Thermal Characterization of Innovative Sustainable Building Materials from Wool Textile Fibers Waste

In the textile sector, fabrics produce waste from the earliest stages of production, particularly during the garment manufacturing process. The reuse of these materials as by-product to create innovative building materials could be a solution to reduce the environmental impact and to limit the waste disposal costs. The use of chitosan as a natural binder was investigated in order to obtain more easily recyclable materials with a lower environmental impact. The physical and thermal performances were tested, studying the correlation between porosity and thermal parameters. The experimental thermal conductivity range was between 0.049 and 0.06 W·m-1·K-1. Results proved the possibility to produce sustainable thermal insulation materials with performances comparable to conventional building products. Heat transfer through fibrous materials involves combined modes of heat transfer (conduction, convection, radiation) through the different phases (solid and gas): conduction in the solid and gas phase, and convection and radiative transfer through the gas phase. This paper focuses on the development and validation of a physical model for effective thermal conductivity in highly porous fibrous materials like wool panels with natural binder. If compared to the models currently available in the literature, the proposed model shows an improved correlation with the experimental data for the materials of interest.