Performance Analysis of Loose-Fill Thermal Insulation from Wood Scobs Coated with Liquid Glass, Tung Oil, and Expandable Graphite Mixture

Abstract

The current study presents the results of monitoring the behavior of loose-fill thermal insulating material for buildings made of wood scobs (WS), which were coated with one, two, and three component-based coatings from liquid glass (LG), tung oil (TO), and expandable graphite (EG). The thermal conductivity of samples in the dry state and under normal laboratory conditions, short-term water absorption by partial immersion, surface wettability, and water vapor permeability were evaluated, and regression equations describing the variations in numerical values of specified properties under different amounts of each coating component were presented. It was shown that LG and TO act as hydrophobic layers that, in conjunction, reduce water absorption by a maximum of 274%, have a contact angle equal to 86°, and lower thermal conductivity by 55% in the dry state due to the specifics of the layer formed on the surface of WS. The addition of EG to LG coating resulted in insignificantly changed water absorption and thermal conductivity values, indicating the potential of this material to be used to improve the fire resistance of wood-based composites in the future. The results showed that the three-component layer of LG/TO/EG reduces water absorption by a maximum of 72%, increases thermal conductivity in the dry state by a minimum of 0.4%, and increases the contact angle to 81° at 100 wt.% LG. The changes in water vapor permeability of all compositions were determined to be insignificant.

Research on Thermal Stability and Flammability of Wood Scob-Based Loose-Fill Thermal Insulation Impregnated with Multicomponent Suspensions

“…The main characteristics of WS were as follows: the average bulk density was 83.0 ± 6.8 kg/m 3 , and the moisture content was 12.1 ± 1.9%. The granulometry of the WS particles can be found in a study by Augaitis et al [ 34 ].…”

“…The results of thermal conductivity, short-term water absorption, contact angle, and water vapor permeability in [ 34 ] showed that the appropriate multicomponent suspension for the WS coating was LG/TO/EG. However, for the proper and more precise interpretation of the thermal stability and fire resistance results, interim compositions of loose-fill thermal insulation composites WS, WS/LG, WS/LG/TO, and WS/LG/EG were selected, and their compositions are presented in Table 1 .…”

“…In order to overcome these drawbacks, the application of wood scobs (WSs) as a loose-fill thermal insulation material and its surface modification with sodium silicate liquid glass (LG) and tung oil (TO) to achieve a proper interface with EG was proposed in a previous work by Augaitis et al [ 34 ]. The results showed a superior improvement in thermal conductivity and water resistance.…”

Research on Thermal Insulation Performance and Impact on Indoor Air Quality of Cellulose-Based Thermal Insulation Materials

“…By doing so, we can minimise transportation's carbon footprint while also strengthening local economies. It is important to note that produced loose-fill insulating materials may have unique properties due to variations in local resources [76,77] and manufacturing techniques [78,79]. One target of this research is to present some differences, where similar products or identical raw materials used in conjunction with different technologies yield notably different results.…”