diameters were considered for the study. By analyzing grey grade matrix, the degree of influence for each controllable process factor on to individual targets can be found. An optimal parameter combination of drilling operation was obtained via GRA. The feed rate was identified to be the most influencing factor on surface roughness and delamination. Additionally, ANOVA (Analysis of Variance) is used to find the interaction between parameters and the possible error in the experiments
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