The potential use of seaweed (posidonia oceanica) as an alternative lignocellulosic raw material for wood composites manufacture

A big challenge in the composites industry is the availability of cheap raw lignocellulosic materials, potential candidates to replace slow growing trees, in order to minimize the production cost. Therefore, a variety of plants were studied and tested worldwide in composites manufacturing. The objective of this study was to investigate the technical feasibility of manufacturing particleboards from seaweed leaves (Possidonia oceanica-PO). The use of such a material may benefit both socioeconomic and environmental development since these leaves settle on seashores and decay. The results showed that an incorporation of up to 10% PO leaves did not significantly affect the mechanical properties of the board. Internal bond strength was more severely affected than the other mechanical properties. The incorporation of PO leaves up to 25% did not significantly improve the dimensional stability of the boards. Markedly, boards made from 50% wood particles and 50% PO leaves showed the best thickness swelling values. It is suggested that higher resin dosage and an alternative resin system, such as isocyanates, may improve the panel properties. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Thermal and mechanical properties of green insulation composites made from cannabis and bark residues

The objective of this paper was to investigate the technical feasibility of manufacturing low density insulation particleboards that were made from two renewable resources, namely hemp fibers (Cannabis sativa) and pine tree bark, which were bonded with a non-toxic methyl cellulose glue, as a binder. Four types of panels were made, which consisted of varying mixtures of tree bark and hemp fibers (tree bark to hemp fibers percentages of 90:10, 80:20, 70:30, and 60:40). An additional set of panels was made, consisting only of bark. The results showed that addition of hemp fibers to furnish improved mechanical properties of boards to reach an acceptable level. The thermal conductivity unfavorably increased as hemp content increased, though all values were still within the acceptable range. Based on cluster analysis, board type 70:30 (with 30% hemp content) produced the highest mechanical properties as well as the optimal thermal conductivity value. It is concluded that low density insulation boards can be successfully produced using these waste raw materials. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Thermal Behavior of a Light Timber-Frame Wall vs. A Theoretical Simulation with Various Insulation Materials

The objective of this paper is to compare the thermal behavior of a light frame timber wall by measuring 15 test samples with various insulation materials versus a theoretical simulation with the use of a software. This work establishes the variance between the two different methods to measure the thermal transmittance coefficient of timber walls. It is verified that the mean percentage alteration between the two methods is 4.25%. Furthermore, this approach proved that with the use of a simulation software, additional readings (humidity, vapor flux, heat flux, and vapor pressure) can also be considered and measured, enhancing the overall development of a timber wall. This can provide additional information regarding to the characteristics of the masonry’s elements assisting in an improved design of a timber wall with upgraded performance. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Thermal transmittance, dimensional stability, and mechanical properties of a three-layer laminated wood made from fir and meranti and its potential application for wood-frame windows

The aim of this paper was to investigate the physical (thermal transmittance and dimensional stability) and mechanical properties of two types of three layer laminated wood made from fir and meranti; fir in surface layers and meranti in core (FMF) and vice versa (MFM) and to examine its potential application for wood-frame windows. An additional objective was to compare the properties of the laminated wood with those of solid wood, namely meranti and fir. Both types of laminated wood had by far substantial lower bending properties than solid wood. MFM laminated wood performed better than the FMF as far as the physical and mechanical properties are concerned. Water absorption and thickness swelling of MFM laminated wood were substantially lower than those of the FMF type, and all the differences were statistically significant. Longitudinal width swelling, and bending properties of MFM laminated wood were higher than those of FMF but these differences were not statistically significant. The thermal transmittance (rate of the heat transferred) of the FMF window is 13.3% better (less) compared to the MFM window. The main reason for this is believed to be the lower overall density of the FMF window, which also makes it more competitive as a result of the reduced manufacturing cost since fir is less expensive compared tomeranti. It was concluded that wood-frame windows can be successfully made from these types of laminated wood, employing therefore easily renewable materials, with low environmental impact, recyclable and manageable in the medium term. © 2021 by the authors. Licensee MDPI, Basel, Switzerland