In our first article devoted to the topic, we have introduced the theme of the current shift towards the integration of green, sustainable, and advanced materials that might produce some future applications in the soundproofing global backdrop.
Strengthened by new research, data, and insights, we continue to bring about an in-depth analysis over the transitional phenomena by showcasing some further solutions that have been studied and proposed throughout some of the latest academic contributions.
The purpose of these experimental investigations was to explore the Sound Absorption and Attenuation potential of products and architectures employing alternative materials, which have been already proved to be a valid substitute to traditional solutions.
1. Sound-absorbing Boards made of maize stem
Ramshankar et. al (2021) have developed a research project that studied soundproofing board made from maize stem. This can already be regarded as a beneficial component in those industries where the need to overcome serious noise pollution is regularly encountered, since these structural elements could significantly give a support to eradicate harmful sounds and so reproduce a better working enviroment as well.
The study lies also on the assumption that many of the soundproofing solutions currently available in the market are not so cost-effective. The usage of soundproofing panels based on agro-waste can represent a better solution in such terms too.
Basing their empirical methodology on the Impendance Test, Ramshankar et. al (2021) have drawn the conclusion that, as for maize stalk, the thickness has a very irrelevant influence if we compare it with other natural fibers. At the same time, by comparing different sound absorption co-efficients, it has been observed that maize stalk performs better than several other materials.
However, the most precious insight is that agro-waste panels does not cause any damage to environment, and, additionally, cost of production are also very restricted when compared with other products. Overall, maize stalk as a soundproofing solution succeeds in achieving three main lenses in a all-in-one: cost-efficiency, sustainability, performance.
2. Metamaterials with an eye to naval soundproofing
Metamaterials are made-from-scratch solutions that reach electromagnetic properties which are not normally part of natural elements. D’amore et. al (2022) have investigated a “metasolution” – as it was called in the study – having the potential to replace traditionally adopted solutions especially regarding marine applications. Noise attenuation techniques intended to soundproof marine and naval equipment are indeed becoming an essential asset to ensure the comfort levels required by the standards on board ships.
As highlighted by D’amore et. al (2022), acoustic metamaterials “are engineered to control, direct, and manipulate sound waves, by transmitting, trapping, and amplifying the sound waves at certain frequencies. This outcome is usually achieved by the periodic repetition in space of an elementary primitive cell, carefully optimized in its topology and geometry”.
Panels made of metamaterials have suitable features, sufficient to be a valid sustainable solution on board ships, especially as an alternative to traditional mineral wool products. This type of solution could pave the way for the slow but unavoidable substitution of traditional solutions for vibration and noise control in other configurations in marine soundproofing.
Stopson Italiana is further growing its awareness of the environmental impact caused by conventional methodologies. It is noted how research and academic studies are largely contributing to powering the transition towards Sustainable Materials by offering plenty of insights.
It is demonstrated that Advanced and Eco-friendly Materials are already an indispensable resource with a view to better manage not only the complexities of soundproofing execution, but also to make the industry more outcome-centric due to their profitability. Technicians and surface specialist are therefore expected to embrace this knowledge and exploit the opportunities offered by the newest solutions.