Thermal and Acoustic Characterization of Innovative and Unconventional Panels Made of Reused Materials

Europe calls for a transition to the circular economy model based on recycling, reuse, the
proper design of products, and repair. Recycling requires energy and chemical products for waste
processing; on the contrary, reusing reduces the impact of transportation and expands the life of
materials that cannot be recycled. This article highlights the characteristics of selected end-of-life
materials; it aims to raise awareness among manufacturers to consider products’ conscious design
to facilitate their reuse in different sectors. Panels 7 cm thick, realized by assembling cardboard
packaging, egg boxes, bulk polyester, and felt, have been experimentally tested to understand whether
they can be installed indoors to improve thermal and acoustic comfort. The panels’ equivalent thermal
conductivity λeq measured through the guarded hot plate method is 0.071 W/m K. Acoustic tests
have been performed in a sound transmission room and a reverberation room. The weighted
sound reduction index Rw is 19 dB, the weighted sound absorption coefficient αw is 0.30, and the
noise reduction coefficient NRC is 0.64. The measured properties have been compared to those
of commercial materials, and the results show that the panels have interesting properties from
the thermal and acoustic points of view. They could be employed in the building sector and in
disadvantaged contexts where low-income people cannot afford commercial insulating materials.
Although other factors, such as fire resistance, need to be evaluated, these results show that the
proposed approach is feasible.