Revolutionary sound absorbers
Together with the company de Cavis, Empa researchers have developed a groundbreaking innovation in the field of sound absorption. The new mineral sound absorbers are not only significantly thinner than conventional materials, but can also be specifically designed for different frequency ranges. This technology could revolutionize the way we combat noise.
Every centimeter counts in the fight against noise. Traditional sound absorbers made from bulky materials such as rock wool or melamine foam are often too thick and restrictive in terms of design. The newly developed sound absorbers made of mineral gypsum or cement foams offer a convincing alternative. They are just as effective as conventional absorbers, but around four times thinner. This opens up completely new possibilities for integration into existing and new construction projects.
The varying pore structure of the mineral foams forces the air particles along a longer path, resulting in a high level of sound absorption despite the low thickness. This patented design makes it possible to tune the absorbers to specific frequency ranges. The foams are also fireproof, recyclable and do not release any harmful particles. Cement foams are also weatherproof, making them ideal for outdoor use.
Practical test in Zurich
An initial prototype of the new sound absorbers has already been tested in a courtyard entrance in Zurich. The results are very promising. The noise level was reduced by up to 4 decibels, especially when cars drove past. The 72 panels with a total thickness of around 5.5 centimetres showed reliable attenuation of low frequencies and a significant reduction in sound transmission in the area of peak absorption.
Versatile applications
The new sound absorbers are suitable for a wide range of applications. They can be integrated in driveways, under balconies, on facades, in stairwells or large indoor spaces such as offices, canteens or sports halls. They are particularly interesting for special applications where limited space, fire protection and design requirements have to be taken into account at the same time.
The future of noise reduction
The idea for these innovative sound absorbers was conceived several years ago, but the breakthrough only came with the combination of material development and acoustic modeling as part of an Innosuisse project. Production is currently still partly carried out by hand, but the material is to be further developed and produced on a larger scale with a suitable industrial partner.
The mineral sound absorbers have the potential to revolutionize noise reduction in various environments. They offer an efficient, space-saving and design-flexible solution to the challenges of modern building acoustics.