The Centre Spatial de Liège participates in research on the recycling of face masks
Within the framework of the Walloon MASK decontamination project, coordinated by the Prof. Eric Haubruge for the University of Liège (ULiège), the Centre Spatial de Liège (CSL) is studying a recycling method that should restore the original filtration efficiency of the masks. The types of masks being studied are both surgical masks and respiratory protection masks (FFP2 or KN95).
he masks are decontaminated by cleaning in a bath of ethanol and water. The efficiency and quality of the reduction of the microbial load (>6Log), measured at the Faculty of Veterinary Medicine of ULiège by Prof. Georges Daube and Etienne Thiry, are excellent.
Conventional open-air drying of masks does not allow the residual water to be completely extracted. This defect is known and leads to a loss of filtration efficiency of the masks, all the more annoying in the case of the FFP2 models.
The solution adopted by CSL consists of treating the masks in a vacuum tank in order to extract the water adsorbed deep within the fibres. At a pressure of about one millionth of atmospheric pressure, the residual water freezes : the innovation proposed by CSL consists in extracting this frozen water by a solid-liquid transition (sublimation) which proves to be particularly minimally invasive and should guarantee that the quality of the fibres is restored to close to the level of a new mask! Validation is awaiting the results of the latest tests.
CSL's know-how in vacuum technology is recognized worldwide for space applications. These applications require extreme cleanliness, which goes hand in hand with a mastery of material outgassing processes.
This synergy between the biomedical and space sciences shows the extent to which modern science calls upon varied, cross-disciplinary knowledge in order to innovate and progress for the benefit of all. The potential for mask recycling is not only in line with the health emergency we are facing, but also with the logic of a more sustainable world in the long term.
Pr Serge HABRAKEN, Faculty of Sciences, ULiège
Scientific & Academic Director of the Centre Spatial de Liège (CSL, Liège Space Center)