Radiative and hygrothermal properties of flax/viscose spunlaced nonwovens

Abstract

Biobased fabrics are now getting widely used as solar shading for managing solar gain and daylight management and reducing building peak load and annual energy consumption of existing buildings. This work proposes to characterize five spunlaced nonwovens made of 65% of flax and 35% of viscose with different grammage. Radiative properties (transmissivity, reflectivity and absorptivity) are evaluated not only over the sun’s spectrum, but also over UV, visible and IR spectra. In addition, hygrothermal properties, such as thermal resistance, specific heat capacity or water vapor resistance, are also evaluated. Results indicate that these nonwovens present low transmittivity, which is interesting in the view of managing solar gain. Furthermore, it was found that radiative properties are mainly influenced by nonwoven’s thickness and porosity, as well the relative humidity. Lastly, hygrothermal properties (thermal resistance, thermal conductivity and water vapor resistance) are impacted mainly by porosity.