On Experimental Evaluation of Tortuosity for Cellulose-Based Highly Porous Composites Used Within Noise Insulation Applications

This study deals with the area of noise insulation using innovative porous composites, and starts from the practical necessity of material characteristics within the acoustics simulation. The authors present a method to experimental identification of tortuosity characteristic for porous materials, taking into account that this parameter has a major importance in empirical formulations of actual numerical models widely used within acoustics simulations. The laboratory tests were performed for a set of innovative highly porous composite materials based on foam-forming processes, from cellulose fibers and biopolymers. This type of composites structures provides a competitive alternative to existing petroleum-based foams materials, currently and widely used in technical applications, and especially on sound insulation. The preliminary results indicate that these new porous composites are able to provide noise insulation performances at comparative level to the commercial products large-scale used nowadays.